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re PR tree-optimization/63748 (wrong may be used uninitialized warning (abnormal edges))

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2014-11-10  Patrick Palka  <ppalka@gcc.gnu.org>

gcc/
	PR middle-end/63748
	* tree-ssa-propagate.c (may_propagate_copy): Allow propagating
	SSA copies whose source and destination names both occur in
	abnormal PHIs.

gcc/testsuite/
	PR middle-end/63748
	* gcc.dg/pr63748.c: New testcase.

From-SVN: r217317
This commit is contained in:
Patrick Palka 2014-11-10 20:43:40 +00:00
parent 3bbddc8e44
commit c7488fba45
4 changed files with 63 additions and 12 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2014-11-10 Patrick Palka <ppalka@gcc.gnu.org>
PR middle-end/63748
* tree-ssa-propagate.c (may_propagate_copy): Allow propagating
SSA copies whose source and destination names both occur in
abnormal PHIs.
2014-11-10 Roman Gareev <gareevroman@gmail.com>
* Makefile.in: Remove the compilation of graphite-clast-to-gimple.o.

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2014-11-10 Patrick Palka <ppalka@gcc.gnu.org>
PR middle-end/63748
* gcc.dg/pr63748.c: New testcase.
2014-11-10 H.J. Lu <hongjiu.lu@intel.com>
* gcc.dg/pr44194-1.c (dg-do): Add missing braces.

36
gcc/testsuite/gcc.dg/pr63748.c Normal file
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@ -0,0 +1,36 @@
/* { dg-do compile } */
/* { dg-options "-O2 -Wall" } */
#include <setjmp.h>
jmp_buf *alloc_jmp_buf ();
int foo (void *);
int
test (int op, int noside)
{
void *argvec = 0;
if (op)
{
jmp_buf *buf = alloc_jmp_buf (); /* { dg-bogus "uninitialized" } */
setjmp (*buf);
if (noside)
goto nosideret;
do_call_it:
if (noside)
goto nosideret;
return foo (argvec);
}
argvec = __builtin_alloca (1);
goto do_call_it;
nosideret:
return 1;
}

27
gcc/tree-ssa-propagate.c
View file

@ -1275,21 +1275,24 @@ may_propagate_copy (tree dest, tree orig)
tree type_d = TREE_TYPE (dest);
tree type_o = TREE_TYPE (orig);
/* If ORIG flows in from an abnormal edge, it cannot be propagated. */
/* If ORIG is a default definition which flows in from an abnormal edge
then the copy can be propagated. It is important that we do so to avoid
uninitialized copies. */
if (TREE_CODE (orig) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig)
/* If it is the default definition and an automatic variable then
we can though and it is important that we do to avoid
uninitialized regular copies. */
&& !(SSA_NAME_IS_DEFAULT_DEF (orig)
&& (SSA_NAME_VAR (orig) == NULL_TREE
|| TREE_CODE (SSA_NAME_VAR (orig)) == VAR_DECL)))
&& SSA_NAME_IS_DEFAULT_DEF (orig)
&& (SSA_NAME_VAR (orig) == NULL_TREE
|| TREE_CODE (SSA_NAME_VAR (orig)) == VAR_DECL))
;
/* Otherwise if ORIG just flows in from an abnormal edge then the copy cannot
be propagated. */
else if (TREE_CODE (orig) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig))
return false;
/* If DEST is an SSA_NAME that flows from an abnormal edge, then it
cannot be replaced. */
if (TREE_CODE (dest) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (dest))
/* Similarly if DEST flows in from an abnormal edge then the copy cannot be
propagated. */
else if (TREE_CODE (dest) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (dest))
return false;
/* Do not copy between types for which we *do* need a conversion. */