[Bug target/29852] x86_64: SSE version missing for fmod{d,s,x}f3

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #9 from ubizjak at gmail dot com  2006-11-29 21:05 -------
(In reply to comment #8)
> The patch doesn't like me ;)
> 
> richard@trick:~/src/trunk/gcc/config/i386$ patch -p0 < /tmp/p
> patching file i386.md
> Hunk #1 succeeded at 3892 (offset -49 lines).
> Hunk #2 succeeded at 3919 (offset -47 lines).
> Hunk #3 succeeded at 3990 (offset -47 lines).
> Hunk #4 succeeded at 4017 (offset -45 lines).
> Hunk #5 FAILED at 15622.
> patch: **** unexpected end of file in patch

That is because I have 4 open projects in one branch. In about an hour, the
regression test will finish and I'll post clean patch to gcc-patches.
> 
> what does it generate for
> 
> double foo(double a, double b)
> {
>   double x = fmod(a, 1.1);
>   return x + b;
> }
> 
> does it do the truncation as part of the x87 -> SSE register move or
> is there extra operations involved?  If we can get all variants optimal
> (store to memory comes to my mind as well) it would be nice!
> 

        movsd   %xmm0, -16(%rsp)
        fldl    -16(%rsp)
        fldl    .LC0(%rip)
        fxch    %st(1)
.L2:
        fprem
        fnstsw  %ax
        testb   $4, %ah
        jne     .L2
        fstp    %st(1)
        fstpl   -8(%rsp)
        movsd   -8(%rsp), %xmm0
        addsd   %xmm1, %xmm0
        ret

The x87 store represents the truncation.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29852