[PATCH] Fix c/68513 for GCC5 (match.pd and SAVE_EXPRs)

[Marek Polacek]

Recently on IRC we've concluded that for GCC 5 the simplest solution
will be to just disable the problematic pattern on GENERIC.  So done
in the following.  (The problem was that the match.pd pattern created
SAVE_EXPRs which then leaked into gimplification.)

Bootstrapped/regtested on x86_64-linux, ok for 5?

2016-01-19  Marek Polacek  <polacek@redhat.com>

	PR c/68513
	* match.pd ((x & ~m) | (y & m)): Only perform on GIMPLE.

	* gcc.dg/pr68513.c: New test.

diff --git gcc/match.pd gcc/match.pd
index e40720e..0b557e6 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -385,8 +385,9 @@ along with GCC; see the file COPYING3.  If not see
 /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
 (simplify
   (bit_ior:c (bit_and:c@3 @0 (bit_not @2)) (bit_and:c@4 @1 @2))
-  (if ((TREE_CODE (@3) != SSA_NAME || has_single_use (@3))
-	&& (TREE_CODE (@4) != SSA_NAME || has_single_use (@4)))
+  (if (GIMPLE
+       && (TREE_CODE (@3) != SSA_NAME || has_single_use (@3))
+       && (TREE_CODE (@4) != SSA_NAME || has_single_use (@4)))
    (bit_xor (bit_and (bit_xor @0 @1) @2) @0)))
 
 
diff --git gcc/testsuite/gcc.dg/pr68513.c gcc/testsuite/gcc.dg/pr68513.c
index e69de29..86f878d 100644
--- gcc/testsuite/gcc.dg/pr68513.c
+++ gcc/testsuite/gcc.dg/pr68513.c
@@ -0,0 +1,125 @@
+/* PR c/68513 */
+/* { dg-do compile } */
+/* { dg-options "-funsafe-math-optimizations -fno-math-errno -O -Wno-div-by-zero" } */
+
+int i;
+unsigned u;
+volatile int *e;
+
+#define E (i ? *e : 0)
+
+/* Can't trigger some of them because operand_equal_p will return false
+   for side-effects.  */
+
+/* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
+int
+fn1 (void)
+{
+  int r = 0;
+  r += (short) (E & ~u | i & u);
+  r += -(short) (E & ~u | i & u);
+  r += (short) -(E & ~u | i & u);
+  return r;
+}
+
+/* sqrt(x) < y is x >= 0 && x != +Inf, when y is large.  */
+double
+fn2 (void)
+{
+  double r;
+  r = __builtin_sqrt (E) < __builtin_inf ();
+  return r;
+}
+
+/* sqrt(x) < c is the same as x >= 0 && x < c*c.  */
+double
+fn3 (void)
+{
+  double r;
+  r = __builtin_sqrt (E) < 1.3;
+  return r;
+}
+
+/* copysign(x,y)*copysign(x,y) -> x*x.  */
+double
+fn4 (double y, double x)
+{
+  return __builtin_copysign (E, y) * __builtin_copysign (E, y);
+}
+
+/* x <= +Inf is the same as x == x, i.e. !isnan(x).  */
+int
+fn5 (void)
+{
+  return E <= __builtin_inf ();
+}
+
+/* Fold (A & ~B) - (A & B) into (A ^ B) - B.  */
+int
+fn6 (void)
+{
+  return (i & ~E) - (i & E);
+}
+
+/* Fold (A & B) - (A & ~B) into B - (A ^ B).  */
+int
+fn7 (void)
+{
+  return (i & E) - (i & ~E);
+}
+
+/* x + (x & 1) -> (x + 1) & ~1 */
+int
+fn8 (void)
+{
+  return E + (E & 1);
+}
+
+/* Simplify comparison of something with itself.  */
+int
+fn9 (void)
+{
+  return E <= E | E >= E;
+}
+
+/* Fold (A & ~B) - (A & B) into (A ^ B) - B.  */
+int
+fn10 (void)
+{
+  return (i & ~E) - (i & E);
+}
+
+/* abs(x)*abs(x) -> x*x.  Should be valid for all types.  */
+int
+fn11 (void)
+{
+  return __builtin_abs (E) * __builtin_abs (E);
+}
+
+/* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */
+int
+fn12 (void)
+{
+  return (E | 11) & 12;
+}
+
+/* fold_range_test */
+int
+fn13 (const char *s)
+{
+  return s[E] != '\0' && s[E] != '/';
+}
+
+/* fold_comparison */
+int
+fn14 (void)
+{
+  return (!!i ? : (u *= E / 0)) >= (u = E);
+}
+
+/* fold_mult_zconjz */
+_Complex int
+fn15 (_Complex volatile int *z)
+{
+  return *z * ~*z;
+}

	Marek