[PATCH] D75016: [X86][TwoAddressInstructionPass] Teach tryInstructionCommute to continue checking for commutable FMA operands in more cases.

[Craig Topper via Phabricator via llvm-commits]

craig.topper marked an inline comment as done.
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Comment at: llvm/test/CodeGen/X86/recip-fastmath.ll:819
+; HASWELL-NEXT:    vfnmadd132ps {{.*#+}} ymm1 = -(ymm1 * ymm2) + ymm2
+; HASWELL-NEXT:    vmovaps %ymm1, %ymm0
 ; HASWELL-NEXT:    retq
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RKSimon wrote:
> Any chance that we can avoid this regression (and the other ones above)?
Not without a new heuristic. We would need to see that one of the kills we're choosing for vfmsub is tied to xmm0 and that the user of the vfmsub def, the vfnmadd132ps, has its def tied to xmm0 and that it's commutable into a form that would allow the output from the vfmsub to be tied to that def.


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  https://reviews.llvm.org/D75016/new/

https://reviews.llvm.org/D75016