[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/ObjCARC/ObjCARCContract.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp
index b1dc2ec..1412181 100644
--- a/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp
+++ b/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp
@@ -440,17 +440,17 @@
// Don't use GetObjCArg because we don't want to look through bitcasts
// and such; to do the replacement, the argument must have type i8*.
- const Value *Arg = cast<CallInst>(Inst)->getArgOperand(0);
+ Value *Arg = cast<CallInst>(Inst)->getArgOperand(0);
for (;;) {
// If we're compiling bugpointed code, don't get in trouble.
if (!isa<Instruction>(Arg) && !isa<Argument>(Arg))
break;
// Look through the uses of the pointer.
- for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end();
+ for (Value::use_iterator UI = Arg->use_begin(), UE = Arg->use_end();
UI != UE; ) {
- Use &U = UI.getUse();
- unsigned OperandNo = UI.getOperandNo();
- ++UI; // Increment UI now, because we may unlink its element.
+ // Increment UI now, because we may unlink its element.
+ Use &U = *UI++;
+ unsigned OperandNo = U.getOperandNo();
// If the call's return value dominates a use of the call's argument
// value, rewrite the use to use the return value. We check for
@@ -476,8 +476,7 @@
if (PHI->getIncomingBlock(i) == BB) {
// Keep the UI iterator valid.
if (&PHI->getOperandUse(
- PHINode::getOperandNumForIncomingValue(i)) ==
- &UI.getUse())
+ PHINode::getOperandNumForIncomingValue(i)) == &U)
++UI;
PHI->setIncomingValue(i, Replacement);
}
diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
index 4e2cf59..eed3cb2 100644
--- a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
+++ b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
@@ -163,12 +163,9 @@
// If we found an identifiable object but it has multiple uses, but they are
// trivial uses, we can still consider this to be a single-use value.
if (IsObjCIdentifiedObject(Arg)) {
- for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end();
- UI != UE; ++UI) {
- const User *U = *UI;
+ for (const User *U : Arg->users())
if (!U->use_empty() || StripPointerCastsAndObjCCalls(U) != Arg)
return 0;
- }
return Arg;
}
@@ -1266,13 +1263,11 @@
Users.push_back(Ptr);
do {
Ptr = Users.pop_back_val();
- for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end();
- UI != UE; ++UI) {
- const User *I = *UI;
- if (isa<ReturnInst>(I) || GetBasicInstructionClass(I) == IC_RetainRV)
+ for (const User *U : Ptr->users()) {
+ if (isa<ReturnInst>(U) || GetBasicInstructionClass(U) == IC_RetainRV)
return;
- if (isa<BitCastInst>(I))
- Users.push_back(I);
+ if (isa<BitCastInst>(U))
+ Users.push_back(U);
}
} while (!Users.empty());
@@ -2787,9 +2782,8 @@
CallInst *Call = cast<CallInst>(Inst);
Value *Arg = Call->getArgOperand(0);
if (AllocaInst *Alloca = dyn_cast<AllocaInst>(Arg)) {
- for (Value::use_iterator UI = Alloca->use_begin(),
- UE = Alloca->use_end(); UI != UE; ++UI) {
- const Instruction *UserInst = cast<Instruction>(*UI);
+ for (User *U : Alloca->users()) {
+ const Instruction *UserInst = cast<Instruction>(U);
switch (GetBasicInstructionClass(UserInst)) {
case IC_InitWeak:
case IC_StoreWeak:
@@ -2800,8 +2794,7 @@
}
}
Changed = true;
- for (Value::use_iterator UI = Alloca->use_begin(),
- UE = Alloca->use_end(); UI != UE; ) {
+ for (auto UI = Alloca->user_begin(), UE = Alloca->user_end(); UI != UE;) {
CallInst *UserInst = cast<CallInst>(*UI++);
switch (GetBasicInstructionClass(UserInst)) {
case IC_InitWeak:
diff --git a/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp b/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp
index ae3c628..22be6fd 100644
--- a/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp
+++ b/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp
@@ -79,11 +79,10 @@
Visited.insert(P);
do {
P = Worklist.pop_back_val();
- for (Value::const_use_iterator UI = P->use_begin(), UE = P->use_end();
- UI != UE; ++UI) {
- const User *Ur = *UI;
+ for (const Use &U : P->uses()) {
+ const User *Ur = U.getUser();
if (isa<StoreInst>(Ur)) {
- if (UI.getOperandNo() == 0)
+ if (U.getOperandNo() == 0)
// The pointer is stored.
return true;
// The pointed is stored through.