diff options
Diffstat (limited to 'lib/Transforms/Utils/DemoteRegToStack.cpp')
-rw-r--r-- | lib/Transforms/Utils/DemoteRegToStack.cpp | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/lib/Transforms/Utils/DemoteRegToStack.cpp b/lib/Transforms/Utils/DemoteRegToStack.cpp index 9972b22..003da58 100644 --- a/lib/Transforms/Utils/DemoteRegToStack.cpp +++ b/lib/Transforms/Utils/DemoteRegToStack.cpp @@ -39,6 +39,19 @@ AllocaInst *llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads, F->getEntryBlock().begin()); } + // We cannot demote invoke instructions to the stack if their normal edge + // is critical. Therefore, split the critical edge and create a basic block + // into which the store can be inserted. + if (InvokeInst *II = dyn_cast<InvokeInst>(&I)) { + if (!II->getNormalDest()->getSinglePredecessor()) { + unsigned SuccNum = GetSuccessorNumber(II->getParent(), II->getNormalDest()); + assert(isCriticalEdge(II, SuccNum) && "Expected a critical edge!"); + BasicBlock *BB = SplitCriticalEdge(II, SuccNum); + assert(BB && "Unable to split critical edge."); + (void)BB; + } + } + // Change all of the users of the instruction to read from the stack slot. while (!I.use_empty()) { Instruction *U = cast<Instruction>(I.user_back()); @@ -71,7 +84,6 @@ AllocaInst *llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads, } } - // Insert stores of the computed value into the stack slot. We have to be // careful if I is an invoke instruction, because we can't insert the store // AFTER the terminator instruction. @@ -79,27 +91,13 @@ AllocaInst *llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads, if (!isa<TerminatorInst>(I)) { InsertPt = &I; ++InsertPt; + for (; isa<PHINode>(InsertPt) || isa<LandingPadInst>(InsertPt); ++InsertPt) + /* empty */; // Don't insert before PHI nodes or landingpad instrs. } else { InvokeInst &II = cast<InvokeInst>(I); - if (II.getNormalDest()->getSinglePredecessor()) - InsertPt = II.getNormalDest()->getFirstInsertionPt(); - else { - // We cannot demote invoke instructions to the stack if their normal edge - // is critical. Therefore, split the critical edge and insert the store - // in the newly created basic block. - unsigned SuccNum = GetSuccessorNumber(I.getParent(), II.getNormalDest()); - TerminatorInst *TI = &cast<TerminatorInst>(I); - assert (isCriticalEdge(TI, SuccNum) && - "Expected a critical edge!"); - BasicBlock *BB = SplitCriticalEdge(TI, SuccNum); - assert (BB && "Unable to split critical edge."); - InsertPt = BB->getFirstInsertionPt(); - } + InsertPt = II.getNormalDest()->getFirstInsertionPt(); } - for (; isa<PHINode>(InsertPt) || isa<LandingPadInst>(InsertPt); ++InsertPt) - /* empty */; // Don't insert before PHI nodes or landingpad instrs. - new StoreInst(&I, Slot, InsertPt); return Slot; } |