RFC: Can I require binutils 2.17 or above for AVX support in gcc?

H.J. Lu hjl.tools@gmail.com
Sat May 24 21:32:00 GMT 2008


Hi,

Binutils 2.17 and above supports both

        movq %rax, %xmm0
        movd %rax, %xmm0

AVX has vmovq and no vmovd. To add AVX vmovq supportt to
patterns with movd, I have 2 choices:

1. Add a new AVX pattern with vmovq. Or
2. Requiring  binutils 2..17 or above,  replace movd with
%vmovq without adding a new pattern.

Requiring  binutils 2.17 or above also improves gcc code
generation due to better linker. I certainly prefer #2. But I
can live with #1.

BTW,  I can add "vmovd" to x86 assembler as the last resort.

Thanks.


H.J.



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