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-rw-r--r--lib/Transforms/Scalar/GVN.cpp133
1 files changed, 69 insertions, 64 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index e2c1eaf58e43f..1e0a22cb14b3e 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -38,7 +38,9 @@
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/PHITransAddr.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CallSite.h"
@@ -69,7 +71,6 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SSAUpdater.h"
#include "llvm/Transforms/Utils/VNCoercion.h"
#include <algorithm>
@@ -765,6 +766,15 @@ static Value *ConstructSSAForLoadSet(LoadInst *LI,
if (SSAUpdate.HasValueForBlock(BB))
continue;
+ // If the value is the load that we will be eliminating, and the block it's
+ // available in is the block that the load is in, then don't add it as
+ // SSAUpdater will resolve the value to the relevant phi which may let it
+ // avoid phi construction entirely if there's actually only one value.
+ if (BB == LI->getParent() &&
+ ((AV.AV.isSimpleValue() && AV.AV.getSimpleValue() == LI) ||
+ (AV.AV.isCoercedLoadValue() && AV.AV.getCoercedLoadValue() == LI)))
+ continue;
+
SSAUpdate.AddAvailableValue(BB, AV.MaterializeAdjustedValue(LI, gvn));
}
@@ -783,9 +793,10 @@ Value *AvailableValue::MaterializeAdjustedValue(LoadInst *LI,
if (Res->getType() != LoadTy) {
Res = getStoreValueForLoad(Res, Offset, LoadTy, InsertPt, DL);
- DEBUG(dbgs() << "GVN COERCED NONLOCAL VAL:\nOffset: " << Offset << " "
- << *getSimpleValue() << '\n'
- << *Res << '\n' << "\n\n\n");
+ LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL VAL:\nOffset: " << Offset
+ << " " << *getSimpleValue() << '\n'
+ << *Res << '\n'
+ << "\n\n\n");
}
} else if (isCoercedLoadValue()) {
LoadInst *Load = getCoercedLoadValue();
@@ -799,20 +810,21 @@ Value *AvailableValue::MaterializeAdjustedValue(LoadInst *LI,
// but then there all of the operations based on it would need to be
// rehashed. Just leave the dead load around.
gvn.getMemDep().removeInstruction(Load);
- DEBUG(dbgs() << "GVN COERCED NONLOCAL LOAD:\nOffset: " << Offset << " "
- << *getCoercedLoadValue() << '\n'
- << *Res << '\n'
- << "\n\n\n");
+ LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL LOAD:\nOffset: " << Offset
+ << " " << *getCoercedLoadValue() << '\n'
+ << *Res << '\n'
+ << "\n\n\n");
}
} else if (isMemIntrinValue()) {
Res = getMemInstValueForLoad(getMemIntrinValue(), Offset, LoadTy,
InsertPt, DL);
- DEBUG(dbgs() << "GVN COERCED NONLOCAL MEM INTRIN:\nOffset: " << Offset
- << " " << *getMemIntrinValue() << '\n'
- << *Res << '\n' << "\n\n\n");
+ LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL MEM INTRIN:\nOffset: " << Offset
+ << " " << *getMemIntrinValue() << '\n'
+ << *Res << '\n'
+ << "\n\n\n");
} else {
assert(isUndefValue() && "Should be UndefVal");
- DEBUG(dbgs() << "GVN COERCED NONLOCAL Undef:\n";);
+ LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL Undef:\n";);
return UndefValue::get(LoadTy);
}
assert(Res && "failed to materialize?");
@@ -825,7 +837,7 @@ static bool isLifetimeStart(const Instruction *Inst) {
return false;
}
-/// \brief Try to locate the three instruction involved in a missed
+/// Try to locate the three instruction involved in a missed
/// load-elimination case that is due to an intervening store.
static void reportMayClobberedLoad(LoadInst *LI, MemDepResult DepInfo,
DominatorTree *DT,
@@ -914,13 +926,11 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
}
}
// Nothing known about this clobber, have to be conservative
- DEBUG(
- // fast print dep, using operator<< on instruction is too slow.
- dbgs() << "GVN: load ";
- LI->printAsOperand(dbgs());
- Instruction *I = DepInfo.getInst();
- dbgs() << " is clobbered by " << *I << '\n';
- );
+ LLVM_DEBUG(
+ // fast print dep, using operator<< on instruction is too slow.
+ dbgs() << "GVN: load "; LI->printAsOperand(dbgs());
+ Instruction *I = DepInfo.getInst();
+ dbgs() << " is clobbered by " << *I << '\n';);
if (ORE->allowExtraAnalysis(DEBUG_TYPE))
reportMayClobberedLoad(LI, DepInfo, DT, ORE);
@@ -978,12 +988,10 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
}
// Unknown def - must be conservative
- DEBUG(
- // fast print dep, using operator<< on instruction is too slow.
