[PATCH] Fix __builtin_round{,f,l} ICE on x86 (PR target/84827)

[Jakub Jelinek]

Hi!

Since r237074 the 387 rounding insns are guarded with
(flag_fp_int_builtin_inexact || !flag_trapping_math), and the
round<mode>2 expander is enabled for 387 fancy math whenever
flag_unsafe_math_optimizations; as the testcase shows, the latter
doesn't imply the former, so this patch adds another guard.

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

2018-03-12  Jakub Jelinek  <ja...@redhat.com>

        PR target/84827
        * config/i386/i386.md (round<mode>2): For 387 fancy math, disable
        pattern if -ftrapping-math -fno-fp-int-builtin-inexact.

        * gcc.target/i386/pr84827.c: New test.

--- gcc/config/i386/i386.md.jj  2018-03-05 16:59:42.881641832 +0100
+++ gcc/config/i386/i386.md     2018-03-12 15:54:28.925304229 +0100
@@ -16311,7 +16311,8 @@ (define_expand "round<mode>2"
   "(TARGET_USE_FANCY_MATH_387
     && (!(SSE_FLOAT_MODE_P (<MODE>mode) && TARGET_SSE_MATH)
        || TARGET_MIX_SSE_I387)
-    && flag_unsafe_math_optimizations)
+    && flag_unsafe_math_optimizations
+    && (flag_fp_int_builtin_inexact || !flag_trapping_math))
    || (SSE_FLOAT_MODE_P (<MODE>mode) && TARGET_SSE_MATH
        && !flag_trapping_math && !flag_rounding_math)"
 {
--- gcc/testsuite/gcc.target/i386/pr84827.c.jj  2018-03-12 16:04:20.195411779 
+0100
+++ gcc/testsuite/gcc.target/i386/pr84827.c     2018-03-12 15:54:58.041309098 
+0100
@@ -0,0 +1,21 @@
+/* PR target/84827 */
+/* { dg-do compile } */
+/* { dg-options "-Ofast -fno-fp-int-builtin-inexact -ftrapping-math 
-fno-associative-math -mfpmath=387" } */
+
+double
+f1 (double a)
+{
+  return __builtin_round (a);
+}
+
+float
+f2 (float a)
+{
+  return __builtin_roundf (a);
+}
+
+long double
+f3 (long double a)
+{
+  return __builtin_roundl (a);
+}

        Jakub