[2/2] tree-ssa-strlen optimization pass

Hi!

Here is an updated tree-ssa-strlen.c optimization pass, which includes
all the optimizations I've initially wanted and adds a lot of testcases
for it (I've been using -ftest-coverage to verify the pass is thoroughly
tested).

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

There is still room for further improvements, e.g. currently if a strcpy
call is transformed into stpcpy to determine destination length (if that is
needed), we could use the same to determine source length as well - but we'd
need to add another field in addition to ptr, so that get_string_length
knows what to subtract.  Example strcpy (p, q); return strlen (q);
(currently we optimize strcpy (p, q); return strlen (q); into
tmp = stpcpy (p, q); return tmp - p; if runtime has stpcpy).
Another possible optimization could be to merge adjacent memcpy calls
from string literals into one, provided the string literals aren't very
large.  Say strcat (p, "abcd"); strcat (p, "efgh"); strcat (p, "ijkl");
could be tmp = p + strlen (p); memcpy (tmp, "abcdefghijkl", 13); instead of
3 separate memcpy calls.

2011-09-15  Jakub Jelinek  <jakub@redhat.com>

	* common.opt: Add -foptimize-strlen option.
	* Makefile.in (OBJS): Add tree-ssa-strlen.o.
	(tree-sssa-strlen.o): Add dependencies.
	* opts.c (default_options_table): Enable -foptimize-strlen
	by default at -O2 if not -Os.
	* passes.c (init_optimization_passes): Add pass_strlen
	after pass_object_sizes.
	* timevar.def (TV_TREE_STRLEN): New timevar.
	* params.def (PARAM_MAX_TRACKED_STRLENS): New parameter.
	* tree-pass.h (pass_strlen): Declare.
	* tree-ssa-strlen.c: New file.
	* c-decl.c (merge_decls): If compatible stpcpy prototype
	is seen, set implicit_built_in_decls[BUILT_IN_STPCPY].
cp/
	* decl.c (duplicate_decls): If compatible stpcpy prototype
	is seen, set implicit_built_in_decls[BUILT_IN_STPCPY].
testsuite/
	* gcc.dg/strlenopt-1.c: New test.
	* gcc.dg/strlenopt-1f.c: New test.
	* gcc.dg/strlenopt-2.c: New test.
	* gcc.dg/strlenopt-2f.c: New test.
	* gcc.dg/strlenopt-3.c: New test.
	* gcc.dg/strlenopt-4.c: New test.
	* gcc.dg/strlenopt-4g.c: New test.
	* gcc.dg/strlenopt-4gf.c: New test.
	* gcc.dg/strlenopt-5.c: New test.
	* gcc.dg/strlenopt-6.c: New test.
	* gcc.dg/strlenopt-7.c: New test.
	* gcc.dg/strlenopt-8.c: New test.
	* gcc.dg/strlenopt-9.c: New test.
	* gcc.dg/strlenopt-10.c: New test.
	* gcc.dg/strlenopt-11.c: New test.
	* gcc.dg/strlenopt-12.c: New test.
	* gcc.dg/strlenopt-12g.c: New test.
	* gcc.dg/strlenopt-13.c: New test.
	* gcc.dg/strlenopt-14g.c: New test.
	* gcc.dg/strlenopt-14gf.c: New test.
	* gcc.dg/strlenopt-15.c: New test.
	* gcc.dg/strlenopt-16g.c: New test.
	* gcc.dg/strlenopt-17g.c: New test.
	* gcc.dg/strlenopt-18g.c: New test.
	* gcc.dg/strlenopt-19.c: New test.
	* gcc.dg/strlenopt-20.c: New test.
	* gcc.dg/strlenopt.h: New file.


	Jakub

On Thu, Sep 15, 2011 at 7:09 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> Here is an updated tree-ssa-strlen.c optimization pass, which includes
> all the optimizations I've initially wanted and adds a lot of testcases
> for it (I've been using -ftest-coverage to verify the pass is thoroughly
> tested).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok if there are no objections form the C/C++ maintainers in 24h.

Btw, can you add a changes.html entry for this?

Thanks,
Richard.

> There is still room for further improvements, e.g. currently if a strcpy
> call is transformed into stpcpy to determine destination length (if that is
> needed), we could use the same to determine source length as well - but we'd
> need to add another field in addition to ptr, so that get_string_length
> knows what to subtract.  Example strcpy (p, q); return strlen (q);
> (currently we optimize strcpy (p, q); return strlen (q); into
> tmp = stpcpy (p, q); return tmp - p; if runtime has stpcpy).
> Another possible optimization could be to merge adjacent memcpy calls
> from string literals into one, provided the string literals aren't very
> large.  Say strcat (p, "abcd"); strcat (p, "efgh"); strcat (p, "ijkl");
> could be tmp = p + strlen (p); memcpy (tmp, "abcdefghijkl", 13); instead of
> 3 separate memcpy calls.
>
> 2011-09-15  Jakub Jelinek  <jakub@redhat.com>
>
>        * common.opt: Add -foptimize-strlen option.
>        * Makefile.in (OBJS): Add tree-ssa-strlen.o.
>        (tree-sssa-strlen.o): Add dependencies.
>        * opts.c (default_options_table): Enable -foptimize-strlen
>        by default at -O2 if not -Os.
>        * passes.c (init_optimization_passes): Add pass_strlen
>        after pass_object_sizes.
>        * timevar.def (TV_TREE_STRLEN): New timevar.
>        * params.def (PARAM_MAX_TRACKED_STRLENS): New parameter.
>        * tree-pass.h (pass_strlen): Declare.
>        * tree-ssa-strlen.c: New file.
>        * c-decl.c (merge_decls): If compatible stpcpy prototype
>        is seen, set implicit_built_in_decls[BUILT_IN_STPCPY].
> cp/
>        * decl.c (duplicate_decls): If compatible stpcpy prototype
>        is seen, set implicit_built_in_decls[BUILT_IN_STPCPY].
> testsuite/
>        * gcc.dg/strlenopt-1.c: New test.
>        * gcc.dg/strlenopt-1f.c: New test.
>        * gcc.dg/strlenopt-2.c: New test.
>        * gcc.dg/strlenopt-2f.c: New test.
>        * gcc.dg/strlenopt-3.c: New test.
>        * gcc.dg/strlenopt-4.c: New test.
>        * gcc.dg/strlenopt-4g.c: New test.
>        * gcc.dg/strlenopt-4gf.c: New test.
>        * gcc.dg/strlenopt-5.c: New test.
>        * gcc.dg/strlenopt-6.c: New test.
>        * gcc.dg/strlenopt-7.c: New test.
>        * gcc.dg/strlenopt-8.c: New test.
>        * gcc.dg/strlenopt-9.c: New test.
>        * gcc.dg/strlenopt-10.c: New test.
>        * gcc.dg/strlenopt-11.c: New test.
>        * gcc.dg/strlenopt-12.c: New test.
>        * gcc.dg/strlenopt-12g.c: New test.
>        * gcc.dg/strlenopt-13.c: New test.
>        * gcc.dg/strlenopt-14g.c: New test.
>        * gcc.dg/strlenopt-14gf.c: New test.
>        * gcc.dg/strlenopt-15.c: New test.
>        * gcc.dg/strlenopt-16g.c: New test.
>        * gcc.dg/strlenopt-17g.c: New test.
>        * gcc.dg/strlenopt-18g.c: New test.
>        * gcc.dg/strlenopt-19.c: New test.
>        * gcc.dg/strlenopt-20.c: New test.
>        * gcc.dg/strlenopt.h: New file.
>
> --- gcc/common.opt.jj   2011-09-15 12:18:37.000000000 +0200
> +++ gcc/common.opt      2011-09-15 12:24:09.000000000 +0200
> @@ -1953,6 +1953,10 @@ ftree-fre
>  Common Report Var(flag_tree_fre) Optimization
>  Enable Full Redundancy Elimination (FRE) on trees
>
> +foptimize-strlen
> +Common Report Var(flag_optimize_strlen) Optimization
> +Enable string length optimizations on trees
> +
>  ftree-loop-distribution
>  Common Report Var(flag_tree_loop_distribution) Optimization
>  Enable loop distribution on trees
> --- gcc/Makefile.in.jj  2011-09-15 12:18:37.000000000 +0200
> +++ gcc/Makefile.in     2011-09-15 12:24:09.000000000 +0200
> @@ -1472,6 +1472,7 @@ OBJS = \
>        tree-ssa-reassoc.o \
>        tree-ssa-sccvn.o \
>        tree-ssa-sink.o \
> +       tree-ssa-strlen.o \
>        tree-ssa-structalias.o \
>        tree-ssa-ter.o \
>        tree-ssa-threadedge.o \
> @@ -3157,6 +3158,9 @@ tree-ssa-ccp.o : tree-ssa-ccp.c $(TREE_F
>    $(TREE_DUMP_H) $(BASIC_BLOCK_H) $(TREE_PASS_H) langhooks.h  $(PARAMS_H) \
>    tree-ssa-propagate.h value-prof.h $(FLAGS_H) $(TARGET_H) $(DIAGNOSTIC_CORE_H) \
>    $(DBGCNT_H) tree-pretty-print.h gimple-pretty-print.h gimple-fold.h
> +tree-ssa-strlen.o : tree-ssa-strlen.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
> +   $(TREE_FLOW_H) $(TREE_PASS_H) domwalk.h alloc-pool.h tree-ssa-propagate.h \
> +   gimple-pretty-print.h $(PARAMS_H)
>  tree-sra.o : tree-sra.c $(CONFIG_H) $(SYSTEM_H) coretypes.h alloc-pool.h \
>    $(TM_H) $(TREE_H) $(GIMPLE_H) $(CGRAPH_H) $(TREE_FLOW_H) \
>    $(IPA_PROP_H) $(DIAGNOSTIC_H) statistics.h $(TREE_DUMP_H) $(TIMEVAR_H) \
> --- gcc/opts.c.jj       2011-09-15 12:18:37.000000000 +0200
> +++ gcc/opts.c  2011-09-15 12:24:09.000000000 +0200
> @@ -484,6 +484,7 @@ static const struct default_options defa
>     { OPT_LEVELS_2_PLUS, OPT_falign_jumps, NULL, 1 },
>     { OPT_LEVELS_2_PLUS, OPT_falign_labels, NULL, 1 },
>     { OPT_LEVELS_2_PLUS, OPT_falign_functions, NULL, 1 },
> +    { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_foptimize_strlen, NULL, 1 },
>
>     /* -O3 optimizations.  */
>     { OPT_LEVELS_3_PLUS, OPT_ftree_loop_distribute_patterns, NULL, 1 },
> --- gcc/params.def.jj   2011-09-15 12:18:37.000000000 +0200
> +++ gcc/params.def      2011-09-15 12:24:09.000000000 +0200
> @@ -921,6 +921,14 @@ DEFPARAM (PARAM_TREE_REASSOC_WIDTH,
>          "reassociated tree. If 0, use the target dependent heuristic.",
>          0, 0, 0)
>
> +/* Maximum number of strings for which strlen optimization pass will
> +   track string lenths.  */
> +DEFPARAM (PARAM_MAX_TRACKED_STRLENS,
> +         "max-tracked-strlens",
> +         "Maximum number of strings for which strlen optimization pass will "
> +         "track string lengths",
> +         1000, 0, 0)
> +
>
>  /*
>  Local variables:
> --- gcc/passes.c.jj     2011-09-15 12:18:37.000000000 +0200
> +++ gcc/passes.c        2011-09-15 12:24:09.000000000 +0200
> @@ -1,7 +1,7 @@
>  /* Top level of GCC compilers (cc1, cc1plus, etc.)
>    Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
> -   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
> -   Free Software Foundation, Inc.
> +   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
> +   2011  Free Software Foundation, Inc.
>
>  This file is part of GCC.
>
> @@ -1321,6 +1321,7 @@ init_optimization_passes (void)
>       NEXT_PASS (pass_forwprop);
>       NEXT_PASS (pass_phiopt);
>       NEXT_PASS (pass_object_sizes);
> +      NEXT_PASS (pass_strlen);
>       NEXT_PASS (pass_ccp);
>       NEXT_PASS (pass_copy_prop);
>       NEXT_PASS (pass_cse_sincos);
> --- gcc/timevar.def.jj  2011-09-15 12:18:37.000000000 +0200
> +++ gcc/timevar.def     2011-09-15 12:24:09.000000000 +0200
> @@ -1,7 +1,7 @@
>  /* This file contains the definitions for timing variables used to
>    measure run-time performance of the compiler.
>    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
> -   2009, 2010
> +   2009, 2010, 2011
>    Free Software Foundation, Inc.
>    Contributed by Alex Samuel <samuel@codesourcery.com>
>
> @@ -183,6 +183,7 @@ DEFTIMEVAR (TV_TREE_COPY_RENAME          , "
>  DEFTIMEVAR (TV_TREE_SSA_VERIFY       , "tree SSA verifier")
>  DEFTIMEVAR (TV_TREE_STMT_VERIFY      , "tree STMT verifier")
>  DEFTIMEVAR (TV_TREE_SWITCH_CONVERSION, "tree switch initialization conversion")
> +DEFTIMEVAR (TV_TREE_STRLEN           , "tree strlen optimization")
>  DEFTIMEVAR (TV_CGRAPH_VERIFY         , "callgraph verifier")
>  DEFTIMEVAR (TV_DOM_FRONTIERS         , "dominance frontiers")
>  DEFTIMEVAR (TV_DOMINANCE             , "dominance computation")
> --- gcc/tree-pass.h.jj  2011-09-15 12:18:37.000000000 +0200
> +++ gcc/tree-pass.h     2011-09-15 12:24:09.000000000 +0200
> @@ -412,6 +412,7 @@ extern struct gimple_opt_pass pass_diagn
>  extern struct gimple_opt_pass pass_expand_omp;
>  extern struct gimple_opt_pass pass_expand_omp_ssa;
>  extern struct gimple_opt_pass pass_object_sizes;
> +extern struct gimple_opt_pass pass_strlen;
>  extern struct gimple_opt_pass pass_fold_builtins;
>  extern struct gimple_opt_pass pass_stdarg;
>  extern struct gimple_opt_pass pass_early_warn_uninitialized;
> --- gcc/tree-ssa-strlen.c.jj    2011-09-15 12:24:09.000000000 +0200
> +++ gcc/tree-ssa-strlen.c       2011-09-15 14:39:14.000000000 +0200
> @@ -0,0 +1,1997 @@
> +/* String length optimization
> +   Copyright (C) 2011 Free Software Foundation, Inc.
> +   Contributed by Jakub Jelinek <jakub@redhat.com>
> +
> +This file is part of GCC.
> +
> +GCC is free software; you can redistribute it and/or modify
> +it under the terms of the GNU General Public License as published by
> +the Free Software Foundation; either version 3, or (at your option)
> +any later version.
> +
> +GCC is distributed in the hope that it will be useful,
> +but WITHOUT ANY WARRANTY; without even the implied warranty of
> +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +GNU General Public License for more details.
> +
> +You should have received a copy of the GNU General Public License
> +along with GCC; see the file COPYING3.  If not see
> +<http://www.gnu.org/licenses/>.  */
> +
> +#include "config.h"
> +#include "system.h"
> +#include "coretypes.h"
> +#include "tree-flow.h"
> +#include "tree-pass.h"
> +#include "domwalk.h"
> +#include "alloc-pool.h"
> +#include "tree-ssa-propagate.h"
> +#include "gimple-pretty-print.h"
> +#include "params.h"
> +
> +/* A vector indexed by SSA_NAME_VERSION.  0 means unknown, positive value
> +   is an index into strinfo vector, negative value stands for
> +   string length of a string literal (~strlen).  */
> +static VEC (int, heap) *ssa_ver_to_stridx;
> +
> +/* Number of currently active string indexes plus one.  */
> +static int max_stridx;
> +
> +/* String information record.  */
> +typedef struct strinfo_struct
> +{
> +  /* String length of this string.  */
> +  tree length;
> +  /* Any of the corresponding pointers for querying alias oracle.  */
> +  tree ptr;
> +  /* Statement for delayed length computation.  */
> +  gimple stmt;
> +  /* Pointer to '\0' if known, if NULL, it can be computed as
> +     ptr + length.  */
> +  tree endptr;
> +  /* Reference count.  Any changes to strinfo entry possibly shared
> +     with dominating basic blocks need unshare_strinfo first, except
> +     for dont_invalidate which affects only the immediately next
> +     maybe_invalidate.  */
> +  int refcount;
> +  /* Copy of index.  get_strinfo (si->idx) should return si;  */
> +  int idx;
> +  /* These 3 fields are for chaining related string pointers together.
