Follow-up fix to r165928: handle memset rewriting for widened integers,

[oota-llvm.git] / lib / Transforms / InstCombine / InstCombineAndOrXor.cpp

diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 1a5655b0966988120fe3477c7954d44e6787ac33..7d0af0d80226f06f3cc4fd1edabac3e44d79cd98 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -87,16 +87,15 @@ static unsigned getFCmpCode(FCmpInst::Predicate CC, bool &isOrdered) {
   default:
     // Not expecting FCMP_FALSE and FCMP_TRUE;
     llvm_unreachable("Unexpected FCmp predicate!");
-    return 0;
   }
 }
 
-/// getICmpValue - This is the complement of getICmpCode, which turns an
+/// getNewICmpValue - This is the complement of getICmpCode, which turns an
 /// opcode and two operands into either a constant true or false, or a brand 
 /// new ICmp instruction. The sign is passed in to determine which kind
 /// of predicate to use in the new icmp instruction.
-Value *getNewICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
-                    InstCombiner::BuilderTy *Builder) {
+static Value *getNewICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
+                              InstCombiner::BuilderTy *Builder) {
   ICmpInst::Predicate NewPred;
   if (Value *NewConstant = getICmpValue(Sign, Code, LHS, RHS, NewPred))
     return NewConstant;
@@ -111,7 +110,7 @@ static Value *getFCmpValue(bool isordered, unsigned code,
                            InstCombiner::BuilderTy *Builder) {
   CmpInst::Predicate Pred;
   switch (code) {
-  default: assert(0 && "Illegal FCmp code!");
+  default: llvm_unreachable("Illegal FCmp code!");
   case 0: Pred = isordered ? FCmpInst::FCMP_ORD : FCmpInst::FCMP_UNO; break;
   case 1: Pred = isordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT; break;
   case 2: Pred = isordered ? FCmpInst::FCMP_OEQ : FCmpInst::FCMP_UEQ; break;
@@ -636,9 +635,9 @@ static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS,
   ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
   unsigned mask = foldLogOpOfMaskedICmpsHelper(A, B, C, D, E, LHS, RHS,
                                                LHSCC, RHSCC);
+  if (mask == 0) return 0;
   assert(ICmpInst::isEquality(LHSCC) && ICmpInst::isEquality(RHSCC) &&
          "foldLogOpOfMaskedICmpsHelper must return an equality predicate.");
-  if (mask == 0) return 0;
 
   if (NEWCC == ICmpInst::ICMP_NE)
     mask >>= 1; // treat "Not"-states as normal states
@@ -754,7 +753,7 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
   // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2
   // where CMAX is the all ones value for the truncated type,
   // iff the lower bits of C2 and CA are zero.
-  if (LHSCC == RHSCC && ICmpInst::isEquality(LHSCC) &&
+  if (LHSCC == ICmpInst::ICMP_EQ && LHSCC == RHSCC &&
       LHS->hasOneUse() && RHS->hasOneUse()) {
     Value *V;
     ConstantInt *AndCst, *SmallCst = 0, *BigCst = 0;
@@ -987,19 +986,23 @@ Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
     bool Op1Ordered;
     unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
     unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
+    // uno && ord -> false
+    if (Op0Pred == 0 && Op1Pred == 0 && Op0Ordered != Op1Ordered)
+        return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
     if (Op1Pred == 0) {
       std::swap(LHS, RHS);
       std::swap(Op0Pred, Op1Pred);
       std::swap(Op0Ordered, Op1Ordered);
     }
     if (Op0Pred == 0) {
-      // uno && ueq -> uno && (uno || eq) -> ueq
+      // uno && ueq -> uno && (uno || eq) -> uno
       // ord && olt -> ord && (ord && lt) -> olt
-      if (Op0Ordered == Op1Ordered)
+      if (!Op0Ordered && (Op0Ordered == Op1Ordered))
+        return LHS;
+      if (Op0Ordered && (Op0Ordered == Op1Ordered))
         return RHS;
       
       // uno && oeq -> uno && (ord && eq) -> false
-      // uno && ord -> false
       if (!Op0Ordered)
         return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
       // ord && ueq -> ord && (uno || eq) -> oeq
@@ -1363,13 +1366,8 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask,
   // part of the value (e.g. byte 3) then it must be shifted right.  If from the
   // low part, it must be shifted left.
   unsigned DestByteNo = InputByteNo + OverallLeftShift;
-  if (InputByteNo < ByteValues.size()/2) {
-    if (ByteValues.size()-1-DestByteNo != InputByteNo)
-      return true;
-  } else {
-    if (ByteValues.size()-1-DestByteNo != InputByteNo)
-      return true;
-  }
+  if (ByteValues.size()-1-DestByteNo != InputByteNo)
+    return true;
   
   // If the destination byte value is already defined, the values are or'd
   // together, which isn't a bswap (unless it's an or of the same bits).
@@ -1555,7 +1553,6 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     case ICmpInst::ICMP_SLT:         // (X != 13 | X s< 15) -> true
       return ConstantInt::getTrue(LHS->getContext());
     }
-    break;
   case ICmpInst::ICMP_ULT:
     switch (RHSCC) {
     default: llvm_unreachable("Unknown integer condition code!");
@@ -1931,15 +1928,23 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
       }
 
   // Canonicalize xor to the RHS.
-  if (match(Op0, m_Xor(m_Value(), m_Value())))
+  bool SwappedForXor = false;
+  if (match(Op0, m_Xor(m_Value(), m_Value()))) {
     std::swap(Op0, Op1);
+    SwappedForXor = true;
+  }
 
   // A | ( A ^ B) -> A |  B
   // A | (~A ^ B) -> A | ~B
+  // (A & B) | (A ^ B)
   if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
     if (Op0 == A || Op0 == B)
       return BinaryOperator::CreateOr(A, B);
 
+    if (match(Op0, m_And(m_Specific(A), m_Specific(B))) ||
+        match(Op0, m_And(m_Specific(B), m_Specific(A))))
+      return BinaryOperator::CreateOr(A, B);
+
     if (Op1->hasOneUse() && match(A, m_Not(m_Specific(Op0)))) {
       Value *Not = Builder->CreateNot(B, B->getName()+".not");
       return BinaryOperator::CreateOr(Not, Op0);
@@ -1963,6 +1968,9 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
         return BinaryOperator::CreateOr(Not, Op0);
       }
 
+  if (SwappedForXor)
+    std::swap(Op0, Op1);
+
   if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
     if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
       if (Value *Res = FoldOrOfICmps(LHS, RHS))
@@ -2213,7 +2221,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
   if (Op0I && Op1I && Op0I->isShift() && 
       Op0I->getOpcode() == Op1I->getOpcode() && 
       Op0I->getOperand(1) == Op1I->getOperand(1) &&
-      (Op1I->hasOneUse() || Op1I->hasOneUse())) {
+      (Op0I->hasOneUse() || Op1I->hasOneUse())) {
     Value *NewOp =
       Builder->CreateXor(Op0I->getOperand(0), Op1I->getOperand(0),
                          Op0I->getName());