From cbb70ce070d220642b038ea101d9c0f9fbf860d6 Mon Sep 17 00:00:00 2001
From: dim <dim@FreeBSD.org>
Date: Sun, 20 Feb 2011 12:57:14 +0000
Subject: Vendor import of llvm trunk r126079:
http://llvm.org/svn/llvm-project/llvm/trunk@126079
---
lib/Transforms/Scalar/LoopUnswitch.cpp | 60 +++++++++++++++-------------------
1 file changed, 27 insertions(+), 33 deletions(-)
(limited to 'lib/Transforms/Scalar/LoopUnswitch.cpp')
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index 9afe428..b4e3d31 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -32,12 +32,12 @@
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
-#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InlineCost.h"
#include "llvm/Analysis/InstructionSimplify.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/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -93,7 +93,9 @@ namespace {
explicit LoopUnswitch(bool Os = false) :
LoopPass(ID), OptimizeForSize(Os), redoLoop(false),
currentLoop(NULL), DT(NULL), loopHeader(NULL),
- loopPreheader(NULL) {}
+ loopPreheader(NULL) {
+ initializeLoopUnswitchPass(*PassRegistry::getPassRegistry());
+ }
bool runOnLoop(Loop *L, LPPassManager &LPM);
bool processCurrentLoop();
@@ -109,6 +111,7 @@ namespace {
AU.addRequiredID(LCSSAID);
AU.addPreservedID(LCSSAID);
AU.addPreserved<DominatorTree>();
+ AU.addPreserved<ScalarEvolution>();
}
private:
@@ -158,7 +161,13 @@ namespace {
};
}
char LoopUnswitch::ID = 0;
-INITIALIZE_PASS(LoopUnswitch, "loop-unswitch", "Unswitch loops", false, false);
+INITIALIZE_PASS_BEGIN(LoopUnswitch, "loop-unswitch", "Unswitch loops",
+ false, false)
+INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
+INITIALIZE_PASS_DEPENDENCY(LoopInfo)
+INITIALIZE_PASS_DEPENDENCY(LCSSA)
+INITIALIZE_PASS_END(LoopUnswitch, "loop-unswitch", "Unswitch loops",
+ false, false)
Pass *llvm::createLoopUnswitchPass(bool Os) {
return new LoopUnswitch(Os);
@@ -450,22 +459,9 @@ bool LoopUnswitch::UnswitchIfProfitable(Value *LoopCond, Constant *Val) {
return true;
}
-// RemapInstruction - Convert the instruction operands from referencing the
-// current values into those specified by VMap.
-//
-static inline void RemapInstruction(Instruction *I,
- ValueMap<const Value *, Value*> &VMap) {
- for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
- Value *Op = I->getOperand(op);
- ValueMap<const Value *, Value*>::iterator It = VMap.find(Op);
- if (It != VMap.end()) Op = It->second;
- I->setOperand(op, Op);
- }
-}
-
/// CloneLoop - Recursively clone the specified loop and all of its children,
/// mapping the blocks with the specified map.
-static Loop *CloneLoop(Loop *L, Loop *PL, ValueMap<const Value*, Value*> &VM,
+static Loop *CloneLoop(Loop *L, Loop *PL, ValueToValueMapTy &VM,
LoopInfo *LI, LPPassManager *LPM) {
Loop *New = new Loop();
LPM->insertLoop(New, PL);
@@ -580,6 +576,9 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
<< " blocks] in Function " << F->getName()
<< " when '" << *Val << "' == " << *LIC << "\n");
+ if (ScalarEvolution *SE = getAnalysisIfAvailable<ScalarEvolution>())
+ SE->forgetLoop(L);
+
LoopBlocks.clear();
NewBlocks.clear();
@@ -609,7 +608,7 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
// the loop preheader and exit blocks), keeping track of the mapping between
// the instructions and blocks.
NewBlocks.reserve(LoopBlocks.size());
- ValueMap<const Value*, Value*> VMap;
+ ValueToValueMapTy VMap;
for (unsigned i = 0, e = LoopBlocks.size(); i != e; ++i) {
BasicBlock *NewBB = CloneBasicBlock(LoopBlocks[i], VMap, ".us", F);
NewBlocks.push_back(NewBB);
@@ -647,7 +646,7 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
for (BasicBlock::iterator I = ExitSucc->begin(); isa<PHINode>(I); ++I) {
PN = cast<PHINode>(I);
Value *V = PN->getIncomingValueForBlock(ExitBlocks[i]);
- ValueMap<const Value *, Value*>::iterator It = VMap.find(V);
+ ValueToValueMapTy::iterator It = VMap.find(V);
if (It != VMap.end()) V = It->second;
PN->addIncoming(V, NewExit);
}
@@ -657,7 +656,7 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
for (unsigned i = 0, e = NewBlocks.size(); i != e; ++i)
for (BasicBlock::iterator I = NewBlocks[i]->begin(),
E = NewBlocks[i]->end(); I != E; ++I)
- RemapInstruction(I, VMap);
+ RemapInstruction(I, VMap,RF_NoModuleLevelChanges|RF_IgnoreMissingEntries);
// Rewrite the original preheader to select between versions of the loop.
BranchInst *OldBR = cast<BranchInst>(loopPreheader->getTerminator());
@@ -961,13 +960,7 @@ void LoopUnswitch::SimplifyCode(std::vector<Instruction*> &Worklist, Loop *L) {
while (!Worklist.empty()) {
Instruction *I = Worklist.back();
Worklist.pop_back();
-
- // Simple constant folding.
- if (Constant *C = ConstantFoldInstruction(I)) {
- ReplaceUsesOfWith(I, C, Worklist, L, LPM);
- continue;
- }
-
+
// Simple DCE.
if (isInstructionTriviallyDead(I)) {
DEBUG(dbgs() << "Remove dead instruction '" << *I);
@@ -982,15 +975,16 @@ void LoopUnswitch::SimplifyCode(std::vector<Instruction*> &Worklist, Loop *L) {
++NumSimplify;
continue;
}
-
+
// See if instruction simplification can hack this up. This is common for
// things like "select false, X, Y" after unswitching made the condition be
// 'false'.
- if (Value *V = SimplifyInstruction(I)) {
- ReplaceUsesOfWith(I, V, Worklist, L, LPM);
- continue;
- }
-
+ if (Value *V = SimplifyInstruction(I, 0, DT))
+ if (LI->replacementPreservesLCSSAForm(I, V)) {
+ ReplaceUsesOfWith(I, V, Worklist, L, LPM);
+ continue;
+ }
+
// Special case hacks that appear commonly in unswitched code.
if (BranchInst *BI = dyn_cast<BranchInst>(I)) {
if (BI->isUnconditional()) {
--
cgit v1.1