[PATCH] D28907: [SLP] Fix for PR30787: Failure to beneficially vectorize 'copyable' elements in integer binary ops.

[Dinar Temirbulatov via Phabricator via llvm-commits]

dtemirbulatov added inline comments.


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Comment at: lib/Transforms/Vectorize/SLPVectorizer.cpp:469
+    return InstructionsState(VL[BaseIndex], cast<Instruction>(VL[BaseIndex]),
+                             cast<Instruction>(VL[AltIndex]), IsNonAlt);
+  else
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RKSimon wrote:
> InstructionState was keeping the Base/Alt instructions the same if AltOpcodeNum ==0 (BaseIndex ==AltIndex) - why are you inserting nulls?
yes, correct, Thanks.


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Comment at: lib/Transforms/Vectorize/SLPVectorizer.cpp:1526
 
+static Value *getDefaultConstantForOpcode(unsigned Opcode, Type *Ty) {
+  switch(Opcode) {
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RKSimon wrote:
> Can we use ConstantExpr::getBinOpIdentity instead?
no, ConstantExpr::getBinOpIdentity does support only commutative operations.


https://reviews.llvm.org/D28907