[InstCombine] Remove the (not (sext)) case from foldBoolSextMaskToSelect and inline the remaining code to match visitOr

Summary:
The (not (sext)) case is really (xor (sext), -1) which should have been simplified to (sext (xor, 1)) before we got here. So we shouldn't need to handle it.

With that taken care of we only need to two cases so don't need the swap anymore. This makes us in sync with the equivalent code in visitOr so inline this to match.

Reviewers: spatel, eli.friedman, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36240

llvm-svn: 310063

1 files changed, 8 insertions, 27 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 62a73cca4b7..a3749a1581b 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1188,31 +1188,6 @@ Instruction *InstCombiner::foldCastedBitwiseLogic(BinaryOperator &I) {
   return nullptr;
 }
 
-static Instruction *foldBoolSextMaskToSelect(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
-  // Canonicalize SExt or Not to the LHS
-  if (match(Op1, m_SExt(m_Value())) || match(Op1, m_Not(m_Value()))) {
-    std::swap(Op0, Op1);
-  }
-
-  // Fold (and (sext bool to A), B) --> (select bool, B, 0)
-  Value *X = nullptr;
-  if (match(Op0, m_SExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1)) {
-    Value *Zero = Constant::getNullValue(Op1->getType());
-    return SelectInst::Create(X, Op1, Zero);
-  }
-
-  // Fold (and ~(sext bool to A), B) --> (select bool, 0, B)
-  if (match(Op0, m_Not(m_SExt(m_Value(X)))) &&
-      X->getType()->isIntOrIntVectorTy(1)) {
-    Value *Zero = Constant::getNullValue(Op0->getType());
-    return SelectInst::Create(X, Zero, Op1);
-  }
-
-  return nullptr;
-}
-
 static Instruction *foldAndToXor(BinaryOperator &I,
                                  InstCombiner::BuilderTy &Builder) {
   assert(I.getOpcode() == Instruction::And);
@@ -1480,8 +1455,14 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
   if (Instruction *CastedAnd = foldCastedBitwiseLogic(I))
     return CastedAnd;
 
-  if (Instruction *Select = foldBoolSextMaskToSelect(I))
-    return Select;
+  // and(sext(A), B) / and(B, sext(A)) --> A ? B : 0, where A is i1 or <N x i1>.
+  Value *A;
+  if (match(Op0, m_OneUse(m_SExt(m_Value(A)))) &&
+      A->getType()->isIntOrIntVectorTy(1))
+    return SelectInst::Create(A, Op1, Constant::getNullValue(I.getType()));
+  if (match(Op1, m_OneUse(m_SExt(m_Value(A)))) &&
+      A->getType()->isIntOrIntVectorTy(1))
+    return SelectInst::Create(A, Op0, Constant::getNullValue(I.getType()));
 
   return Changed ? &I : nullptr;
 }