> +     E.g. for
> +     bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl;
> +     strcpy (c, d); e = c + dl;
> +     strinfo(a) -> strinfo(c) -> strinfo(e)
> +     All have ->first field equal to strinfo(a)->idx and are doubly
> +     chained through prev/next fields.  The later strinfos are required
> +     to point into the same string with zero or more bytes after
> +     the previous pointer and all bytes in between the two pointers
> +     must be non-zero.  Functions like strcpy or memcpy are supposed
> +     to adjust all previous strinfo lengths, but not following strinfo
> +     lengths (those are uncertain, usually invalidated during
> +     maybe_invalidate, except when the alias oracle knows better).
> +     Functions like strcat on the other side adjust the whole
> +     related strinfo chain.
> +     They are updated lazily, so to use the chain the same first fields
> +     and si->prev->next == si->idx needs to be verified.  */
> +  int first;
> +  int next;
> +  int prev;
> +  /* A flag whether the string is known to be written in the current
> +     function.  */
> +  bool writable;
> +  /* A flag for the next maybe_invalidate that this strinfo shouldn't
> +     be invalidated.  Always cleared by maybe_invalidate.  */
> +  bool dont_invalidate;
> +} *strinfo;
> +DEF_VEC_P(strinfo);
> +DEF_VEC_ALLOC_P(strinfo,heap);
> +
> +/* Pool for allocating strinfo_struct entries.  */
> +static alloc_pool strinfo_pool;
> +
> +/* Vector mapping positive string indexes to strinfo, for the
> +   current basic block.  The first pointer in the vector is special,
> +   it is either NULL, meaning the vector isn't shared, or it is
> +   a basic block pointer to the owner basic_block if shared.
> +   If some other bb wants to modify the vector, the vector needs
> +   to be unshared first, and only the owner bb is supposed to free it.  */
> +static VEC(strinfo, heap) *stridx_to_strinfo;
> +
> +/* One OFFSET->IDX mapping.  */
> +struct stridxlist
> +{
> +  struct stridxlist *next;
> +  HOST_WIDE_INT offset;
> +  int idx;
> +};
> +
> +/* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings.  */
> +struct decl_stridxlist_map
> +{
> +  struct tree_map_base base;
> +  struct stridxlist list;
> +};
> +
> +/* Hash table for mapping decls to a chained list of offset -> idx
> +   mappings.  */
> +static htab_t decl_to_stridxlist_htab;
> +
> +/* Obstack for struct stridxlist and struct decl_stridxlist_map.  */
> +static struct obstack stridx_obstack;
> +
> +/* Last memcpy statement if it could be adjusted if the trailing
> +   '\0' written is immediately overwritten, or
> +   *x = '\0' store that could be removed if it is immediately overwritten.  */
> +struct laststmt_struct
> +{
> +  gimple stmt;
> +  tree len;
> +  int stridx;
> +} laststmt;
> +
> +/* Hash a from tree in a decl_stridxlist_map.  */
> +
> +static unsigned int
> +decl_to_stridxlist_hash (const void *item)
> +{
> +  return DECL_UID (((const struct decl_stridxlist_map *) item)->base.from);
> +}
> +
> +/* Helper function for get_stridx.  */
> +
> +static int
> +get_addr_stridx (tree exp)
> +{
> +  HOST_WIDE_INT off;
> +  struct decl_stridxlist_map ent, *e;
> +  struct stridxlist *list;
> +  tree base;
> +
> +  if (decl_to_stridxlist_htab == NULL)
> +    return 0;
> +
> +  base = get_addr_base_and_unit_offset (exp, &off);
> +  if (base == NULL || !DECL_P (base))
> +    return 0;
> +
> +  ent.base.from = base;
> +  e = (struct decl_stridxlist_map *)
> +      htab_find_with_hash (decl_to_stridxlist_htab, &ent, DECL_UID (base));
> +  if (e == NULL)
> +    return 0;
> +
> +  list = &e->list;
> +  do
> +    {
> +      if (list->offset == off)
> +       return list->idx;
> +      list = list->next;
> +    }
> +  while (list);
> +  return 0;
> +}
> +
> +/* Return string index for EXP.  */
> +
> +static int
> +get_stridx (tree exp)
> +{
> +  tree l;
> +
> +  if (TREE_CODE (exp) == SSA_NAME)
> +    return VEC_index (int, ssa_ver_to_stridx, SSA_NAME_VERSION (exp));
> +
> +  if (TREE_CODE (exp) == ADDR_EXPR)
> +    {
> +      int idx = get_addr_stridx (TREE_OPERAND (exp, 0));
> +      if (idx != 0)
> +       return idx;
> +    }
> +
> +  l = c_strlen (exp, 0);
> +  if (l != NULL_TREE
> +      && host_integerp (l, 1))
> +    {
> +      unsigned HOST_WIDE_INT len = tree_low_cst (l, 1);
> +      if (len == (unsigned int) len
> +         && (int) len >= 0)
> +       return ~(int) len;
> +    }
> +  return 0;
> +}
> +
> +/* Return true if strinfo vector is shared with the immediate dominator.  */
> +
> +static inline bool
> +strinfo_shared (void)
> +{
> +  return VEC_length (strinfo, stridx_to_strinfo)
> +        && VEC_index (strinfo, stridx_to_strinfo, 0) != NULL;
> +}
> +
> +/* Unshare strinfo vector that is shared with the immediate dominator.  */
> +
> +static void
> +unshare_strinfo_vec (void)
> +{
> +  strinfo si;
> +  unsigned int i = 0;
> +
> +  gcc_assert (strinfo_shared ());
> +  stridx_to_strinfo = VEC_copy (strinfo, heap, stridx_to_strinfo);
> +  for (i = 1; VEC_iterate (strinfo, stridx_to_strinfo, i, si); ++i)
> +    if (si != NULL)
> +      si->refcount++;
> +  VEC_replace (strinfo, stridx_to_strinfo, 0, NULL);
> +}
> +
> +/* Attempt to create a string index for exp, ADDR_EXPR's operand.
> +   Return a pointer to the location where the string index can
> +   be stored (if 0) or is stored, or NULL if this can't be tracked.  */
> +
> +static int *
> +addr_stridxptr (tree exp)
> +{
> +  void **slot;
> +  struct decl_stridxlist_map ent;
> +  struct stridxlist *list;
> +  HOST_WIDE_INT off;
> +
> +  tree base = get_addr_base_and_unit_offset (exp, &off);
> +  if (base == NULL_TREE || !DECL_P (base))
> +    return NULL;
> +
> +  if (decl_to_stridxlist_htab == NULL)
> +    {
> +      decl_to_stridxlist_htab
> +       = htab_create (64, decl_to_stridxlist_hash, tree_map_base_eq, NULL);
> +      gcc_obstack_init (&stridx_obstack);
> +    }
> +  ent.base.from = base;
> +  slot = htab_find_slot_with_hash (decl_to_stridxlist_htab, &ent,
> +                                  DECL_UID (base), INSERT);
> +  if (*slot)
> +    {
> +      int i;
> +      list = &((struct decl_stridxlist_map *)*slot)->list;
> +      for (i = 0; i < 16; i++)
> +       {
> +         if (list->offset == off)
> +           return &list->idx;
> +         if (list->next == NULL)
> +           break;
> +       }
> +      if (i == 16)
> +       return NULL;
> +      list->next = XOBNEW (&stridx_obstack, struct stridxlist);
> +      list = list->next;
> +    }
> +  else
> +    {
> +      struct decl_stridxlist_map *e
> +       = XOBNEW (&stridx_obstack, struct decl_stridxlist_map);
> +      e->base.from = base;
> +      *slot = (void *) e;
> +      list = &e->list;
> +    }
> +  list->next = NULL;
> +  list->offset = off;
> +  list->idx = 0;
> +  return &list->idx;
> +}
> +
> +/* Create a new string index, or return 0 if reached limit.  */
> +
> +static int
> +new_stridx (tree exp)
> +{
> +  int idx;
> +  if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS))
> +    return 0;
> +  if (TREE_CODE (exp) == SSA_NAME)
> +    {
> +      if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp))
> +       return 0;
> +      idx = max_stridx++;
> +      VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (exp), idx);
> +      return idx;
> +    }
> +  if (TREE_CODE (exp) == ADDR_EXPR)
> +    {
> +      int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0));
> +      if (pidx != NULL)
> +       {
> +         gcc_assert (*pidx == 0);
> +         *pidx = max_stridx++;
> +         return *pidx;
> +       }
> +    }
> +  return 0;
> +}
> +
> +/* Like new_stridx, but for ADDR_EXPR's operand instead.  */
> +
> +static int
> +new_addr_stridx (tree exp)
> +{
> +  int *pidx;
> +  if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS))
> +    return 0;
> +  pidx = addr_stridxptr (exp);
> +  if (pidx != NULL)
> +    {
> +      gcc_assert (*pidx == 0);
> +      *pidx = max_stridx++;
> +      return *pidx;
> +    }
> +  return 0;
> +}
> +
> +/* Create a new strinfo.  */
> +
> +static strinfo
> +new_strinfo (tree ptr, int idx, tree length)
> +{
> +  strinfo si = (strinfo) pool_alloc (strinfo_pool);
> +  si->length = length;
> +  si->ptr = ptr;
> +  si->stmt = NULL;
> +  si->endptr = NULL_TREE;
> +  si->refcount = 1;
> +  si->idx = idx;
> +  si->first = 0;
> +  si->prev = 0;
> +  si->next = 0;
> +  si->writable = false;
> +  si->dont_invalidate = false;
> +  return si;
> +}
> +
> +/* Decrease strinfo refcount and free it if not referenced anymore.  */
> +
> +static inline void
> +free_strinfo (strinfo si)
> +{
> +  if (si && --si->refcount == 0)
> +    pool_free (strinfo_pool, si);
> +}
> +
> +/* Return strinfo vector entry IDX.  */
> +
> +static inline strinfo
> +get_strinfo (int idx)
> +{
> +  if (VEC_length (strinfo, stridx_to_strinfo) <= (unsigned int) idx)
> +    return NULL;
> +  return VEC_index (strinfo, stridx_to_strinfo, idx);
> +}
> +
> +/* Set strinfo in the vector entry IDX to SI.  */
> +
> +static inline void
> +set_strinfo (int idx, strinfo si)
> +{
> +  if (VEC_length (strinfo, stridx_to_strinfo) && VEC_index (strinfo, stridx_to_strinfo, 0))
> +    unshare_strinfo_vec ();
> +  if (VEC_length (strinfo, stridx_to_strinfo) <= (unsigned int) idx)
> +    VEC_safe_grow_cleared (strinfo, heap, stridx_to_strinfo, idx + 1);
> +  VEC_replace (strinfo, stridx_to_strinfo, idx, si);
> +}
> +
> +/* Return string length, or NULL if it can't be computed.  */
> +
> +static tree
> +get_string_length (strinfo si)
> +{
> +  if (si->length)
> +    return si->length;
> +
> +  if (si->stmt)
> +    {
> +      gimple stmt = si->stmt, lenstmt;
> +      tree callee, lhs, lhs_var, fn, tem;
> +      location_t loc;
> +      gimple_stmt_iterator gsi;
> +
> +      gcc_assert (is_gimple_call (stmt));
> +      callee = gimple_call_fndecl (stmt);
> +      gcc_assert (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL);
> +      lhs = gimple_call_lhs (stmt);
> +      gcc_assert (implicit_built_in_decls[BUILT_IN_STRCPY] != NULL_TREE);
> +      /* unshare_strinfo is intentionally not called here.  The (delayed)
> +        transformation of strcpy or strcat into stpcpy is done at the place
> +        of the former strcpy/strcat call and so can affect all the strinfos
> +        with the same stmt.  If they were unshared before and transformation
> +        has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should
> +        just compute the right length.  */
> +      switch (DECL_FUNCTION_CODE (callee))
> +       {
> +       case BUILT_IN_STRCAT:
> +       case BUILT_IN_STRCAT_CHK:
> +         gsi = gsi_for_stmt (stmt);
> +         fn = implicit_built_in_decls[BUILT_IN_STRLEN];
> +         gcc_assert (lhs == NULL_TREE);
> +         lhs_var = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL);
> +         add_referenced_var (lhs_var);
> +         tem = unshare_expr (gimple_call_arg (stmt, 0));
> +         lenstmt = gimple_build_call (fn, 1, tem);
> +         lhs = make_ssa_name (lhs_var, lenstmt);
> +         gimple_call_set_lhs (lenstmt, lhs);
> +         gimple_set_vuse (lenstmt, gimple_vuse (stmt));
> +         gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT);
> +         lhs_var = create_tmp_var (TREE_TYPE (gimple_call_arg (stmt, 0)),
> +                                   NULL);
> +         add_referenced_var (lhs_var);
> +         tem = gimple_call_arg (stmt, 0);
> +         lenstmt
> +           = gimple_build_assign_with_ops (POINTER_PLUS_EXPR,
> +                                           make_ssa_name (lhs_var, NULL),
> +                                           tem, lhs);
> +         gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT);
> +         gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt));
> +         lhs = NULL_TREE;
> +         /* FALLTHRU */
> +       case BUILT_IN_STRCPY:
> +       case BUILT_IN_STRCPY_CHK:
> +         if (gimple_call_num_args (stmt) == 2)
> +           fn = implicit_built_in_decls[BUILT_IN_STPCPY];
> +         else
> +           fn = built_in_decls[BUILT_IN_STPCPY_CHK];
> +         gcc_assert (lhs == NULL_TREE);
> +         if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +           {
> +             fprintf (dump_file, "Optimizing: ");
> +             print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +           }
> +         gimple_call_set_fndecl (stmt, fn);
> +         lhs_var = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL);
> +         add_referenced_var (lhs_var);
> +         lhs = make_ssa_name (lhs_var, stmt);
> +         gimple_call_set_lhs (stmt, lhs);
> +         update_stmt (stmt);
> +         if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +           {
> +             fprintf (dump_file, "into: ");
> +             print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +           }
> +         /* FALLTHRU */
> +       case BUILT_IN_STPCPY:
> +       case BUILT_IN_STPCPY_CHK:
> +         gcc_assert (lhs != NULL_TREE);
> +         loc = gimple_location (stmt);
> +         si->endptr = lhs;
> +         si->stmt = NULL;
> +         lhs = fold_convert_loc (loc, size_type_node, lhs);
> +         si->length = fold_convert_loc (loc, size_type_node, si->ptr);
> +         si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node,
> +                                       lhs, si->length);
> +         break;
> +       default:
> +         gcc_unreachable ();
> +         break;
> +       }
> +    }
> +
> +  return si->length;
> +}
> +
> +/* Invalidate string length information for strings whose length
> +   might change due to stores in stmt.  */
> +
> +static bool
> +maybe_invalidate (gimple stmt)
> +{
> +  strinfo si;
> +  unsigned int i;
> +  bool nonempty = false;
> +
> +  for (i = 1; VEC_iterate (strinfo, stridx_to_strinfo, i, si); ++i)
> +    if (si != NULL)
> +      {
> +       if (!si->dont_invalidate)
> +         {
> +           ao_ref r;
> +           ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE);
> +           if (stmt_may_clobber_ref_p_1 (stmt, &r))
> +             {
> +               set_strinfo (i, NULL);
> +               free_strinfo (si);
> +               continue;
> +             }
> +         }
> +       si->dont_invalidate = false;
> +       nonempty = true;
> +      }
> +  return nonempty;
> +}
> +
> +/* Unshare strinfo record SI, if it has recount > 1 or
> +   if stridx_to_strinfo vector is shared with some other
> +   bbs.  */
> +
> +static strinfo
> +unshare_strinfo (strinfo si)
> +{
> +  strinfo nsi;
> +
> +  if (si->refcount == 1 && !strinfo_shared ())
> +    return si;
> +
> +  nsi = new_strinfo (si->ptr, si->idx, si->length);
> +  nsi->stmt = si->stmt;
> +  nsi->endptr = si->endptr;
> +  nsi->first = si->first;
> +  nsi->prev = si->prev;
> +  nsi->next = si->next;
> +  nsi->writable = si->writable;
> +  set_strinfo (si->idx, nsi);
> +  free_strinfo (si);
> +  return nsi;
> +}
> +
> +/* Return first strinfo in the related strinfo chain
> +   if all strinfos in between belong to the chain, otherwise
> +   NULL.  */
> +
> +static strinfo
> +verify_related_strinfos (strinfo origsi)
> +{
