[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/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index e9e0bc3..15f0035 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -354,8 +354,8 @@
/// true when there are no uses or multiple uses that all refer to the same
/// value.
static bool areAllUsesEqual(Instruction *I) {
- Value::use_iterator UI = I->use_begin();
- Value::use_iterator UE = I->use_end();
+ Value::user_iterator UI = I->user_begin();
+ Value::user_iterator UE = I->user_end();
if (UI == UE)
return true;
@@ -376,7 +376,7 @@
const TargetLibraryInfo *TLI) {
SmallPtrSet<Instruction*, 4> Visited;
for (Instruction *I = PN; areAllUsesEqual(I) && !I->mayHaveSideEffects();
- I = cast<Instruction>(*I->use_begin())) {
+ I = cast<Instruction>(*I->user_begin())) {
if (I->use_empty())
return RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
@@ -752,10 +752,9 @@
if (!Succ->getSinglePredecessor()) {
BasicBlock::iterator BBI = BB->begin();
while (isa<PHINode>(*BBI)) {
- for (Value::use_iterator UI = BBI->use_begin(), E = BBI->use_end();
- UI != E; ++UI) {
- if (PHINode* PN = dyn_cast<PHINode>(*UI)) {
- if (PN->getIncomingBlock(UI) != BB)
+ for (Use &U : BBI->uses()) {
+ if (PHINode* PN = dyn_cast<PHINode>(U.getUser())) {
+ if (PN->getIncomingBlock(U) != BB)
return false;
} else {
return false;
@@ -1056,11 +1055,10 @@
// We only remove the dbg.declare intrinsic if all uses are
// converted to dbg.value intrinsics.
bool RemoveDDI = true;
- for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
- UI != E; ++UI)
- if (StoreInst *SI = dyn_cast<StoreInst>(*UI))
+ for (User *U : AI->users())
+ if (StoreInst *SI = dyn_cast<StoreInst>(U))
ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
- else if (LoadInst *LI = dyn_cast<LoadInst>(*UI))
+ else if (LoadInst *LI = dyn_cast<LoadInst>(U))
ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
else
RemoveDDI = false;
@@ -1075,9 +1073,8 @@
/// alloca 'V', if any.
DbgDeclareInst *llvm::FindAllocaDbgDeclare(Value *V) {
if (MDNode *DebugNode = MDNode::getIfExists(V->getContext(), V))
- 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))
return DDI;
return 0;