Remove redunant optimizations from InstCombine, instead call the appropriate functions from SimplifyInstruction

llvm-svn: 169941

1 files changed, 5 insertions, 17 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index d8257e64d83..5faf6474df6 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -351,18 +351,8 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
   bool Changed = SimplifyAssociativeOrCommutative(I);
   Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
 
-  if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
-    // X + 0 --> X
-    if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) {
-      if (CFP->isExactlyValue(ConstantFP::getNegativeZero
-                              (I.getType())->getValueAPF()))
-        return ReplaceInstUsesWith(I, LHS);
-    }
-
-    if (isa<PHINode>(LHS))
-      if (Instruction *NV = FoldOpIntoPhi(I))
-        return NV;
-  }
+  if (Value *V = SimplifyFAddInst(LHS, RHS, I.getFastMathFlags(), TD))
+    return ReplaceInstUsesWith(I, V);
 
   // -A + B  -->  B - A
   // -A + -B  -->  -(A + B)
@@ -374,11 +364,6 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
     if (Value *V = dyn_castFNegVal(RHS))
       return BinaryOperator::CreateFSub(LHS, V);
 
-  // Check for X+0.0.  Simplify it to X if we know X is not -0.0.
-  if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHS))
-    if (CFP->getValueAPF().isPosZero() && CannotBeNegativeZero(LHS))
-      return ReplaceInstUsesWith(I, LHS);
-
   // Check for (fadd double (sitofp x), y), see if we can merge this into an
   // integer add followed by a promotion.
   if (SIToFPInst *LHSConv = dyn_cast<SIToFPInst>(LHS)) {
@@ -653,6 +638,9 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
 Instruction *InstCombiner::visitFSub(BinaryOperator &I) {
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
 
+  if (Value *V = SimplifyFSubInst(Op0, Op1, I.getFastMathFlags(), TD))
+    return ReplaceInstUsesWith(I, V);
+
   // If this is a 'B = x-(-A)', change to B = x+A...
   if (Value *V = dyn_castFNegVal(Op1))
     return BinaryOperator::CreateFAdd(Op0, V);