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authordim <dim@FreeBSD.org>2012-12-02 13:10:19 +0000
committerdim <dim@FreeBSD.org>2012-12-02 13:10:19 +0000
commit6de2c08bc400b4aca9fb46684e8bdb56eed9b09f (patch)
tree32b4679ab4b8f28e5228daafc65e9dc436935353 /lib/Transforms/Utils/LCSSA.cpp
parent4dc93743c9d40c29c0a3bec2aae328cac0d289e8 (diff)
downloadFreeBSD-src-6de2c08bc400b4aca9fb46684e8bdb56eed9b09f.zip
FreeBSD-src-6de2c08bc400b4aca9fb46684e8bdb56eed9b09f.tar.gz
Vendor import of llvm release_32 branch r168974 (effectively, 3.2 RC2):
http://llvm.org/svn/llvm-project/llvm/branches/release_32@168974
Diffstat (limited to 'lib/Transforms/Utils/LCSSA.cpp')
-rw-r--r--lib/Transforms/Utils/LCSSA.cpp15
1 files changed, 14 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp
index b654111..5e05c83 100644
--- a/lib/Transforms/Utils/LCSSA.cpp
+++ b/lib/Transforms/Utils/LCSSA.cpp
@@ -53,6 +53,8 @@ namespace {
// Cached analysis information for the current function.
DominatorTree *DT;
+ LoopInfo *LI;
+ ScalarEvolution *SE;
std::vector<BasicBlock*> LoopBlocks;
PredIteratorCache PredCache;
Loop *L;
@@ -117,6 +119,8 @@ bool LCSSA::runOnLoop(Loop *TheLoop, LPPassManager &LPM) {
L = TheLoop;
DT = &getAnalysis<DominatorTree>();
+ LI = &getAnalysis<LoopInfo>();
+ SE = getAnalysisIfAvailable<ScalarEvolution>();
// Get the set of exiting blocks.
SmallVector<BasicBlock*, 8> ExitBlocks;
@@ -156,6 +160,12 @@ bool LCSSA::runOnLoop(Loop *TheLoop, LPPassManager &LPM) {
MadeChange |= ProcessInstruction(I, ExitBlocks);
}
}
+
+ // If we modified the code, remove any caches about the loop from SCEV to
+ // avoid dangling entries.
+ // FIXME: This is a big hammer, can we clear the cache more selectively?
+ if (SE && MadeChange)
+ SE->forgetLoop(L);
assert(L->isLCSSAForm(*DT));
PredCache.clear();
@@ -245,7 +255,7 @@ bool LCSSA::ProcessInstruction(Instruction *Inst,
// Remember that this phi makes the value alive in this block.
SSAUpdate.AddAvailableValue(ExitBB, PN);
}
-
+
// Rewrite all uses outside the loop in terms of the new PHIs we just
// inserted.
for (unsigned i = 0, e = UsesToRewrite.size(); i != e; ++i) {
@@ -260,6 +270,9 @@ bool LCSSA::ProcessInstruction(Instruction *Inst,
if (isa<PHINode>(UserBB->begin()) &&
isExitBlock(UserBB, ExitBlocks)) {
+ // Tell the VHs that the uses changed. This updates SCEV's caches.
+ if (UsesToRewrite[i]->get()->hasValueHandle())
+ ValueHandleBase::ValueIsRAUWd(*UsesToRewrite[i], UserBB->begin());
UsesToRewrite[i]->set(UserBB->begin());
continue;
}
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