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[PATCH] Fix execute/20000225-1.c
- To: gcc-patches at gcc dot gnu dot org
- Subject: [PATCH] Fix execute/20000225-1.c
- From: Franz Sirl <Franz dot Sirl-kernel at lauterbach dot com>
- Date: Thu, 28 Sep 2000 19:51:07 +0200
- Cc: "Jose Luu" <jluu at mainsoft dot com>,Jeffrey A Law <law at cygnus dot com>
Hi,
finally I got annoyed enough to look at this testcase and fixed it. The fix
is based on Jose's patch:
<http://gcc.gnu.org/ml/gcc-patches/2000-01/msg00783.html>
and Jeff's comments here:
<http://gcc.gnu.org/ml/gcc-patches/2000-02/msg00828.html>
It fixes the testcase and bootstraps without regression on powerpc-linux-gnu.
OK to commit?
Franz.
2000-09-28 Jose Luu <jluu@mainsoft.com>
Franz Sirl <Franz.Sirl-kernel@lauterbach.com>
* loop.c (check_final_value): A GIV is not replaceable if used before the
set.
Index: gcc/loop.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/loop.c,v
retrieving revision 1.288
diff -u -p -r1.288 loop.c
--- loop.c 2000/09/19 16:01:13 1.288
+++ loop.c 2000/09/28 17:04:06
@@ -5094,6 +5094,7 @@ check_final_value (loop, v)
or all uses follow that insn in the same basic block),
- its final value can be calculated (this condition is different
than the one above in record_giv)
+ - it's not used before it's set
- no assignments to the biv occur during the giv's lifetime. */
#if 0
@@ -5105,7 +5106,7 @@ check_final_value (loop, v)
if ((final_value = final_giv_value (loop, v))
&& (v->always_computable || last_use_this_basic_block (v->dest_reg, v->insn)))
{
- int biv_increment_seen = 0;
+ int biv_increment_seen = 0, before_giv_insn = 0;
rtx p = v->insn;
rtx last_giv_use;
@@ -5135,7 +5136,10 @@ check_final_value (loop, v)
{
p = NEXT_INSN (p);
if (p == loop->end)
- p = NEXT_INSN (loop->start);
+ {
+ before_giv_insn = 1;
+ p = NEXT_INSN (loop->start);
+ }
if (p == v->insn)
break;
@@ -5153,7 +5157,7 @@ check_final_value (loop, v)
if (reg_mentioned_p (v->dest_reg, PATTERN (p)))
{
- if (biv_increment_seen)
+ if (biv_increment_seen || before_giv_insn)
{
v->replaceable = 0;
v->not_replaceable = 1;