[InstCombine, SCCP] Consolidate code used to remove instructions
InstCombine and SCCP both want to remove dead code in a very particular
way but using identical means to do so. Share the code between the two.
No functionality change is intended.
llvm-svn: 258653
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 0ccd79a..329a1f1 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3012,24 +3012,9 @@
if (Visited.count(&*BB))
continue;
- // Delete the instructions backwards, as it has a reduced likelihood of
- // having to update as many def-use and use-def chains.
- Instruction *EndInst = BB->getTerminator(); // Last not to be deleted.
- while (EndInst != BB->begin()) {
- // Delete the next to last instruction.
- Instruction *Inst = &*--EndInst->getIterator();
- if (!Inst->use_empty() && !Inst->getType()->isTokenTy())
- Inst->replaceAllUsesWith(UndefValue::get(Inst->getType()));
- if (Inst->isEHPad() || Inst->getType()->isTokenTy()) {
- EndInst = Inst;
- continue;
- }
- if (!isa<DbgInfoIntrinsic>(Inst)) {
- ++NumDeadInst;
- MadeIRChange = true;
- }
- Inst->eraseFromParent();
- }
+ unsigned NumDeadInstInBB = removeAllNonTerminatorAndEHPadInstructions(&*BB);
+ MadeIRChange |= NumDeadInstInBB > 0;
+ NumDeadInst += NumDeadInstInBB;
}
return MadeIRChange;