[PATCH] D149889: [TTI] Use users of GEP to guess access type in getGEPCost

[Luke Lau via Phabricator via llvm-commits]

luke added inline comments.


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Comment at: llvm/include/llvm/Analysis/TargetTransformInfo.h:301
+    GEPUser(const Value *User);
+  };
+
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Not overly thrilled with introducing a struct just for this, nor with the constructors. Suggestions are very welcome here


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Comment at: llvm/lib/Analysis/TargetTransformInfo.cpp:224-255
+TargetTransformInfo::GEPUser::GEPUser(Type *Ty) : AccessType(Ty) {}
+
+TargetTransformInfo::GEPUser::GEPUser(const Value *User) {
+  if (auto *L = dyn_cast<LoadInst>(User))
+    AccessType = L->getType();
+  else if (auto *S = dyn_cast<StoreInst>(User))
+    AccessType = S->getValueOperand()->getType();
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I remember seeing this logic being duplicated in a few places across llvm, earlycse is the first one that comes to mind. It might be worthwhile addressing this in a follow up patch


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Comment at: llvm/test/Transforms/SLPVectorizer/RISCV/gep.ll:18
+; CHECK-NEXT:    [[Q2:%.*]] = getelementptr i8, ptr [[Q]], i32 17
+; CHECK-NEXT:    store i8 [[X2]], ptr [[Q2]], align 1
 ; CHECK-NEXT:    ret void
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This is the main result from all the noise in the test cases.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D149889/new/

https://reviews.llvm.org/D149889