Changes in directory llvm/lib/Transforms/Utils:
CloneFunction.cpp updated: 1.39 -> 1.40
---
Log message:
Fix bugs in the inliner having to do with single-entry phi nodes and valuemap
updating. These were exposed by Devang's recent passmgr changes (with
non-default passorderings) because now the inliner can be interleved with
the LCSSA pass.
---
Diffs of the changes: (+12 -12)
CloneFunction.cpp | 24 ++++++++++++------------
1 files changed, 12 insertions(+), 12 deletions(-)
Index: llvm/lib/Transforms/Utils/CloneFunction.cpp
diff -u llvm/lib/Transforms/Utils/CloneFunction.cpp:1.39
llvm/lib/Transforms/Utils/CloneFunction.cpp:1.40
--- llvm/lib/Transforms/Utils/CloneFunction.cpp:1.39 Tue Jan 30 17:46:24 2007
+++ llvm/lib/Transforms/Utils/CloneFunction.cpp Thu Feb 1 12:48:38 2007
@@ -431,18 +431,12 @@
PN->eraseFromParent();
++OldI;
}
- } else if (PN->getNumIncomingValues() == 1) {
- BasicBlock::iterator I = NewBB->begin();
- BasicBlock::const_iterator OldI = OldBB->begin();
- while ((PN = dyn_cast<PHINode>(I++))) {
- Value *NV = PN->getIncomingValue(0);
- PN->replaceAllUsesWith(NV);
- assert(ValueMap[OldI] == PN && "ValueMap mismatch");
- ValueMap[OldI] = NV;
- PN->eraseFromParent();
- ++OldI;
- }
}
+ // NOTE: We cannot eliminate single entry phi nodes here, because of
+ // ValueMap. Single entry phi nodes can have multiple ValueMap entries
+ // pointing at them. Thus, deleting one would require scanning the
ValueMap
+ // to update any entries in it that would require that. This would be
+ // really slow.
}
// Now that the inlined function body has been fully constructed, go through
@@ -454,8 +448,14 @@
BranchInst *BI = dyn_cast<BranchInst>(I->getTerminator());
if (!BI || BI->isConditional()) { ++I; continue; }
+ // Note that we can't eliminate uncond branches if the destination has
+ // single-entry PHI nodes. Eliminating the single-entry phi nodes would
+ // require scanning the ValueMap to update any entries that point to the
phi
+ // node.
BasicBlock *Dest = BI->getSuccessor(0);
- if (!Dest->getSinglePredecessor()) { ++I; continue; }
+ if (!Dest->getSinglePredecessor() || isa<PHINode>(Dest->begin())) {
+ ++I; continue;
+ }
// We know all single-entry PHI nodes in the inlined function have been
// removed, so we just need to splice the blocks.
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