[Bug rtl-optimization/50107] [IRA, i386] allocates regiters in very non-optimal way

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50107

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-08-18
     Ever Confirmed|0                           |1

--- Comment #9 from H.J. Lu <hjl.tools at gmail dot com> 2011-08-18 15:23:59 
UTC ---
With revision 177865 + MULX change, I got

[hjl@gnu-6 pr50107]$ cat uti-2.i
unsigned __int128 test_mul_64 (unsigned long long a, unsigned long long b)
{
  return (unsigned __int128) a*b;
}
[hjl@gnu-6 pr50107]$ make uti-2.s
/export/build/gnu/gcc-hsw/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-hsw/build-x86_64-linux/gcc/ -S -o uti-2.s -O2 -mbmi2 
uti-2.i
[hjl@gnu-6 pr50107]$ cat uti-2.s
    .file    "uti-2.i"
    .text
    .p2align 4,,15
    .globl    test_mul_64
    .type    test_mul_64, @function
test_mul_64:
.LFB0:
    .cfi_startproc
    movq    %rdi, %rdx
    mulx    %rsi, %rax, %rsi
    movq    %rsi, %rdx
    ret
    .cfi_endproc
.LFE0:
    .size    test_mul_64, .-test_mul_64
    .ident    "GCC: (GNU) 4.7.0 20110818 (experimental)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-6 pr50107]$ 

I would expect

    movq    %rdi, %rdx
    mulx    %rsi, %rax, %rdx
    ret