Revert r160602.

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

diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 05e702fa43b53129abbde3e7bfd81ae782facc45..99b62f8d05a75065873e349452ff40bf64f7c74c 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -170,10 +170,11 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
   // -A + B  -->  B - A
   // -A + -B  -->  -(A + B)
   if (Value *LHSV = dyn_castNegVal(LHS)) {
-    if (Value *RHSV = dyn_castNegVal(RHS)) {
-      Value *NewAdd = Builder->CreateAdd(LHSV, RHSV, "sum");
-      return BinaryOperator::CreateNeg(NewAdd);
-    }
+    if (!isa<Constant>(RHS))
+      if (Value *RHSV = dyn_castNegVal(RHS)) {
+        Value *NewAdd = Builder->CreateAdd(LHSV, RHSV, "sum");
+        return BinaryOperator::CreateNeg(NewAdd);
+      }
     
     return BinaryOperator::CreateSub(RHS, LHSV);
   }
@@ -329,6 +330,20 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
     }
   }
 
+  // Check for (x & y) + (x ^ y)
+  {
+    Value *A = 0, *B = 0;
+    if (match(RHS, m_Xor(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)))))
+      return BinaryOperator::CreateOr(A, B);
+
+    if (match(LHS, m_Xor(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)))))
+      return BinaryOperator::CreateOr(A, B);
+  }
+
   return Changed ? &I : 0;
 }
 
@@ -406,66 +421,6 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
 }
 
 
-/// EmitGEPOffset - Given a getelementptr instruction/constantexpr, emit the
-/// code necessary to compute the offset from the base pointer (without adding
-/// in the base pointer).  Return the result as a signed integer of intptr size.
-Value *InstCombiner::EmitGEPOffset(User *GEP) {
-  TargetData &TD = *getTargetData();
-  gep_type_iterator GTI = gep_type_begin(GEP);
-  Type *IntPtrTy = TD.getIntPtrType(GEP->getContext());
-  Value *Result = Constant::getNullValue(IntPtrTy);
-
-  // If the GEP is inbounds, we know that none of the addressing operations will
-  // overflow in an unsigned sense.
-  bool isInBounds = cast<GEPOperator>(GEP)->isInBounds();
-  
-  // Build a mask for high order bits.
-  unsigned IntPtrWidth = TD.getPointerSizeInBits();
-  uint64_t PtrSizeMask = ~0ULL >> (64-IntPtrWidth);
-
-  for (User::op_iterator i = GEP->op_begin() + 1, e = GEP->op_end(); i != e;
-       ++i, ++GTI) {
-    Value *Op = *i;
-    uint64_t Size = TD.getTypeAllocSize(GTI.getIndexedType()) & PtrSizeMask;
-    if (ConstantInt *OpC = dyn_cast<ConstantInt>(Op)) {
-      if (OpC->isZero()) continue;
-      
-      // Handle a struct index, which adds its field offset to the pointer.
-      if (StructType *STy = dyn_cast<StructType>(*GTI)) {
-        Size = TD.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
-        
-        if (Size)
-          Result = Builder->CreateAdd(Result, ConstantInt::get(IntPtrTy, Size),
-                                      GEP->getName()+".offs");
-        continue;
-      }
-      
-      Constant *Scale = ConstantInt::get(IntPtrTy, Size);
-      Constant *OC =
-              ConstantExpr::getIntegerCast(OpC, IntPtrTy, true /*SExt*/);
-      Scale = ConstantExpr::getMul(OC, Scale, isInBounds/*NUW*/);
-      // Emit an add instruction.
-      Result = Builder->CreateAdd(Result, Scale, GEP->getName()+".offs");
-      continue;
-    }
-    // Convert to correct type.
-    if (Op->getType() != IntPtrTy)
-      Op = Builder->CreateIntCast(Op, IntPtrTy, true, Op->getName()+".c");
-    if (Size != 1) {
-      // We'll let instcombine(mul) convert this to a shl if possible.
-      Op = Builder->CreateMul(Op, ConstantInt::get(IntPtrTy, Size),
-                              GEP->getName()+".idx", isInBounds /*NUW*/);
-    }
-
-    // Emit an add instruction.
-    Result = Builder->CreateAdd(Op, Result, GEP->getName()+".offs");
-  }
-  return Result;
-}
-
-
-
-
 /// Optimize pointer differences into the same array into a size.  Consider:
 ///  &A[10] - &A[0]: we should compile this to "10".  LHS/RHS are the pointer
 /// operands to the ptrtoint instructions for the LHS/RHS of the subtract.
@@ -589,11 +544,6 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
       if (Instruction *R = FoldOpIntoSelect(I, SI))
         return R;
 
-    // C - zext(bool) -> bool ? C - 1 : C
-    if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1))
-      if (ZI->getSrcTy()->isIntegerTy(1))
-        return SelectInst::Create(ZI->getOperand(0), SubOne(C), C);
-
     // C-(X+C2) --> (C-C2)-X
     ConstantInt *C2;
     if (match(Op1, m_Add(m_Value(X), m_ConstantInt(C2))))