factor some logic out of instcombine into a new SimplifyAddInst method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90011 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 7a7eb6b..b53ac13 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -21,10 +21,38 @@
using namespace llvm;
using namespace llvm::PatternMatch;
+/// SimplifyAddInst - Given operands for an Add, see if we can
+/// fold the result. If not, this returns null.
+Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(),
+ Ops, 2, TD);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
+ // X + undef -> undef
+ if (isa<UndefValue>(Op1C))
+ return Op1C;
+
+ // X + 0 --> X
+ if (Op1C->isNullValue())
+ return Op0;
+ }
+
+ // FIXME: Could pull several more out of instcombine.
+ return 0;
+}
+
/// SimplifyAndInst - Given operands for an And, see if we can
/// fold the result. If not, this returns null.
-Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1,
- const TargetData *TD) {
+Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
@@ -83,8 +111,7 @@
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
-Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1,
- const TargetData *TD) {
+Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
@@ -142,8 +169,6 @@
}
-
-
static const Type *GetCompareTy(Value *Op) {
return CmpInst::makeCmpResultType(Op->getType());
}
@@ -327,6 +352,10 @@
switch (I->getOpcode()) {
default:
return ConstantFoldInstruction(I, TD);
+ case Instruction::Add:
+ return SimplifyAddInst(I->getOperand(0), I->getOperand(1),
+ cast<BinaryOperator>(I)->hasNoSignedWrap(),
+ cast<BinaryOperator>(I)->hasNoUnsignedWrap(), TD);
case Instruction::And:
return SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD);
case Instruction::Or: