Message ID | 0c48f7c0-6fff-c8f3-5680-e4a0fc3203bf@redhat.com |
---|---|
State | New |
Headers | show |
On Wed, Jun 28, 2017 at 9:56 AM, Aldy Hernandez <aldyh@redhat.com> wrote: > > > On 06/27/2017 06:38 AM, Jakub Jelinek wrote: >> >> On Tue, Jun 27, 2017 at 06:26:46AM -0400, Aldy Hernandez wrote: >>> >>> How about this? >> >> >> @@ -360,6 +363,22 @@ set_range_info (tree name, enum value_range_type >> range_type, >> } >> } >> +/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name >> + NAME while making sure we don't store useless range info. */ >> + >> +void >> +set_range_info (tree name, enum value_range_type range_type, >> + const wide_int_ref &min, const wide_int_ref &max) >> +{ >> + /* A range of the entire domain is really no range at all. */ >> + tree type = TREE_TYPE (name); >> + if (min == wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type)) >> + && max == wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type))) >> + return; >> + >> + set_range_info_raw (name, range_type, min, max); >> +} >> + >> >> Won't this misbehave if we have a narrower range on some SSA_NAME and >> call set_range_info to make it VARYING? >> In that case (i.e. SSA_NAME_RANGE_INFO (name) != NULL), we should either >> set_range_info_raw too (if nonzero_bits is not all ones) or clear >> SSA_NAME_RANGE_INFO (otherwise). > > > Good point. Fixed. > >> /* Gets range information MIN, MAX and returns enum value_range_type >> corresponding to tree ssa_name NAME. enum value_range_type returned >> @@ -419,9 +438,13 @@ set_nonzero_bits (tree name, const wide_int_ref >> &mask) >> { >> gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); >> if (SSA_NAME_RANGE_INFO (name) == NULL) >> - set_range_info (name, VR_RANGE, >> - TYPE_MIN_VALUE (TREE_TYPE (name)), >> - TYPE_MAX_VALUE (TREE_TYPE (name))); >> + { >> + if (mask == -1) >> + return; >> + set_range_info_raw (name, VR_RANGE, >> + TYPE_MIN_VALUE (TREE_TYPE (name)), >> + TYPE_MAX_VALUE (TREE_TYPE (name))); >> + } >> range_info_def *ri = SSA_NAME_RANGE_INFO (name); >> ri->set_nonzero_bits (mask); >> >> Similarly, if SSA_NAME_RANGE_INFO is previously non-NULL, but min/max >> are VARYING and the new mask is -1, shouldn't we free it rather than >> set it to the default? > > > Here, if SSA_NAME_RANGE_INFO is previously non-NULL then we proceed as > always-- just set the nonzero bits to whatever was specified (without > clearning SSA_NAME_RANGE_INFO). A mask of -1 and an SSA_NAME_RANGE_INFO of > non-NULL can coexist just fine. > > How about this? Ok. Thanks, Richard. > Aldy
diff --git a/gcc/testsuite/gcc.dg/Walloca-14.c b/gcc/testsuite/gcc.dg/Walloca-14.c index 723dbe5..f3e3f57 100644 --- a/gcc/testsuite/gcc.dg/Walloca-14.c +++ b/gcc/testsuite/gcc.dg/Walloca-14.c @@ -9,5 +9,6 @@ g (int *p) extern void f (void *); void *q = __builtin_alloca (p); /* { dg-warning "passing argument 1" } */ + /* { dg-warning "unbounded use of 'alloca'" "unbounded" { target *-*-* } 11 } */ f (q); } diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c index 353c7b1..0053b01 100644 --- a/gcc/tree-ssanames.c +++ b/gcc/tree-ssanames.c @@ -320,11 +320,14 @@ make_ssa_name_fn (struct function *fn, tree var, gimple *stmt, return t; } -/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name NAME. */ +/* Helper function for set_range_info. + + Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name + NAME. */ void -set_range_info (tree name, enum value_range_type range_type, - const wide_int_ref &min, const wide_int_ref &max) +set_range_info_raw (tree name, enum value_range_type range_type, + const wide_int_ref &min, const wide_int_ref &max) { gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); @@ -360,6 +363,34 @@ set_range_info (tree name, enum value_range_type range_type, } } +/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name + NAME while making sure we don't store useless range info. */ + +void +set_range_info (tree name, enum value_range_type range_type, + const wide_int_ref &min, const wide_int_ref &max) +{ + gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); + + /* A range of the entire domain is really no range at all. */ + tree type = TREE_TYPE (name); + if (min == wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type)) + && max == wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type))) + { + range_info_def *ri = SSA_NAME_RANGE_INFO (name); + if (ri == NULL) + return; + if (ri->get_nonzero_bits () == -1) + { + ggc_free (ri); + SSA_NAME_RANGE_INFO (name) = NULL; + return; + } + } + + set_range_info_raw (name, range_type, min, max); +} + /* Gets range information MIN, MAX and returns enum value_range_type corresponding to tree ssa_name NAME. enum value_range_type returned @@ -419,9 +450,13 @@ set_nonzero_bits (tree name, const wide_int_ref &mask) { gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); if (SSA_NAME_RANGE_INFO (name) == NULL) - set_range_info (name, VR_RANGE, - TYPE_MIN_VALUE (TREE_TYPE (name)), - TYPE_MAX_VALUE (TREE_TYPE (name))); + { + if (mask == -1) + return; + set_range_info_raw (name, VR_RANGE, + TYPE_MIN_VALUE (TREE_TYPE (name)), + TYPE_MAX_VALUE (TREE_TYPE (name))); + } range_info_def *ri = SSA_NAME_RANGE_INFO (name); ri->set_nonzero_bits (mask); } diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h index 9a18394..f7e032f 100644 --- a/gcc/tree-ssanames.h +++ b/gcc/tree-ssanames.h @@ -69,6 +69,9 @@ struct GTY ((variable_size)) range_info_def { /* Sets the value range to SSA. */ extern void set_range_info (tree, enum value_range_type, const wide_int_ref &, const wide_int_ref &); +extern void set_range_info_raw (tree, enum value_range_type, + const wide_int_ref &, + const wide_int_ref &); /* Gets the value range from SSA. */ extern enum value_range_type get_range_info (const_tree, wide_int *, wide_int *);