6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-12 13:38:21 +00:00
Code Issues Projects Releases Wiki Activity

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

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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30275 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2006-09-12 19:17:09 +00:00
parent 431a80ade7
commit 92f7365740
1 changed files with 4 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
lib/Transforms/Scalar/LICM.cpp
View File

@ -447,6 +447,8 @@ void LICM::sink(Instruction &I) {
if (!isExitBlockDominatedByBlockInLoop(ExitBlocks[0], I.getParent())) { if (!isExitBlockDominatedByBlockInLoop(ExitBlocks[0], I.getParent())) {
// Instruction is not used, just delete it. // Instruction is not used, just delete it.
CurAST->deleteValue(&I); CurAST->deleteValue(&I);
if (!I.use_empty()) // If I has users in unreachable blocks, eliminate.
I.replaceAllUsesWith(UndefValue::get(I.getType()));
I.eraseFromParent(); I.eraseFromParent();
} else { } else {
// Move the instruction to the start of the exit block, after any PHI // 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) { } else if (ExitBlocks.size() == 0) {
// The instruction is actually dead if there ARE NO exit blocks. // The instruction is actually dead if there ARE NO exit blocks.
CurAST->deleteValue(&I); CurAST->deleteValue(&I);
if (!I.use_empty()) // If I has users in unreachable blocks, eliminate.
I.replaceAllUsesWith(UndefValue::get(I.getType()));
I.eraseFromParent(); I.eraseFromParent();
} else { } else {
// Otherwise, if we have multiple exits, use the PromoteMem2Reg function to // Otherwise, if we have multiple exits, use the PromoteMem2Reg function to