Bail out earlier

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21786 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-05-08 21:33:47 +00:00
parent f33151aff0
commit 6f156856ca

View File

@ -341,10 +341,6 @@ static Value *NegateValue(Value *V, Instruction *BI) {
/// only used by an add, transform this into (X+(0-Y)) to promote better
/// reassociation.
static Instruction *BreakUpSubtract(Instruction *Sub) {
// Reject cases where it is pointless to do this.
if (Sub->getType()->isFloatingPoint())
return 0; // Floating point adds are not associative.
// Don't bother to break this up unless either the LHS is an associable add or
// if this is only used by one.
if (!isReassociableOp(Sub->getOperand(0), Instruction::Add) &&
@ -560,6 +556,10 @@ static void PrintOps(unsigned Opcode, const std::vector<ValueEntry> &Ops,
/// reassociating them as we go.
void Reassociate::ReassociateBB(BasicBlock *BB) {
for (BasicBlock::iterator BI = BB->begin(); BI != BB->end(); ++BI) {
// Reject cases where it is pointless to do this.
if (!isa<BinaryOperator>(BI) || BI->getType()->isFloatingPoint())
continue; // Floating point ops are not associative.
// If this is a subtract instruction which is not already in negate form,
// see if we can convert it to X+-Y.
if (BI->getOpcode() == Instruction::Sub) {