> +  strinfo si = origsi, psi;
> +
> +  if (origsi->first == 0)
> +    return NULL;
> +  for (; si->prev; si = psi)
> +    {
> +      if (si->first != origsi->first)
> +       return NULL;
> +      psi = get_strinfo (si->prev);
> +      if (psi == NULL)
> +       return NULL;
> +      if (psi->next != si->idx)
> +       return NULL;
> +    }
> +  if (si->idx != si->first)
> +    return NULL;
> +  return si;
> +}
> +
> +/* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points
> +   to a zero-length string and if possible chain it to a related strinfo
> +   chain whose part is or might be CHAINSI.  */
> +
> +static strinfo
> +zero_length_string (tree ptr, strinfo chainsi)
> +{
> +  strinfo si;
> +  int idx;
> +  gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME
> +                      && get_stridx (ptr) == 0);
> +
> +  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr))
> +    return NULL;
> +  if (chainsi != NULL)
> +    {
> +      si = verify_related_strinfos (chainsi);
> +      if (si)
> +       {
> +         chainsi = si;
> +         for (; chainsi->next; chainsi = si)
> +           {
> +             if (chainsi->endptr == NULL_TREE)
> +               {
> +                 chainsi = unshare_strinfo (chainsi);
> +                 chainsi->endptr = ptr;
> +               }
> +             si = get_strinfo (chainsi->next);
> +             if (si == NULL
> +                 || si->first != chainsi->first
> +                 || si->prev != chainsi->idx)
> +               break;
> +           }
> +         gcc_assert (chainsi->length);
> +         if (chainsi->endptr == NULL_TREE)
> +           {
> +             chainsi = unshare_strinfo (chainsi);
> +             chainsi->endptr = ptr;
> +           }
> +         if (integer_zerop (chainsi->length))
> +           {
> +             if (chainsi->next)
> +               {
> +                 chainsi = unshare_strinfo (chainsi);
> +                 chainsi->next = 0;
> +               }
> +             VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (ptr),
> +                          chainsi->idx);
> +             return chainsi;
> +           }
> +       }
> +      else if (chainsi->first || chainsi->prev || chainsi->next)
> +       {
> +         chainsi = unshare_strinfo (chainsi);
> +         chainsi->first = 0;
> +         chainsi->prev = 0;
> +         chainsi->next = 0;
> +       }
> +    }
> +  idx = new_stridx (ptr);
> +  if (idx == 0)
> +    return NULL;
> +  si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0));
> +  set_strinfo (idx, si);
> +  si->endptr = ptr;
> +  if (chainsi != NULL)
> +    {
> +      chainsi = unshare_strinfo (chainsi);
> +      if (chainsi->first == 0)
> +       chainsi->first = chainsi->idx;
> +      chainsi->next = idx;
> +      si->prev = chainsi->idx;
> +      si->first = chainsi->first;
> +      si->writable = chainsi->writable;
> +    }
> +  return si;
> +}
> +
> +/* For strinfo ORIGSI whose length has been just updated
> +   update also related strinfo lengths (add ADJ to each,
> +   but don't adjust ORIGSI).  */
> +
> +static void
> +adjust_related_strinfos (location_t loc, strinfo origsi, tree adj)
> +{
> +  strinfo si = verify_related_strinfos (origsi);
> +
> +  if (si == NULL)
> +    return;
> +
> +  while (1)
> +    {
> +      strinfo nsi;
> +
> +      if (si != origsi)
> +       {
> +         tree tem;
> +
> +         si = unshare_strinfo (si);
> +         gcc_assert (si->length);
> +         tem = fold_convert_loc (loc, TREE_TYPE (si->length), adj);
> +         si->length = fold_build2_loc (loc, PLUS_EXPR,
> +                                       TREE_TYPE (si->length), si->length,
> +                                       tem);
> +         si->endptr = NULL_TREE;
> +         si->dont_invalidate = true;
> +       }
> +      if (si->next == 0)
> +       return;
> +      nsi = get_strinfo (si->next);
> +      if (nsi == NULL
> +         || nsi->first != si->first
> +         || nsi->prev != si->idx)
> +       return;
> +      si = nsi;
> +    }
> +}
> +
> +/* Find if there are other SSA_NAME pointers equal to PTR
> +   for which we don't track their string lengths yet.  If so, use
> +   IDX for them.  */
> +
> +static void
> +find_equal_ptrs (tree ptr, int idx)
> +{
> +  if (TREE_CODE (ptr) != SSA_NAME)
> +    return;
> +  while (1)
> +    {
> +      gimple stmt = SSA_NAME_DEF_STMT (ptr);
> +      if (!is_gimple_assign (stmt))
> +       return;
> +      ptr = gimple_assign_rhs1 (stmt);
> +      switch (gimple_assign_rhs_code (stmt))
> +       {
> +       case SSA_NAME:
> +         break;
> +       case ADDR_EXPR:
> +         {
> +           int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0));
> +           if (pidx != NULL && *pidx == 0)
> +             *pidx = idx;
> +           return;
> +         }
> +       CASE_CONVERT:
> +         if (POINTER_TYPE_P (TREE_TYPE (ptr)))
> +           break;
> +         return;
> +       default:
> +         return;
> +       }
> +
> +      /* We might find an endptr created in this pass.  Grow the
> +        vector in that case.  */
> +      if (VEC_length (int, ssa_ver_to_stridx) <= SSA_NAME_VERSION (ptr))
> +       VEC_safe_grow_cleared (int, heap, ssa_ver_to_stridx, num_ssa_names);
> +
> +      if (VEC_index (int, ssa_ver_to_stridx, SSA_NAME_VERSION (ptr)) != 0)
> +       return;
> +      VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (ptr), idx);
> +    }
> +}
> +
> +/* If the last .MEM setter statement before STMT is
> +   memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT
> +   and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to
> +   just memcpy (x, y, strlen (y)).  SI must be the zero length
> +   strinfo.  */
> +
> +static void
> +adjust_last_stmt (strinfo si, gimple stmt, bool is_strcat)
> +{
> +  tree vuse, callee, len;
> +  struct laststmt_struct last = laststmt;
> +  strinfo lastsi, firstsi;
> +
> +  laststmt.stmt = NULL;
> +  laststmt.len = NULL_TREE;
> +  laststmt.stridx = 0;
> +
> +  if (last.stmt == NULL)
> +    return;
> +
> +  vuse = gimple_vuse (stmt);
> +  if (vuse == NULL_TREE
> +      || SSA_NAME_DEF_STMT (vuse) != last.stmt
> +      || !has_single_use (vuse))
> +    return;
> +
> +  gcc_assert (last.stridx > 0);
> +  lastsi = get_strinfo (last.stridx);
> +  if (lastsi == NULL)
> +    return;
> +
> +  if (lastsi != si)
> +    {
> +      if (lastsi->first == 0 || lastsi->first != si->first)
> +       return;
> +
> +      firstsi = verify_related_strinfos (si);
> +      if (firstsi == NULL)
> +       return;
> +      while (firstsi != lastsi)
> +       {
> +         strinfo nextsi;
> +         if (firstsi->next == 0)
> +           return;
> +         nextsi = get_strinfo (firstsi->next);
> +         if (nextsi == NULL
> +             || nextsi->prev != firstsi->idx
> +             || nextsi->first != si->first)
> +           return;
> +         firstsi = nextsi;
> +       }
> +    }
> +
> +  if (!is_strcat)
> +    {
> +      if (si->length == NULL_TREE || !integer_zerop (si->length))
> +       return;
> +    }
> +
> +  if (is_gimple_assign (last.stmt))
> +    {
> +      gimple_stmt_iterator gsi;
> +
> +      if (!integer_zerop (gimple_assign_rhs1 (last.stmt)))
> +       return;
> +      if (stmt_could_throw_p (last.stmt))
> +       return;
> +      gsi = gsi_for_stmt (last.stmt);
> +      unlink_stmt_vdef (last.stmt);
> +      release_defs (last.stmt);
> +      gsi_remove (&gsi, true);
> +      return;
> +    }
> +
> +  if (!is_gimple_call (last.stmt))
> +    return;
> +  callee = gimple_call_fndecl (last.stmt);
> +  if (callee == NULL_TREE || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL)
> +    return;
> +
> +  switch (DECL_FUNCTION_CODE (callee))
> +    {
> +    case BUILT_IN_MEMCPY:
> +    case BUILT_IN_MEMCPY_CHK:
> +      break;
> +    default:
> +      return;
> +    }
> +
> +  len = gimple_call_arg (last.stmt, 2);
> +  if (host_integerp (len, 1))
> +    {
> +      if (!host_integerp (last.len, 1)
> +         || integer_zerop (len)
> +         || (unsigned HOST_WIDE_INT) tree_low_cst (len, 1)
> +            != (unsigned HOST_WIDE_INT) tree_low_cst (last.len, 1) + 1)
> +       return;
> +      /* Don't adjust the length if it is divisible by 4, it is more efficient
> +        to store the extra '\0' in that case.  */
> +      if ((((unsigned HOST_WIDE_INT) tree_low_cst (len, 1)) & 3) == 0)
> +       return;
> +    }
> +  else if (TREE_CODE (len) == SSA_NAME)
> +    {
> +      gimple def_stmt = SSA_NAME_DEF_STMT (len);
> +      if (!is_gimple_assign (def_stmt)
> +         || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR
> +         || gimple_assign_rhs1 (def_stmt) != last.len
> +         || !integer_onep (gimple_assign_rhs2 (def_stmt)))
> +       return;
> +    }
> +  else
> +    return;
> +
> +  gimple_call_set_arg (last.stmt, 2, last.len);
> +  update_stmt (last.stmt);
> +}
> +
> +/* Handle a strlen call.  If strlen of the argument is known, replace
> +   the strlen call with the known value, otherwise remember that strlen
> +   of the argument is stored in the lhs SSA_NAME.  */
> +
> +static void
> +handle_builtin_strlen (gimple_stmt_iterator *gsi)
> +{
> +  int idx;
> +  tree src;
> +  gimple stmt = gsi_stmt (*gsi);
> +  tree lhs = gimple_call_lhs (stmt);
> +
> +  if (lhs == NULL_TREE)
> +    return;
> +
> +  src = gimple_call_arg (stmt, 0);
> +  idx = get_stridx (src);
> +  if (idx)
> +    {
> +      strinfo si = NULL;
> +      tree rhs;
> +
> +      if (idx < 0)
> +       rhs = build_int_cst (TREE_TYPE (lhs), ~idx);
> +      else
> +       {
> +         rhs = NULL_TREE;
> +         si = get_strinfo (idx);
> +         if (si != NULL)
> +           rhs = get_string_length (si);
> +       }
> +      if (rhs != NULL_TREE)
> +       {
> +         if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +           {
> +             fprintf (dump_file, "Optimizing: ");
> +             print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +           }
> +         rhs = unshare_expr (rhs);
> +         if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
> +           rhs = fold_convert_loc (gimple_location (stmt),
> +                                   TREE_TYPE (lhs), rhs);
> +         if (!update_call_from_tree (gsi, rhs))
> +           gimplify_and_update_call_from_tree (gsi, rhs);
> +         stmt = gsi_stmt (*gsi);
> +         update_stmt (stmt);
> +         if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +           {
> +             fprintf (dump_file, "into: ");
> +             print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +           }
> +         if (si != NULL
> +             && TREE_CODE (si->length) != SSA_NAME
> +             && TREE_CODE (si->length) != INTEGER_CST
> +             && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> +           {
> +             si = unshare_strinfo (si);
> +             si->length = lhs;
> +           }
> +         return;
> +       }
> +    }
> +  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> +    return;
> +  if (idx == 0)
> +    idx = new_stridx (src);
> +  else if (get_strinfo (idx) != NULL)
> +    return;
> +  if (idx)
> +    {
> +      strinfo si = new_strinfo (src, idx, lhs);
> +      set_strinfo (idx, si);
> +      find_equal_ptrs (src, idx);
> +    }
> +}
> +
> +/* Handle a strchr call.  If strlen of the first argument is known, replace
> +   the strchr (x, 0) call with the endptr or x + strlen, otherwise remember
> +   that lhs of the call is endptr and strlen of the argument is endptr - x.  */
> +
> +static void
> +handle_builtin_strchr (gimple_stmt_iterator *gsi)
> +{
> +  int idx;
> +  tree src;
> +  gimple stmt = gsi_stmt (*gsi);
> +  tree lhs = gimple_call_lhs (stmt);
> +
> +  if (lhs == NULL_TREE)
> +    return;
> +
> +  if (!integer_zerop (gimple_call_arg (stmt, 1)))
> +    return;
> +
> +  src = gimple_call_arg (stmt, 0);
> +  idx = get_stridx (src);
> +  if (idx)
> +    {
> +      strinfo si = NULL;
> +      tree rhs;
> +
> +      if (idx < 0)
> +       rhs = build_int_cst (size_type_node, ~idx);
> +      else
> +       {
> +         rhs = NULL_TREE;
> +         si = get_strinfo (idx);
> +         if (si != NULL)
> +           rhs = get_string_length (si);
> +       }
> +      if (rhs != NULL_TREE)
> +       {
> +         location_t loc = gimple_location (stmt);
> +
> +         if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +           {
> +             fprintf (dump_file, "Optimizing: ");
> +             print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +           }
> +         if (si != NULL && si->endptr != NULL_TREE)
> +           {
> +             rhs = unshare_expr (si->endptr);
> +             if (!useless_type_conversion_p (TREE_TYPE (lhs),
> +                                             TREE_TYPE (rhs)))
> +               rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
> +           }
> +         else
> +           {
> +             rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs));
> +             rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR,
> +                                    TREE_TYPE (src), src, rhs);
> +             if (!useless_type_conversion_p (TREE_TYPE (lhs),
> +                                             TREE_TYPE (rhs)))
> +               rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
> +           }
> +         if (!update_call_from_tree (gsi, rhs))
> +           gimplify_and_update_call_from_tree (gsi, rhs);
> +         stmt = gsi_stmt (*gsi);
> +         update_stmt (stmt);
> +         if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +           {
> +             fprintf (dump_file, "into: ");
> +             print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +           }
> +         if (si != NULL
> +             && si->endptr == NULL_TREE
> +             && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> +           {
> +             si = unshare_strinfo (si);
> +             si->endptr = lhs;
> +           }
> +         zero_length_string (lhs, si);
> +         return;
> +       }
> +    }
> +  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> +    return;
> +  if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src))
> +    {
> +      if (idx == 0)
> +       idx = new_stridx (src);
> +      else if (get_strinfo (idx) != NULL)
> +       {
> +         zero_length_string (lhs, NULL);
> +         return;
> +       }
> +      if (idx)
> +       {
> +         location_t loc = gimple_location (stmt);
> +         tree lhsu = fold_convert_loc (loc, size_type_node, lhs);
> +         tree srcu = fold_convert_loc (loc, size_type_node, src);
> +         tree length = fold_build2_loc (loc, MINUS_EXPR,
> +                                        size_type_node, lhsu, srcu);
> +         strinfo si = new_strinfo (src, idx, length);
> +         si->endptr = lhs;
> +         set_strinfo (idx, si);
> +         find_equal_ptrs (src, idx);
> +         zero_length_string (lhs, si);
> +       }
> +    }
> +  else
> +    zero_length_string (lhs, NULL);
> +}
> +
> +/* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call.
