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Convert LoopSimplify and LoopExtractor from FunctionPass to LoopPass.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82990 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman
2009-09-28 14:37:51 +00:00
parent 522ce97532
commit d84db11333
4 changed files with 91 additions and 149 deletions
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lib/Transforms/IPO/LoopExtractor.cpp
+40 -62
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@@ -20,7 +20,7 @@
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Transforms/Scalar.h"
@@ -33,23 +33,19 @@ using namespace llvm;
STATISTIC(NumExtracted, "Number of loops extracted");
namespace {
// FIXME: This is not a function pass, but the PassManager doesn't allow
// Module passes to require FunctionPasses, so we can't get loop info if we're
// not a function pass.
struct VISIBILITY_HIDDEN LoopExtractor : public FunctionPass {
struct VISIBILITY_HIDDEN LoopExtractor : public LoopPass {
static char ID; // Pass identification, replacement for typeid
unsigned NumLoops;
explicit LoopExtractor(unsigned numLoops = ~0)
: FunctionPass(&ID), NumLoops(numLoops) {}
: LoopPass(&ID), NumLoops(numLoops) {}
virtual bool runOnFunction(Function &F);
virtual bool runOnLoop(Loop *L, LPPassManager &LPM);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequiredID(BreakCriticalEdgesID);
AU.addRequiredID(LoopSimplifyID);
AU.addRequired<DominatorTree>();
AU.addRequired<LoopInfo>();
}
};
}
@@ -73,68 +69,50 @@ Y("loop-extract-single", "Extract at most one loop into a new function");
// createLoopExtractorPass - This pass extracts all natural loops from the
// program into a function if it can.
//
FunctionPass *llvm::createLoopExtractorPass() { return new LoopExtractor(); }
Pass *llvm::createLoopExtractorPass() { return new LoopExtractor(); }
bool LoopExtractor::runOnFunction(Function &F) {
LoopInfo &LI = getAnalysis<LoopInfo>();
// If this function has no loops, there is nothing to do.
if (LI.empty())
bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &LPM) {
// Only visit top-level loops.
if (L->getParentLoop())
return false;
DominatorTree &DT = getAnalysis<DominatorTree>();
bool Changed = false;
// If there is more than one top-level loop in this function, extract all of
// the loops.
bool Changed = false;
if (LI.end()-LI.begin() > 1) {
for (LoopInfo::iterator i = LI.begin(), e = LI.end(); i != e; ++i) {
if (NumLoops == 0) return Changed;
--NumLoops;
Changed |= ExtractLoop(DT, *i) != 0;
++NumExtracted;
}
} else {
// Otherwise there is exactly one top-level loop. If this function is more
// than a minimal wrapper around the loop, extract the loop.
Loop *TLL = *LI.begin();
bool ShouldExtractLoop = false;
// the loops. Otherwise there is exactly one top-level loop; in this case if
// this function is more than a minimal wrapper around the loop, extract
// the loop.
bool ShouldExtractLoop = false;
// Extract the loop if the entry block doesn't branch to the loop header.
TerminatorInst *EntryTI = F.getEntryBlock().getTerminator();
if (!isa<BranchInst>(EntryTI) ||
!cast<BranchInst>(EntryTI)->isUnconditional() ||
EntryTI->getSuccessor(0) != TLL->getHeader())
ShouldExtractLoop = true;
else {
// Check to see if any exits from the loop are more than just return
// blocks.
SmallVector<BasicBlock*, 8> ExitBlocks;
TLL->getExitBlocks(ExitBlocks);
for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
if (!isa<ReturnInst>(ExitBlocks[i]->getTerminator())) {
ShouldExtractLoop = true;
break;
}
}
if (ShouldExtractLoop) {
if (NumLoops == 0) return Changed;
--NumLoops;
Changed |= ExtractLoop(DT, TLL) != 0;
++NumExtracted;
} else {
// Okay, this function is a minimal container around the specified loop.
// If we extract the loop, we will continue to just keep extracting it
// infinitely... so don't extract it. However, if the loop contains any
// subloops, extract them.
for (Loop::iterator i = TLL->begin(), e = TLL->end(); i != e; ++i) {
if (NumLoops == 0) return Changed;
--NumLoops;
Changed |= ExtractLoop(DT, *i) != 0;
++NumExtracted;
// Extract the loop if the entry block doesn't branch to the loop header.
TerminatorInst *EntryTI =
L->getHeader()->getParent()->getEntryBlock().getTerminator();
if (!isa<BranchInst>(EntryTI) ||
!cast<BranchInst>(EntryTI)->isUnconditional() ||
EntryTI->getSuccessor(0) != L->getHeader())
ShouldExtractLoop = true;
else {
// Check to see if any exits from the loop are more than just return
// blocks.
SmallVector<BasicBlock*, 8> ExitBlocks;
L->getExitBlocks(ExitBlocks);
for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
if (!isa<ReturnInst>(ExitBlocks[i]->getTerminator())) {
ShouldExtractLoop = true;
break;
}
}
if (ShouldExtractLoop) {
if (NumLoops == 0) return Changed;
--NumLoops;
if (ExtractLoop(DT, L) != 0) {
Changed = true;
// After extraction, the loop is replaced by a function call, so
// we shouldn't try to run any more loop passes on it.
LPM.deleteLoopFromQueue(L);
}
++NumExtracted;
}
return Changed;
@@ -143,7 +121,7 @@ bool LoopExtractor::runOnFunction(Function &F) {
// createSingleLoopExtractorPass - This pass extracts one natural loop from the
// program into a function if it can. This is used by bugpoint.
//
FunctionPass *llvm::createSingleLoopExtractorPass() {
Pass *llvm::createSingleLoopExtractorPass() {
return new SingleLoopExtractor();
}