if the terminator is a branch depending upon the side effects of a

previous cmp; a copy can not be inserted here if the copy insn also has
 side effects. We don't have access to the attributes of copy insn here;
 so just play safe by finding a safe locations for branch terminators.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74898 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjiv Gupta 2009-07-07 08:04:51 +00:00
parent 40289b041a
commit 1dd35b4c35

View File

@ -169,9 +169,15 @@ MachineBasicBlock::iterator PNE::FindCopyInsertPoint(MachineBasicBlock &MBB,
return MBB.begin();
// If this basic block does not contain an invoke, then control flow always
// reaches the end of it, so place the copy there. The logic below works in
// this case too, but is more expensive.
if (!isa<InvokeInst>(MBB.getBasicBlock()->getTerminator()))
// reaches the end of it, so place the copy there.
// If the terminator is a branch depending upon the side effects of a
// previous cmp; a copy can not be inserted here if the copy insn also
// side effects. We don't have access to the attributes of copy insn here;
// so just play safe by finding a safe locations for branch terminators.
//
// The logic below works in this case too, but is more expensive.
const TerminatorInst *TermInst = MBB.getBasicBlock()->getTerminator();
if (!(isa<InvokeInst>(TermInst) || isa<BranchInst>(TermInst)))
return MBB.getFirstTerminator();
// Discover any definition/uses in this basic block.