[InstCombine] add helper to foldXorOfICmps(); NFCI

Also, fix the old-style capitalization of the related functions
and move them to the 'private' section of the class since they
are just helpers of the visit* functions.

As shown in the post-commit comments for D32143, we are missing
folds for xor-of-icmps. 

llvm-svn: 303381

2 files changed, 48 insertions, 41 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 82dc88f1b3a..4227b2d01be 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -764,7 +764,7 @@ foldAndOrOfEqualityCmpsWithConstants(ICmpInst *LHS, ICmpInst *RHS,
 }
 
 /// Fold (icmp)&(icmp) if possible.
-Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
+Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
   ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
 
   // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
@@ -943,7 +943,7 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
 
 /// Optimize (fcmp)&(fcmp).  NOTE: Unlike the rest of instcombine, this returns
 /// a Value which should already be inserted into the function.
-Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
+Value *InstCombiner::foldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
   Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
   Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
   FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
@@ -1126,8 +1126,8 @@ Instruction *InstCombiner::foldCastedBitwiseLogic(BinaryOperator &I) {
   ICmpInst *ICmp0 = dyn_cast<ICmpInst>(Cast0Src);
   ICmpInst *ICmp1 = dyn_cast<ICmpInst>(Cast1Src);
   if (ICmp0 && ICmp1) {
-    Value *Res = LogicOpc == Instruction::And ? FoldAndOfICmps(ICmp0, ICmp1)
-                                              : FoldOrOfICmps(ICmp0, ICmp1, &I);
+    Value *Res = LogicOpc == Instruction::And ? foldAndOfICmps(ICmp0, ICmp1)
+                                              : foldOrOfICmps(ICmp0, ICmp1, &I);
     if (Res)
       return CastInst::Create(CastOpcode, Res, DestTy);
     return nullptr;
@@ -1138,8 +1138,8 @@ Instruction *InstCombiner::foldCastedBitwiseLogic(BinaryOperator &I) {
   FCmpInst *FCmp0 = dyn_cast<FCmpInst>(Cast0Src);
   FCmpInst *FCmp1 = dyn_cast<FCmpInst>(Cast1Src);
   if (FCmp0 && FCmp1) {
-    Value *Res = LogicOpc == Instruction::And ? FoldAndOfFCmps(FCmp0, FCmp1)
-                                              : FoldOrOfFCmps(FCmp0, FCmp1);
+    Value *Res = LogicOpc == Instruction::And ? foldAndOfFCmps(FCmp0, FCmp1)
+                                              : foldOrOfFCmps(FCmp0, FCmp1);
     if (Res)
       return CastInst::Create(CastOpcode, Res, DestTy);
     return nullptr;
@@ -1425,7 +1425,7 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
     ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
     ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
     if (LHS && RHS)
-      if (Value *Res = FoldAndOfICmps(LHS, RHS))
+      if (Value *Res = foldAndOfICmps(LHS, RHS))
         return replaceInstUsesWith(I, Res);
 
     // TODO: Make this recursive; it's a little tricky because an arbitrary
@@ -1433,18 +1433,18 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
     Value *X, *Y;
     if (LHS && match(Op1, m_OneUse(m_And(m_Value(X), m_Value(Y))))) {
       if (auto *Cmp = dyn_cast<ICmpInst>(X))
-        if (Value *Res = FoldAndOfICmps(LHS, Cmp))
+        if (Value *Res = foldAndOfICmps(LHS, Cmp))
           return replaceInstUsesWith(I, Builder->CreateAnd(Res, Y));
       if (auto *Cmp = dyn_cast<ICmpInst>(Y))
-        if (Value *Res = FoldAndOfICmps(LHS, Cmp))
+        if (Value *Res = foldAndOfICmps(LHS, Cmp))
           return replaceInstUsesWith(I, Builder->CreateAnd(Res, X));
     }
     if (RHS && match(Op0, m_OneUse(m_And(m_Value(X), m_Value(Y))))) {
       if (auto *Cmp = dyn_cast<ICmpInst>(X))
-        if (Value *Res = FoldAndOfICmps(Cmp, RHS))
+        if (Value *Res = foldAndOfICmps(Cmp, RHS))
           return replaceInstUsesWith(I, Builder->CreateAnd(Res, Y));
       if (auto *Cmp = dyn_cast<ICmpInst>(Y))
-        if (Value *Res = FoldAndOfICmps(Cmp, RHS))
+        if (Value *Res = foldAndOfICmps(Cmp, RHS))
           return replaceInstUsesWith(I, Builder->CreateAnd(Res, X));
     }
   }
@@ -1452,7 +1452,7 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
   // If and'ing two fcmp, try combine them into one.
   if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
     if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
-      if (Value *Res = FoldAndOfFCmps(LHS, RHS))
+      if (Value *Res = foldAndOfFCmps(LHS, RHS))
         return replaceInstUsesWith(I, Res);
 
   if (Instruction *CastedAnd = foldCastedBitwiseLogic(I))
@@ -1589,7 +1589,7 @@ static Value *matchSelectFromAndOr(Value *A, Value *C, Value *B, Value *D,
 }
 
 /// Fold (icmp)|(icmp) if possible.
-Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
+Value *InstCombiner::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
                                    Instruction *CxtI) {
   ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
 
