[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/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index d404d20..1aba3df 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -144,7 +144,7 @@
private:
Liveness MarkIfNotLive(RetOrArg Use, UseVector &MaybeLiveUses);
- Liveness SurveyUse(Value::const_use_iterator U, UseVector &MaybeLiveUses,
+ Liveness SurveyUse(const Use *U, UseVector &MaybeLiveUses,
unsigned RetValNum = 0);
Liveness SurveyUses(const Value *V, UseVector &MaybeLiveUses);
@@ -260,7 +260,7 @@
// to pass in a smaller number of arguments into the new function.
//
std::vector<Value*> Args;
- for (Value::use_iterator I = Fn.use_begin(), E = Fn.use_end(); I != E; ) {
+ for (Value::user_iterator I = Fn.user_begin(), E = Fn.user_end(); I != E; ) {
CallSite CS(*I++);
if (!CS)
continue;
@@ -382,10 +382,9 @@
bool Changed = false;
- for (Function::use_iterator I = Fn.use_begin(), E = Fn.use_end();
- I != E; ++I) {
- CallSite CS(*I);
- if (!CS || !CS.isCallee(I))
+ for (Use &U : Fn.uses()) {
+ CallSite CS(U.getUser());
+ if (!CS || !CS.isCallee(&U))
continue;
// Now go through all unused args and replace them with "undef".
@@ -436,9 +435,9 @@
/// RetValNum is the return value number to use when this use is used in a
/// return instruction. This is used in the recursion, you should always leave
/// it at 0.
-DAE::Liveness DAE::SurveyUse(Value::const_use_iterator U,
+DAE::Liveness DAE::SurveyUse(const Use *U,
UseVector &MaybeLiveUses, unsigned RetValNum) {
- const User *V = *U;
+ const User *V = U->getUser();
if (const ReturnInst *RI = dyn_cast<ReturnInst>(V)) {
// The value is returned from a function. It's only live when the
// function's return value is live. We use RetValNum here, for the case
@@ -449,7 +448,7 @@
return MarkIfNotLive(Use, MaybeLiveUses);
}
if (const InsertValueInst *IV = dyn_cast<InsertValueInst>(V)) {
- if (U.getOperandNo() != InsertValueInst::getAggregateOperandIndex()
+ if (U->getOperandNo() != InsertValueInst::getAggregateOperandIndex()
&& IV->hasIndices())
// The use we are examining is inserted into an aggregate. Our liveness
// depends on all uses of that aggregate, but if it is used as a return
@@ -460,9 +459,8 @@
// we don't change RetValNum, but do survey all our uses.
Liveness Result = MaybeLive;
- for (Value::const_use_iterator I = IV->use_begin(),
- E = V->use_end(); I != E; ++I) {
- Result = SurveyUse(I, MaybeLiveUses, RetValNum);
+ for (const Use &UU : IV->uses()) {
+ Result = SurveyUse(&UU, MaybeLiveUses, RetValNum);
if (Result == Live)
break;
}
@@ -485,7 +483,7 @@
return Live;
assert(CS.getArgument(ArgNo)
- == CS->getOperand(U.getOperandNo())
+ == CS->getOperand(U->getOperandNo())
&& "Argument is not where we expected it");
// Value passed to a normal call. It's only live when the corresponding
@@ -508,9 +506,8 @@
// Assume it's dead (which will only hold if there are no uses at all..).
Liveness Result = MaybeLive;
// Check each use.
- for (Value::const_use_iterator I = V->use_begin(),
- E = V->use_end(); I != E; ++I) {
- Result = SurveyUse(I, MaybeLiveUses);
+ for (const Use &U : V->uses()) {
+ Result = SurveyUse(&U, MaybeLiveUses);
if (Result == Live)
break;
}
@@ -564,12 +561,11 @@
unsigned NumLiveRetVals = 0;
Type *STy = dyn_cast<StructType>(F.getReturnType());
// Loop all uses of the function.
- for (Value::const_use_iterator I = F.use_begin(), E = F.use_end();
- I != E; ++I) {
+ for (const Use &U : F.uses()) {
// If the function is PASSED IN as an argument, its address has been
// taken.
- ImmutableCallSite CS(*I);
- if (!CS || !CS.isCallee(I)) {
+ ImmutableCallSite CS(U.getUser());
+ if (!CS || !CS.isCallee(&U)) {
MarkLive(F);
return;
}
@@ -588,9 +584,8 @@
if (NumLiveRetVals != RetCount) {
if (STy) {
// Check all uses of the return value.
- for (Value::const_use_iterator I = TheCall->use_begin(),
- E = TheCall->use_end(); I != E; ++I) {
- const ExtractValueInst *Ext = dyn_cast<ExtractValueInst>(*I);
+ for (const User *U : TheCall->users()) {
+ const ExtractValueInst *Ext = dyn_cast<ExtractValueInst>(U);
if (Ext && Ext->hasIndices()) {
// This use uses a part of our return value, survey the uses of
// that part and store the results for this index only.
@@ -893,7 +888,7 @@
//
std::vector<Value*> Args;
while (!F->use_empty()) {
- CallSite CS(F->use_back());
+ CallSite CS(F->user_back());
Instruction *Call = CS.getInstruction();
AttributesVec.clear();