> +   If strlen of the second argument is known, strlen of the first argument
> +   is the same after this call.  Furthermore, attempt to convert it to
> +   memcpy.  */
> +
> +static void
> +handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi)
> +{
> +  int idx, didx;
> +  tree src, dst, srclen, len, lhs, args, type, fn, oldlen;
> +  bool success;
> +  gimple stmt = gsi_stmt (*gsi);
> +  strinfo si, dsi, olddsi, zsi;
> +  location_t loc;
> +
> +  src = gimple_call_arg (stmt, 1);
> +  dst = gimple_call_arg (stmt, 0);
> +  lhs = gimple_call_lhs (stmt);
> +  idx = get_stridx (src);
> +  si = NULL;
> +  if (idx > 0)
> +    si = get_strinfo (idx);
> +
> +  didx = get_stridx (dst);
> +  olddsi = NULL;
> +  oldlen = NULL_TREE;
> +  if (didx > 0)
> +    olddsi = get_strinfo (didx);
> +  else if (didx < 0)
> +    return;
> +
> +  if (olddsi != NULL)
> +    adjust_last_stmt (olddsi, stmt, false);
> +
> +  srclen = NULL_TREE;
> +  if (si != NULL)
> +    srclen = get_string_length (si);
> +  else if (idx < 0)
> +    srclen = build_int_cst (size_type_node, ~idx);
> +
> +  loc = gimple_location (stmt);
> +  if (srclen == NULL_TREE)
> +    switch (bcode)
> +      {
> +      case BUILT_IN_STRCPY:
> +      case BUILT_IN_STRCPY_CHK:
> +       if (implicit_built_in_decls[BUILT_IN_STPCPY] == NULL_TREE
> +           || lhs != NULL_TREE)
> +         return;
> +       break;
> +      case BUILT_IN_STPCPY:
> +      case BUILT_IN_STPCPY_CHK:
> +       if (lhs == NULL_TREE)
> +         return;
> +       else
> +         {
> +           tree lhsuint = fold_convert_loc (loc, size_type_node, lhs);
> +           srclen = fold_convert_loc (loc, size_type_node, dst);
> +           srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node,
> +                                     lhsuint, srclen);
> +         }
> +       break;
> +      default:
> +       gcc_unreachable ();
> +      }
> +
> +  if (didx == 0)
> +    {
> +      didx = new_stridx (dst);
> +      if (didx == 0)
> +       return;
> +    }
> +  if (olddsi != NULL)
> +    {
> +      oldlen = olddsi->length;
> +      dsi = unshare_strinfo (olddsi);
> +      dsi->length = srclen;
> +      /* Break the chain, so adjust_related_strinfo on later pointers in
> +        the chain won't adjust this one anymore.  */
> +      dsi->next = 0;
> +      dsi->stmt = NULL;
> +      dsi->endptr = NULL_TREE;
> +    }
> +  else
> +    {
> +      dsi = new_strinfo (dst, didx, srclen);
> +      set_strinfo (didx, dsi);
> +      find_equal_ptrs (dst, didx);
> +    }
> +  dsi->writable = true;
> +  dsi->dont_invalidate = true;
> +
> +  if (dsi->length == NULL_TREE)
> +    {
> +      /* If string length of src is unknown, use delayed length
> +        computation.  If string lenth of dst will be needed, it
> +        can be computed by transforming this strcpy call into
> +        stpcpy and subtracting dst from the return value.  */
> +      dsi->stmt = stmt;
> +      return;
> +    }
> +
> +  if (olddsi != NULL)
> +    {
> +      tree adj = NULL_TREE;
> +      if (oldlen == NULL_TREE)
> +       ;
> +      else if (integer_zerop (oldlen))
> +       adj = srclen;
> +      else if (TREE_CODE (oldlen) == INTEGER_CST
> +              || TREE_CODE (srclen) == INTEGER_CST)
> +       adj = fold_build2_loc (loc, MINUS_EXPR,
> +                              TREE_TYPE (srclen), srclen,
> +                              fold_convert_loc (loc, TREE_TYPE (srclen),
> +                                                oldlen));
> +      if (adj != NULL_TREE)
> +       adjust_related_strinfos (loc, dsi, adj);
> +      else
> +       dsi->prev = 0;
> +    }
> +  /* strcpy src may not overlap dst, so src doesn't need to be
> +     invalidated either.  */
> +  if (si != NULL)
> +    si->dont_invalidate = true;
> +
> +  fn = NULL_TREE;
> +  zsi = NULL;
> +  switch (bcode)
> +    {
> +    case BUILT_IN_STRCPY:
> +      fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
> +      if (lhs)
> +       VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs), didx);
> +      break;
> +    case BUILT_IN_STRCPY_CHK:
> +      fn = built_in_decls[BUILT_IN_MEMCPY_CHK];
> +      if (lhs)
> +       VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs), didx);
> +      break;
> +    case BUILT_IN_STPCPY:
> +      /* This would need adjustment of the lhs (subtract one),
> +        or detection that the trailing '\0' doesn't need to be
> +        written, if it will be immediately overwritten.
> +      fn = built_in_decls[BUILT_IN_MEMPCPY];  */
> +      if (lhs)
> +       {
> +         dsi->endptr = lhs;
> +         zsi = zero_length_string (lhs, dsi);
> +       }
> +      break;
> +    case BUILT_IN_STPCPY_CHK:
> +      /* This would need adjustment of the lhs (subtract one),
> +        or detection that the trailing '\0' doesn't need to be
> +        written, if it will be immediately overwritten.
> +      fn = built_in_decls[BUILT_IN_MEMPCPY_CHK];  */
> +      if (lhs)
> +       {
> +         dsi->endptr = lhs;
> +         zsi = zero_length_string (lhs, dsi);
> +       }
> +      break;
> +    default:
> +      gcc_unreachable ();
> +    }
> +  if (zsi != NULL)
> +    zsi->dont_invalidate = true;
> +
> +  if (fn == NULL_TREE)
> +    return;
> +
> +  args = TYPE_ARG_TYPES (TREE_TYPE (fn));
> +  type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
> +
> +  len = fold_convert_loc (loc, type, unshare_expr (srclen));
> +  len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1));
> +  len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true,
> +                                 GSI_SAME_STMT);
> +  if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +    {
> +      fprintf (dump_file, "Optimizing: ");
> +      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +    }
> +  if (gimple_call_num_args (stmt) == 2)
> +    success = update_gimple_call (gsi, fn, 3, dst, src, len);
> +  else
> +    success = update_gimple_call (gsi, fn, 4, dst, src, len,
> +                                 gimple_call_arg (stmt, 2));
> +  if (success)
> +    {
> +      stmt = gsi_stmt (*gsi);
> +      update_stmt (stmt);
> +      if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +       {
> +         fprintf (dump_file, "into: ");
> +         print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +       }
> +      /* Allow adjust_last_stmt to decrease this memcpy's size.  */
> +      laststmt.stmt = stmt;
> +      laststmt.len = srclen;
> +      laststmt.stridx = dsi->idx;
> +    }
> +  else if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +    fprintf (dump_file, "not possible.\n");
> +}
> +
> +/* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call.
> +   If strlen of the second argument is known and length of the third argument
> +   is that plus one, strlen of the first argument is the same after this
> +   call.  */
> +
> +static void
> +handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi)
> +{
> +  int idx, didx;
> +  tree src, dst, len, lhs, oldlen, newlen;
> +  gimple stmt = gsi_stmt (*gsi);
> +  strinfo si, dsi, olddsi;
> +
> +  len = gimple_call_arg (stmt, 2);
> +  src = gimple_call_arg (stmt, 1);
> +  dst = gimple_call_arg (stmt, 0);
> +  idx = get_stridx (src);
> +  if (idx == 0)
> +    return;
> +
> +  didx = get_stridx (dst);
> +  olddsi = NULL;
> +  if (didx > 0)
> +    olddsi = get_strinfo (didx);
> +  else if (didx < 0)
> +    return;
> +
> +  if (olddsi != NULL
> +      && host_integerp (len, 1)
> +      && !integer_zerop (len))
> +    adjust_last_stmt (olddsi, stmt, false);
> +
> +  if (idx > 0)
> +    {
> +      gimple def_stmt;
> +
> +      /* Handle memcpy (x, y, l) where l is strlen (y) + 1.  */
> +      si = get_strinfo (idx);
> +      if (si == NULL || si->length == NULL_TREE)
> +       return;
> +      if (TREE_CODE (len) != SSA_NAME)
> +       return;
> +      def_stmt = SSA_NAME_DEF_STMT (len);
> +      if (!is_gimple_assign (def_stmt)
> +         || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR
> +         || gimple_assign_rhs1 (def_stmt) != si->length
> +         || !integer_onep (gimple_assign_rhs2 (def_stmt)))
> +       return;
> +    }
> +  else
> +    {
> +      si = NULL;
> +      /* Handle memcpy (x, "abcd", 5) or
> +        memcpy (x, "abc\0uvw", 7).  */
> +      if (!host_integerp (len, 1)
> +         || (unsigned HOST_WIDE_INT) tree_low_cst (len, 1)
> +            <= (unsigned HOST_WIDE_INT) ~idx)
> +       return;
> +    }
> +
> +  if (olddsi != NULL && TREE_CODE (len) == SSA_NAME)
> +    adjust_last_stmt (olddsi, stmt, false);
> +
> +  if (didx == 0)
> +    {
> +      didx = new_stridx (dst);
> +      if (didx == 0)
> +       return;
> +    }
> +  if (si != NULL)
> +    newlen = si->length;
> +  else
> +    newlen = build_int_cst (TREE_TYPE (len), ~idx);
> +  oldlen = NULL_TREE;
> +  if (olddsi != NULL)
> +    {
> +      dsi = unshare_strinfo (olddsi);
> +      oldlen = olddsi->length;
> +      dsi->length = newlen;
> +      /* Break the chain, so adjust_related_strinfo on later pointers in
> +        the chain won't adjust this one anymore.  */
> +      dsi->next = 0;
> +      dsi->stmt = NULL;
> +      dsi->endptr = NULL_TREE;
> +    }
> +  else
> +    {
> +      dsi = new_strinfo (dst, didx, newlen);
> +      set_strinfo (didx, dsi);
> +      find_equal_ptrs (dst, didx);
> +    }
> +  dsi->writable = true;
> +  dsi->dont_invalidate = true;
> +  if (olddsi != NULL)
> +    {
> +      tree adj = NULL_TREE;
> +      location_t loc = gimple_location (stmt);
> +      if (oldlen == NULL_TREE)
> +       ;
> +      else if (integer_zerop (oldlen))
> +       adj = dsi->length;
> +      else if (TREE_CODE (oldlen) == INTEGER_CST
> +              || TREE_CODE (dsi->length) == INTEGER_CST)
> +       adj = fold_build2_loc (loc, MINUS_EXPR,
> +                              TREE_TYPE (dsi->length), dsi->length,
> +                              fold_convert_loc (loc, TREE_TYPE (dsi->length),
> +                                                oldlen));
> +      if (adj != NULL_TREE)
> +       adjust_related_strinfos (loc, dsi, adj);
> +      else
> +       dsi->prev = 0;
> +    }
> +  /* memcpy src may not overlap dst, so src doesn't need to be
> +     invalidated either.  */
> +  if (si != NULL)
> +    si->dont_invalidate = true;
> +
> +  lhs = gimple_call_lhs (stmt);
> +  switch (bcode)
> +    {
> +    case BUILT_IN_MEMCPY:
> +    case BUILT_IN_MEMCPY_CHK:
> +      /* Allow adjust_last_stmt to decrease this memcpy's size.  */
> +      laststmt.stmt = stmt;
> +      laststmt.len = dsi->length;
> +      laststmt.stridx = dsi->idx;
> +      if (lhs)
> +       VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs), didx);
> +      break;
> +    case BUILT_IN_MEMPCPY:
> +    case BUILT_IN_MEMPCPY_CHK:
> +      break;
> +    default:
> +      gcc_unreachable ();
> +    }
> +}
> +
> +/* Handle a strcat-like ({strcat,__strcat_chk}) call.
> +   If strlen of the second argument is known, strlen of the first argument
> +   is increased by the length of the second argument.  Furthermore, attempt
> +   to convert it to memcpy/strcpy if the length of the first argument
> +   is known.  */
> +
> +static void
> +handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi)
> +{
> +  int idx, didx;
> +  tree src, dst, srclen, dstlen, len, lhs, args, type, fn, objsz, endptr;
> +  bool success;
> +  gimple stmt = gsi_stmt (*gsi);
> +  strinfo si, dsi;
> +  location_t loc;
> +
> +  src = gimple_call_arg (stmt, 1);
> +  dst = gimple_call_arg (stmt, 0);
> +  lhs = gimple_call_lhs (stmt);
> +
> +  didx = get_stridx (dst);
> +  if (didx < 0)
> +    return;
> +
> +  dsi = NULL;
> +  if (didx > 0)
> +    dsi = get_strinfo (didx);
> +  if (dsi == NULL || get_string_length (dsi) == NULL_TREE)
> +    {
> +      /* strcat (p, q) can be transformed into
> +        tmp = p + strlen (p); endptr = strpcpy (tmp, q);
> +        with length endptr - p if we need to compute the length
> +        later on.  Don't do this transformation if we don't need
> +        it.  */
> +      if (implicit_built_in_decls[BUILT_IN_STPCPY] != NULL_TREE
> +         && lhs == NULL_TREE)
> +       {
> +         if (didx == 0)
> +           {
> +             didx = new_stridx (dst);
> +             if (didx == 0)
> +               return;
> +           }
> +         if (dsi == NULL)
> +           {
> +             dsi = new_strinfo (dst, didx, NULL_TREE);
> +             set_strinfo (didx, dsi);
> +             find_equal_ptrs (dst, didx);
> +           }
> +         else
> +           {
> +             dsi = unshare_strinfo (dsi);
> +             dsi->length = NULL_TREE;
> +             dsi->next = 0;
> +             dsi->endptr = NULL_TREE;
> +           }
> +         dsi->writable = true;
> +         dsi->stmt = stmt;
> +         dsi->dont_invalidate = true;
> +       }
> +      return;
> +    }
> +
> +  srclen = NULL_TREE;
> +  si = NULL;
> +  idx = get_stridx (src);
> +  if (idx < 0)
> +    srclen = build_int_cst (size_type_node, ~idx);
> +  else if (idx > 0)
> +    {
> +      si = get_strinfo (idx);
> +      if (si != NULL)
> +       srclen = get_string_length (si);
> +    }
> +
> +  loc = gimple_location (stmt);
> +  dstlen = dsi->length;
> +  endptr = dsi->endptr;
> +
> +  dsi = unshare_strinfo (dsi);
> +  dsi->endptr = NULL_TREE;
> +  dsi->stmt = NULL;
> +  dsi->writable = true;
> +
> +  if (srclen != NULL_TREE)
> +    {
> +      dsi->length = fold_build2_loc (loc, PLUS_EXPR, TREE_TYPE (dsi->length),
> +                                    dsi->length, srclen);
> +      adjust_related_strinfos (loc, dsi, srclen);
> +      dsi->dont_invalidate = true;
> +    }
> +  else
> +    {
> +      dsi->length = NULL;
> +      if (implicit_built_in_decls[BUILT_IN_STPCPY] != NULL_TREE
> +         && lhs == NULL_TREE)
> +       dsi->dont_invalidate = true;
> +    }
> +
> +  if (si != NULL)
> +    /* strcat src may not overlap dst, so src doesn't need to be
> +       invalidated either.  */
> +    si->dont_invalidate = true;
> +
> +  /* For now.  Could remove the lhs from the call and add
> +     lhs = dst; afterwards.  */
> +  if (lhs)
> +    return;
> +
> +  fn = NULL_TREE;
> +  objsz = NULL_TREE;
> +  switch (bcode)
> +    {
> +    case BUILT_IN_STRCAT:
> +      if (srclen != NULL_TREE)
> +       fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
> +      else
> +       fn = implicit_built_in_decls[BUILT_IN_STRCPY];
> +      break;
> +    case BUILT_IN_STRCAT_CHK:
> +      if (srclen != NULL_TREE)
> +       fn = built_in_decls[BUILT_IN_MEMCPY_CHK];
> +      else
> +       fn = built_in_decls[BUILT_IN_STRCPY_CHK];
> +      objsz = gimple_call_arg (stmt, 2);
> +      break;
> +    default:
> +      gcc_unreachable ();
> +    }
> +
> +  if (fn == NULL_TREE)
> +    return;
> +
> +  len = NULL_TREE;
> +  if (srclen != NULL_TREE)
> +    {
> +      args = TYPE_ARG_TYPES (TREE_TYPE (fn));
> +      type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
> +
> +      len = fold_convert_loc (loc, type, unshare_expr (srclen));
> +      len = fold_build2_loc (loc, PLUS_EXPR, type, len,
> +                            build_int_cst (type, 1));
> +      len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true,
> +                                     GSI_SAME_STMT);
> +    }
> +  if (endptr)
> +    dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr));
> +  else
> +    dst = fold_build2_loc (loc, POINTER_PLUS_EXPR,
> +                          TREE_TYPE (dst), unshare_expr (dst),
> +                          fold_convert_loc (loc, sizetype,
> +                                            unshare_expr (dstlen)));
> +  dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true,
> +                                 GSI_SAME_STMT);
> +  if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +    {
> +      fprintf (dump_file, "Optimizing: ");
> +      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +    }
> +  if (srclen != NULL_TREE)
> +    success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE),
> +                                 dst, src, len, objsz);
> +  else
> +    success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE),
> +                                 dst, src, objsz);
> +  if (success)
> +    {
> +      stmt = gsi_stmt (*gsi);
> +      update_stmt (stmt);
> +      if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +       {
> +         fprintf (dump_file, "into: ");
> +         print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> +       }
> +      /* If srclen == NULL, note that current string length can be
> +        computed by transforming this strcpy into stpcpy.  */
> +      if (srclen == NULL_TREE && dsi->dont_invalidate)
> +       dsi->stmt = stmt;
> +      adjust_last_stmt (dsi, stmt, true);
> +      if (srclen != NULL_TREE)
> +       {
> +         laststmt.stmt = stmt;
> +         laststmt.len = srclen;
> +         laststmt.stridx = dsi->idx;
> +       }
> +    }
> +  else if (dump_file && (dump_flags & TDF_DETAILS) != 0)
> +    fprintf (dump_file, "not possible.\n");
> +}
> +
> +/* Handle a POINTER_PLUS_EXPR statement.