@@ -1846,7 +1846,7 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
 
 /// Optimize (fcmp)|(fcmp).  NOTE: Unlike the rest of instcombine, this returns
 /// a Value which should already be inserted into the function.
-Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
+Value *InstCombiner::foldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
   Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
   Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
   FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
@@ -2197,7 +2197,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
     ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
     ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
     if (LHS && RHS)
-      if (Value *Res = FoldOrOfICmps(LHS, RHS, &I))
+      if (Value *Res = foldOrOfICmps(LHS, RHS, &I))
         return replaceInstUsesWith(I, Res);
 
     // TODO: Make this recursive; it's a little tricky because an arbitrary
@@ -2205,18 +2205,18 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
     Value *X, *Y;
     if (LHS && match(Op1, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
       if (auto *Cmp = dyn_cast<ICmpInst>(X))
-        if (Value *Res = FoldOrOfICmps(LHS, Cmp, &I))
+        if (Value *Res = foldOrOfICmps(LHS, Cmp, &I))
           return replaceInstUsesWith(I, Builder->CreateOr(Res, Y));
       if (auto *Cmp = dyn_cast<ICmpInst>(Y))
-        if (Value *Res = FoldOrOfICmps(LHS, Cmp, &I))
+        if (Value *Res = foldOrOfICmps(LHS, Cmp, &I))
           return replaceInstUsesWith(I, Builder->CreateOr(Res, X));
     }
     if (RHS && match(Op0, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
       if (auto *Cmp = dyn_cast<ICmpInst>(X))
-        if (Value *Res = FoldOrOfICmps(Cmp, RHS, &I))
+        if (Value *Res = foldOrOfICmps(Cmp, RHS, &I))
           return replaceInstUsesWith(I, Builder->CreateOr(Res, Y));
       if (auto *Cmp = dyn_cast<ICmpInst>(Y))
-        if (Value *Res = FoldOrOfICmps(Cmp, RHS, &I))
+        if (Value *Res = foldOrOfICmps(Cmp, RHS, &I))
           return replaceInstUsesWith(I, Builder->CreateOr(Res, X));
     }
   }
@@ -2224,7 +2224,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
   // (fcmp uno x, c) | (fcmp uno y, c)  -> (fcmp uno x, y)
   if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
     if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
-      if (Value *Res = FoldOrOfFCmps(LHS, RHS))
+      if (Value *Res = foldOrOfFCmps(LHS, RHS))
         return replaceInstUsesWith(I, Res);
 
   if (Instruction *CastedOr = foldCastedBitwiseLogic(I))
@@ -2320,6 +2320,24 @@ static Instruction *foldXorToXor(BinaryOperator &I) {
   return nullptr;
 }
 
+Value *InstCombiner::foldXorOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
+  if (PredicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
+    if (LHS->getOperand(0) == RHS->getOperand(1) &&
+        LHS->getOperand(1) == RHS->getOperand(0))
+      LHS->swapOperands();
+    if (LHS->getOperand(0) == RHS->getOperand(0) &&
+        LHS->getOperand(1) == RHS->getOperand(1)) {
+      // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
+      Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
+      unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
+      bool isSigned = LHS->isSigned() || RHS->isSigned();
+      return getNewICmpValue(isSigned, Code, Op0, Op1, Builder);
+    }
+  }
+
+  return nullptr;
+}
+
 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
 // 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.
@@ -2579,23 +2597,10 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
       match(Op1, m_Not(m_Specific(A))))
     return BinaryOperator::CreateNot(Builder->CreateAnd(A, B));
 
-  // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
-  if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
-    if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
-      if (PredicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
-        if (LHS->getOperand(0) == RHS->getOperand(1) &&
-            LHS->getOperand(1) == RHS->getOperand(0))
-          LHS->swapOperands();
-        if (LHS->getOperand(0) == RHS->getOperand(0) &&
-            LHS->getOperand(1) == RHS->getOperand(1)) {
-          Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
-          unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
-          bool isSigned = LHS->isSigned() || RHS->isSigned();
-          return replaceInstUsesWith(I,
-                               getNewICmpValue(isSigned, Code, Op0, Op1,
-                                               Builder));
-        }
-      }
+  if (auto *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
+    if (auto *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
+      if (Value *V = foldXorOfICmps(LHS, RHS))
+        return replaceInstUsesWith(I, V);
 
   if (Instruction *CastedXor = foldCastedBitwiseLogic(I))
     return CastedXor;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
index f88a2c6acc3..4b683cb192d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -275,11 +275,7 @@ public:
   Instruction *visitSDiv(BinaryOperator &I);
   Instruction *visitFDiv(BinaryOperator &I);
   Value *simplifyRangeCheck(ICmpInst *Cmp0, ICmpInst *Cmp1, bool Inverted);
-  Value *FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS);
-  Value *FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
   Instruction *visitAnd(BinaryOperator &I);
-  Value *FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS, Instruction *CxtI);
-  Value *FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
   Instruction *FoldOrWithConstants(BinaryOperator &I, Value *Op, Value *A,
                                    Value *B, Value *C);
   Instruction *FoldXorWithConstants(BinaryOperator &I, Value *Op, Value *A,
@@ -445,6 +441,12 @@ private:
   Instruction::CastOps isEliminableCastPair(const CastInst *CI1,
                                             const CastInst *CI2);
 
+  Value *foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS);
+  Value *foldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
+  Value *foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS, Instruction *CxtI);
+  Value *foldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
+  Value *foldXorOfICmps(ICmpInst *LHS, ICmpInst *RHS);
+
 public:
   /// \brief Inserts an instruction \p New before instruction \p Old
   ///