[PATCH] Fix simplify_merge_mask (PR rtl-optimization/87918)

[Jakub Jelinek]

Hi!

The BINARY_P predicate is true not just for arithmetic binary ops, but
for relational ones too; for the latter, we must not call
simplify_gen_binary, but simplify_gen_relational instead.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2018-11-13  Jakub Jelinek  <ja...@redhat.com>

        PR rtl-optimization/87918
        * simplify-rtx.c (simplify_merge_mask): For COMPARISON_P, use
        simplify_gen_relational rather than simplify_gen_binary.

        * gcc.target/i386/pr87918.c: New test.

--- gcc/simplify-rtx.c.jj       2018-11-08 18:07:08.716852316 +0100
+++ gcc/simplify-rtx.c  2018-11-12 18:20:22.196580659 +0100
@@ -5647,9 +5647,19 @@ simplify_merge_mask (rtx x, rtx mask, in
       rtx top0 = simplify_merge_mask (XEXP (x, 0), mask, op);
       rtx top1 = simplify_merge_mask (XEXP (x, 1), mask, op);
       if (top0 || top1)
-       return simplify_gen_binary (GET_CODE (x), GET_MODE (x),
-                                   top0 ? top0 : XEXP (x, 0),
-                                   top1 ? top1 : XEXP (x, 1));
+       {
+         if (COMPARISON_P (x))
+           return simplify_gen_relational (GET_CODE (x), GET_MODE (x),
+                                           GET_MODE (XEXP (x, 0)) != VOIDmode
+                                           ? GET_MODE (XEXP (x, 0))
+                                           : GET_MODE (XEXP (x, 1)),
+                                           top0 ? top0 : XEXP (x, 0),
+                                           top1 ? top1 : XEXP (x, 1));
+         else
+           return simplify_gen_binary (GET_CODE (x), GET_MODE (x),
+                                       top0 ? top0 : XEXP (x, 0),
+                                       top1 ? top1 : XEXP (x, 1));
+       }
     }
   if (GET_RTX_CLASS (GET_CODE (x)) == RTX_TERNARY
       && VECTOR_MODE_P (GET_MODE (XEXP (x, 0)))
--- gcc/testsuite/gcc.target/i386/pr87918.c.jj  2018-11-12 18:17:49.075088126 
+0100
+++ gcc/testsuite/gcc.target/i386/pr87918.c     2018-11-12 18:18:36.239316318 
+0100
@@ -0,0 +1,14 @@
+/* PR rtl-optimization/87918 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -msse2" } */
+
+#include <x86intrin.h>
+
+__m128 b, c, d;
+
+void
+foo (float f)
+{
+  c = _mm_set_ss (f);
+  d = _mm_cmple_ss (c, b);
+}

        Jakub