On Mon, 9 Jan 2012, Uros Bizjak wrote:
> Hello!
>
> Attached patch fixes oversight with AND pattern and 0xffffffff
> immediate. While ANDs with 0xff and 0xffff are converted to equivalent
> zero_extend pattern, AND with 0xffffffff isn't. This problem leaves
> important optimization that would substitute "movq %rdi, %rax; andl
> $4294967295, %eax" sequence with "movl %edi, %eax" ineffective.
>
> This optimization happens ~100 times in cc1.
>
> Moving to stage4 got me by a bit of surprise (I was away from the
> keyboard for the weekend), so I will leave to RMs if this (otherwise
> fairly safe patch) is OK for mainline.
>
> 2012-01-09 Uros Bizjak <ubiz...@gmail.com>
>
> PR target/51681
> * config/i386/constraints.md ("L"): Return true for 0xffffffff.
> * config/i386/i386.c (*anddi_1): Emit AND with 0xffffffff as MOV.
>
> So, OK for mainline?
Ok from a RM perspective.
Richard.
