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authorrdivacky <rdivacky@FreeBSD.org>2009-10-15 16:26:17 +0000
committerrdivacky <rdivacky@FreeBSD.org>2009-10-15 16:26:17 +0000
commit1adacceba9c9ee0f16e54388e56c9a249b296f75 (patch)
treefbc3e1401bc9623b861166be5940c750f5ca52da /lib/Analysis
parent5effb5c6a161c1bdbdd9585dfdc97a6105e3df66 (diff)
downloadFreeBSD-src-1adacceba9c9ee0f16e54388e56c9a249b296f75.zip
FreeBSD-src-1adacceba9c9ee0f16e54388e56c9a249b296f75.tar.gz
Delete all stale files.
Diffstat (limited to 'lib/Analysis')
-rw-r--r--lib/Analysis/LoopVR.cpp291
1 files changed, 0 insertions, 291 deletions
diff --git a/lib/Analysis/LoopVR.cpp b/lib/Analysis/LoopVR.cpp
deleted file mode 100644
index ae715ac..0000000
--- a/lib/Analysis/LoopVR.cpp
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@@ -1,291 +0,0 @@
-//===- LoopVR.cpp - Value Range analysis driven by loop information -------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// FIXME: What does this do?
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "loopvr"
-#include "llvm/Analysis/LoopVR.h"
-#include "llvm/Constants.h"
-#include "llvm/Instructions.h"
-#include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/Assembly/Writer.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-char LoopVR::ID = 0;
-static RegisterPass<LoopVR> X("loopvr", "Loop Value Ranges", false, true);
-
-/// getRange - determine the range for a particular SCEV within a given Loop
-ConstantRange LoopVR::getRange(const SCEV* S, Loop *L, ScalarEvolution &SE) {
- const SCEV* T = SE.getBackedgeTakenCount(L);
- if (isa<SCEVCouldNotCompute>(T))
- return ConstantRange(cast<IntegerType>(S->getType())->getBitWidth(), true);
-
- T = SE.getTruncateOrZeroExtend(T, S->getType());
- return getRange(S, T, SE);
-}
-
-/// getRange - determine the range for a particular SCEV with a given trip count
-ConstantRange LoopVR::getRange(const SCEV* S, const SCEV* T, ScalarEvolution &SE){
-
- if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
- return ConstantRange(C->getValue()->getValue());
-
- ConstantRange FullSet(cast<IntegerType>(S->getType())->getBitWidth(), true);
-
- // {x,+,y,+,...z}. We detect overflow by checking the size of the set after
- // summing the upper and lower.
- if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
- ConstantRange X = getRange(Add->getOperand(0), T, SE);
- if (X.isFullSet()) return FullSet;
- for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i) {
- ConstantRange Y = getRange(Add->getOperand(i), T, SE);
- if (Y.isFullSet()) return FullSet;
-
- APInt Spread_X = X.getSetSize(), Spread_Y = Y.getSetSize();
- APInt NewLower = X.getLower() + Y.getLower();
- APInt NewUpper = X.getUpper() + Y.getUpper() - 1;
- if (NewLower == NewUpper)
- return FullSet;
-
- X = ConstantRange(NewLower, NewUpper);
- if (X.getSetSize().ult(Spread_X) || X.getSetSize().ult(Spread_Y))
- return FullSet; // we've wrapped, therefore, full set.
- }
- return X;
- }
-
- // {x,*,y,*,...,z}. In order to detect overflow, we use k*bitwidth where
- // k is the number of terms being multiplied.
- if (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(S)) {
- ConstantRange X = getRange(Mul->getOperand(0), T, SE);
- if (X.isFullSet()) return FullSet;
-
- const IntegerType *Ty = IntegerType::get(X.getBitWidth());
- const IntegerType *ExTy = IntegerType::get(X.getBitWidth() *
- Mul->getNumOperands());
- ConstantRange XExt = X.zeroExtend(ExTy->getBitWidth());
-
- for (unsigned i = 1, e = Mul->getNumOperands(); i != e; ++i) {
- ConstantRange Y = getRange(Mul->getOperand(i), T, SE);
- if (Y.isFullSet()) return FullSet;
-
- ConstantRange YExt = Y.zeroExtend(ExTy->getBitWidth());
- XExt = ConstantRange(XExt.getLower() * YExt.getLower(),
- ((XExt.getUpper()-1) * (YExt.getUpper()-1)) + 1);
- }
- return XExt.truncate(Ty->getBitWidth());
- }
-
- // X smax Y smax ... Z is: range(smax(X_smin, Y_smin, ..., Z_smin),
- // smax(X_smax, Y_smax, ..., Z_smax))
- // It doesn't matter if one of the SCEVs has FullSet because we're taking
- // a maximum of the minimums across all of them.
