[PATCH] D36240: [InstCombine] Remove the (not (sext)) case from foldBoolSextMaskToSelect and inline the remaining code to match visitOr

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.

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.


https://reviews.llvm.org/D36240

Files:
  lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  test/Transforms/InstCombine/vector-casts.ll


Index: test/Transforms/InstCombine/vector-casts.ll
===================================================================
--- test/Transforms/InstCombine/vector-casts.ll
+++ test/Transforms/InstCombine/vector-casts.ll
@@ -61,7 +61,7 @@
 ; CHECK-LABEL: @test5(
 ; CHECK-NEXT:    [[CMP:%.*]] = fcmp ult <4 x float> %a, zeroinitializer
 ; CHECK-NEXT:    [[CMP4:%.*]] = fcmp ult <4 x float> %b, zeroinitializer
-; CHECK-NEXT:    [[NARROW:%.*]] = and <4 x i1> [[CMP4]], [[CMP]]
+; CHECK-NEXT:    [[NARROW:%.*]] = and <4 x i1> [[CMP]], [[CMP4]]
 ; CHECK-NEXT:    [[AND:%.*]] = sext <4 x i1> [[NARROW]] to <4 x i32>
 ; CHECK-NEXT:    [[CONV:%.*]] = bitcast <4 x i32> [[AND]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[CONV]]
Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1188,31 +1188,6 @@
   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 @@
   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;
 }


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