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Re: [Bug optimization/14553][tree-ssa] segfault involving pointers
- From: Diego Novillo <dnovillo at redhat dot com>
- To: "gcc-bugzilla at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 12 Mar 2004 23:30:44 -0500
- Subject: Re: [Bug optimization/14553][tree-ssa] segfault involving pointers
- Organization: Red Hat Canada
- References: <20040312134458.14553.schnetter@aei.mpg.de> <20040312150254.29252.qmail@sources.redhat.com>
On Fri, 2004-03-12 at 10:02, reichelt at gcc dot gnu dot org wrote:
> ------- Additional Comments From reichelt at gcc dot gnu dot org 2004-03-12 15:02 -------
> Redux (crashes gcc and g++, just compile with -O3):
>
> ===============================================
> void foo(int* p)
> {
> int i;
> for (i=1; i>0; --i, ++p)
> *p=0;
> }
>
> void bar(int* p) { foo(p); }
> ===============================================
>
> Might be related to PR 14433, where the bug magically disappeared today.
>
It wasn't. This was another case of a pass doing value propagation not
using propagate_value. Fixed with patch below. Will commit after tests
are finished.
Diego.
PR optimization/14553
* tree-ssa.c (replace_immediate_uses): Call propagate_value to
update operands.
Index: tree-ssa.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa.c,v
retrieving revision 1.1.4.211
diff -d -c -p -d -u -p -r1.1.4.211 tree-ssa.c
--- tree-ssa.c 12 Mar 2004 04:19:06 -0000 1.1.4.211
+++ tree-ssa.c 13 Mar 2004 03:44:52 -0000
@@ -3850,19 +3850,19 @@ replace_immediate_uses (tree var, tree r
uses = STMT_USE_OPS (stmt);
for (j = 0; j < (int) NUM_USES (uses); j++)
if (USE_OP (uses, j) == var)
- *USE_OP_PTR (uses, j) = repl;
+ propagate_value (USE_OP_PTR (uses, j), repl);
}
else
{
vuses = STMT_VUSE_OPS (stmt);
for (j = 0; j < (int) NUM_VUSES (vuses); j++)
if (VUSE_OP (vuses, j) == var)
- *VUSE_OP_PTR (vuses, j) = repl;
+ propagate_value (VUSE_OP_PTR (vuses, j), repl);
vdefs = STMT_VDEF_OPS (stmt);
for (j = 0; j < (int) NUM_VDEFS (vdefs); j++)
if (VDEF_OP (vdefs, j) == var)
- *VDEF_OP_PTR (vdefs, j) = repl;
+ propagate_value (VDEF_OP_PTR (vdefs, j), repl);
}
modify_stmt (stmt);