[InstCombine] simplify binops before trying other folds

This is outwardly NFC from what I can tell, but it should be more efficient 
to simplify first (despite the name, SimplifyAssociativeOrCommutative does
not actually simplify as InstSimplify does - it creates/morphs instructions).

This should make it easier to refactor duplicated code that runs for all binops.

llvm-svn: 335258
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 9be0455..1101f72 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -1121,13 +1121,12 @@
 }
 
 Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
-  if (Value *V =
-          SimplifyAddInst(LHS, RHS, I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
-                          SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyAddInst(I.getOperand(0), I.getOperand(1),
+                                 I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
+                                 SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
@@ -1140,6 +1139,7 @@
 
   // FIXME: This should be moved into the above helper function to allow these
   // transforms for general constant or constant splat vectors.
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
   Type *Ty = I.getType();
   if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
     Value *XorLHS = nullptr; ConstantInt *XorRHS = nullptr;
@@ -1378,18 +1378,19 @@
 }
 
 Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
-  if (Value *V = SimplifyFAddInst(LHS, RHS, I.getFastMathFlags(),
+  if (Value *V = SimplifyFAddInst(I.getOperand(0), I.getOperand(1),
+                                  I.getFastMathFlags(),
                                   SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
   if (Instruction *FoldedFAdd = foldBinOpIntoSelectOrPhi(I))
     return FoldedFAdd;
 
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
   Value *X;
   // (-X) + Y --> Y - X
   if (match(LHS, m_FNeg(m_Value(X))))
@@ -1555,10 +1556,9 @@
 }
 
 Instruction *InstCombiner::visitSub(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V =
-          SimplifySubInst(Op0, Op1, I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
-                          SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifySubInst(I.getOperand(0), I.getOperand(1),
+                                 I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
+                                 SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -1569,6 +1569,7 @@
     return replaceInstUsesWith(I, V);
 
   // If this is a 'B = x-(-A)', change to B = x+A.
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (Value *V = dyn_castNegVal(Op1)) {
     BinaryOperator *Res = BinaryOperator::CreateAdd(Op0, V);
 
@@ -1808,8 +1809,8 @@
 }
 
 Instruction *InstCombiner::visitFSub(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyFSubInst(Op0, Op1, I.getFastMathFlags(),
+  if (Value *V = SimplifyFSubInst(I.getOperand(0), I.getOperand(1),
+                                  I.getFastMathFlags(),
                                   SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
@@ -1818,6 +1819,7 @@
 
   // Subtraction from -0.0 is the canonical form of fneg.
   // fsub nsz 0, X ==> fsub nsz -0.0, X
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (I.hasNoSignedZeros() && match(Op0, m_PosZeroFP()))
     return BinaryOperator::CreateFNegFMF(Op1, &I);
 
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 7bf9547..6c78b9c 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1401,11 +1401,11 @@
 // here. We should standardize that construct where it is needed or choose some
 // other way to ensure that commutated variants of patterns are not missed.
 Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyAndInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyAndInst(I.getOperand(0), I.getOperand(1),
+                                 SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
@@ -1425,6 +1425,7 @@
   if (Value *V = SimplifyBSwap(I, Builder))
     return replaceInstUsesWith(I, V);
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   const APInt *C;
   if (match(Op1, m_APInt(C))) {
     Value *X, *Y;
@@ -2015,11 +2016,11 @@
 // here. We should standardize that construct where it is needed or choose some
 // other way to ensure that commutated variants of patterns are not missed.
 Instruction *InstCombiner::visitOr(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyOrInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyOrInst(I.getOperand(0), I.getOperand(1),
+                                SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
@@ -2046,6 +2047,7 @@
   if (Instruction *BSwap = MatchBSwap(I))
     return BSwap;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   {
     Value *A;
     const APInt *C;
@@ -2468,11 +2470,11 @@
 // here. We should standardize that construct where it is needed or choose some
 // other way to ensure that commutated variants of patterns are not missed.
 Instruction *InstCombiner::visitXor(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyXorInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyXorInst(I.getOperand(0), I.getOperand(1),
+                                 SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
@@ -2492,6 +2494,7 @@
     return replaceInstUsesWith(I, V);
 
   // A^B --> A|B iff A and B have no bits set in common.
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (haveNoCommonBitsSet(Op0, Op1, DL, &AC, &I, &DT))
     return BinaryOperator::CreateOr(Op0, Op1);
 
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index a62581e..c2293f0 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -126,11 +126,11 @@
 }
 
 Instruction *InstCombiner::visitMul(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyMulInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyMulInst(I.getOperand(0), I.getOperand(1),
+                                 SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
@@ -138,6 +138,7 @@
     return replaceInstUsesWith(I, V);
 
   // X * -1 == 0 - X
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (match(Op1, m_AllOnes())) {
     BinaryOperator *BO = BinaryOperator::CreateNeg(Op0, I.getName());
     if (I.hasNoSignedWrap())
@@ -406,12 +407,12 @@
 }
 
 Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
-  bool Changed = SimplifyAssociativeOrCommutative(I);
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyFMulInst(Op0, Op1, I.getFastMathFlags(),
+  if (Value *V = SimplifyFMulInst(I.getOperand(0), I.getOperand(1),
+                                  I.getFastMathFlags(),
                                   SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
+  bool Changed = SimplifyAssociativeOrCommutative(I);
   if (Instruction *X = foldShuffledBinop(I))
     return X;
 
@@ -419,6 +420,7 @@
     return FoldedMul;
 
   // X * -1.0 --> -X
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (match(Op1, m_SpecificFP(-1.0)))
     return BinaryOperator::CreateFNegFMF(Op0, &I);
 
@@ -936,8 +938,8 @@
 }
 
 Instruction *InstCombiner::visitUDiv(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyUDivInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyUDivInst(I.getOperand(0), I.getOperand(1),
+                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -948,6 +950,7 @@
     return Common;
 
   // (x lshr C1) udiv C2 --> x udiv (C2 << C1)
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   {
     Value *X;
     const APInt *C1, *C2;
@@ -1004,8 +1007,8 @@
 }
 
 Instruction *InstCombiner::visitSDiv(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifySDivInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifySDivInst(I.getOperand(0), I.getOperand(1),
+                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -1015,6 +1018,7 @@
   if (Instruction *Common = commonIDivTransforms(I))
     return Common;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   const APInt *Op1C;
   if (match(Op1, m_APInt(Op1C))) {
     // sdiv X, -1 == -X
@@ -1147,8 +1151,8 @@
 }
 
 Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyFDivInst(Op0, Op1, I.getFastMathFlags(),
+  if (Value *V = SimplifyFDivInst(I.getOperand(0), I.getOperand(1),
+                                  I.getFastMathFlags(),
                                   SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
@@ -1161,6 +1165,7 @@
   if (Instruction *R = foldFDivConstantDividend(I))
     return R;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (isa<Constant>(Op0))
     if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
       if (Instruction *R = FoldOpIntoSelect(I, SI))
@@ -1276,8 +1281,8 @@
 }
 
 Instruction *InstCombiner::visitURem(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyURemInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyURemInst(I.getOperand(0), I.getOperand(1),
+                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -1290,6 +1295,7 @@
     return NarrowRem;
 
   // X urem Y -> X and Y-1, where Y is a power of 2,
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/ true, 0, &I)) {
     Constant *N1 = Constant::getAllOnesValue(I.getType());
     Value *Add = Builder.CreateAdd(Op1, N1);
@@ -1314,8 +1320,8 @@
 }
 
 Instruction *InstCombiner::visitSRem(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifySRemInst(Op0, Op1, SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifySRemInst(I.getOperand(0), I.getOperand(1),
+                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -1325,6 +1331,7 @@
   if (Instruction *Common = commonIRemTransforms(I))
     return Common;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   {
     const APInt *Y;
     // X % -Y -> X % Y
@@ -1386,8 +1393,8 @@
 }
 
 Instruction *InstCombiner::visitFRem(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V = SimplifyFRemInst(Op0, Op1, I.getFastMathFlags(),
+  if (Value *V = SimplifyFRemInst(I.getOperand(0), I.getOperand(1),
+                                  I.getFastMathFlags(),
                                   SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
index d8166de..34f8037 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
@@ -588,10 +588,9 @@
 }
 
 Instruction *InstCombiner::visitShl(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V =
-          SimplifyShlInst(Op0, Op1, I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
-                          SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyShlInst(I.getOperand(0), I.getOperand(1),
+                                 I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
+                                 SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -600,11 +599,12 @@
   if (Instruction *V = commonShiftTransforms(I))
     return V;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Type *Ty = I.getType();
   const APInt *ShAmtAPInt;
   if (match(Op1, m_APInt(ShAmtAPInt))) {
     unsigned ShAmt = ShAmtAPInt->getZExtValue();
-    unsigned BitWidth = I.getType()->getScalarSizeInBits();
+    unsigned BitWidth = Ty->getScalarSizeInBits();
 
     // shl (zext X), ShAmt --> zext (shl X, ShAmt)
     // This is only valid if X would have zeros shifted out.
@@ -693,9 +693,8 @@
 }
 
 Instruction *InstCombiner::visitLShr(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V =
-          SimplifyLShrInst(Op0, Op1, I.isExact(), SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyLShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
+                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -704,6 +703,7 @@
   if (Instruction *R = commonShiftTransforms(I))
     return R;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Type *Ty = I.getType();
   const APInt *ShAmtAPInt;
   if (match(Op1, m_APInt(ShAmtAPInt))) {
@@ -821,9 +821,8 @@
 }
 
 Instruction *InstCombiner::visitAShr(BinaryOperator &I) {
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-  if (Value *V =
-          SimplifyAShrInst(Op0, Op1, I.isExact(), SQ.getWithInstruction(&I)))
+  if (Value *V = SimplifyAShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
+                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
   if (Instruction *X = foldShuffledBinop(I))
@@ -832,6 +831,7 @@
   if (Instruction *R = commonShiftTransforms(I))
     return R;
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Type *Ty = I.getType();
   unsigned BitWidth = Ty->getScalarSizeInBits();
   const APInt *ShAmtAPInt;