re PR target/48774 (gcc-4.6.0 optimization regression on x86_64-unknown-linux-gnu)

	PR target/48774
	* config/i386/i386.c (ix86_match_ccmode): For CC{A,C,O,S}mode
	only succeed if req_mode is the same as set_mode.

	* gcc.dg/pr48774.c: New test.

From-SVN: r173301

gcc/ChangeLog

+2011-05-03  Uros Bizjak  <ubizjak@gmail.com>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/48774
+	* config/i386/i386.c (ix86_match_ccmode): For CC{A,C,O,S}mode
+	only succeed if req_mode is the same as set_mode.
+
 2011-05-03  Bernd Schmidt  <bernds@codesourcery.com>
 
 	* gengenrtl.c (special_rtx): PC, CC0 and RETURN are special.

gcc/config/i386/i386.c

@@ -17299,11 +17299,15 @@ ix86_match_ccmode (rtx insn, enum machine_mode req_mode)
       if (req_mode == CCZmode)
 	return false;
       /* FALLTHRU */
+    case CCZmode:
+      break;
+
     case CCAmode:
     case CCCmode:
     case CCOmode:
     case CCSmode:
-    case CCZmode:
+      if (set_mode != req_mode)
+	return false;
       break;
 
     default:

gcc/testsuite/ChangeLog

+2011-05-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/48774
+	* gcc.dg/pr48774.c: New test.
+
 2011-05-03  Richard Guenther  <rguenther@suse.de>
 
 	* gcc.dg/large-size-array-5.c: New testcase.

gcc/testsuite/gcc.dg/pr48774.c

+/* PR target/48774 */
+/* { dg-do run } */
+/* { dg-options "-O2 -funroll-loops" } */
+
+extern void abort (void);
+unsigned long int s[24]
+  = { 12, ~1, 12, ~2, 12, ~4, 12, ~8, 12, ~16, 12, ~32,
+      12, ~64, 12, ~128, 12, ~256, 12, ~512, 12, ~1024, 12, ~2048 };
+struct { int n; unsigned long *e[12]; } g
+  = { 12, { &s[0], &s[2], &s[4], &s[6], &s[8], &s[10], &s[12], &s[14],
+	    &s[16], &s[18], &s[20], &s[22] } };
+int c[12];
+
+__attribute__((noinline, noclone)) void
+foo (void)
+{
+  int i, j;
+  for (i = 0; i < g.n; i++)
+    for (j = 0; j < g.n; j++)
+      {
+	if (i == j && j < g.e[0][0] && (g.e[i][1] & (1UL << j)))
+	  abort ();
+	if (j < g.e[0][0] && (g.e[i][1] & (1UL << j)))
+	  c[i]++;
+      }
+}
+
+int
+main ()
+{
+  int i;
+  asm volatile ("" : "+m" (s), "+m" (g), "+m" (c));
+  foo ();
+  for (i = 0; i < 12; i++)
+    if (c[i] != 11)
+      abort ();
+  return 0;
+}