> +   For p = "abcd" + 2; compute associated length, or if
> +   p = q + off is pointing to a '\0' character of a string, call
> +   zero_length_string on it.  */
> +
> +static void
> +handle_pointer_plus (gimple_stmt_iterator *gsi)
> +{
> +  gimple stmt = gsi_stmt (*gsi);
> +  tree lhs = gimple_assign_lhs (stmt), off;
> +  int idx = get_stridx (gimple_assign_rhs1 (stmt));
> +  strinfo si, zsi;
> +
> +  if (idx == 0)
> +    return;
> +
> +  if (idx < 0)
> +    {
> +      tree off = gimple_assign_rhs2 (stmt);
> +      if (host_integerp (off, 1)
> +         && (unsigned HOST_WIDE_INT) tree_low_cst (off, 1)
> +            <= (unsigned HOST_WIDE_INT) ~idx)
> +       VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs),
> +                    ~(~idx - (int) tree_low_cst (off, 1)));
> +      return;
> +    }
> +
> +  si = get_strinfo (idx);
> +  if (si == NULL || si->length == NULL_TREE)
> +    return;
> +
> +  off = gimple_assign_rhs2 (stmt);
> +  zsi = NULL;
> +  if (operand_equal_p (si->length, off, 0))
> +    zsi = zero_length_string (lhs, si);
> +  else if (TREE_CODE (off) == SSA_NAME)
> +    {
> +      gimple def_stmt = SSA_NAME_DEF_STMT (off);
> +      if (gimple_assign_single_p (def_stmt)
> +         && operand_equal_p (si->length, gimple_assign_rhs1 (def_stmt), 0))
> +       zsi = zero_length_string (lhs, si);
> +    }
> +  if (zsi != NULL
> +      && si->endptr != NULL_TREE
> +      && si->endptr != lhs
> +      && TREE_CODE (si->endptr) == SSA_NAME)
> +    {
> +      enum tree_code rhs_code
> +       = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr))
> +         ? SSA_NAME : NOP_EXPR;
> +      gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr, NULL_TREE);
> +      gcc_assert (gsi_stmt (*gsi) == stmt);
> +      update_stmt (stmt);
> +    }
> +}
> +
> +/* Handle a single character store.  */
> +
> +static bool
> +handle_char_store (gimple_stmt_iterator *gsi)
> +{
> +  int idx = -1;
> +  strinfo si = NULL;
> +  gimple stmt = gsi_stmt (*gsi);
> +  tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt);
> +
> +  if (TREE_CODE (lhs) == MEM_REF
> +      && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME)
> +    {
> +      if (integer_zerop (TREE_OPERAND (lhs, 1)))
> +       {
> +         ssaname = TREE_OPERAND (lhs, 0);
> +         idx = get_stridx (ssaname);
> +       }
> +    }
> +  else
> +    idx = get_addr_stridx (lhs);
> +
> +  if (idx > 0)
> +    {
> +      si = get_strinfo (idx);
> +      if (si != NULL && si->length != NULL_TREE && integer_zerop (si->length))
> +       {
> +         if (initializer_zerop (gimple_assign_rhs1 (stmt)))
> +           {
> +             /* When storing '\0', the store can be removed
> +                if we know it has been stored in the current function.  */
> +             if (!stmt_could_throw_p (stmt) && si->writable)
> +               {
> +                 unlink_stmt_vdef (stmt);
> +                 release_defs (stmt);
> +                 gsi_remove (gsi, true);
> +                 return false;
> +               }
> +             else
> +               {
> +                 si->writable = true;
> +                 si->dont_invalidate = true;
> +               }
> +           }
> +         else
> +           /* Otherwise this statement overwrites the '\0' with
> +              something, if the previous stmt was a memcpy,
> +              its length may be decreased.  */
> +           adjust_last_stmt (si, stmt, false);
> +       }
> +      else if (si != NULL)
> +       {
> +         si = unshare_strinfo (si);
> +         si->length = build_int_cst (size_type_node, 0);
> +         si->endptr = NULL;
> +         si->prev = 0;
> +         si->next = 0;
> +         si->stmt = NULL;
> +         si->first = 0;
> +         si->writable = true;
> +         if (ssaname && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname))
> +           si->endptr = ssaname;
> +         si->dont_invalidate = true;
> +       }
> +    }
> +  else if (idx == 0 && initializer_zerop (gimple_assign_rhs1 (stmt)))
> +    {
> +      if (ssaname)
> +       {
> +         si = zero_length_string (ssaname, NULL);
> +         if (si != NULL)
> +           si->dont_invalidate = true;
> +       }
> +      else
> +       {
> +         int idx = new_addr_stridx (lhs);
> +         if (idx != 0)
> +           {
> +             si = new_strinfo (build_fold_addr_expr (lhs), idx,
> +                               build_int_cst (size_type_node, 0));
> +             set_strinfo (idx, si);
> +             si->dont_invalidate = true;
> +           }
> +       }
> +      if (si != NULL)
> +       si->writable = true;
> +    }
> +
> +  if (si != NULL && initializer_zerop (gimple_assign_rhs1 (stmt)))
> +    {
> +      /* Allow adjust_last_stmt to remove it if the stored '\0'
> +        is immediately overwritten.  */
> +      laststmt.stmt = stmt;
> +      laststmt.len = build_int_cst (size_type_node, 1);
> +      laststmt.stridx = si->idx;
> +    }
> +  return true;
> +}
> +
> +/* Attempt to optimize a single statement at *GSI using string length
> +   knowledge.  */
> +
> +static bool
> +strlen_optimize_stmt (gimple_stmt_iterator *gsi)
> +{
> +  gimple stmt = gsi_stmt (*gsi);
> +
> +  if (is_gimple_call (stmt))
> +    {
> +      tree callee = gimple_call_fndecl (stmt);
> +      if (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
> +       switch (DECL_FUNCTION_CODE (callee))
> +         {
> +         case BUILT_IN_STRLEN:
> +           handle_builtin_strlen (gsi);
> +           break;
> +         case BUILT_IN_STRCHR:
> +           handle_builtin_strchr (gsi);
> +           break;
> +         case BUILT_IN_STRCPY:
> +         case BUILT_IN_STRCPY_CHK:
> +         case BUILT_IN_STPCPY:
> +         case BUILT_IN_STPCPY_CHK:
> +           handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi);
> +           break;
> +         case BUILT_IN_MEMCPY:
> +         case BUILT_IN_MEMCPY_CHK:
> +         case BUILT_IN_MEMPCPY:
> +         case BUILT_IN_MEMPCPY_CHK:
> +           handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi);
> +           break;
> +         case BUILT_IN_STRCAT:
> +         case BUILT_IN_STRCAT_CHK:
> +           handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi);
> +           break;
> +         default:
> +           break;
> +         }
> +    }
> +  else if (is_gimple_assign (stmt))
> +    {
> +      tree lhs = gimple_assign_lhs (stmt);
> +
> +      if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (lhs)))
> +       {
> +         if (gimple_assign_single_p (stmt)
> +             || (gimple_assign_cast_p (stmt)
> +                 && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))))
> +           {
> +             int idx = get_stridx (gimple_assign_rhs1 (stmt));
> +             VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs),
> +                          idx);
> +           }
> +         else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
> +           handle_pointer_plus (gsi);
> +       }
> +      else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs))
> +       {
> +         tree type = TREE_TYPE (lhs);
> +         if (TREE_CODE (type) == ARRAY_TYPE)
> +           type = TREE_TYPE (type);
> +         if (TREE_CODE (type) == INTEGER_TYPE
> +             && TYPE_MODE (type) == TYPE_MODE (char_type_node)
> +             && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node))
> +           {
> +             if (! handle_char_store (gsi))
> +               return false;
> +           }
> +       }
> +    }
> +
> +  if (gimple_vdef (stmt))
> +    maybe_invalidate (stmt);
> +  return true;
> +}
> +
> +/* Recursively call maybe_invalidate on stmts that might be executed
> +   in between dombb and current bb and that contain a vdef.  Stop when
> +   *count stmts are inspected, or if the whole strinfo vector has
> +   been invalidated.  */
> +
> +static void
> +do_invalidate (basic_block dombb, gimple phi, bitmap visited, int *count)
> +{
> +  unsigned int i, n = gimple_phi_num_args (phi);
> +
> +  for (i = 0; i < n; i++)
> +    {
> +      tree vuse = gimple_phi_arg_def (phi, i);
> +      gimple stmt = SSA_NAME_DEF_STMT (vuse);
> +      basic_block bb = gimple_bb (stmt);
> +      if (bb == NULL
> +         || bb == dombb
> +         || !bitmap_set_bit (visited, bb->index)
> +         || !dominated_by_p (CDI_DOMINATORS, bb, dombb))
> +       continue;
> +      while (1)
> +       {
> +         if (gimple_code (stmt) == GIMPLE_PHI)
> +           {
> +             do_invalidate (dombb, stmt, visited, count);
> +             if (*count == 0)
> +               return;
> +             break;
> +           }
> +         if (--*count == 0)
> +           return;
> +         if (!maybe_invalidate (stmt))
> +           {
> +             *count = 0;
> +             return;
> +           }
> +         vuse = gimple_vuse (stmt);
> +         stmt = SSA_NAME_DEF_STMT (vuse);
> +         if (gimple_bb (stmt) != bb)
> +           {
> +             bb = gimple_bb (stmt);
> +             if (bb == NULL
> +                 || bb == dombb
> +                 || !bitmap_set_bit (visited, bb->index)
> +                 || !dominated_by_p (CDI_DOMINATORS, bb, dombb))
> +               break;
> +           }
> +       }
> +    }
> +}
> +
> +/* Callback for walk_dominator_tree.  Attempt to optimize various
> +   string ops by remembering string lenths pointed by pointer SSA_NAMEs.  */
> +
> +static void
> +strlen_enter_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
> +                   basic_block bb)
> +{
> +  gimple_stmt_iterator gsi;
> +  basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb);
> +
> +  if (dombb == NULL)
> +    stridx_to_strinfo = NULL;
> +  else
> +    {
> +      stridx_to_strinfo = (VEC(strinfo, heap) *) dombb->aux;
> +      if (stridx_to_strinfo)
> +       {
> +         for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
> +           {
> +             gimple phi = gsi_stmt (gsi);
> +             if (!is_gimple_reg (gimple_phi_result (phi)))
> +               {
> +                 bitmap visited = BITMAP_ALLOC (NULL);
> +                 int count_vdef = 100;
> +                 do_invalidate (dombb, phi, visited, &count_vdef);
> +                 BITMAP_FREE (visited);
> +                 break;
> +               }
> +           }
> +       }
> +    }
> +
> +  /* If all PHI arguments have the same string index, the PHI result
> +     has it as well.  */
> +  for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
> +    {
> +      gimple phi = gsi_stmt (gsi);
> +      tree result = gimple_phi_result (phi);
> +      if (is_gimple_reg (result) && POINTER_TYPE_P (TREE_TYPE (result)))
> +       {
> +         int idx = get_stridx (gimple_phi_arg_def (phi, 0));
> +         if (idx != 0)
> +           {
> +             unsigned int i, n = gimple_phi_num_args (phi);
> +             for (i = 1; i < n; i++)
> +               if (idx != get_stridx (gimple_phi_arg_def (phi, i)))
> +                 break;
> +             if (i == n)
> +               VEC_replace (int, ssa_ver_to_stridx,
> +                            SSA_NAME_VERSION (result), idx);
> +           }
> +       }
> +    }
> +
> +  /* Attempt to optimize individual statements.  */
> +  for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
> +    if (strlen_optimize_stmt (&gsi))
> +      gsi_next (&gsi);
> +
> +  bb->aux = stridx_to_strinfo;
> +  if (VEC_length (strinfo, stridx_to_strinfo) && !strinfo_shared ())
> +    VEC_replace (strinfo, stridx_to_strinfo, 0, (strinfo) bb);
> +}
> +
> +/* Callback for walk_dominator_tree.  Free strinfo vector if it is
> +   owned by the current bb, clear bb->aux.  */
> +
> +static void
> +strlen_leave_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
> +                   basic_block bb)
> +{
> +  if (bb->aux)
> +    {
> +      stridx_to_strinfo = (VEC(strinfo, heap) *) bb->aux;
> +      if (VEC_length (strinfo, stridx_to_strinfo)
> +         && VEC_index (strinfo, stridx_to_strinfo, 0) == (strinfo) bb)
> +       {
> +         unsigned int i;
> +         strinfo si;
> +
> +         for (i = 1; VEC_iterate (strinfo, stridx_to_strinfo, i, si); ++i)
> +           free_strinfo (si);
> +         VEC_free (strinfo, heap, stridx_to_strinfo);
> +       }
> +      bb->aux = NULL;
> +    }
> +}
> +
> +/* Main entry point.  */
> +
> +static unsigned int
> +tree_ssa_strlen (void)
> +{
> +  struct dom_walk_data walk_data;
> +
> +  VEC_safe_grow_cleared (int, heap, ssa_ver_to_stridx, num_ssa_names);
> +  max_stridx = 1;
> +  strinfo_pool = create_alloc_pool ("strinfo_struct pool",
> +                                   sizeof (struct strinfo_struct), 64);
> +
> +  calculate_dominance_info (CDI_DOMINATORS);
> +
> +  /* String length optimization is implemented as a walk of the dominator
> +     tree and a forward walk of statements within each block.  */
> +  walk_data.dom_direction = CDI_DOMINATORS;
> +  walk_data.initialize_block_local_data = NULL;
> +  walk_data.before_dom_children = strlen_enter_block;
> +  walk_data.after_dom_children = strlen_leave_block;
> +  walk_data.block_local_data_size = 0;
> +  walk_data.global_data = NULL;
> +
> +  /* Initialize the dominator walker.  */
> +  init_walk_dominator_tree (&walk_data);
> +
> +  /* Recursively walk the dominator tree.  */
> +  walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
> +
> +  /* Finalize the dominator walker.  */
> +  fini_walk_dominator_tree (&walk_data);