- if (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(S)) {
- ConstantRange X = getRange(SMax->getOperand(0), T, SE);
- if (X.isFullSet()) return FullSet;
-
- APInt smin = X.getSignedMin(), smax = X.getSignedMax();
- for (unsigned i = 1, e = SMax->getNumOperands(); i != e; ++i) {
- ConstantRange Y = getRange(SMax->getOperand(i), T, SE);
- smin = APIntOps::smax(smin, Y.getSignedMin());
- smax = APIntOps::smax(smax, Y.getSignedMax());
- }
- if (smax + 1 == smin) return FullSet;
- return ConstantRange(smin, smax + 1);
- }
-
- // X umax Y umax ... Z is: range(umax(X_umin, Y_umin, ..., Z_umin),
- // umax(X_umax, Y_umax, ..., Z_umax))
- // It doesn't matter if one of the SCEVs has FullSet because we're taking
- // a maximum of the minimums across all of them.
- if (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(S)) {
- ConstantRange X = getRange(UMax->getOperand(0), T, SE);
- if (X.isFullSet()) return FullSet;
-
- APInt umin = X.getUnsignedMin(), umax = X.getUnsignedMax();
- for (unsigned i = 1, e = UMax->getNumOperands(); i != e; ++i) {
- ConstantRange Y = getRange(UMax->getOperand(i), T, SE);
- umin = APIntOps::umax(umin, Y.getUnsignedMin());
- umax = APIntOps::umax(umax, Y.getUnsignedMax());
- }
- if (umax + 1 == umin) return FullSet;
- return ConstantRange(umin, umax + 1);
- }
-
- // L udiv R. Luckily, there's only ever 2 sides to a udiv.
- if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
- ConstantRange L = getRange(UDiv->getLHS(), T, SE);
- ConstantRange R = getRange(UDiv->getRHS(), T, SE);
- if (L.isFullSet() && R.isFullSet()) return FullSet;
-
- if (R.getUnsignedMax() == 0) {
- // RHS must be single-element zero. Return an empty set.
- return ConstantRange(R.getBitWidth(), false);
- }
-
- APInt Lower = L.getUnsignedMin().udiv(R.getUnsignedMax());
-
- APInt Upper;
-
- if (R.getUnsignedMin() == 0) {
- // Just because it contains zero, doesn't mean it will also contain one.
- // Use maximalIntersectWith to get the right behaviour.
- ConstantRange NotZero(APInt(L.getBitWidth(), 1),
- APInt::getNullValue(L.getBitWidth()));
- R = R.maximalIntersectWith(NotZero);
- }
-
- // But, the maximal intersection might still include zero. If it does, then
- // we know it also included one.
- if (R.contains(APInt::getNullValue(L.getBitWidth())))
- Upper = L.getUnsignedMax();
- else
- Upper = L.getUnsignedMax().udiv(R.getUnsignedMin());
-
- return ConstantRange(Lower, Upper);
- }
-
- // ConstantRange already implements the cast operators.
