diff options
author | Dan Gohman <gohman@apple.com> | 2009-06-26 00:31:13 +0000 |
---|---|---|
committer | Dan Gohman <gohman@apple.com> | 2009-06-26 00:31:13 +0000 |
commit | 6b9c959c61e77b1bc78a93ee4a6cac8eaa656a21 (patch) | |
tree | 4ec94480766a2d191c0fdf3d6dd6dba7031b6c4a /lib/Transforms/Utils/LCSSA.cpp | |
parent | 151b9afdee10995add2f28790194570e7735f03c (diff) | |
download | external_llvm-6b9c959c61e77b1bc78a93ee4a6cac8eaa656a21.zip external_llvm-6b9c959c61e77b1bc78a93ee4a6cac8eaa656a21.tar.gz external_llvm-6b9c959c61e77b1bc78a93ee4a6cac8eaa656a21.tar.bz2 |
Fix LCSSA to avoid emitting a PHI node for the unwind destination of
an invoke instruction, since the value isn't really live across that
edge.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74242 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Utils/LCSSA.cpp')
-rw-r--r-- | lib/Transforms/Utils/LCSSA.cpp | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp index 7d4f3a3..d5e7303 100644 --- a/lib/Transforms/Utils/LCSSA.cpp +++ b/lib/Transforms/Utils/LCSSA.cpp @@ -149,7 +149,16 @@ void LCSSA::ProcessInstruction(Instruction *Instr, // Keep track of the blocks that have the value available already. DenseMap<DomTreeNode*, Value*> Phis; - DomTreeNode *InstrNode = DT->getNode(Instr->getParent()); + BasicBlock *DomBB = Instr->getParent(); + + // Invoke instructions are special in that their result value is not available + // along their unwind edge. The code below tests to see whether DomBB dominates + // the value, so adjust DomBB to the normal destination block, which is + // effectively where the value is first usable. + if (InvokeInst *Inv = dyn_cast<InvokeInst>(Instr)) + DomBB = Inv->getNormalDest(); + + DomTreeNode *DomNode = DT->getNode(DomBB); // Insert the LCSSA phi's into the exit blocks (dominated by the value), and // add them to the Phi's map. @@ -158,7 +167,7 @@ void LCSSA::ProcessInstruction(Instruction *Instr, BasicBlock *BB = *BBI; DomTreeNode *ExitBBNode = DT->getNode(BB); Value *&Phi = Phis[ExitBBNode]; - if (!Phi && DT->dominates(InstrNode, ExitBBNode)) { + if (!Phi && DT->dominates(DomNode, ExitBBNode)) { PHINode *PN = PHINode::Create(Instr->getType(), Instr->getName()+".lcssa", BB->begin()); PN->reserveOperandSpace(PredCache.GetNumPreds(BB)); |