[Bug target/103008] poor inlined builtin_fmod on x86_64

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-10-31
     Ever confirmed|0                           |1

--- Comment #6 from Uroš Bizjak <ubizjak at gmail dot com> ---
Please see PR29852. The only way to avoid the libcall in 2006 was to inline the
x87 version also for SSE math. Nowadays a (generic) arithmetic sequence can be
provided and x87 fmod builtins can be enabled for x87 math only with:

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index e733a40fc90..ed818232ae7 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -17378,6 +17378,8 @@
    (use (match_operand:MODEF 1 "general_operand"))
    (use (match_operand:MODEF 2 "general_operand"))]
   "TARGET_USE_FANCY_MATH_387
+   && (!(SSE_FLOAT_MODE_P (<MODE>mode) && TARGET_SSE_MATH)
+       || TARGET_MIX_SSE_I387)
    && flag_finite_math_only"
 {
   rtx (*gen_truncxf) (rtx, rtx);