Fix InstCombine/2004-04-04-InstCombineReplaceAllUsesWith.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12658 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-04-05 02:10:19 +00:00
parent ec3f8cd551
commit 15a76c0b35

View File

@ -151,8 +151,15 @@ namespace {
//
Instruction *ReplaceInstUsesWith(Instruction &I, Value *V) {
AddUsersToWorkList(I); // Add all modified instrs to worklist
I.replaceAllUsesWith(V);
return &I;
if (&I != V) {
I.replaceAllUsesWith(V);
return &I;
} else {
// If we are replacing the instruction with itself, this must be in a
// segment of unreachable code, so just clobber the instruction.
I.replaceAllUsesWith(Constant::getNullValue(I.getType()));
return &I;
}
}
// EraseInstFromFunction - When dealing with an instruction that has side
@ -424,7 +431,12 @@ Instruction *AssociativeOpt(BinaryOperator &Root, const Functor &F) {
// Make what used to be the LHS of the root be the user of the root...
Value *ExtraOperand = TmpLHSI->getOperand(1);
Root.replaceAllUsesWith(TmpLHSI); // Users now use TmpLHSI
if (&Root != TmpLHSI)
Root.replaceAllUsesWith(TmpLHSI); // Users now use TmpLHSI
else {
Root.replaceAllUsesWith(Constant::getNullValue(TmpLHSI->getType()));
return 0;
}
TmpLHSI->setOperand(1, &Root); // TmpLHSI now uses the root
BB->getInstList().remove(&Root); // Remove root from the BB
BB->getInstList().insert(TmpLHSI, &Root); // Insert root before TmpLHSI