[InstCombine] reduce code duplication in visitMul(); NFC

1 files changed, 19 insertions, 25 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 829b619..7df8e7f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -141,8 +141,8 @@ static Value *foldMulSelectToNegate(BinaryOperator &I,
 }
 
 Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
-  if (Value *V = simplifyMulInst(I.getOperand(0), I.getOperand(1),
-                                 SQ.getWithInstruction(&I)))
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+  if (Value *V = simplifyMulInst(Op0, Op1, SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (SimplifyAssociativeOrCommutative(I))
@@ -157,16 +157,15 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
   if (Value *V = SimplifyUsingDistributiveLaws(I))
     return replaceInstUsesWith(I, V);
 
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Type *Ty = I.getType();
-  unsigned BitWidth = Ty->getScalarSizeInBits();
+  const unsigned BitWidth = Ty->getScalarSizeInBits();
+  const bool HasNSW = I.hasNoSignedWrap();
+  const bool HasNUW = I.hasNoUnsignedWrap();
 
-  // X * -1 == 0 - X
+  // X * -1 --> 0 - X
   if (match(Op1, m_AllOnes())) {
-    BinaryOperator *BO = BinaryOperator::CreateNeg(Op0, I.getName());
-    if (I.hasNoSignedWrap())
-      BO->setHasNoSignedWrap();
-    return BO;
+    return HasNSW ? BinaryOperator::CreateNSWNeg(Op0)
+                  : BinaryOperator::CreateNeg(Op0);
   }
 
   // Also allow combining multiply instructions on vectors.
@@ -181,10 +180,9 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
       Constant *Shl = ConstantExpr::getShl(C1, C2);
       BinaryOperator *Mul = cast<BinaryOperator>(I.getOperand(0));
       BinaryOperator *BO = BinaryOperator::CreateMul(NewOp, Shl);
-      if (I.hasNoUnsignedWrap() && Mul->hasNoUnsignedWrap())
+      if (HasNUW && Mul->hasNoUnsignedWrap())
         BO->setHasNoUnsignedWrap();
-      if (I.hasNoSignedWrap() && Mul->hasNoSignedWrap() &&
-          Shl->isNotMinSignedValue())
+      if (HasNSW && Mul->hasNoSignedWrap() && Shl->isNotMinSignedValue())
         BO->setHasNoSignedWrap();
       return BO;
     }
@@ -194,9 +192,9 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
       if (Constant *NewCst = ConstantExpr::getExactLogBase2(C1)) {
         BinaryOperator *Shl = BinaryOperator::CreateShl(NewOp, NewCst);
 
-        if (I.hasNoUnsignedWrap())
+        if (HasNUW)
           Shl->setHasNoUnsignedWrap();
-        if (I.hasNoSignedWrap()) {
+        if (HasNSW) {
           const APInt *V;
           if (match(NewCst, m_APInt(V)) && *V != V->getBitWidth() - 1)
             Shl->setHasNoSignedWrap();
@@ -257,7 +255,7 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
           (BOp0->getOpcode() == Instruction::Or || BOp0->hasNoUnsignedWrap());
       Value *NewMul = Builder.CreateMul(X, MulC);
       auto *BO = BinaryOperator::CreateAdd(NewMul, NewC);
-      if (I.hasNoUnsignedWrap() && Op0NUW) {
+      if (HasNUW && Op0NUW) {
         // If NewMulBO is constant we also can set BO to nuw.
         if (auto *NewMulBO = dyn_cast<BinaryOperator>(NewMul))
           NewMulBO->setHasNoUnsignedWrap();
@@ -288,8 +286,7 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
   // -X * -Y --> X * Y
   if (match(Op0, m_Neg(m_Value(X))) && match(Op1, m_Neg(m_Value(Y)))) {
     auto *NewMul = BinaryOperator::CreateMul(X, Y);
-    if (I.hasNoSignedWrap() &&
-        cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap() &&
+    if (HasNSW && cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap() &&
         cast<OverflowingBinaryOperator>(Op1)->hasNoSignedWrap())
       NewMul->setHasNoSignedWrap();
     return NewMul;
@@ -359,10 +356,8 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
       ShlNSW = cast<ShlOperator>(Op1)->hasNoSignedWrap();
     }
     if (BO) {
-      if (I.hasNoUnsignedWrap())
-        BO->setHasNoUnsignedWrap();
-      if (I.hasNoSignedWrap() && ShlNSW)
-        BO->setHasNoSignedWrap();
+      BO->setHasNoUnsignedWrap(HasNUW);
+      BO->setHasNoSignedWrap(HasNSW && ShlNSW);
       return BO;
     }
   }
@@ -436,8 +431,7 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
                                m_One()),
                           m_Deferred(X)))) {
     Value *Abs = Builder.CreateBinaryIntrinsic(
-        Intrinsic::abs, X,
-        ConstantInt::getBool(I.getContext(), I.hasNoSignedWrap()));
+        Intrinsic::abs, X, ConstantInt::getBool(I.getContext(), HasNSW));
     Abs->takeName(&I);
     return replaceInstUsesWith(I, Abs);
   }
@@ -446,12 +440,12 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) {
     return Ext;
 
   bool Changed = false;
-  if (!I.hasNoSignedWrap() && willNotOverflowSignedMul(Op0, Op1, I)) {
+  if (!HasNSW && willNotOverflowSignedMul(Op0, Op1, I)) {
     Changed = true;
     I.setHasNoSignedWrap(true);
   }
 
-  if (!I.hasNoUnsignedWrap() && willNotOverflowUnsignedMul(Op0, Op1, I)) {
+  if (!HasNUW && willNotOverflowUnsignedMul(Op0, Op1, I)) {
     Changed = true;
     I.setHasNoUnsignedWrap(true);
   }