- dbgs() << "GVN: load ";
- LI->printAsOperand(dbgs());
- dbgs() << " has unknown def " << *DepInst << '\n';
- );
+ LLVM_DEBUG(
+ // fast print dep, using operator<< on instruction is too slow.
+ dbgs() << "GVN: load "; LI->printAsOperand(dbgs());
+ dbgs() << " has unknown def " << *DepInst << '\n';);
return false;
}
@@ -1065,7 +1073,7 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// It is illegal to move the array access to any point above the guard,
// because if the index is out of bounds we should deoptimize rather than
// access the array.
- // Check that there is no guard in this block above our intruction.
+ // Check that there is no guard in this block above our instruction.
if (!IsSafeToSpeculativelyExecute) {
auto It = FirstImplicitControlFlowInsts.find(TmpBB);
if (It != FirstImplicitControlFlowInsts.end()) {
@@ -1113,9 +1121,9 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// If any predecessor block is an EH pad that does not allow non-PHI
// instructions before the terminator, we can't PRE the load.
if (Pred->getTerminator()->isEHPad()) {
- DEBUG(dbgs()
- << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD PREDECESSOR '"
- << Pred->getName() << "': " << *LI << '\n');
+ LLVM_DEBUG(
+ dbgs() << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD PREDECESSOR '"
+ << Pred->getName() << "': " << *LI << '\n');
return false;
}
@@ -1125,15 +1133,16 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
if (Pred->getTerminator()->getNumSuccessors() != 1) {
if (isa<IndirectBrInst>(Pred->getTerminator())) {
- DEBUG(dbgs() << "COULD NOT PRE LOAD BECAUSE OF INDBR CRITICAL EDGE '"
- << Pred->getName() << "': " << *LI << '\n');
+ LLVM_DEBUG(
+ dbgs() << "COULD NOT PRE LOAD BECAUSE OF INDBR CRITICAL EDGE '"
+ << Pred->getName() << "': " << *LI << '\n');
return false;
}
if (LoadBB->isEHPad()) {
- DEBUG(dbgs()
- << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD CRITICAL EDGE '"
- << Pred->getName() << "': " << *LI << '\n');
+ LLVM_DEBUG(
+ dbgs() << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD CRITICAL EDGE '"
+ << Pred->getName() << "': " << *LI << '\n');
return false;
}
@@ -1161,8 +1170,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
BasicBlock *NewPred = splitCriticalEdges(OrigPred, LoadBB);
assert(!PredLoads.count(OrigPred) && "Split edges shouldn't be in map!");
PredLoads[NewPred] = nullptr;
- DEBUG(dbgs() << "Split critical edge " << OrigPred->getName() << "->"
- << LoadBB->getName() << '\n');
+ LLVM_DEBUG(dbgs() << "Split critical edge " << OrigPred->getName() << "->"
+ << LoadBB->getName() << '\n');
}
// Check if the load can safely be moved to all the unavailable predecessors.
@@ -1186,8 +1195,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// If we couldn't find or insert a computation of this phi translated value,
// we fail PRE.
if (!LoadPtr) {
- DEBUG(dbgs() << "COULDN'T INSERT PHI TRANSLATED VALUE OF: "
- << *LI->getPointerOperand() << "\n");
+ LLVM_DEBUG(dbgs() << "COULDN'T INSERT PHI TRANSLATED VALUE OF: "
+ << *LI->getPointerOperand() << "\n");
CanDoPRE = false;
break;
}
@@ -1208,10 +1217,10 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// Okay, we can eliminate this load by inserting a reload in the predecessor
// and using PHI construction to get the value in the other predecessors, do
// it.
- DEBUG(dbgs() << "GVN REMOVING PRE LOAD: " << *LI << '\n');
- DEBUG(if (!NewInsts.empty())
- dbgs() << "INSERTED " << NewInsts.size() << " INSTS: "
- << *NewInsts.back() << '\n');
+ LLVM_DEBUG(dbgs() << "GVN REMOVING PRE LOAD: " << *LI << '\n');
+ LLVM_DEBUG(if (!NewInsts.empty()) dbgs()
+ << "INSERTED " << NewInsts.size() << " INSTS: " << *NewInsts.back()
+ << '\n');
// Assign value numbers to the new instructions.
for (Instruction *I : NewInsts) {
@@ -1262,7 +1271,7 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
ValuesPerBlock.push_back(AvailableValueInBlock::get(UnavailablePred,
NewLoad));
MD->invalidateCachedPointerInfo(LoadPtr);
- DEBUG(dbgs() << "GVN INSERTED " << *NewLoad << '\n');
+ LLVM_DEBUG(dbgs() << "GVN INSERTED " << *NewLoad << '\n');
}
// Perform PHI construction.
