[X86][Haswell][SchedModel] Add architecture specific scheduling models.

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

diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index f8d7e0ecf443394abbf33a87b95456ae270b6254..22cc34d861a59b5a165426ad5c8594c970827ea4 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -32,7 +32,7 @@ namespace {
   ///
   class FAddendCoef {
   public:
-    // The constructor has to initialize a APFloat, which is uncessary for
+    // The constructor has to initialize a APFloat, which is unnecessary for
     // most addends which have coefficient either 1 or -1. So, the constructor
     // is expensive. In order to avoid the cost of the constructor, we should
     // reuse some instances whenever possible. The pre-created instances
@@ -961,8 +961,8 @@ bool InstCombiner::WillNotOverflowUnsignedAdd(Value *LHS, Value *RHS) {
 //   ADD(XOR(OR(Z, NOT(C)), C)), 1) == NEG(AND(Z, C))
 //   ADD(XOR(AND(Z, C), C), 1) == NEG(OR(Z, ~C))
 //   XOR(AND(Z, C), (C + 1)) == NEG(OR(Z, ~C)) if C is even
-Value *checkForNegativeOperand(BinaryOperator &I,
-                               InstCombiner::BuilderTy *Builder) {
+static Value *checkForNegativeOperand(BinaryOperator &I,
+                                      InstCombiner::BuilderTy *Builder) {
   Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
 
   // This function creates 2 instructions to replace ADD, we need at least one
@@ -1240,7 +1240,7 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
     }
   }
 
-  // Check for (x & y) + (x ^ y)
+  // (add (xor A, B) (and A, B)) --> (or A, B)
   {
     Value *A = nullptr, *B = nullptr;
     if (match(RHS, m_Xor(m_Value(A), m_Value(B))) &&
@@ -1254,6 +1254,28 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
       return BinaryOperator::CreateOr(A, B);
   }
 
+  // (add (or A, B) (and A, B)) --> (add A, B)
+  {
+    Value *A = nullptr, *B = nullptr;
+    if (match(RHS, m_Or(m_Value(A), m_Value(B))) &&
+        (match(LHS, m_And(m_Specific(A), m_Specific(B))) ||
+         match(LHS, m_And(m_Specific(B), m_Specific(A))))) {
+      auto *New = BinaryOperator::CreateAdd(A, B);
+      New->setHasNoSignedWrap(I.hasNoSignedWrap());
+      New->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
+      return New;
+    }
+
+    if (match(LHS, m_Or(m_Value(A), m_Value(B))) &&
+        (match(RHS, m_And(m_Specific(A), m_Specific(B))) ||
+         match(RHS, m_And(m_Specific(B), m_Specific(A))))) {
+      auto *New = BinaryOperator::CreateAdd(A, B);
+      New->setHasNoSignedWrap(I.hasNoSignedWrap());
+      New->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
+      return New;
+    }
+  }
+
   // TODO(jingyue): Consider WillNotOverflowSignedAdd and
   // WillNotOverflowUnsignedAdd to reduce the number of invocations of
   // computeKnownBits.
@@ -1462,11 +1484,17 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
   if (Value *V = SimplifyUsingDistributiveLaws(I))
     return ReplaceInstUsesWith(I, V);
 
-  // If this is a 'B = x-(-A)', change to B = x+A.  This preserves NSW/NUW.
+  // If this is a 'B = x-(-A)', change to B = x+A.
   if (Value *V = dyn_castNegVal(Op1)) {
     BinaryOperator *Res = BinaryOperator::CreateAdd(Op0, V);
-    Res->setHasNoSignedWrap(I.hasNoSignedWrap());
-    Res->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
+
+    if (const auto *BO = dyn_cast<BinaryOperator>(Op1)) {
+      assert(BO->getOpcode() == Instruction::Sub &&
+             "Expected a subtraction operator!");
+      if (BO->hasNoSignedWrap() && I.hasNoSignedWrap())
+        Res->setHasNoSignedWrap(true);
+    }
+
     return Res;
   }
 
@@ -1553,9 +1581,9 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
       return BinaryOperator::CreateAnd(Op0,
                                   Builder->CreateNot(Y, Y->getName() + ".not"));
 
-    // 0 - (X sdiv C)  -> (X sdiv -C)
-    if (match(Op1, m_SDiv(m_Value(X), m_Constant(C))) &&
-        match(Op0, m_Zero()))
+    // 0 - (X sdiv C)  -> (X sdiv -C)  provided the negation doesn't overflow.
+    if (match(Op1, m_SDiv(m_Value(X), m_Constant(C))) && match(Op0, m_Zero()) &&
+        !C->isMinSignedValue() && !C->isOneValue())
       return BinaryOperator::CreateSDiv(X, ConstantExpr::getNeg(C));
 
     // 0 - (X << Y)  -> (-X << Y)   when X is freely negatable.