[PATCH] D41811: X86: Add pattern matching for PMADDWD

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: test/CodeGen/X86/madd.ll:358
 ; SSE2-NEXT:    paddd %xmm5, %xmm0
 ; SSE2-NEXT:    retq
 ;
----------------
zvi wrote:
> RKSimon wrote:
> > Whats missing to get SSE2 to lower to 2 x pmaddwd? (TBH I'm more interested in AVX1 but it'd be good for SSE as well).
> That's a good idea. Though it might be tricky to split the 'mul' operands so that type-legalization won't mess-up illegal types. I can try to rework this patch or leave it as a follow-up if it gets too messy.
> 
> 
> 
> 
> 
I did something similar in D41440 for PAVG - we could pull out and generalize the 'LowerToAVG' code to split into legal ops and  concat the results.


https://reviews.llvm.org/D41811