[IR] Introduce helpers to skip debug instructions (NFC)
This patch introduces two helpers to make it easier to ignore debug
intrinsics:
- Instruction::getNextNonDebugInstruction()
This is just like Instruction::getNextNode(), except that it skips debug
info.
- skipDebugInfo(BasicBlock::iterator)
A free function which advances a BasicBlock iterator past any debug
info. This is a no-op when the iterator already points to a non-debug
instruction.
Part of: llvm.org/PR37728
Related to: https://reviews.llvm.org/D47874
Differential Revision: https://reviews.llvm.org/D48305
llvm-svn: 335083
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 9e046c9..3dde762 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -3614,13 +3614,8 @@
// happen when variable allocas are DCE'd.
if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getArgOperand(0))) {
if (SS->getIntrinsicID() == Intrinsic::stacksave) {
- // Skip over debug info instructions.
- // FIXME: This should be an utility in Instruction.h
- auto It = SS->getIterator();
- It++;
- while (isa<DbgInfoIntrinsic>(*It))
- It++;
- if (&*It == II) {
+ // Skip over debug info.
+ if (SS->getNextNonDebugInstruction() == II) {
return eraseInstFromFunction(CI);
}
}
@@ -3804,10 +3799,7 @@
// Fence instruction simplification
Instruction *InstCombiner::visitFenceInst(FenceInst &FI) {
// Remove identical consecutive fences.
- Instruction *Next = FI.getNextNode();
- while (Next != nullptr && isa<DbgInfoIntrinsic>(Next))
- Next = Next->getNextNode();
-
+ Instruction *Next = FI.getNextNonDebugInstruction();
if (auto *NFI = dyn_cast<FenceInst>(Next))
if (FI.isIdenticalTo(NFI))
return eraseInstFromFunction(FI);