> +
> +  VEC_free (int, heap, ssa_ver_to_stridx);
> +  free_alloc_pool (strinfo_pool);
> +  if (decl_to_stridxlist_htab)
> +    {
> +      obstack_free (&stridx_obstack, NULL);
> +      htab_delete (decl_to_stridxlist_htab);
> +      decl_to_stridxlist_htab = NULL;
> +    }
> +  laststmt.stmt = NULL;
> +  laststmt.len = NULL_TREE;
> +  laststmt.stridx = 0;
> +
> +  return 0;
> +}
> +
> +static bool
> +gate_strlen (void)
> +{
> +  return flag_optimize_strlen != 0;
> +}
> +
> +struct gimple_opt_pass pass_strlen =
> +{
> + {
> +  GIMPLE_PASS,
> +  "strlen",                    /* name */
> +  gate_strlen,                 /* gate */
> +  tree_ssa_strlen,             /* execute */
> +  NULL,                                /* sub */
> +  NULL,                                /* next */
> +  0,                           /* static_pass_number */
> +  TV_TREE_STRLEN,              /* tv_id */
> +  PROP_cfg | PROP_ssa,         /* properties_required */
> +  0,                           /* properties_provided */
> +  0,                           /* properties_destroyed */
> +  0,                           /* todo_flags_start */
> +  TODO_ggc_collect
> +    | TODO_verify_ssa          /* todo_flags_finish */
> + }
> +};
> --- gcc/c-decl.c.jj     2011-09-15 12:18:54.000000000 +0200
> +++ gcc/c-decl.c        2011-09-15 12:24:09.000000000 +0200
> @@ -2369,7 +2369,21 @@ merge_decls (tree newdecl, tree olddecl,
>          DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl);
>          C_DECL_DECLARED_BUILTIN (newdecl) = 1;
>          if (new_is_prototype)
> -           C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0;
> +           {
> +             C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0;
> +             if (DECL_BUILT_IN_CLASS (newdecl) == BUILT_IN_NORMAL)
> +               switch (DECL_FUNCTION_CODE (newdecl))
> +                 {
> +                 /* If a compatible prototype of these builtin functions
> +                    is seen, assume the runtime implements it with the
> +                    expected semantics.  */
> +                 case BUILT_IN_STPCPY:
> +                   implicit_built_in_decls[DECL_FUNCTION_CODE (newdecl)]
> +                     = built_in_decls[DECL_FUNCTION_CODE (newdecl)];
> +                 default:
> +                   break;
> +                 }
> +           }
>          else
>            C_DECL_BUILTIN_PROTOTYPE (newdecl)
>              = C_DECL_BUILTIN_PROTOTYPE (olddecl);
> --- gcc/cp/decl.c.jj    2011-09-15 12:18:45.000000000 +0200
> +++ gcc/cp/decl.c       2011-09-15 12:24:09.000000000 +0200
> @@ -2135,6 +2135,18 @@ duplicate_decls (tree newdecl, tree oldd
>              /* If we're keeping the built-in definition, keep the rtl,
>                 regardless of declaration matches.  */
>              COPY_DECL_RTL (olddecl, newdecl);
> +             if (DECL_BUILT_IN_CLASS (newdecl) == BUILT_IN_NORMAL)
> +               switch (DECL_FUNCTION_CODE (newdecl))
> +                 {
> +                   /* If a compatible prototype of these builtin functions
> +                      is seen, assume the runtime implements it with the
> +                      expected semantics.  */
> +                 case BUILT_IN_STPCPY:
> +                   implicit_built_in_decls[DECL_FUNCTION_CODE (newdecl)]
> +                     = built_in_decls[DECL_FUNCTION_CODE (newdecl)];
> +                 default:
> +                   break;
> +                 }
>            }
>
>          DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
> --- gcc/testsuite/gcc.dg/strlenopt-1.c.jj       2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-1.c  2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,47 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +foo (char *p, char *r)
> +{
> +  char *q = malloc (strlen (p) + strlen (r) + 64);
> +  if (q == NULL) return NULL;
> +  /* This strcpy can be optimized into memcpy, using the remembered
> +     strlen (p).  */
> +  strcpy (q, p);
> +  /* These two strcat can be optimized into memcpy.  The first one
> +     could be even optimized into a *ptr = '/'; store as the '\0'
> +     is immediately overwritten.  */
> +  strcat (q, "/");
> +  strcat (q, "abcde");
> +  /* Due to inefficient PTA (PR50262) the above calls invalidate
> +     string length of r, so it is optimized just into strcpy instead
> +     of memcpy.  */
> +  strcat (q, r);
> +  return q;
> +}
> +
> +int
> +main ()
> +{
> +  char *volatile p = "string1";
> +  char *volatile r = "string2";
> +  char *q = foo (p, r);
> +  if (q != NULL)
> +    {
> +      if (strcmp (q, "string1/abcdestring2"))
> +       abort ();
> +      free (q);
> +    }
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-1f.c.jj      2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-1f.c 2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,18 @@
> +/* This test needs runtime that provides __*_chk functions.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define FORTIFY_SOURCE 2
> +#include "strlenopt-1.c"
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__memcpy_chk \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcpy_chk \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcat_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__stpcpy_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-2.c.jj       2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-2.c  2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,49 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +foo (char *p, char *r)
> +{
> +  char buf[26];
> +  if (strlen (p) + strlen (r) + 9 > 26)
> +    return NULL;
> +  /* This strcpy can be optimized into memcpy, using the remembered
> +     strlen (p).  */
> +  strcpy (buf, p);
> +  /* These two strcat can be optimized into memcpy.  The first one
> +     could be even optimized into a *ptr = '/'; store as the '\0'
> +     is immediately overwritten.  */
> +  strcat (buf, "/");
> +  strcat (buf, "abcde");
> +  /* This strcpy can be optimized into memcpy, using the remembered
> +     strlen (r).  */
> +  strcat (buf, r);
> +  /* And this can be optimized into memcpy too.  */
> +  strcat (buf, "fg");
> +  return strdup (buf);
> +}
> +
> +int
> +main ()
> +{
> +  char *volatile p = "string1";
> +  char *volatile r = "string2";
> +  char *q = foo (p, r);
> +  if (q != NULL)
> +    {
> +      if (strcmp (q, "string1/abcdestring2fg"))
> +       abort ();
> +      free (q);
> +    }
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 5 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-2f.c.jj      2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-2f.c 2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,18 @@
> +/* This test needs runtime that provides __*_chk functions.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define FORTIFY_SOURCE 2
> +#include "strlenopt-2.c"
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__memcpy_chk \\(" 5 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcpy_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcat_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__stpcpy_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-3.c.jj       2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-3.c  2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,66 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen -fdump-tree-optimized" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) size_t
> +fn1 (char *p, char *q)
> +{
> +  size_t s = strlen (q);
> +  strcpy (p, q);
> +  return s - strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn2 (char *p, char *q)
> +{
> +  size_t s = strlen (q);
> +  memcpy (p, q, s + 1);
> +  return s - strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn3 (char *p)
> +{
> +  memcpy (p, "abcd", 5);
> +  return strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn4 (char *p)
> +{
> +  memcpy (p, "efg\0hij", 6);
> +  return strlen (p);
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  char *volatile p = buf;
> +  char *volatile q = "ABCDEF";
> +  buf[7] = 'G';
> +  if (fn1 (p, q) != 0 || memcmp (buf, "ABCDEF\0G", 8))
> +    abort ();
> +  q = "HIJ";
> +  if (fn2 (p + 1, q) != 0 || memcmp (buf, "AHIJ\0F\0G", 8))
> +    abort ();
> +  buf[6] = 'K';
> +  if (fn3 (p + 1) != 4 || memcmp (buf, "Aabcd\0KG", 8))
> +    abort ();
> +  if (fn4 (p) != 3 || memcmp (buf, "efg\0hiKG", 8))
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "return 0" 3 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "return 4" 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "return 3" 1 "optimized" } } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-4.c.jj       2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-4.c  2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,75 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +/* If stpcpy can't be used, this is optimized into
> +   strcpy (p, q); strcat (p, r); memcpy (p + strlen (p), "abcd", 5);
> +   If stpcpy can be used (see strlenopt-4g.c test),
> +   this is optimized into
> +   memcpy (stpcpy (stpcpy (p, q), r), "abcd", 5);  */
> +__attribute__((noinline, noclone)) void
> +foo (char *p, const char *q, const char *r)
> +{
> +  strcpy (p, q);
> +  strcat (p, r);
> +  strcat (p, "abcd");
> +}
> +
> +/* If stpcpy can't be used, this is optimized into
> +   memcpy (p, "abcd", 4); strcpy (p + 4, q); strcat (p, r);
> +   If stpcpy can be used, this is optimized into
> +   memcpy (p, "abcd", 4); strcpy (stpcpy (p + 4, q), r);  */
> +__attribute__((noinline, noclone)) void
> +bar (char *p, const char *q, const char *r)
> +{
> +  strcpy (p, "abcd");
> +  strcat (p, q);
> +  strcat (p, r);
> +}
> +
> +/* If stpcpy can't be used, this is optimized into
> +   strcat (p, q); memcpy (t1 = p + strlen (p), "abcd", 4);
> +   strcpy (t1 + 4, r); memcpy (p + strlen (p), "efgh", 5);
> +   If stpcpy can be used, this is optimized into
> +   t1 = stpcpy (p + strlen (p), q); memcpy (t1, "abcd", 4);
> +   memcpy (stpcpy (t1 + 4, r), "efgh", 5);  */
> +__attribute__((noinline, noclone)) void
> +baz (char *p, const char *q, const char *r)
> +{
> +  strcat (p, q);
> +  strcat (p, "abcd");
> +  strcat (p, r);
> +  strcat (p, "efgh");
> +}
> +
> +char buf[64];
> +
> +int
> +main ()
> +{
> +  char *volatile p = buf;
> +  const char *volatile q = "ij";
> +  const char *volatile r = "klmno";
> +  foo (p, q, r);
> +  if (memcmp (buf, "ijklmnoabcd\0\0\0\0\0\0\0\0", 20) != 0)
> +    abort ();
> +  memset (buf, '\0', sizeof buf);
> +  bar (p, q, r);
> +  if (memcmp (buf, "abcdijklmno\0\0\0\0\0\0\0\0", 20) != 0)
> +    abort ();
> +  memset (buf, 'v', 3);
> +  memset (buf + 3, '\0', -3 + sizeof buf);
> +  baz (p, q, r);
> +  if (memcmp (buf, "vvvijabcdklmnoefgh\0", 20) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-4g.c.jj      2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-4g.c 2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,14 @@
> +/* This test needs runtime that provides stpcpy function.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define USE_GNU
> +#include "strlenopt-4.c"
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 5 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-4gf.c.jj     2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-4gf.c        2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,19 @@
> +/* This test needs runtime that provides stpcpy and __*_chk functions.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define USE_GNU
> +#define FORTIFY_SOURCE 2
> +#include "strlenopt-4.c"
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__memcpy_chk \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcpy_chk \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcat_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__stpcpy_chk \\(" 5 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-5.c.jj       2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-5.c  2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,57 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +foo (char *p, const char *q)
> +{
> +  char *e = strchr (p, '\0');
> +  strcat (p, q);
> +  return e;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +bar (char *p)
> +{
> +  memcpy (p, "abcd", 5);
> +  return strchr (p, '\0');
> +}
> +
> +__attribute__((noinline, noclone)) void
> +baz (char *p)
> +{
> +  char *e = strchr (p, '\0');
> +  strcat (e, "abcd");
> +}
> +
> +char buf[64];
> +
> +int
> +main ()
> +{
> +  char *volatile p = buf;
> +  const char *volatile q = "ij";
> +  memset (buf, 'v', 3);
> +  if (foo (p, q) != buf + 3
> +      || memcmp (buf, "vvvij\0\0\0\0", 10) != 0)
> +    abort ();
> +  memset (buf, '\0', sizeof buf);
> +  if (bar (p) != buf + 4
> +      || memcmp (buf, "abcd\0\0\0\0\0", 10) != 0)
> +    abort ();
> +  memset (buf, 'v', 2);
> +  memset (buf + 2, '\0', -2 + sizeof buf);
> +  baz (p);
> +  if (memcmp (buf, "vvabcd\0\0\0", 10) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-6.c.jj       2011-09-15 12:24:09.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-6.c  2011-09-15 12:24:09.000000000 +0200
> @@ -0,0 +1,86 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +foo (char *x)
> +{
> +#ifdef PR50262_FIXED
> +  /* Once PTA is fixed, we'll need just one strlen here,
> +     without the memcpy.  */
> +  char *p = x;
> +  char *q = malloc (strlen (p) + 64);
> +#else
> +  /* This is here just because PTA can't figure that
> +     *q = '\0' store below can't change p's length.
