[PATCH] D70966: [ARM] Teach the Arm cost model that a Shift can be folded into other instructions

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


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Comment at: llvm/include/llvm/Analysis/TargetTransformInfo.h:910
+      ArrayRef<const Value *> Args = ArrayRef<const Value *>(),
+      const Instruction *I = nullptr) const;
 
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+1 to documenting the argument. Also, in InstSimplify and possibly some other places, this param is called the context instruction and spelled "CxtI". I've never liked that abbreviation, but that would still help the casual reader understand the intent.


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Comment at: llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp:795-796
+
+    if (Opcode != Instruction::Shl && Opcode != Instruction::AShr &&
+        Opcode != Instruction::LShr)
+      return false;
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This can use "isShift(unsigned Opcode)" from Instruction.h - or the class member version: I->isShift().


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  https://reviews.llvm.org/D70966/new/

https://reviews.llvm.org/D70966