Re: [RFC][PATCH 2/3] math128: Introduce {mult,add,cmp}_u128

From: H. Peter Anvin
Date: Tue Apr 24 2012 - 20:10:00 EST


On 04/24/2012 02:54 PM, Peter Zijlstra wrote:
> - andl $4294967295, %edx
> shrq $32, %rcx
> - andl $4294967295, %esi
> + mov %esi, %esi

If you can *ever* get gcc to generate those andl instructions on x86,
then please file a gcc bug report: the constant is 0xffffffff and those
are plain zero-extension instructions which is much better done with mov.

-hpa

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