[PATCH] D114650: [SCEV] Construct SCEV iteratively.

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:7264
+    Ops.push_back(BO->LHS);
+    Ops.push_back(BO->RHS);
+    return nullptr;
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Add and mul currently have special code that tries to combine multiple sequential adds/mul into one getAddExpr/getMulExpr call. This is effectively lost here (or maybe worse, we end up doing both -- each add individually here, and then a multiple-add variant in getSCEV).

I think if we're going to change this (which might well make sense), we should probably change that separately, and also in the createSCEV() code as well. I suspect that this might account for both some of the codegen changes and some of the compile-time impact.


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Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:7290
+  case Instruction::GetElementPtr:
+    if (cast<GEPOperator>(U)->getSourceElementType()->isSized()) {
+      for (Value *Index : U->operands())
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https://github.com/llvm/llvm-project/commit/327307d9d4da0045f762f75343fe66b0f10ecc63 ;)


Repository:
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  https://reviews.llvm.org/D114650/new/

https://reviews.llvm.org/D114650