-
- if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
- T = SE.getTruncateOrZeroExtend(T, ZExt->getOperand()->getType());
- ConstantRange X = getRange(ZExt->getOperand(), T, SE);
- return X.zeroExtend(cast<IntegerType>(ZExt->getType())->getBitWidth());
- }
-
- if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
- T = SE.getTruncateOrZeroExtend(T, SExt->getOperand()->getType());
- ConstantRange X = getRange(SExt->getOperand(), T, SE);
- return X.signExtend(cast<IntegerType>(SExt->getType())->getBitWidth());
- }
-
- if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
- T = SE.getTruncateOrZeroExtend(T, Trunc->getOperand()->getType());
- ConstantRange X = getRange(Trunc->getOperand(), T, SE);
- if (X.isFullSet()) return FullSet;
- return X.truncate(cast<IntegerType>(Trunc->getType())->getBitWidth());
- }
-
- if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
- const SCEVConstant *Trip = dyn_cast<SCEVConstant>(T);
- if (!Trip) return FullSet;
-
- if (AddRec->isAffine()) {
- const SCEV* StartHandle = AddRec->getStart();
- const SCEV* StepHandle = AddRec->getOperand(1);
-
- const SCEVConstant *Step = dyn_cast<SCEVConstant>(StepHandle);
- if (!Step) return FullSet;
-
- uint32_t ExWidth = 2 * Trip->getValue()->getBitWidth();
- APInt TripExt = Trip->getValue()->getValue(); TripExt.zext(ExWidth);
- APInt StepExt = Step->getValue()->getValue(); StepExt.zext(ExWidth);
- if ((TripExt * StepExt).ugt(APInt::getLowBitsSet(ExWidth, ExWidth >> 1)))
- return FullSet;
-
- const SCEV* EndHandle = SE.getAddExpr(StartHandle,
- SE.getMulExpr(T, StepHandle));
- const SCEVConstant *Start = dyn_cast<SCEVConstant>(StartHandle);
- const SCEVConstant *End = dyn_cast<SCEVConstant>(EndHandle);
- if (!Start || !End) return FullSet;
-
- const APInt &StartInt = Start->getValue()->getValue();
- const APInt &EndInt = End->getValue()->getValue();
- const APInt &StepInt = Step->getValue()->getValue();
-
- if (StepInt.isNegative()) {
- if (EndInt == StartInt + 1) return FullSet;
- return ConstantRange(EndInt, StartInt + 1);
- } else {
- if (StartInt == EndInt + 1) return FullSet;
- return ConstantRange(StartInt, EndInt + 1);
- }
- }
- }
-
- // TODO: non-affine addrec, udiv, SCEVUnknown (narrowed from elsewhere)?
-
- return FullSet;
-}
-
-bool LoopVR::runOnFunction(Function &F) { Map.clear(); return false; }
-
-void LoopVR::print(std::ostream &os, const Module *) const {
- raw_os_ostream OS(os);
- for (std::map<Value *, ConstantRange *>::const_iterator I = Map.begin(),
- E = Map.end(); I != E; ++I) {
- OS << *I->first << ": " << *I->second << '\n';
- }
-}
-
-void LoopVR::releaseMemory() {
- for (std::map<Value *, ConstantRange *>::iterator I = Map.begin(),
- E = Map.end(); I != E; ++I) {
- delete I->second;
- }
-
- Map.clear();
-}
-
-ConstantRange LoopVR::compute(Value *V) {
- if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return ConstantRange(CI->getValue());
-
- Instruction *I = dyn_cast<Instruction>(V);
- if (!I)
- return ConstantRange(cast<IntegerType>(V->getType())->getBitWidth(), false);
-
- LoopInfo &LI = getAnalysis<LoopInfo>();
-
- Loop *L = LI.getLoopFor(I->getParent());
- if (!L || L->isLoopInvariant(I))
- return ConstantRange(cast<IntegerType>(V->getType())->getBitWidth(), false);
-
- ScalarEvolution &SE = getAnalysis<ScalarEvolution>();
-
- const SCEV* S = SE.getSCEV(I);
- if (isa<SCEVUnknown>(S) || isa<SCEVCouldNotCompute>(S))
- return ConstantRange(cast<IntegerType>(V->getType())->getBitWidth(), false);
-
- return ConstantRange(getRange(S, L, SE));
-}
-
-ConstantRange LoopVR::get(Value *V) {
- std::map<Value *, ConstantRange *>::iterator I = Map.find(V);
- if (I == Map.end()) {
- ConstantRange *CR = new ConstantRange(compute(V));
- Map[V] = CR;
- return *CR;
- }
-
- return *I->second;
-}
-
-void LoopVR::remove(Value *V) {
- std::map<Value *, ConstantRange *>::iterator I = Map.find(V);
- if (I != Map.end()) {
- delete I->second;
- Map.erase(I);
- }
-}
-
-void LoopVR::narrow(Value *V, const ConstantRange &CR) {
- if (CR.isFullSet()) return;
-
- std::map<Value *, ConstantRange *>::iterator I = Map.find(V);
- if (I == Map.end())
- Map[V] = new ConstantRange(CR);
- else
- Map[V] = new ConstantRange(Map[V]->maximalIntersectWith(CR));
-}
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