[llvm-commits] [llvm] r37966 - /llvm/trunk/lib/Transforms/Scalar/LoopRotation.cpp
Nick Lewycky
nicholas at mxc.ca
Sat Jul 7 09:23:34 PDT 2007
Author: nicholas
Date: Sat Jul 7 11:23:34 2007
New Revision: 37966
URL: http://llvm.org/viewvc/llvm-project?rev=37966&view=rev
Log:
Back out Devang's fix for PR1320 because it causes PR1542.
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopRotation.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/LoopRotation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopRotation.cpp?rev=37966&r1=37965&r2=37966&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopRotation.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopRotation.cpp Sat Jul 7 11:23:34 2007
@@ -18,10 +18,7 @@
#include "llvm/Instructions.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/Dominators.h"
-#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/Statistic.h"
@@ -58,17 +55,6 @@
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequiredID(LCSSAID);
AU.addPreservedID(LCSSAID);
- AU.addPreserved<ScalarEvolution>();
- AU.addPreserved<LoopInfo>();
- AU.addRequiredID(LoopSimplifyID);
- AU.addPreservedID(LoopSimplifyID);
- AU.addPreserved<DominatorTree>();
- // Request DominanceFrontier now, even though Loop Rotate does
- // not use it. This allows Pass Manager to schedule Dominance
- // Frontier early enough such that one LPPassManager can handle
- // loop rotate as well as licm pass.
- AU.addRequired<DominanceFrontier>();
- AU.addPreserved<DominanceFrontier>();
}
// Helper functions
@@ -104,7 +90,7 @@
BasicBlock *OrigLatch;
BasicBlock *NewHeader;
BasicBlock *Exit;
- LPPassManager *LPM_Ptr;
+
SmallVector<RenameData, MAX_HEADER_SIZE> LoopHeaderInfo;
};
@@ -120,7 +106,6 @@
bool RotatedOneLoop = false;
initialize();
- LPM_Ptr = &LPM;
// One loop can be rotated multiple times.
while (rotateLoop(Lp,LPM)) {
@@ -167,13 +152,6 @@
if (ExitBlocks.size() > 1)
return false;
- // Check size of original header and reject
- // loop if it is very big.
- if (OrigHeader->getInstList().size() > MAX_HEADER_SIZE)
- return false;
-
- // Now, this loop is suitable for rotation.
-
// Find new Loop header. NewHeader is a Header's one and only successor
// that is inside loop. Header's other successor is out side the
// loop. Otherwise loop is not suitable for rotation.
@@ -185,6 +163,13 @@
assert(L->contains(NewHeader) && !L->contains(Exit) &&
"Unable to determine loop header and exit blocks");
+ // Check size of original header and reject
+ // loop if it is very big.
+ if (OrigHeader->getInstList().size() > MAX_HEADER_SIZE)
+ return false;
+
+ // Now, this loop is suitable for rotation.
+
// Copy PHI nodes and other instructions from original header
// into original pre-header. Unlike original header, original pre-header is
// not a member of loop.
@@ -329,24 +314,18 @@
U->replaceUsesOfWith(OldPhi, NewPhi);
continue;
}
-
+
// Used inside Exit Block. Since we are in LCSSA form, U must be PHINode.
- if (U->getParent() == Exit) {
- assert (isa<PHINode>(U) && "Use in Exit Block that is not PHINode");
-
- PHINode *UPhi = cast<PHINode>(U);
- // UPhi already has one incoming argument from original header.
- // Add second incoming argument from new Pre header.
- UPhi->addIncoming(ILoopHeaderInfo.PreHeader, OrigPreHeader);
- } else {
- // Used outside Exit block. Create a new PHI node from exit block
- // to receive value from ne new header ane pre header.
- PHINode *PN = new PHINode(U->getType(), U->getName());
- PN->addIncoming(ILoopHeaderInfo.PreHeader, OrigPreHeader);
- PN->addIncoming(OldPhi, OrigHeader);
- Exit->getInstList().push_front(PN);
- U->replaceUsesOfWith(OldPhi, PN);
- }
+ assert (U->getParent() == Exit
+ && "Need to propagate new PHI into Exit blocks");
+ assert (isa<PHINode>(U) && "Use in Exit Block that is not PHINode");
+
+ PHINode *UPhi = cast<PHINode>(U);
+
+ // UPhi already has one incoming argument from original header.
+ // Add second incoming argument from new Pre header.
+
+ UPhi->addIncoming(ILoopHeaderInfo.PreHeader, OrigPreHeader);
}
}
@@ -482,63 +461,10 @@
"Expected only one incoming value from Original PreHeader");
}
- SplitEdge(L->getLoopLatch(), Exit, this);
-
- if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) {
- DT->addNewBlock(NewPreHeader, OrigPreHeader);
- DT->changeImmediateDominator(L->getHeader(), NewPreHeader);
- DT->changeImmediateDominator(Exit, OrigPreHeader);
- for (Loop::block_iterator BI = L->block_begin(), BE = L->block_end();
- BI != BE; ++BI) {
- BasicBlock *B = *BI;
- if (L->getHeader() != B) {
- DomTreeNode *Node = DT->getNode(B);
- if (Node && Node->getBlock() == OrigHeader)
- DT->changeImmediateDominator(*BI, L->getHeader());
- }
- }
- DT->changeImmediateDominator(OrigHeader, OrigLatch);
- }
-
- if(DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>()) {
-
- // New Preheader's dominance frontier is same as original preheader.
- DominanceFrontier::iterator DFI = DF->find(OrigPreHeader);
- if (DFI != DF->end()) {
- DominanceFrontier::DomSetType NPHSet(DFI->second), NHSet(DFI->second);
- // NPHSet.insert(DFI->second.begin(), DFI->second.end(), NPHSet.begin());
- DF->addBasicBlock(NewPreHeader, NPHSet);
-
- DominanceFrontier::iterator DHI = DF->find(L->getHeader());
- if (DHI != DF->end()) {
- DominanceFrontier::DomSetType DHSet = DHI->second;
- DHSet.clear();
- DHSet.insert(DFI->second.begin(), DFI->second.end());
- } else {
- DominanceFrontier::DomSetType NHSet(DFI->second);
- // NHSet.insert(DFI->second.begin(), DFI->second.end(), NHSet.begin());
- DF->addBasicBlock(L->getHeader(), NHSet);
- }
- }
-
- // Original header no longer dominates Exit
- DFI = DF->find(OrigHeader);
- if (DFI != DF->end()) {
- for (succ_iterator SI = succ_begin(Exit), SE = succ_end(Exit);
- SI != SE; ++SI) {
- BasicBlock *Succ = *SI;
- DominanceFrontier::DomSetType::iterator DSI = DFI->second.find(Succ);
- if (DSI != DFI->second.end())
- DFI->second.erase(DSI);
- }
- }
- }
-
assert (NewHeader && L->getHeader() == NewHeader
&& "Invalid loop header after loop rotation");
assert (NewPreHeader && L->getLoopPreheader() == NewPreHeader
&& "Invalid loop preheader after loop rotation");
assert (L->getLoopLatch()
&& "Invalid loop latch after loop rotation");
-
}
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