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/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
index 11d7a21..1298011 100644
--- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
@@ -142,6 +142,8 @@
BasicBlock *PreheaderBB;
PreheaderBB = SplitBlockPredecessors(Header, OutsideBlocks, ".preheader", DT,
LI, PreserveLCSSA);
+ if (!PreheaderBB)
+ return nullptr;
DEBUG(dbgs() << "LoopSimplify: Creating pre-header "
<< PreheaderBB->getName() << "\n");
@@ -178,6 +180,8 @@
NewExitBB = SplitBlockPredecessors(Exit, LoopBlocks, ".loopexit", DT, LI,
PreserveLCSSA);
+ if (!NewExitBB)
+ return nullptr;
DEBUG(dbgs() << "LoopSimplify: Creating dedicated exit block "
<< NewExitBB->getName() << "\n");
@@ -256,8 +260,10 @@
return nullptr;
// The header is not a landing pad; preheader insertion should ensure this.
- assert(!L->getHeader()->isLandingPad() &&
- "Can't insert backedge to landing pad");
+ BasicBlock *Header = L->getHeader();
+ assert(!Header->isLandingPad() && "Can't insert backedge to landing pad");
+ if (!Header->canSplitPredecessors())
+ return nullptr;
PHINode *PN = findPHIToPartitionLoops(L, DT, AC);
if (!PN) return nullptr; // No known way to partition.
@@ -285,7 +291,6 @@
bool PreserveLCSSA = PP->mustPreserveAnalysisID(LCSSAID);
- BasicBlock *Header = L->getHeader();
BasicBlock *NewBB = SplitBlockPredecessors(Header, OuterLoopPreds, ".outer",
DT, LI, PreserveLCSSA);