aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Transforms/Scalar/DeadStoreElimination.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Transforms/Scalar/DeadStoreElimination.cpp')
-rw-r--r--lib/Transforms/Scalar/DeadStoreElimination.cpp60
1 files changed, 29 insertions, 31 deletions
diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp
index c2ce1d5..cb8981b 100644
--- a/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -23,6 +23,7 @@
#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
@@ -33,7 +34,7 @@
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
@@ -78,7 +79,8 @@ namespace {
bool HandleFree(CallInst *F);
bool handleEndBlock(BasicBlock &BB);
void RemoveAccessedObjects(const AliasAnalysis::Location &LoadedLoc,
- SmallSetVector<Value*, 16> &DeadStackObjects);
+ SmallSetVector<Value *, 16> &DeadStackObjects,
+ const DataLayout &DL);
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesCFG();
@@ -194,18 +196,12 @@ static bool hasMemoryWrite(Instruction *I, const TargetLibraryInfo *TLI) {
/// describe the memory operations for this instruction.
static AliasAnalysis::Location
getLocForWrite(Instruction *Inst, AliasAnalysis &AA) {
- const DataLayout *DL = AA.getDataLayout();
if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
return AA.getLocation(SI);
if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(Inst)) {
// memcpy/memmove/memset.
AliasAnalysis::Location Loc = AA.getLocationForDest(MI);
- // If we don't have target data around, an unknown size in Location means
- // that we should use the size of the pointee type. This isn't valid for
- // memset/memcpy, which writes more than an i8.
- if (Loc.Size == AliasAnalysis::UnknownSize && DL == nullptr)
- return AliasAnalysis::Location();
return Loc;
}
@@ -215,11 +211,6 @@ getLocForWrite(Instruction *Inst, AliasAnalysis &AA) {
switch (II->getIntrinsicID()) {
default: return AliasAnalysis::Location(); // Unhandled intrinsic.
case Intrinsic::init_trampoline:
- // If we don't have target data around, an unknown size in Location means
- // that we should use the size of the pointee type. This isn't valid for
- // init.trampoline, which writes more than an i8.
- if (!DL) return AliasAnalysis::Location();
-
// FIXME: We don't know the size of the trampoline, so we can't really
// handle it here.
return AliasAnalysis::Location(II->getArgOperand(0));
@@ -321,9 +312,10 @@ static Value *getStoredPointerOperand(Instruction *I) {
return CS.getArgument(0);
}
-static uint64_t getPointerSize(const Value *V, AliasAnalysis &AA) {
+static uint64_t getPointerSize(const Value *V, const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
uint64_t Size;
- if (getObjectSize(V, Size, AA.getDataLayout(), AA.getTargetLibraryInfo()))
+ if (getObjectSize(V, Size, DL, TLI))
return Size;
return AliasAnalysis::UnknownSize;
}
@@ -343,10 +335,9 @@ namespace {
/// overwritten by 'Later', or 'OverwriteUnknown' if nothing can be determined
static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
const AliasAnalysis::Location &Earlier,
- AliasAnalysis &AA,
- int64_t &EarlierOff,
- int64_t &LaterOff) {
- const DataLayout *DL = AA.getDataLayout();
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI,
+ int64_t &EarlierOff, int64_t &LaterOff) {
const Value *P1 = Earlier.Ptr->stripPointerCasts();
const Value *P2 = Later.Ptr->stripPointerCasts();
@@ -367,7 +358,7 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
// Otherwise, we have to have size information, and the later store has to be
// larger than the earlier one.
if (Later.Size == AliasAnalysis::UnknownSize ||
- Earlier.Size == AliasAnalysis::UnknownSize || DL == nullptr)
+ Earlier.Size == AliasAnalysis::UnknownSize)
return OverwriteUnknown;
// Check to see if the later store is to the entire object (either a global,
@@ -382,7 +373,7 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
return OverwriteUnknown;
// If the "Later" store is to a recognizable object, get its size.
