| Message ID | 20160219162156.GA16767@virgil.suse.cz |
|---|---|
| State | New |
| Headers | show |
On February 19, 2016 5:21:56 PM GMT+01:00, Martin Jambor <mjambor@suse.cz> wrote: >Hi, > >in PR 69666, SRA attempts to turn a load from an aggregate that is >uninitialized into a load from a default definition SSA name (which >something it does to generate an appropriate warning later) but >unfortunately it does so using an access structure which is >representable with __int128 when the load in question is smaller. It >then attempts to fix it up only to create an invalid V_C_E. In this >case, the correct thing to do is not to attempt the transformation, >when there are smaller accesses, which can be figured out by looking >at the unscalarizable_region flag of the access. > >Bootstrapped and tested on x86_64, OK for trunk and later for the 5 >branch? OK. Richard. >Thanks, > >Martin > > >2016-02-19 Martin Jambor <mjambor@suse.cz> > > PR tree-optimization/69666 > * tree-sra.c (sra_modify_assign): Do not attempt to create > defaut_def replacements for unscalarizable regions. > >testsuite/ > * gcc.dg/tree-ssa/pr69666.c: New test. >--- > gcc/testsuite/gcc.dg/tree-ssa/pr69666.c | 16 ++++++++++++++++ > gcc/tree-sra.c | 1 + > 2 files changed, 17 insertions(+) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr69666.c > >diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr69666.c >b/gcc/testsuite/gcc.dg/tree-ssa/pr69666.c >new file mode 100644 >index 0000000..9be77ea >--- /dev/null >+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr69666.c >@@ -0,0 +1,16 @@ >+/* { dg-do compile } */ >+/* { dg-options "-O2 -w" } */ >+ >+int a, c, d; >+float b; >+void *memcpy(); >+int fun1(int p1, unsigned char *p2) { >+ p2[p1] = b; >+ return a; >+} >+void fun2() { >+ unsigned char e[16]; >+ fun1(16, e); >+ d = e[d]; >+ memcpy(&c, e, sizeof(e)); >+} >diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c >index 72157ed..663ded2 100644 >--- a/gcc/tree-sra.c >+++ b/gcc/tree-sra.c >@@ -3339,6 +3339,7 @@ sra_modify_assign (gimple *stmt, >gimple_stmt_iterator *gsi) > } > else if (racc > && !racc->grp_unscalarized_data >+ && !racc->grp_unscalarizable_region > && TREE_CODE (lhs) == SSA_NAME > && !access_has_replacements_p (racc)) > {
On Fri, Feb 19, 2016 at 8:21 AM, Martin Jambor <mjambor@suse.cz> wrote: > Hi, > > in PR 69666, SRA attempts to turn a load from an aggregate that is > uninitialized into a load from a default definition SSA name (which > something it does to generate an appropriate warning later) but > unfortunately it does so using an access structure which is > representable with __int128 when the load in question is smaller. It > then attempts to fix it up only to create an invalid V_C_E. In this > case, the correct thing to do is not to attempt the transformation, > when there are smaller accesses, which can be figured out by looking > at the unscalarizable_region flag of the access. > > Bootstrapped and tested on x86_64, OK for trunk and later for the 5 > branch? > This may have caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69920
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr69666.c b/gcc/testsuite/gcc.dg/tree-ssa/pr69666.c new file mode 100644 index 0000000..9be77ea --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr69666.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -w" } */ + +int a, c, d; +float b; +void *memcpy(); +int fun1(int p1, unsigned char *p2) { + p2[p1] = b; + return a; +} +void fun2() { + unsigned char e[16]; + fun1(16, e); + d = e[d]; + memcpy(&c, e, sizeof(e)); +} diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c index 72157ed..663ded2 100644 --- a/gcc/tree-sra.c +++ b/gcc/tree-sra.c @@ -3339,6 +3339,7 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi) } else if (racc && !racc->grp_unscalarized_data + && !racc->grp_unscalarizable_region && TREE_CODE (lhs) == SSA_NAME && !access_has_replacements_p (racc)) {