@@ -1320,11 +1329,8 @@ bool GVN::processNonLocalLoad(LoadInst *LI) {
// clobber in the current block. Reject this early.
if (NumDeps == 1 &&
!Deps[0].getResult().isDef() && !Deps[0].getResult().isClobber()) {
- DEBUG(
- dbgs() << "GVN: non-local load ";
- LI->printAsOperand(dbgs());
- dbgs() << " has unknown dependencies\n";
- );
+ LLVM_DEBUG(dbgs() << "GVN: non-local load "; LI->printAsOperand(dbgs());
+ dbgs() << " has unknown dependencies\n";);
return false;
}
@@ -1353,7 +1359,7 @@ bool GVN::processNonLocalLoad(LoadInst *LI) {
// load, then it is fully redundant and we can use PHI insertion to compute
// its value. Insert PHIs and remove the fully redundant value now.
if (UnavailableBlocks.empty()) {
- DEBUG(dbgs() << "GVN REMOVING NONLOCAL LOAD: " << *LI << '\n');
+ LLVM_DEBUG(dbgs() << "GVN REMOVING NONLOCAL LOAD: " << *LI << '\n');
// Perform PHI construction.
Value *V = ConstructSSAForLoadSet(LI, ValuesPerBlock, *this);
@@ -1506,12 +1512,10 @@ bool GVN::processLoad(LoadInst *L) {
// Only handle the local case below
if (!Dep.isDef() && !Dep.isClobber()) {
// This might be a NonFuncLocal or an Unknown
- DEBUG(
- // fast print dep, using operator<< on instruction is too slow.
- dbgs() << "GVN: load ";
- L->printAsOperand(dbgs());
- dbgs() << " has unknown dependence\n";
- );
+ LLVM_DEBUG(
+ // fast print dep, using operator<< on instruction is too slow.
+ dbgs() << "GVN: load "; L->printAsOperand(dbgs());
+ dbgs() << " has unknown dependence\n";);
return false;
}
@@ -1695,8 +1699,8 @@ bool GVN::replaceOperandsWithConsts(Instruction *Instr) const {
if (it != ReplaceWithConstMap.end()) {
assert(!isa<Constant>(Operand) &&
"Replacing constants with constants is invalid");
- DEBUG(dbgs() << "GVN replacing: " << *Operand << " with " << *it->second
- << " in instruction " << *Instr << '\n');
+ LLVM_DEBUG(dbgs() << "GVN replacing: " << *Operand << " with "
+ << *it->second << " in instruction " << *Instr << '\n');
Instr->setOperand(OpNum, it->second);
Changed = true;
}
@@ -2038,7 +2042,7 @@ bool GVN::runImpl(Function &F, AssumptionCache &RunAC, DominatorTree &RunDT,
unsigned Iteration = 0;
while (ShouldContinue) {
- DEBUG(dbgs() << "GVN iteration: " << Iteration << "\n");
+ LLVM_DEBUG(dbgs() << "GVN iteration: " << Iteration << "\n");
ShouldContinue = iterateOnFunction(F);
Changed |= ShouldContinue;
++Iteration;
@@ -2104,9 +2108,10 @@ bool GVN::processBlock(BasicBlock *BB) {
const Instruction *MaybeFirstICF = FirstImplicitControlFlowInsts.lookup(BB);
for (auto *I : InstrsToErase) {
assert(I->getParent() == BB && "Removing instruction from wrong block?");
- DEBUG(dbgs() << "GVN removed: " << *I << '\n');
+ LLVM_DEBUG(dbgs() << "GVN removed: " << *I << '\n');
+ salvageDebugInfo(*I);
if (MD) MD->removeInstruction(I);
- DEBUG(verifyRemoved(I));
+ LLVM_DEBUG(verifyRemoved(I));
if (MaybeFirstICF == I) {
// We have erased the first ICF in block. The map needs to be updated.
InvalidateImplicitCF = true;
@@ -2288,7 +2293,7 @@ bool GVN::performScalarPRE(Instruction *CurInst) {
PREInstr = CurInst->clone();
if (!performScalarPREInsertion(PREInstr, PREPred, CurrentBlock, ValNo)) {
// If we failed insertion, make sure we remove the instruction.
- DEBUG(verifyRemoved(PREInstr));
+ LLVM_DEBUG(verifyRemoved(PREInstr));
PREInstr->deleteValue();
return false;
}
@@ -2326,10 +2331,10 @@ bool GVN::performScalarPRE(Instruction *CurInst) {
VN.erase(CurInst);
removeFromLeaderTable(ValNo, CurInst, CurrentBlock);
- DEBUG(dbgs() << "GVN PRE removed: " << *CurInst << '\n');
+ LLVM_DEBUG(dbgs() << "GVN PRE removed: " << *CurInst << '\n');
if (MD)
MD->removeInstruction(CurInst);
- DEBUG(verifyRemoved(CurInst));
+ LLVM_DEBUG(verifyRemoved(CurInst));
bool InvalidateImplicitCF =
FirstImplicitControlFlowInsts.lookup(CurInst->getParent()) == CurInst;
// FIXME: Intended to be markInstructionForDeletion(CurInst), but it causes
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-04 00:24:29 +0000