vendor/llvm/llvm-trunk-r305575

1 files changed, 69 insertions, 44 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 4fe3225a21722..a881bda5ba98d 100644
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -763,8 +763,54 @@ foldAndOrOfEqualityCmpsWithConstants(ICmpInst *LHS, ICmpInst *RHS,
   return nullptr;
 }
 
+// Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2)
+// Fold (!iszero(A & K1) & !iszero(A & K2)) -> (A & (K1 | K2)) == (K1 | K2)
+Value *InstCombiner::foldAndOrOfICmpsOfAndWithPow2(ICmpInst *LHS, ICmpInst *RHS,
+                                                   bool JoinedByAnd,
+                                                   Instruction &CxtI) {
+  ICmpInst::Predicate Pred = LHS->getPredicate();
+  if (Pred != RHS->getPredicate())
+    return nullptr;
+  if (JoinedByAnd && Pred != ICmpInst::ICMP_NE)
+    return nullptr;
+  if (!JoinedByAnd && Pred != ICmpInst::ICMP_EQ)
+    return nullptr;
+
+  // TODO support vector splats
+  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
+  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
+  if (!LHSC || !RHSC || !LHSC->isZero() || !RHSC->isZero())
+    return nullptr;
+
+  Value *A, *B, *C, *D;
+  if (match(LHS->getOperand(0), m_And(m_Value(A), m_Value(B))) &&
+      match(RHS->getOperand(0), m_And(m_Value(C), m_Value(D)))) {
+    if (A == D || B == D)
+      std::swap(C, D);
+    if (B == C)
+      std::swap(A, B);
+
+    if (A == C &&
+        isKnownToBeAPowerOfTwo(B, false, 0, &CxtI) &&
+        isKnownToBeAPowerOfTwo(D, false, 0, &CxtI)) {
+      Value *Mask = Builder->CreateOr(B, D);
+      Value *Masked = Builder->CreateAnd(A, Mask);
+      auto NewPred = JoinedByAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
+      return Builder->CreateICmp(NewPred, Masked, Mask);
+    }
+  }
+
+  return nullptr;
+}
+
 /// Fold (icmp)&(icmp) if possible.
-Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
+Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
+                                    Instruction &CxtI) {
+  // Fold (!iszero(A & K1) & !iszero(A & K2)) ->  (A & (K1 | K2)) == (K1 | K2)
+  // if K1 and K2 are a one-bit mask.
+  if (Value *V = foldAndOrOfICmpsOfAndWithPow2(LHS, RHS, true, CxtI))
+    return V;
+
   ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
 
   // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
@@ -1127,8 +1173,8 @@ 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, I)
+                                              : foldOrOfICmps(ICmp0, ICmp1, I);
     if (Res)
       return CastInst::Create(CastOpcode, Res, DestTy);
     return nullptr;
@@ -1426,7 +1472,7 @@ 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, I))
         return replaceInstUsesWith(I, Res);
 
     // TODO: Make this recursive; it's a little tricky because an arbitrary
@@ -1434,18 +1480,18 @@ 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, I))
           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, I))
           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, I))
           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, I))
           return replaceInstUsesWith(I, Builder->CreateAnd(Res, X));
     }
   }
@@ -1591,41 +1637,16 @@ static Value *matchSelectFromAndOr(Value *A, Value *C, Value *B, Value *D,
 
 /// Fold (icmp)|(icmp) if possible.
 Value *InstCombiner::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
-                                   Instruction *CxtI) {
-  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
-
+                                   Instruction &CxtI) {
   // Fold (iszero(A & K1) | iszero(A & K2)) ->  (A & (K1 | K2)) != (K1 | K2)
   // if K1 and K2 are a one-bit mask.
-  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
-  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
+  if (Value *V = foldAndOrOfICmpsOfAndWithPow2(LHS, RHS, false, CxtI))
+    return V;
 
-  if (LHS->getPredicate() == ICmpInst::ICMP_EQ && LHSC && LHSC->isZero() &&
-      RHS->getPredicate() == ICmpInst::ICMP_EQ && RHSC && RHSC->isZero()) {
-
-    BinaryOperator *LAnd = dyn_cast<BinaryOperator>(LHS->getOperand(0));
-    BinaryOperator *RAnd = dyn_cast<BinaryOperator>(RHS->getOperand(0));
-    if (LAnd && RAnd && LAnd->hasOneUse() && RHS->hasOneUse() &&
-        LAnd->getOpcode() == Instruction::And &&
-        RAnd->getOpcode() == Instruction::And) {
-
-      Value *Mask = nullptr;
-      Value *Masked = nullptr;
-      if (LAnd->getOperand(0) == RAnd->getOperand(0) &&
-          isKnownToBeAPowerOfTwo(LAnd->getOperand(1), false, 0, CxtI) &&
-          isKnownToBeAPowerOfTwo(RAnd->getOperand(1), false, 0, CxtI)) {
-        Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1));
-        Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask);
-      } else if (LAnd->getOperand(1) == RAnd->getOperand(1) &&
-                 isKnownToBeAPowerOfTwo(LAnd->getOperand(0), false, 0, CxtI) &&
-                 isKnownToBeAPowerOfTwo(RAnd->getOperand(0), false, 0, CxtI)) {
-        Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0));
-        Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask);
-      }
+  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
 
-      if (Masked)
-        return Builder->CreateICmp(ICmpInst::ICMP_NE, Masked, Mask);
-    }
-  }
+  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
+  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
 
   // Fold (icmp ult/ule (A + C1), C3) | (icmp ult/ule (A + C2), C3)
   //                   -->  (icmp ult/ule ((A & ~(C1 ^ C2)) + max(C1, C2)), C3)
@@ -2117,12 +2138,16 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
   }
 
   // (A ^ B) | ((B ^ C) ^ A) -> (A ^ B) | C
+  // FIXME: The two hasOneUse calls here are the same call, maybe we were
+  // supposed to check Op1->operand(0)?
   if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
     if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
       if (Op1->hasOneUse() || cast<BinaryOperator>(Op1)->hasOneUse())
         return BinaryOperator::CreateOr(Op0, C);
 
   // ((A ^ C) ^ B) | (B ^ A) -> (B ^ A) | C
+  // FIXME: The two hasOneUse calls here are the same call, maybe we were
+  // supposed to check Op0->operand(0)?
   if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
     if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
       if (Op0->hasOneUse() || cast<BinaryOperator>(Op0)->hasOneUse())
@@ -2194,7 +2219,7 @@ 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
@@ -2202,18 +2227,18 @@ 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));
     }
   }