[C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
detail
2) Change it to actually be a *Use* iterator rather than a *User*
iterator.
3) Add an adaptor which is a User iterator that always looks through the
Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
they wanted a use_iterator (and to explicitly dig out the User when
needed), or a user_iterator which makes the Use itself totally
opaque.
Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.
The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.
However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]
llvm-svn: 203364
diff --git a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index 36c0f74..e7b5ab2 100644
--- a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -466,10 +466,10 @@
/// SawVec flag.
bool ConvertToScalarInfo::CanConvertToScalar(Value *V, uint64_t Offset,
Value* NonConstantIdx) {
- for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) {
- Instruction *User = cast<Instruction>(*UI);
+ for (User *U : V->users()) {
+ Instruction *UI = cast<Instruction>(U);
- if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
+ if (LoadInst *LI = dyn_cast<LoadInst>(UI)) {
// Don't break volatile loads.
if (!LI->isSimple())
return false;
@@ -481,7 +481,7 @@
continue;
}
- if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
+ if (StoreInst *SI = dyn_cast<StoreInst>(UI)) {
// Storing the pointer, not into the value?
if (SI->getOperand(0) == V || !SI->isSimple()) return false;
// Don't touch MMX operations.
@@ -492,7 +492,7 @@
continue;
}
- if (BitCastInst *BCI = dyn_cast<BitCastInst>(User)) {
+ if (BitCastInst *BCI = dyn_cast<BitCastInst>(UI)) {
if (!onlyUsedByLifetimeMarkers(BCI))
IsNotTrivial = true; // Can't be mem2reg'd.
if (!CanConvertToScalar(BCI, Offset, NonConstantIdx))
@@ -500,7 +500,7 @@
continue;
}
- if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
+ if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(UI)) {
// If this is a GEP with a variable indices, we can't handle it.
PointerType* PtrTy = dyn_cast<PointerType>(GEP->getPointerOperandType());
if (!PtrTy)
@@ -532,7 +532,7 @@
// If this is a constant sized memset of a constant value (e.g. 0) we can
// handle it.
- if (MemSetInst *MSI = dyn_cast<MemSetInst>(User)) {
+ if (MemSetInst *MSI = dyn_cast<MemSetInst>(UI)) {
// Store to dynamic index.
if (NonConstantIdx)
return false;
@@ -559,7 +559,7 @@
// If this is a memcpy or memmove into or out of the whole allocation, we
// can handle it like a load or store of the scalar type.
- if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(User)) {
+ if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(UI)) {
// Store to dynamic index.
if (NonConstantIdx)
return false;
@@ -572,7 +572,7 @@
}
// If this is a lifetime intrinsic, we can handle it.
- if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(User)) {
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(UI)) {
if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
II->getIntrinsicID() == Intrinsic::lifetime_end) {
continue;
@@ -597,7 +597,7 @@
uint64_t Offset,
Value* NonConstantIdx) {
while (!Ptr->use_empty()) {
- Instruction *User = cast<Instruction>(Ptr->use_back());
+ Instruction *User = cast<Instruction>(Ptr->user_back());
if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) {
ConvertUsesToScalar(CI, NewAI, Offset, NonConstantIdx);
@@ -1060,11 +1060,10 @@
// Remember which alloca we're promoting (for isInstInList).
this->AI = AI;
if (MDNode *DebugNode = MDNode::getIfExists(AI->getContext(), AI)) {
- for (Value::use_iterator UI = DebugNode->use_begin(),
- E = DebugNode->use_end(); UI != E; ++UI)
- if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(*UI))
+ for (User *U : DebugNode->users())
+ if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U))
DDIs.push_back(DDI);
- else if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(*UI))
+ else if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(U))
DVIs.push_back(DVI);
}
@@ -1142,9 +1141,8 @@
bool TDerefable = SI->getTrueValue()->isDereferenceablePointer();
bool FDerefable = SI->getFalseValue()->isDereferenceablePointer();
- for (Value::use_iterator UI = SI->use_begin(), UE = SI->use_end();
- UI != UE; ++UI) {
- LoadInst *LI = dyn_cast<LoadInst>(*UI);
+ for (User *U : SI->users()) {
+ LoadInst *LI = dyn_cast<LoadInst>(U);
if (LI == 0 || !LI->isSimple()) return false;
// Both operands to the select need to be dereferencable, either absolutely
@@ -1183,9 +1181,8 @@
// TODO: Allow stores.
BasicBlock *BB = PN->getParent();
unsigned MaxAlign = 0;
- for (Value::use_iterator UI = PN->use_begin(), UE = PN->use_end();
- UI != UE; ++UI) {
- LoadInst *LI = dyn_cast<LoadInst>(*UI);
+ for (User *U : PN->users()) {
+ LoadInst *LI = dyn_cast<LoadInst>(U);
if (LI == 0 || !LI->isSimple()) return false;
// For now we only allow loads in the same block as the PHI. This is a
@@ -1243,10 +1240,7 @@
static bool tryToMakeAllocaBePromotable(AllocaInst *AI, const DataLayout *DL) {
SetVector<Instruction*, SmallVector<Instruction*, 4>,
SmallPtrSet<Instruction*, 4> > InstsToRewrite;
-
- for (Value::use_iterator UI = AI->use_begin(), UE = AI->use_end();
- UI != UE; ++UI) {
- User *U = *UI;
+ for (User *U : AI->users()) {
if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
if (!LI->isSimple())
return false;
@@ -1316,12 +1310,9 @@
for (unsigned i = 0, e = InstsToRewrite.size(); i != e; ++i) {
if (BitCastInst *BCI = dyn_cast<BitCastInst>(InstsToRewrite[i])) {
// This could only be a bitcast used by nothing but lifetime intrinsics.
