* 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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@69076 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 84a6e50e080aa6deaa64938500d323a4b2f705ec..c2621df17dfbeea7251936e6f673679818a6d950 100644 (file)
--- 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 5ee11fb1baba0f94920e0b96e76a07a381c2fcfd..79d98c1e9dbee18ff6e085b0cdd1a86694a496a2 100644 (file)
--- 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 (file)
index 0000000..7c4619a
--- /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 955136e0b03b02b01e420932332688b535c845fb..e557cb2c1e595e31292177d9ed60dd097bf3bb9b 100644 (file)
--- 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;