[llvm-commits] [PATCH] Add missing X86 FMA patterns to folding tables

[Craig Topper]

That's true too. I've been meaning to go through and remove the alignments
from all the AVX patterns in X86InstrSSE.td and in X86InstrInfo.cpp. I
believe FMA4 already doesn't alignments in the td file.

On Tue, Oct 30, 2012 at 12:05 PM, Cameron McInally <cameron.mcinally at nyu.edu
> wrote:

> On Tue, Oct 30, 2012 at 1:58 PM, Craig Topper <craig.topper at gmail.com>wrote:
>
>> LGTM. But I also noticed that all the SS/SD versions of FMA4 shouldn't
>> have any aligns on them so if you want to fix that too that would be great.
>
>
> Along those lines, should the PS/PD versions of FMA4s have alignment
> requirements? I do not believe those checks are needed.
>
> From the Intel AVX Ref:
>
> "With the exception of explicitly aligned 16 or 32 byte SIMD load/store
> instructions, most VEX-encoded, arithmetic and data processing instructions
> operate in a flexible environment regarding memory address alignment, i.e.
> VEX-encoded instruction with with 32-byte or 16-byte load semantics will
> support unaligned load operation by default. Memory arguments for most
> instructions with VEX prefix operate normally without causing #GP(0) on any
> byte-granularity alignment (unlike Legacy SSE instructions). The
> instructions that require explicit memory alignment requirements are listed
> in Table 2-4."
>
> -Cameron
>



-- 
~Craig
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