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An sinkable instruction may exist with uses, if those uses are in dead blocks. 

Handle this.  This fixes PR908 and Transforms/LICM/2006-09-12-DeadUserOfSunkInstr.ll

llvm-svn: 30275
This commit is contained in:
Chris Lattner 2006-09-12 19:17:09 +00:00
parent 726bc70c43
commit 1d7ec20a4d
1 changed files with 4 additions and 0 deletions
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4
llvm/lib/Transforms/Scalar/LICM.cpp
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@ -447,6 +447,8 @@ void LICM::sink(Instruction &I) {
if (!isExitBlockDominatedByBlockInLoop(ExitBlocks[0], I.getParent())) {
// Instruction is not used, just delete it.
CurAST->deleteValue(&I);
if (!I.use_empty()) // If I has users in unreachable blocks, eliminate.
I.replaceAllUsesWith(UndefValue::get(I.getType()));
I.eraseFromParent();
} else {
// Move the instruction to the start of the exit block, after any PHI
@ -460,6 +462,8 @@ void LICM::sink(Instruction &I) {
} else if (ExitBlocks.size() == 0) {
// The instruction is actually dead if there ARE NO exit blocks.
CurAST->deleteValue(&I);
if (!I.use_empty()) // If I has users in unreachable blocks, eliminate.
I.replaceAllUsesWith(UndefValue::get(I.getType()));
I.eraseFromParent();
} else {
// Otherwise, if we have multiple exits, use the PromoteMem2Reg function to