> +     In this case we have one strlen and one memcpy here.  */
> +  char b[64];
> +  char *q = malloc (strlen (x) + 64);
> +  char *p = strcpy (b, x);
> +#endif
> +  char *r;
> +  if (q == NULL) return NULL;
> +  /* This store can be optimized away once strcat is
> +     replaced with memcpy.  */
> +  *q = '\0';
> +  /* These two strcat calls can be optimized into memcpy calls.  */
> +  strcat (q, p);
> +  strcat (q, "/");
> +  /* The strchr can be optimized away, as we know the current
> +     string length as well as end pointer.  */
> +  r = strchr (q, '\0');
> +  /* This store can go, as it is overwriting '\0' with the same
> +     character.  */
> +  *r = '\0';
> +  /* And this strcat can be again optimized into memcpy call.  */
> +  strcat (q, "abcde");
> +  return q;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +bar (char *p)
> +{
> +  char buf[26];
> +  char *r;
> +  if (strlen (p) + 9 > 26)
> +    return NULL;
> +  *buf = '\0';
> +  strcat (buf, p);
> +  strcat (buf, "/");
> +  r = strchr (buf, '\0');
> +  *r = '\0';
> +  strcat (buf, "abcde");
> +  return strdup (buf);
> +}
> +
> +int
> +main ()
> +{
> +  char *volatile p = "string1";
> +  char *volatile r = "string2";
> +  char *q = foo (p);
> +  if (q != NULL)
> +    {
> +      if (strcmp (q, "string1/abcde"))
> +       abort ();
> +      memset (q, '\0', 14);
> +      free (q);
> +    }
> +  q = bar (p);
> +  if (q != NULL)
> +    {
> +      if (strcmp (q, "string1/abcde"))
> +       abort ();
> +      free (q);
> +    }
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-7.c.jj       2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-7.c  2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,53 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen -fdump-tree-optimized" } */
> +
> +#include "strlenopt.h"
> +
> +char buf[64];
> +
> +__attribute__((noinline, noclone)) size_t
> +foo (void)
> +{
> +  char *p = memcpy (buf, "abcdefgh", 9);
> +  /* This store can be optimized away as... */
> +  *p = '\0';
> +  /* ... the following strcat can be optimized into memcpy,
> +     which overwrites that '\0'.  */
> +  strcat (p, "ijk");
> +  /* This should be optimized into return 3.  */
> +  return strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +bar (char *p)
> +{
> +  char *r = strchr (p, '\0');
> +  /* This store shouldn't be optimized away, because we
> +     want to crash if p is e.g. a string literal.  */
> +  *r = '\0';
> +  /* This strlen can be optimized into 0.  */
> +  return strlen (r);
> +}
> +
> +int
> +main ()
> +{
> +  char *volatile p = buf;
> +  if (foo () != 3 || memcmp (buf, "ijk\0efgh\0", 10) != 0)
> +    abort ();
> +  if (bar (p) != 0 || memcmp (buf, "ijk\0efgh\0", 10) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "\\*r_\[0-9\]* = 0;" 1 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "return 3;" 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "return 0;" 2 "optimized" } } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-8.c.jj       2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-8.c  2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,52 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +/* Yes, there are people who write code like this.  */
> +
> +__attribute__((noinline, noclone)) char *
> +foo (int r)
> +{
> +  char buf[10] = "";
> +  strcat (buf, r ? "r" : "w");
> +  strcat (buf, "b");
> +  return strdup (buf);
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +bar (int r)
> +{
> +  char buf[10] = {};
> +  strcat (buf, r ? "r" : "w");
> +  strcat (buf, "b");
> +  return strdup (buf);
> +}
> +
> +int
> +main ()
> +{
> +  char *q = foo (1);
> +  if (q != NULL)
> +    {
> +      if (strcmp (q, "rb"))
> +       abort ();
> +      free (q);
> +    }
> +  q = bar (0);
> +  if (q != NULL)
> +    {
> +      if (strcmp (q, "wb"))
> +       abort ();
> +      free (q);
> +    }
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-9.c.jj       2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-9.c  2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,109 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen -fdump-tree-optimized" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +fn1 (int r)
> +{
> +  char *p = r ? "a" : "bc";
> +  /* String length for p varies, therefore strchr below isn't
> +     optimized away.  */
> +  return strchr (p, '\0');
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn2 (int r)
> +{
> +  char *p, q[10];
> +  strcpy (q, "abc");
> +  p = r ? "a" : q;
> +  /* String length for p varies, therefore strlen below isn't
> +     optimized away.  */
> +  return strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn3 (char *p, int n)
> +{
> +  int i;
> +  p = strchr (p, '\0');
> +  /* strcat here can be optimized into memcpy.  */
> +  strcat (p, "abcd");
> +  for (i = 0; i < n; i++)
> +    if ((i % 123) == 53)
> +      /* strcat here is optimized into strlen and memcpy.  */
> +      strcat (p, "efg");
> +  /* The strlen here can't be optimized away, as in the loop string
> +     length of p might change.  */
> +  return strlen (p);
> +}
> +
> +char buf[64];
> +
> +__attribute__((noinline, noclone)) size_t
> +fn4 (char *x, int n)
> +{
> +  int i;
> +  size_t l;
> +  char a[64];
> +  char *p = strchr (x, '\0');
> +  /* strcpy here is optimized into memcpy, length computed as p - x + 1.  */
> +  strcpy (a, x);
> +  /* strcat here is optimized into memcpy.  */
> +  strcat (p, "abcd");
> +  for (i = 0; i < n; i++)
> +    if ((i % 123) == 53)
> +      /* strcat here is optimized into strlen and memcpy.  */
> +      strcat (a, "efg");
> +  /* The strlen should be optimized here into 4.  */
> +  l = strlen (p);
> +  /* This stays strcpy.  */
> +  strcpy (buf, a);
> +  return l;
> +}
> +
> +int
> +main ()
> +{
> +  volatile int l = 1;
> +  char b[64];
> +
> +  if (memcmp (fn1 (l) - 1, "a", 2) != 0)
> +    abort ();
> +  if (memcmp (fn1 (!l) - 2, "bc", 3) != 0)
> +    abort ();
> +  if (fn2 (l) != 1 || fn2 (!l) != 3)
> +    abort ();
> +  memset (b, '\0', sizeof b);
> +  memset (b, 'a', 3);
> +  if (fn3 (b, 10) != 4 || memcmp (b, "aaaabcd", 8) != 0)
> +    abort ();
> +  if (fn3 (b, 128) != 7 || memcmp (b, "aaaabcdabcdefg", 15) != 0)
> +    abort ();
> +  if (fn3 (b, 256) != 10 || memcmp (b, "aaaabcdabcdefgabcdefgefg", 25) != 0)
> +    abort ();
> +  if (fn4 (b, 10) != 4
> +      || memcmp (b, "aaaabcdabcdefgabcdefgefgabcd", 29) != 0
> +      || memcmp (buf, "aaaabcdabcdefgabcdefgefg", 25) != 0)
> +    abort ();
> +  if (fn4 (b, 128) != 4
> +      || memcmp (b, "aaaabcdabcdefgabcdefgefgabcdabcd", 33) != 0
> +      || memcmp (buf, "aaaabcdabcdefgabcdefgefgabcdefg", 32) != 0)
> +    abort ();
> +  if (fn4 (b, 256) != 4
> +      || memcmp (b, "aaaabcdabcdefgabcdefgefgabcdabcdabcd", 37) != 0
> +      || memcmp (buf, "aaaabcdabcdefgabcdefgefgabcdabcdefgefg", 39) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "return 4;" 1 "optimized" } } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-10.c.jj      2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-10.c 2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,80 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) size_t
> +fn1 (char *p)
> +{
> +  char *q;
> +  /* This can be optimized into memcpy and the size can be decreased to one,
> +     as it is immediately overwritten.  */
> +  strcpy (p, "z");
> +  q = strchr (p, '\0');
> +  *q = 32;
> +  /* This strlen can't be optimized away, string length is unknown here.  */
> +  return strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) void
> +fn2 (char *p, const char *z, size_t *lp)
> +{
> +  char *q, *r;
> +  char buf[64];
> +  size_t l[10];
> +  /* The first strlen stays, all the strcpy calls can be optimized
> +     into memcpy and all other strlen calls and all strchr calls
> +     optimized away.  */
> +  l[0] = strlen (z);
> +  strcpy (buf, z);
> +  strcpy (p, "abcde");
> +  q = strchr (p, '\0');
> +  strcpy (q, "efghi");
> +  r = strchr (q, '\0');
> +  strcpy (r, "jkl");
> +  l[1] = strlen (p);
> +  l[2] = strlen (q);
> +  l[3] = strlen (r);
> +  strcpy (r, buf);
> +  l[4] = strlen (p);
> +  l[5] = strlen (q);
> +  l[6] = strlen (r);
> +  strcpy (r, "mnopqr");
> +  l[7] = strlen (p);
> +  l[8] = strlen (q);
> +  l[9] = strlen (r);
> +  memcpy (lp, l, sizeof l);
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  size_t l[10];
> +  const char *volatile z = "ABCDEFG";
> +  memset (buf, '\0', sizeof buf);
> +  if (fn1 (buf) != 2 || buf[0] != 'z' || buf[1] != 32 || buf[2] != '\0')
> +    abort ();
> +  fn2 (buf, z, l);
> +  if (memcmp (buf, "abcdeefghimnopqr", 17) != 0)
> +    abort ();
> +  if (l[0] != 7)
> +    abort ();
> +  if (l[1] != 13 || l[2] != 8 || l[3] != 3)
> +    abort ();
> +  if (l[4] != 17 || l[5] != 12 || l[6] != 7)
> +    abort ();
> +  if (l[7] != 16 || l[8] != 11 || l[9] != 6)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 8 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "\\*q_\[0-9\]* = 32;" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(\[^\n\r\]*, 1\\)" 1 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-11.c.jj      2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-11.c 2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,70 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) void
> +fn1 (char *p, const char *z, size_t *lp)
> +{
> +  char *q, *r, *s;
> +  char buf[64];
> +  size_t l[11];
> +  /* The first strlen stays, all the strcpy calls can be optimized
> +     into memcpy and most other strlen calls and all strchr calls
> +     optimized away.  l[6] = strlen (r); and l[9] = strlen (r); need
> +     to stay, because we need to invalidate the knowledge about
> +     r strlen after strcpy (q, "jklmnopqrst").  */
> +  l[0] = strlen (z);
> +  strcpy (buf, z);
> +  strcpy (p, "abcde");
> +  q = strchr (p, '\0');
> +  strcpy (q, "efghi");
> +  r = strchr (q, '\0');
> +  strcpy (r, buf);
> +  l[1] = strlen (p);
> +  l[2] = strlen (q);
> +  l[3] = strlen (r);
> +  strcpy (q, "jklmnopqrst");
> +  l[4] = strlen (p);
> +  l[5] = strlen (q);
> +  l[6] = strlen (r);
> +  s = strchr (q, '\0');
> +  strcpy (s, buf);
> +  l[7] = strlen (p);
> +  l[8] = strlen (q);
> +  l[9] = strlen (r);
> +  l[10] = strlen (s);
> +  memcpy (lp, l, sizeof l);
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  size_t l[11];
> +  const char *volatile z = "ABCDEFG";
> +  memset (buf, '\0', sizeof buf);
> +  fn1 (buf, z, l);
> +  if (memcmp (buf, "abcdejklmnopqrstABCDEFG", 24) != 0)
> +    abort ();
> +  if (l[0] != 7)
> +    abort ();
> +  if (l[1] != 17 || l[2] != 12 || l[3] != 7)
> +    abort ();
> +  if (l[4] != 16 || l[5] != 11 || l[6] != 6)
> +    abort ();
> +  if (l[7] != 23 || l[8] != 18 || l[9] != 13 || l[10] != 7)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.0. = " 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.6. = " 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.9. = " 1 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-12.c.jj      2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-12.c 2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,90 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +fn1 (char *p, size_t *l)
> +{
> +  char *q = strcat (p, "abcde");
> +  *l = strlen (p);
> +  return q;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn2 (char *p, const char *q, size_t *l1, size_t *l2)
> +{
> +  size_t l = strlen (q);
> +  char *r = strcat (p, q);
> +  *l1 = l;
> +  *l2 = strlen (p);
> +  return r;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn3 (char *p, const char *q, size_t *l)
> +{
> +  char *r = strcpy (p, q);
> +  *l = strlen (p);
> +  return r;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn4 (char *p, const char *q, size_t *l)
> +{
> +  char *r = strcat (p, q);
> +  *l = strlen (p);
> +  return r;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn5 (char *p, const char *q, size_t *l1, size_t *l2, size_t *l3)
> +{
> +  size_t l = strlen (q);
> +  size_t ll = strlen (p);
> +  char *r = strcat (p, q);
> +  *l1 = l;
> +  *l2 = strlen (p);
> +  *l3 = ll;
> +  return r;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn6 (char *p, const char *q, size_t *l1, size_t *l2)
> +{
> +  size_t l = strlen (p);
> +  char *r = strcat (p, q);
> +  *l1 = strlen (p);
> +  *l2 = l;
> +  return r;
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  const char *volatile q = "fgh";
> +  size_t l, l1, l2, l3;
> +  memset (buf, '\0', sizeof buf);
> +  memset (buf, 'a', 3);
> +  if (fn1 (buf, &l) != buf || l != 8 || memcmp (buf, "aaaabcde", 9) != 0)
> +    abort ();
> +  if (fn2 (buf, q, &l1, &l2) != buf || l1 != 3 || l2 != 11
> +      || memcmp (buf, "aaaabcdefgh", 12) != 0)
> +    abort ();
> +  if (fn3 (buf, q, &l) != buf || l != 3
> +      || memcmp (buf, "fgh\0bcdefgh", 12) != 0)
> +    abort ();
> +  if (fn4 (buf, q, &l) != buf || l != 6
> +      || memcmp (buf, "fghfgh\0efgh", 12) != 0)
> +    abort ();
> +  l1 = 0;
> +  l2 = 0;
> +  if (fn5 (buf, q, &l1, &l2, &l3) != buf || l1 != 3 || l2 != 9 || l3 != 6
> +      || memcmp (buf, "fghfghfgh\0h", 12) != 0)
> +    abort ();
> +  if (fn6 (buf, q, &l1, &l2) != buf || l1 != 12 || l2 != 9
> +      || memcmp (buf, "fghfghfghfgh", 13) != 0)
> +    abort ();
> +  return 0;
> +}
> --- gcc/testsuite/gcc.dg/strlenopt-12g.c.jj     2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-12g.c        2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,6 @@
> +/* This test needs runtime that provides stpcpy function.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2" } */
> +
> +#define USE_GNU
> +#include "strlenopt-12.c"
> --- gcc/testsuite/gcc.dg/strlenopt-13.c.jj      2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-13.c 2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,68 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) void
> +fn1 (char *p, const char *y, const char *z, size_t *lp)
> +{
> +  char *q, *r, *s;
> +  char buf1[64], buf2[64];
> +  size_t l[8];
> +  /* These two strlen calls stay, all strcpy calls are optimized into
> +     memcpy, all strchr calls optimized away, and most other strlen
> +     calls too.  */
> +  l[0] = strlen (y);
> +  l[1] = strlen (z);
> +  strcpy (buf1, y);
> +  strcpy (buf2, z);
> +  strcpy (p, "abcde");
> +  q = strchr (p, '\0');
> +  strcpy (q, "efghi");
> +  r = strchr (q, '\0');
> +  strcpy (r, buf1);
> +  l[2] = strlen (p);
> +  l[3] = strlen (q);
> +  l[4] = strlen (r);
> +  strcpy (r, buf2);
> +  /* Except for these two calls, strlen (r) before and after the above
> +     is non-constant, so adding l[4] - l[1] to all previous strlens
> +     might make the expressions already too complex.  */
> +  l[5] = strlen (p);
> +  l[6] = strlen (q);
> +  /* This one is of course optimized, it is l[1].  */
> +  l[7] = strlen (r);
> +  memcpy (lp, l, sizeof l);
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  size_t l[8];
> +  const char *volatile y = "ABCDEFG";
> +  const char *volatile z = "HIJK";
> +  memset (buf, '\0', sizeof buf);
> +  fn1 (buf, y, z, l);
> +  if (memcmp (buf, "abcdeefghiHIJK", 15) != 0)
> +    abort ();
> +  if (l[0] != 7 || l[1] != 4)
> +    abort ();
> +  if (l[2] != 17 || l[3] != 12 || l[4] != 7)
> +    abort ();
> +  if (l[5] != 14 || l[6] != 9 || l[7] != 4)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.0. = " 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.1. = " 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.5. = " 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "  D\.\[0-9_\]* = strlen \\(\[^\n\r\]*;\[\n\r\]*  l.6. = " 1 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-14g.c.jj     2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-14g.c        2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,115 @@
> +/* This test needs runtime that provides stpcpy and mempcpy functions.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define USE_GNU
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +fn1 (char *p, size_t *l1, size_t *l2)
> +{
> +  char *a = mempcpy (p, "abcde", 6);
> +  /* This strlen needs to stay.  */
> +  size_t la = strlen (a);
