[PATCH] D49829: [X86] Add pattern matching for PMADDUBSW

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: lib/Target/X86/X86ISelLowering.cpp:36837
+  // is being performed:
+  //  A[2 * i] * B[2 * i] + A[2 * i + 1] * B[2 * i + 1]
+  SDValue ZExtIn, SExtIn;
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RKSimon wrote:
> I always get nervous when we add vectorization detection in the DAG.
Nervous how?


https://reviews.llvm.org/D49829