- uint64_t ObjectSize = getPointerSize(UO2, AA);
+ uint64_t ObjectSize = getPointerSize(UO2, DL, TLI);
if (ObjectSize != AliasAnalysis::UnknownSize)
if (ObjectSize == Later.Size && ObjectSize >= Earlier.Size)
return OverwriteComplete;
@@ -560,8 +551,10 @@ bool DSE::runOnBasicBlock(BasicBlock &BB) {
if (isRemovable(DepWrite) &&
!isPossibleSelfRead(Inst, Loc, DepWrite, *AA)) {
int64_t InstWriteOffset, DepWriteOffset;
- OverwriteResult OR = isOverwrite(Loc, DepLoc, *AA,
- DepWriteOffset, InstWriteOffset);
+ const DataLayout &DL = BB.getModule()->getDataLayout();
+ OverwriteResult OR =
+ isOverwrite(Loc, DepLoc, DL, AA->getTargetLibraryInfo(),
+ DepWriteOffset, InstWriteOffset);
if (OR == OverwriteComplete) {
DEBUG(dbgs() << "DSE: Remove Dead Store:\n DEAD: "
<< *DepWrite << "\n KILLER: " << *Inst << '\n');
@@ -655,6 +648,7 @@ bool DSE::HandleFree(CallInst *F) {
AliasAnalysis::Location Loc = AliasAnalysis::Location(F->getOperand(0));
SmallVector<BasicBlock *, 16> Blocks;
Blocks.push_back(F->getParent());
+ const DataLayout &DL = F->getModule()->getDataLayout();
while (!Blocks.empty()) {
BasicBlock *BB = Blocks.pop_back_val();
@@ -668,7 +662,7 @@ bool DSE::HandleFree(CallInst *F) {
break;
Value *DepPointer =
- GetUnderlyingObject(getStoredPointerOperand(Dependency));
+ GetUnderlyingObject(getStoredPointerOperand(Dependency), DL);
// Check for aliasing.
if (!AA->isMustAlias(F->getArgOperand(0), DepPointer))
@@ -728,6 +722,8 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
if (AI->hasByValOrInAllocaAttr())
DeadStackObjects.insert(AI);
+ const DataLayout &DL = BB.getModule()->getDataLayout();
+
// Scan the basic block backwards
for (BasicBlock::iterator BBI = BB.end(); BBI != BB.begin(); ){
--BBI;
@@ -736,7 +732,7 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
if (hasMemoryWrite(BBI, TLI) && isRemovable(BBI)) {
// See through pointer-to-pointer bitcasts
SmallVector<Value *, 4> Pointers;
- GetUnderlyingObjects(getStoredPointerOperand(BBI), Pointers);
+ GetUnderlyingObjects(getStoredPointerOperand(BBI), Pointers, DL);
// Stores to stack values are valid candidates for removal.
bool AllDead = true;
@@ -799,8 +795,8 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
// the call is live.
DeadStackObjects.remove_if([&](Value *I) {
// See if the call site touches the value.
- AliasAnalysis::ModRefResult A =
- AA->getModRefInfo(CS, I, getPointerSize(I, *AA));
+ AliasAnalysis::ModRefResult A = AA->getModRefInfo(
+ CS, I, getPointerSize(I, DL, AA->getTargetLibraryInfo()));
return A == AliasAnalysis::ModRef || A == AliasAnalysis::Ref;
});
@@ -835,7 +831,7 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
// Remove any allocas from the DeadPointer set that are loaded, as this
// makes any stores above the access live.
- RemoveAccessedObjects(LoadedLoc, DeadStackObjects);
+ RemoveAccessedObjects(LoadedLoc, DeadStackObjects, DL);
// If all of the allocas were clobbered by the access then we're not going
// to find anything else to process.
@@ -850,8 +846,9 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
/// of the stack objects in the DeadStackObjects set. If so, they become live
/// because the location is being loaded.
void DSE::RemoveAccessedObjects(const AliasAnalysis::Location &LoadedLoc,
- SmallSetVector<Value*, 16> &DeadStackObjects) {
- const Value *UnderlyingPointer = GetUnderlyingObject(LoadedLoc.Ptr);
+ SmallSetVector<Value *, 16> &DeadStackObjects,
+ const DataLayout &DL) {
+ const Value *UnderlyingPointer = GetUnderlyingObject(LoadedLoc.Ptr, DL);
// A constant can't be in the dead pointer set.
if (isa<Constant>(UnderlyingPointer))
@@ -867,7 +864,8 @@ void DSE::RemoveAccessedObjects(const AliasAnalysis::Location &LoadedLoc,
// Remove objects that could alias LoadedLoc.
DeadStackObjects.remove_if([&](Value *I) {
// See if the loaded location could alias the stack location.
- AliasAnalysis::Location StackLoc(I, getPointerSize(I, *AA));
+ AliasAnalysis::Location StackLoc(
+ I, getPointerSize(I, DL, AA->getTargetLibraryInfo()));
return !AA->isNoAlias(StackLoc, LoadedLoc);
});
}
generated by cgit v1.1 at 2024-12-22 11:18:39 +0000