RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-02-01 05:01:59 +01:00
Code Issues Projects Releases Wiki Activity

TransformUtils: Avoid getNodePtrUnchecked() in integer division, NFC

Browse Source 
Stop relying on `getNodePtrUnchecked()` being useful on invalid
iterators.  This function is documented to be for internal use only, and
the pointer type will eventually have to change to remove UB from
ilist_iterator.  Instead, check the iterator before it has been
invalidated.

llvm-svn: 261497
This commit is contained in:
Duncan P. N. Exon Smith 2016-02-21 20:14:29 +00:00
parent 9a2563de7c
commit 37982bac02
1 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
lib/Transforms/Utils/IntegerDivision.cpp
View File

@ -390,6 +390,8 @@ bool llvm::expandRemainder(BinaryOperator *Rem) {
Value *Remainder = generateSignedRemainderCode(Rem->getOperand(0), Value *Remainder = generateSignedRemainderCode(Rem->getOperand(0),
Rem->getOperand(1), Builder); Rem->getOperand(1), Builder);
// Check whether this is the insert point while Rem is still valid.
bool IsInsertPoint = Rem->getIterator() == Builder.GetInsertPoint();
Rem->replaceAllUsesWith(Remainder); Rem->replaceAllUsesWith(Remainder);
Rem->dropAllReferences(); Rem->dropAllReferences();
Rem->eraseFromParent(); Rem->eraseFromParent();
@ -397,7 +399,7 @@ bool llvm::expandRemainder(BinaryOperator *Rem) {
// If we didn't actually generate an urem instruction, we're done // If we didn't actually generate an urem instruction, we're done
// This happens for example if the input were constant. In this case the // This happens for example if the input were constant. In this case the
// Builder insertion point was unchanged // Builder insertion point was unchanged
if (Rem == Builder.GetInsertPoint().getNodePtrUnchecked()) if (IsInsertPoint)
return true; return true;
BinaryOperator *BO = dyn_cast<BinaryOperator>(Builder.GetInsertPoint()); BinaryOperator *BO = dyn_cast<BinaryOperator>(Builder.GetInsertPoint());
@ -446,6 +448,9 @@ bool llvm::expandDivision(BinaryOperator *Div) {
// Lower the code to unsigned division, and reset Div to point to the udiv. // Lower the code to unsigned division, and reset Div to point to the udiv.
Value *Quotient = generateSignedDivisionCode(Div->getOperand(0), Value *Quotient = generateSignedDivisionCode(Div->getOperand(0),
Div->getOperand(1), Builder); Div->getOperand(1), Builder);
// Check whether this is the insert point while Div is still valid.
bool IsInsertPoint = Div->getIterator() == Builder.GetInsertPoint();
Div->replaceAllUsesWith(Quotient); Div->replaceAllUsesWith(Quotient);
Div->dropAllReferences(); Div->dropAllReferences();
Div->eraseFromParent(); Div->eraseFromParent();
@ -453,7 +458,7 @@ bool llvm::expandDivision(BinaryOperator *Div) {
// If we didn't actually generate an udiv instruction, we're done // If we didn't actually generate an udiv instruction, we're done
// This happens for example if the input were constant. In this case the // This happens for example if the input were constant. In this case the
// Builder insertion point was unchanged // Builder insertion point was unchanged
if (Div == Builder.GetInsertPoint().getNodePtrUnchecked()) if (IsInsertPoint)
return true; return true;
BinaryOperator *BO = dyn_cast<BinaryOperator>(Builder.GetInsertPoint()); BinaryOperator *BO = dyn_cast<BinaryOperator>(Builder.GetInsertPoint());