New EH representation for MSVC compatibility
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.
Differential Revision: http://reviews.llvm.org/D11097
llvm-svn: 243766
diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 74ca0a1..1bf92e3 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -117,8 +117,9 @@
// Don't break self-loops.
if (PredBB == BB) return false;
- // Don't break invokes.
- if (isa<InvokeInst>(PredBB->getTerminator())) return false;
+ // Don't break unwinding instructions.
+ if (PredBB->getTerminator()->isExceptional())
+ return false;
succ_iterator SI(succ_begin(PredBB)), SE(succ_end(PredBB));
BasicBlock *OnlySucc = BB;
@@ -283,7 +284,7 @@
BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt,
DominatorTree *DT, LoopInfo *LI) {
BasicBlock::iterator SplitIt = SplitPt;
- while (isa<PHINode>(SplitIt) || isa<LandingPadInst>(SplitIt))
+ while (isa<PHINode>(SplitIt) || SplitIt->isEHPad())
++SplitIt;
BasicBlock *New = Old->splitBasicBlock(SplitIt, Old->getName()+".split");
@@ -474,6 +475,10 @@
ArrayRef<BasicBlock *> Preds,
const char *Suffix, DominatorTree *DT,
LoopInfo *LI, bool PreserveLCSSA) {
+ // Do not attempt to split that which cannot be split.
+ if (!BB->canSplitPredecessors())
+ return nullptr;
+
// For the landingpads we need to act a bit differently.
// Delegate this work to the SplitLandingPadPredecessors.
if (BB->isLandingPad()) {