InstCombine: Remove a special case pattern

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

diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 3e88bd3122075583299aefda04d7a9b1f38f0548..ed6253532e098a875863cebdda86834ccc93d57d 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1101,7 +1101,6 @@ Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
   return nullptr;
 }
 
-
 Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
   bool Changed = SimplifyAssociativeOrCommutative(I);
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
@@ -1307,11 +1306,34 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
       return BinaryOperator::CreateAnd(A, B);
   }
 
-  if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1))
-    if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0))
+  {
+    ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
+    ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
+    if (LHS && RHS)
       if (Value *Res = FoldAndOfICmps(LHS, RHS))
         return ReplaceInstUsesWith(I, Res);
 
+    // TODO: Make this recursive; it's a little tricky because an arbitrary
+    // number of 'and' instructions might have to be created.
+    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))
+          return ReplaceInstUsesWith(I, Builder->CreateAnd(Res, Y));
+      if (auto *Cmp = dyn_cast<ICmpInst>(Y))
+        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))
+          return ReplaceInstUsesWith(I, Builder->CreateAnd(Res, Y));
+      if (auto *Cmp = dyn_cast<ICmpInst>(Y))
+        if (Value *Res = FoldAndOfICmps(Cmp, RHS))
+          return ReplaceInstUsesWith(I, Builder->CreateAnd(Res, X));
+    }
+  }
+
   // 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)))
@@ -1351,20 +1373,6 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
       }
     }
 
-  // (X >> Z) & (Y >> Z)  -> (X&Y) >> Z  for all shifts.
-  if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
-    if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
-      if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
-          SI0->getOperand(1) == SI1->getOperand(1) &&
-          (SI0->hasOneUse() || SI1->hasOneUse())) {
-        Value *NewOp =
-          Builder->CreateAnd(SI0->getOperand(0), SI1->getOperand(0),
-                             SI0->getName());
-        return BinaryOperator::Create(SI1->getOpcode(), NewOp,
-                                      SI1->getOperand(1));
-      }
-  }
-
   {
     Value *X = nullptr;
     bool OpsSwapped = false;
@@ -2227,19 +2235,6 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
   if (match(Op0, m_And(m_Or(m_Specific(Op1), m_Value(C)), m_Value(A))))
     return BinaryOperator::CreateOr(Op1, Builder->CreateAnd(A, C));
 
-  // (X >> Z) | (Y >> Z)  -> (X|Y) >> Z  for all shifts.
-  if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
-    if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
-      if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
-          SI0->getOperand(1) == SI1->getOperand(1) &&
-          (SI0->hasOneUse() || SI1->hasOneUse())) {
-        Value *NewOp = Builder->CreateOr(SI0->getOperand(0), SI1->getOperand(0),
-                                         SI0->getName());
-        return BinaryOperator::Create(SI1->getOpcode(), NewOp,
-                                      SI1->getOperand(1));
-      }
-  }
-
   // (~A | ~B) == (~(A & B)) - De Morgan's Law
   if (Value *Op0NotVal = dyn_castNotVal(Op0))
     if (Value *Op1NotVal = dyn_castNotVal(Op1))
@@ -2585,18 +2580,6 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
     }
   }
 
-  // (X >> Z) ^ (Y >> Z)  -> (X^Y) >> Z  for all shifts.
-  if (Op0I && Op1I && Op0I->isShift() &&
-      Op0I->getOpcode() == Op1I->getOpcode() &&
-      Op0I->getOperand(1) == Op1I->getOperand(1) &&
-      (Op0I->hasOneUse() || Op1I->hasOneUse())) {
-    Value *NewOp =
-      Builder->CreateXor(Op0I->getOperand(0), Op1I->getOperand(0),
-                         Op0I->getName());
-    return BinaryOperator::Create(Op1I->getOpcode(), NewOp,
-                                  Op1I->getOperand(1));
-  }
-
   if (Op0I && Op1I) {
     Value *A, *B, *C, *D;
     // (A & B)^(A | B) -> A ^ B
@@ -2631,17 +2614,25 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
         match(Op1I, m_And(m_Specific(A), m_Not(m_Specific(B))))) {
       return BinaryOperator::CreateXor(A, B);
     }
-    // (A ^ B)^(A | B) -> A & B
-    if (match(Op0I, m_Xor(m_Value(A), m_Value(B))) &&
-        match(Op1I, m_Or(m_Value(C), m_Value(D)))) {
-      if ((A == C && B == D) || (A == D && B == C))
-        return BinaryOperator::CreateAnd(A, B);
-    }
-    // (A | B)^(A ^ B) -> A & B
+    // (A ^ C)^(A | B) -> ((~A) & B) ^ C
+    if (match(Op0I, m_Xor(m_Value(D), m_Value(C))) &&
+        match(Op1I, m_Or(m_Value(A), m_Value(B)))) {
+      if (D == A)
+        return BinaryOperator::CreateXor(
+            Builder->CreateAnd(Builder->CreateNot(A), B), C);
+      if (D == B)
+        return BinaryOperator::CreateXor(
+            Builder->CreateAnd(Builder->CreateNot(B), A), C);
+    }
+    // (A | B)^(A ^ C) -> ((~A) & B) ^ C
     if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
-        match(Op1I, m_Xor(m_Value(C), m_Value(D)))) {
-      if ((A == C && B == D) || (A == D && B == C))
-        return BinaryOperator::CreateAnd(A, B);
+        match(Op1I, m_Xor(m_Value(D), m_Value(C)))) {
+      if (D == A)
+        return BinaryOperator::CreateXor(
+            Builder->CreateAnd(Builder->CreateNot(A), B), C);
+      if (D == B)
+        return BinaryOperator::CreateXor(
+            Builder->CreateAnd(Builder->CreateNot(B), A), C);
     }
     // (A & B) ^ (A ^ B) -> (A | B)
     if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
@@ -2653,12 +2644,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
       return BinaryOperator::CreateOr(A, B);
   }
 
-  // (A | B)^(~A) -> (A | ~B)
   Value *A = nullptr, *B = nullptr;
-  if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
-      match(Op1, m_Not(m_Specific(A))))
-    return BinaryOperator::CreateOr(A, Builder->CreateNot(B));
-
   // (A & ~B) ^ (~A) -> ~(A & B)
   if (match(Op0, m_And(m_Value(A), m_Not(m_Value(B)))) &&
       match(Op1, m_Not(m_Specific(A))))