- for (BitCastInst::use_iterator I = BCI->use_begin(), E = BCI->use_end();
- I != E;) {
- Use &U = I.getUse();
- ++I;
- cast<Instruction>(U.getUser())->eraseFromParent();
- }
+ for (BitCastInst::user_iterator I = BCI->user_begin(), E = BCI->user_end();
+ I != E;)
+ cast<Instruction>(*I++)->eraseFromParent();
BCI->eraseFromParent();
continue;
}
@@ -1330,7 +1321,7 @@
// Selects in InstsToRewrite only have load uses. Rewrite each as two
// loads with a new select.
while (!SI->use_empty()) {
- LoadInst *LI = cast<LoadInst>(SI->use_back());
+ LoadInst *LI = cast<LoadInst>(SI->user_back());
IRBuilder<> Builder(LI);
LoadInst *TrueLoad =
@@ -1371,13 +1362,13 @@
// Get the TBAA tag and alignment to use from one of the loads. It doesn't
// matter which one we get and if any differ, it doesn't matter.
- LoadInst *SomeLoad = cast<LoadInst>(PN->use_back());
+ LoadInst *SomeLoad = cast<LoadInst>(PN->user_back());
MDNode *TBAATag = SomeLoad->getMetadata(LLVMContext::MD_tbaa);
unsigned Align = SomeLoad->getAlignment();
// Rewrite all loads of the PN to use the new PHI.
while (!PN->use_empty()) {
- LoadInst *LI = cast<LoadInst>(PN->use_back());
+ LoadInst *LI = cast<LoadInst>(PN->user_back());
LI->replaceAllUsesWith(NewPN);
LI->eraseFromParent();
}
@@ -1437,9 +1428,8 @@
AllocaInst *AI = Allocas[i];
// Build list of instructions to promote.
- for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
- UI != E; ++UI)
- Insts.push_back(cast<Instruction>(*UI));
+ for (User *U : AI->users())
+ Insts.push_back(cast<Instruction>(U));
AllocaPromoter(Insts, SSA, &DIB).run(AI, Insts);
Insts.clear();
}
@@ -1602,8 +1592,8 @@
/// referenced by this instruction.
void SROA::isSafeForScalarRepl(Instruction *I, uint64_t Offset,
AllocaInfo &Info) {
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E; ++UI) {
- Instruction *User = cast<Instruction>(*UI);
+ for (Use &U : I->uses()) {
+ Instruction *User = cast<Instruction>(U.getUser());
if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) {
isSafeForScalarRepl(BC, Offset, Info);
@@ -1620,7 +1610,7 @@
return MarkUnsafe(Info, User);
isSafeMemAccess(Offset, Length->getZExtValue(), 0,
- UI.getOperandNo() == 0, Info, MI,
+ U.getOperandNo() == 0, Info, MI,
true /*AllowWholeAccess*/);
} else if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
if (!LI->isSimple())
@@ -1669,39 +1659,39 @@
if (!Info.CheckedPHIs.insert(PN))
return;
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E; ++UI) {
- Instruction *User = cast<Instruction>(*UI);
+ for (User *U : I->users()) {
+ Instruction *UI = cast<Instruction>(U);
- if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) {
+ if (BitCastInst *BC = dyn_cast<BitCastInst>(UI)) {
isSafePHISelectUseForScalarRepl(BC, Offset, Info);
- } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) {
+ } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(UI)) {
// Only allow "bitcast" GEPs for simplicity. We could generalize this,
// but would have to prove that we're staying inside of an element being
// promoted.
if (!GEPI->hasAllZeroIndices())
- return MarkUnsafe(Info, User);
+ return MarkUnsafe(Info, UI);
isSafePHISelectUseForScalarRepl(GEPI, Offset, Info);
- } else if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
+ } else if (LoadInst *LI = dyn_cast<LoadInst>(UI)) {
if (!LI->isSimple())
- return MarkUnsafe(Info, User);
+ return MarkUnsafe(Info, UI);
Type *LIType = LI->getType();
isSafeMemAccess(Offset, DL->getTypeAllocSize(LIType),
LIType, false, Info, LI, false /*AllowWholeAccess*/);
Info.hasALoadOrStore = true;
- } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(UI)) {
// Store is ok if storing INTO the pointer, not storing the pointer
if (!SI->isSimple() || SI->getOperand(0) == I)
- return MarkUnsafe(Info, User);
+ return MarkUnsafe(Info, UI);
Type *SIType = SI->getOperand(0)->getType();
isSafeMemAccess(Offset, DL->getTypeAllocSize(SIType),
SIType, true, Info, SI, false /*AllowWholeAccess*/);
Info.hasALoadOrStore = true;
- } else if (isa<PHINode>(User) || isa<SelectInst>(User)) {
- isSafePHISelectUseForScalarRepl(User, Offset, Info);
+ } else if (isa<PHINode>(UI) || isa<SelectInst>(UI)) {
+ isSafePHISelectUseForScalarRepl(UI, Offset, Info);
} else {
- return MarkUnsafe(Info, User);
+ return MarkUnsafe(Info, UI);
}
if (Info.isUnsafe) return;
}
@@ -1871,8 +1861,8 @@
void SROA::RewriteForScalarRepl(Instruction *I, AllocaInst *AI, uint64_t Offset,
SmallVectorImpl<AllocaInst *> &NewElts) {
for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E;) {
- Use &TheUse = UI.getUse();
- Instruction *User = cast<Instruction>(*UI++);
+ Use &TheUse = *UI++;
+ Instruction *User = cast<Instruction>(TheUse.getUser());
if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) {
RewriteBitCast(BC, AI, Offset, NewElts);