re PR tree-optimization/70586 (wrong code at -O2 and -O3 on x86_64-linux-gnu in…

re PR tree-optimization/70586 (wrong code at -O2 and -O3 on x86_64-linux-gnu in 32-bit and 64-bit modes)

	PR tree-optimization/70586
	* tree-ssa-ifcombine.c (bb_no_side_effects_p): Return false
	for any calls.

	* gcc.c-torture/execute/pr70586.c: New test.

From-SVN: r234849

gcc/ChangeLog

+2016-04-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/70586
+	* tree-ssa-ifcombine.c (bb_no_side_effects_p): Return false
+	for any calls.
+
 2016-04-08  Cesar Philippidis  <cesar@codesourcery.com>
 
 	PR lto/70289

gcc/testsuite/ChangeLog

+2016-04-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/70586
+	* gcc.c-torture/execute/pr70586.c: New test.
+
 2016-04-09  Dominique d'Humieres  <dominiq@lps.ens.fr>
 
 	PR sanitizer/70573

gcc/testsuite/gcc.c-torture/execute/pr70586.c

+/* PR tree-optimization/70586 */
+
+int a, e, f;
+short b, c, d;
+
+int
+foo (int x, int y)
+{
+  return (y == 0 || (x && y == 1)) ? x : x % y;
+}
+
+static short
+bar (void)
+{
+  int i = foo (c, f);
+  f = foo (d, 2);
+  int g = foo (b, c);
+  int h = foo (g > 0, c);
+  c = (3 >= h ^ 7) <= foo (i, c);
+  if (foo (e, 1))
+    return a;
+  return 0;
+}
+
+int
+main ()
+{
+  bar ();
+  return 0;
+}

gcc/tree-ssa-ifcombine.c

@@ -125,7 +125,14 @@ bb_no_side_effects_p (basic_block bb)
       if (gimple_has_side_effects (stmt)
 	  || gimple_uses_undefined_value_p (stmt)
 	  || gimple_could_trap_p (stmt)
-	  || gimple_vuse (stmt))
+	  || gimple_vuse (stmt)
+	  /* const calls don't match any of the above, yet they could
+	     still have some side-effects - they could contain
+	     gimple_could_trap_p statements, like floating point
+	     exceptions or integer division by zero.  See PR70586.
+	     FIXME: perhaps gimple_has_side_effects or gimple_could_trap_p
+	     should handle this.  */
+	  || is_gimple_call (stmt))
 	return false;
     }