From 8df63efa77a00e164cf9a72379d338fcd21d92ca Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 8 Jul 2003 09:26:27 +0200
Subject: [PATCH] unroll.c (reg_dead_after_loop): Check for reg in REG_EQUAL
and REG_EQUIV notes as well.
* unroll.c (reg_dead_after_loop): Check for reg in REG_EQUAL and
REG_EQUIV notes as well.
* g++.dg/opt/strength-reduce.C: New test.
From-SVN: r69076
---
gcc/ChangeLog | 5 +++
gcc/testsuite/ChangeLog | 4 ++
gcc/testsuite/g++.dg/opt/strength-reduce.C | 51 ++++++++++++++++++++++
gcc/unroll.c | 6 ++-
4 files changed, 65 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/opt/strength-reduce.C
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 84a6e50e080a..c2621df17dfb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-07-08 Jakub Jelinek <jakub@redhat.com>
+
+ * unroll.c (reg_dead_after_loop): Check for reg in REG_EQUAL and
+ REG_EQUIV notes as well.
+
2003-07-08 Kazu Hirata <kazu@cs.umass.edu>
* doc/md.texi: Fix the description of addmodecc.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5ee11fb1baba..79d98c1e9dbe 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-07-08 Jakub Jelinek <jakub@redhat.com>
+
+ * g++.dg/opt/strength-reduce.C: New test.
+
2003-07-07 Roger Sayle <roger@eyesopen.com>
PR target/10979
diff --git a/gcc/testsuite/g++.dg/opt/strength-reduce.C b/gcc/testsuite/g++.dg/opt/strength-reduce.C
new file mode 100644
index 000000000000..7c4619a36fa0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/strength-reduce.C
@@ -0,0 +1,51 @@
+// This testcase was miscompiled on s390x, because strength-reduction
+// did not see biv in C::foo as used after loop, but it was used
+// in a REG_EQUAL note.
+// { dg-do run }
+// { dg-options "-O2" }
+
+extern "C" void abort (void);
+
+struct C
+{
+ int foo (char ch, int offset = 0x7fffffff) const;
+ int bar (int offset, char c) const;
+ char *a;
+};
+
+int C::bar (int offset, char c) const
+{
+ char ch = a[offset];
+ if (ch < c)
+ return -1;
+ if (ch > c)
+ return 1;
+ return 0;
+}
+
+int C::foo (char ch, int offset) const
+{
+ int len = __builtin_strlen (a);
+ if (len == 0)
+ return 0x7fffffff;
+ if (offset >= len)
+ offset = len - 1;
+
+ while (bar (offset, ch) != 0)
+ {
+ if (offset == 0)
+ return 0x7fffffff;
+ offset--;
+ }
+
+ return offset;
+}
+
+int main (void)
+{
+ C c;
+ c.a = "/some/dir/file.ext";
+ if (c.foo ('/') != 9)
+ abort ();
+ return 0;
+}
diff --git a/gcc/unroll.c b/gcc/unroll.c
index 955136e0b03b..e557cb2c1e59 100644
--- a/gcc/unroll.c
+++ b/gcc/unroll.c
@@ -2899,11 +2899,15 @@ reg_dead_after_loop (const struct loop *loop, rtx reg)
code = GET_CODE (insn);
if (GET_RTX_CLASS (code) == 'i')
{
- rtx set;
+ rtx set, note;
if (reg_referenced_p (reg, PATTERN (insn)))
return 0;
+ note = find_reg_equal_equiv_note (insn);
+ if (note && reg_overlap_mentioned_p (reg, XEXP (note, 0)))
+ return 0;
+
set = single_set (insn);
if (set && rtx_equal_p (SET_DEST (set), reg))
break;
--
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