> +  /* This strlen can be optimized into 5.  */
> +  size_t lp = strlen (p);
> +  *l1 = la;
> +  *l2 = lp;
> +  return a;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn2 (char *p, const char *q, size_t *l1, size_t *l2, size_t *l3)
> +{
> +  /* This strlen needs to stay.  */
> +  size_t lq = strlen (q);
> +  char *a = mempcpy (p, q, lq + 1);
> +  /* This strlen needs to stay.  */
> +  size_t la = strlen (a);
> +  /* This strlen can be optimized into lq.  */
> +  size_t lp = strlen (p);
> +  *l1 = lq;
> +  *l2 = la;
> +  *l3 = lp;
> +  return a;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn3 (char *p, size_t *l1, size_t *l2)
> +{
> +  char *a = stpcpy (p, "abcde");
> +  /* This strlen can be optimized into 0.  */
> +  size_t la = strlen (a);
> +  /* This strlen can be optimized into 5.  */
> +  size_t lp = strlen (p);
> +  *l1 = la;
> +  *l2 = lp;
> +  return a;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn4 (char *p, const char *q, size_t *l1, size_t *l2, size_t *l3)
> +{
> +  /* This strlen needs to stay.  */
> +  size_t lq = strlen (q);
> +  char *a = stpcpy (p, q);
> +  /* This strlen can be optimized into 0.  */
> +  size_t la = strlen (a);
> +  /* This strlen can be optimized into lq.  */
> +  size_t lp = strlen (p);
> +  *l1 = lq;
> +  *l2 = la;
> +  *l3 = lp;
> +  return a;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn5 (char *p, const char *q, size_t *l1, size_t *l2)
> +{
> +  char *a = stpcpy (p, q);
> +  /* This strlen can be optimized into 0.  */
> +  size_t la = strlen (a);
> +  /* This strlen can be optimized into a - p.  */
> +  size_t lp = strlen (p);
> +  *l1 = la;
> +  *l2 = lp;
> +  return a;
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  const char *volatile q = "ABCDEFGH";
> +  size_t l1, l2, l3;
> +  memset (buf, '\0', sizeof buf);
> +  memset (buf + 6, 'z', 7);
> +  if (fn1 (buf, &l1, &l2) != buf + 6 || l1 != 7 || l2 != 5
> +      || memcmp (buf, "abcde\0zzzzzzz", 14) != 0)
> +    abort ();
> +  if (fn2 (buf, q, &l1, &l2, &l3) != buf + 9 || l1 != 8 || l2 != 4 || l3 != 8
> +      || memcmp (buf, "ABCDEFGH\0zzzz", 14) != 0)
> +    abort ();
> +  if (fn3 (buf, &l1, &l2) != buf + 5 || l1 != 0 || l2 != 5
> +      || memcmp (buf, "abcde\0GH\0zzzz", 14) != 0)
> +    abort ();
> +  l3 = 0;
> +  memset (buf, 'n', 9);
> +  if (fn4 (buf, q, &l1, &l2, &l3) != buf + 8 || l1 != 8 || l2 != 0 || l3 != 8
> +      || memcmp (buf, "ABCDEFGH\0zzzz", 14) != 0)
> +    abort ();
> +  memset (buf, 'm', 9);
> +  if (fn5 (buf, q, &l1, &l2) != buf + 8 || l1 != 0 || l2 != 8
> +      || memcmp (buf, "ABCDEFGH\0zzzz", 14) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "mempcpy \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 2 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-14gf.c.jj    2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-14gf.c       2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,24 @@
> +/* This test needs runtime that provides stpcpy, mempcpy and __*_chk
> +   functions.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define FORTIFY_SOURCE 2
> +#include "strlenopt-14g.c"
> +
> +/* Compared to strlenopt-14gf.c, strcpy_chk with string literal as
> +   second argument isn't being optimized by builtins.c into
> +   memcpy.  */
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__memcpy_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__mempcpy_chk \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcpy_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__strcat_chk \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "__stpcpy_chk \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "mempcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-15.c.jj      2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-15.c 2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,60 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) size_t
> +fn1 (char *p, size_t l)
> +{
> +  memcpy (p, "abcdef", l);
> +  /* This strlen can't be optimized, as l is unknown.  */
> +  return strlen (p);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn2 (char *p, const char *q, size_t *lp)
> +{
> +  size_t l = strlen (q), l2;
> +  memcpy (p, q, 7);
> +  /* This strlen can't be optimized, as l might be bigger than 7.  */
> +  l2 = strlen (p);
> +  *lp = l;
> +  return l2;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn3 (char *p)
> +{
> +  *p = 0;
> +  return p + 1;
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  const char *volatile q = "ABCDEFGH";
> +  const char *volatile q2 = "IJ\0KLMNOPQRS";
> +  size_t l;
> +  memset (buf, '\0', sizeof buf);
> +  memset (buf + 2, 'a', 7);
> +  if (fn1 (buf, 3) != 9 || memcmp (buf, "abcaaaaaa", 10) != 0)
> +    abort ();
> +  if (fn1 (buf, 7) != 6 || memcmp (buf, "abcdef\0aa", 10) != 0)
> +    abort ();
> +  if (fn2 (buf, q, &l) != 9 || l != 8 || memcmp (buf, "ABCDEFGaa", 10) != 0)
> +    abort ();
> +  if (fn2 (buf, q2, &l) != 2 || l != 2 || memcmp (buf, "IJ\0KLMNaa", 10) != 0)
> +    abort ();
> +  if (fn3 (buf) != buf + 1 || memcmp (buf, "\0J\0KLMNaa", 10) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-16g.c.jj     2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-16g.c        2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,34 @@
> +/* This test needs runtime that provides stpcpy function.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define USE_GNU
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +fn1 (char *p, const char *q)
> +{
> +  /* This strcpy can be optimized into stpcpy.  */
> +  strcpy (p, q);
> +  /* And this strchr into the return value from it.  */
> +  return strchr (p, '\0');
> +}
> +
> +int
> +main ()
> +{
> +  char buf[64];
> +  const char *volatile q = "ABCDEFGH";
> +  if (fn1 (buf, q) != buf + 8 || memcmp (buf, "ABCDEFGH", 9) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "mempcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 1 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-17g.c.jj     2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-17g.c        2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,57 @@
> +/* This test needs runtime that provides stpcpy function.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define USE_GNU
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) int
> +foo (const char *p)
> +{
> +  static int c;
> +  const char *q[] = { "123498765abcde", "123498765..", "129abcde", "129abcde" };
> +  if (strcmp (p, q[c]) != 0)
> +    abort ();
> +  return c++;
> +}
> +
> +__attribute__((noinline, noclone)) void
> +bar (const char *p, const char *q)
> +{
> +  size_t l;
> +  /* This strlen stays.  */
> +  char *a = __builtin_alloca (strlen (p) + 50);
> +  /* strcpy can be optimized into memcpy.  */
> +  strcpy (a, p);
> +  /* strcat into stpcpy.  */
> +  strcat (a, q);
> +  /* This strlen can be optimized away.  */
> +  l = strlen (a);
> +  /* This becomes memcpy.  */
> +  strcat (a, "abcde");
> +  if (!foo (a))
> +    /* And this one too.  */
> +    strcpy (a + l, "..");
> +  foo (a);
> +}
> +
> +int
> +main ()
> +{
> +  const char *volatile s1 = "1234";
> +  const char *volatile s2 = "98765";
> +  const char *volatile s3 = "12";
> +  const char *volatile s4 = "9";
> +  bar (s1, s2);
> +  bar (s3, s4);
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 3 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "mempcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 1 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-18g.c.jj     2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-18g.c        2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,82 @@
> +/* This test needs runtime that provides stpcpy function.  */
> +/* { dg-do run { target *-*-linux* } } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#define USE_GNU
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +fn1 (int x, int y, int z)
> +{
> +  static char buf[40];
> +  const char *p;
> +  switch (x)
> +    {
> +    case 0:
> +      p = "abcd";
> +      break;
> +    case 1:
> +      p = "efgh";
> +      break;
> +    case 2:
> +      p = "ijkl";
> +      break;
> +    default:
> +      p = "mnopq";
> +      break;
> +    }
> +  if (y)
> +    {
> +      strcpy (buf, p);
> +      if (z)
> +       strcat (buf, "ABCDEFG");
> +      else
> +       strcat (buf, "HIJKLMN");
> +    }
> +  else
> +    {
> +      strcpy (buf, p + 1);
> +      if (z)
> +       strcat (buf, "OPQ");
> +      else
> +       strcat (buf, "RST");
> +    }
> +  return buf;
> +}
> +
> +int
> +main ()
> +{
> +  int i;
> +  for (i = 0; i < 5; i++)
> +    {
> +      const char *p = "abcdefghijklmnopq" + (i < 3 ? i : 3) * 4;
> +      const char *q;
> +      int j = i >= 3;
> +      fn1 (i ? 0 : 1, 1, 1);
> +      q = fn1 (i, 0, 0);
> +      if (memcmp (q, p + 1, 3 + j) != 0 || memcmp (q + 3 + j, "RST", 4) != 0)
> +       abort ();
> +      fn1 (i ? 0 : 1, 0, 1);
> +      q = fn1 (i, 1, 0);
> +      if (memcmp (q, p, 4 + j) != 0 || memcmp (q + 4 + j, "HIJKLMN", 8) != 0)
> +       abort ();
> +      fn1 (i ? 0 : 1, 1, 0);
> +      q = fn1 (i, 0, 1);
> +      if (memcmp (q, p + 1, 3 + j) != 0 || memcmp (q + 3 + j, "OPQ", 4) != 0)
> +       abort ();
> +      fn1 (i ? 0 : 1, 0, 0);
> +      q = fn1 (i, 1, 1);
> +      if (memcmp (q, p, 4 + j) != 0 || memcmp (q + 4 + j, "ABCDEFG", 8) != 0)
> +       abort ();
> +    }
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 2 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-19.c.jj      2011-09-15 14:08:48.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-19.c 2011-09-15 14:05:11.000000000 +0200
> @@ -0,0 +1,81 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) char *
> +fn1 (int x, int y, int z)
> +{
> +  static char buf[40];
> +  const char *p;
> +  switch (x)
> +    {
> +    case 0:
> +      p = "abcd";
> +      /* Prevent cswitch optimization.  */
> +      asm volatile ("" : : : "memory");
> +      break;
> +    case 1:
> +      p = "efgh";
> +      break;
> +    case 2:
> +      p = "ijkl";
> +      break;
> +    default:
> +      p = "mnop";
> +      break;
> +    }
> +  if (y)
> +    {
> +      strcpy (buf, p);
> +      if (z)
> +       strcat (buf, "ABCDEFG");
> +      else
> +       strcat (buf, "HIJKLMN");
> +    }
> +  else
> +    {
> +      strcpy (buf, p + 1);
> +      if (z)
> +       strcat (buf, "OPQ");
> +      else
> +       strcat (buf, "RST");
> +    }
> +  return buf;
> +}
> +
> +int
> +main ()
> +{
> +  int i;
> +  for (i = 0; i < 5; i++)
> +    {
> +      const char *p = "abcdefghijklmnop" + (i < 3 ? i : 3) * 4;
> +      const char *q;
> +      fn1 (i ? 0 : 1, 1, 1);
> +      q = fn1 (i, 0, 0);
> +      if (memcmp (q, p + 1, 3) != 0 || memcmp (q + 3, "RST", 4) != 0)
> +       abort ();
> +      fn1 (i ? 0 : 1, 0, 1);
> +      q = fn1 (i, 1, 0);
> +      if (memcmp (q, p, 4) != 0 || memcmp (q + 4, "HIJKLMN", 8) != 0)
> +       abort ();
> +      fn1 (i ? 0 : 1, 1, 0);
> +      q = fn1 (i, 0, 1);
> +      if (memcmp (q, p + 1, 3) != 0 || memcmp (q + 3, "OPQ", 4) != 0)
> +       abort ();
> +      fn1 (i ? 0 : 1, 0, 0);
> +      q = fn1 (i, 1, 1);
> +      if (memcmp (q, p, 4) != 0 || memcmp (q + 4, "ABCDEFG", 8) != 0)
> +       abort ();
> +    }
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt-20.c.jj      2011-09-15 14:47:56.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt-20.c 2011-09-15 14:47:34.000000000 +0200
> @@ -0,0 +1,95 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +#include "strlenopt.h"
> +
> +__attribute__((noinline, noclone)) const char *
> +fn1 (int x, int y)
> +{
> +  const char *p;
> +  switch (x)
> +    {
> +    case 0:
> +      p = "abcd";
> +      /* Prevent cswitch optimization.  */
> +      asm volatile ("" : : : "memory");
> +      break;
> +    case 1:
> +      p = "efgh";
> +      break;
> +    case 2:
> +      p = "ijkl";
> +      break;
> +    default:
> +      p = "mnop";
> +      break;
> +    }
> +  if (y)
> +    /* strchr should be optimized into p + 4 here.  */
> +    return strchr (p, '\0');
> +  else
> +    /* and strlen into 3.  */
> +    return p + strlen (p + 1);
> +}
> +
> +__attribute__((noinline, noclone)) size_t
> +fn2 (char *p, char *q)
> +{
> +  size_t l;
> +  /* Both strcpy calls can be optimized into memcpy, strlen needs to stay.  */
> +  strcpy (p, "abc");
> +  p[3] = 'd';
> +  l = strlen (p);
> +  strcpy (q, p);
> +  return l;
> +}
> +
> +__attribute__((noinline, noclone)) char *
> +fn3 (char *p)
> +{
> +  char *c;
> +  /* The strcpy call can be optimized into memcpy, strchr needs to stay,
> +     strcat is optimized into memcpy.  */
> +  strcpy (p, "abc");
> +  p[3] = 'd';
> +  c = strchr (p, '\0');
> +  strcat (p, "efgh");
> +  return c;
> +}
> +
> +int
> +main ()
> +{
> +  int i;
> +  char buf[64], buf2[64];
> +  for (i = 0; i < 5; i++)
> +    {
> +      const char *p = "abcdefghijklmnop" + (i < 3 ? i : 3) * 4;
> +      const char *q;
> +      q = fn1 (i, 1);
> +      if (memcmp (q - 4, p, 4) != 0 || q[0] != '\0')
> +       abort ();
> +      q = fn1 (i, 0);
> +      if (memcmp (q - 3, p, 4) != 0 || q[1] != '\0')
> +       abort ();
> +    }
> +  memset (buf, '\0', sizeof buf);
> +  memset (buf + 4, 'z', 2);
> +  if (fn2 (buf, buf2) != 6
> +      || memcmp (buf, "abcdzz", 7) != 0
> +      || memcmp (buf2, "abcdzz", 7) != 0)
> +    abort ();
> +  memset (buf, '\0', sizeof buf);
> +  memset (buf + 4, 'z', 2);
> +  if (fn3 (buf) != buf + 6 || memcmp (buf, "abcdzzefgh", 11) != 0)
> +    abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
> +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
> +/* { dg-final { cleanup-tree-dump "strlen" } } */
> --- gcc/testsuite/gcc.dg/strlenopt.h.jj 2011-09-15 12:24:10.000000000 +0200
> +++ gcc/testsuite/gcc.dg/strlenopt.h    2011-09-15 12:24:10.000000000 +0200
> @@ -0,0 +1,59 @@
> +/* This is a replacement of needed parts from stdlib.h and string.h
> +   for -foptimize-strlen testing, to ensure we are testing the builtins
> +   rather than whatever the OS has in its headers.  */
> +
> +#define NULL ((void *) 0)
> +typedef __SIZE_TYPE__ size_t;
> +extern void abort (void);
> +void *malloc (size_t);
> +void free (void *);
> +char *strdup (const char *);
> +size_t strlen (const char *);
> +void *memcpy (void *__restrict, const void *__restrict, size_t);
> +char *strcpy (char *__restrict, const char *__restrict);
> +char *strcat (char *__restrict, const char *__restrict);
> +char *strchr (const char *, int);
> +void *memset (void *, int, size_t);
> +int memcmp (const void *, const void *, size_t);
> +int strcmp (const char *, const char *);
> +#ifdef USE_GNU
> +void *mempcpy (void *__restrict, const void *__restrict, size_t);
> +char *stpcpy (char *__restrict, const char *__restrict);
> +#endif
> +
> +#if defined(FORTIFY_SOURCE) && FORTIFY_SOURCE > 0 && __OPTIMIZE__
> +# define bos(ptr) __builtin_object_size (ptr, FORTIFY_SOURCE > 0)
> +# define bos0(ptr) __builtin_object_size (ptr, 0)
> +
> +extern inline __attribute__((gnu_inline, always_inline, artificial)) void *
> +memcpy (void *__restrict dest, const void *__restrict src, size_t len)
> +{
> +  return __builtin___memcpy_chk (dest, src, len, bos0 (dest));
> +}
> +
> +extern inline __attribute__((gnu_inline, always_inline, artificial)) char *
> +strcpy (char *__restrict dest, const char *__restrict src)
> +{
> +  return __builtin___strcpy_chk (dest, src, bos (dest));
> +}
> +
> +extern inline __attribute__((gnu_inline, always_inline, artificial)) char *
> +strcat (char *__restrict dest, const char *__restrict src)
> +{
> +  return __builtin___strcat_chk (dest, src, bos (dest));
> +}
> +
> +# ifdef USE_GNU
> +extern inline __attribute__((gnu_inline, always_inline, artificial)) void *
> +mempcpy (void *__restrict dest, const void *__restrict src, size_t len)
> +{
> +  return __builtin___mempcpy_chk (dest, src, len, bos0 (dest));
> +}
> +
> +extern inline __attribute__((gnu_inline, always_inline, artificial)) char *
> +stpcpy (char *__restrict dest, const char *__restrict src)
> +{
> +  return __builtin___stpcpy_chk (dest, src, bos (dest));
> +}
> +# endif
> +#endif
>
>        Jakub
>