[PATCH] D143373: [InstCombine] fold icmp of the sum of ext bool based on limited range

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:5836
+  // when C == -1 means, X == false ,Y == true
+  // C == 0 means , X == Y
+  // C == 1 means, X == true, Y == false
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This description does not make sense to me. We need to specify the predicate along with the constant value to know the correct transform?


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:5849
+        return BinaryOperator::CreateAnd(Builder.CreateNot(X), Y);
+      if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_SGT)
+        return BinaryOperator::CreateOr(X, Builder.CreateNot(Y));
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Include "ULT" here?


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Comment at: llvm/test/Transforms/InstCombine/icmp-range.ll:662
 
 define i1 @zext_sext_add_icmp_sgt_minus1(i1 %a, i1 %b) {
 ; CHECK-LABEL: @zext_sext_add_icmp_sgt_minus1(
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Where do we transform this pattern? Is it possible that the existing code can be extended to handle more predicates?


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  https://reviews.llvm.org/D143373/new/

https://reviews.llvm.org/D143373