[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. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chandler Carruth
2014-03-09 03:16:01 +00:00
parent b033b03c23
commit 36b699f2b1
100 changed files with 920 additions and 1075 deletions

View File

@ -171,9 +171,8 @@ void CodeExtractor::findInputsOutputs(ValueSet &Inputs,
if (definedInCaller(Blocks, *OI))
Inputs.insert(*OI);
for (Value::use_iterator UI = II->use_begin(), UE = II->use_end();
UI != UE; ++UI)
if (!definedInRegion(Blocks, *UI)) {
for (User *U : II->users())
if (!definedInRegion(Blocks, U)) {
Outputs.insert(II);
break;
}
@ -369,7 +368,7 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
} else
RewriteVal = AI++;
std::vector<User*> Users(inputs[i]->use_begin(), inputs[i]->use_end());
std::vector<User*> Users(inputs[i]->user_begin(), inputs[i]->user_end());
for (std::vector<User*>::iterator use = Users.begin(), useE = Users.end();
use != useE; ++use)
if (Instruction* inst = dyn_cast<Instruction>(*use))
@ -389,7 +388,7 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
// Rewrite branches to basic blocks outside of the loop to new dummy blocks
// within the new function. This must be done before we lose track of which
// blocks were originally in the code region.
std::vector<User*> Users(header->use_begin(), header->use_end());
std::vector<User*> Users(header->user_begin(), header->user_end());
for (unsigned i = 0, e = Users.size(); i != e; ++i)
// The BasicBlock which contains the branch is not in the region
// modify the branch target to a new block
@ -405,13 +404,12 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
/// that uses the value within the basic block, and return the predecessor
/// block associated with that use, or return 0 if none is found.
static BasicBlock* FindPhiPredForUseInBlock(Value* Used, BasicBlock* BB) {
for (Value::use_iterator UI = Used->use_begin(),
UE = Used->use_end(); UI != UE; ++UI) {
PHINode *P = dyn_cast<PHINode>(*UI);
for (Use &U : Used->uses()) {
PHINode *P = dyn_cast<PHINode>(U.getUser());
if (P && P->getParent() == BB)
return P->getIncomingBlock(UI);
return P->getIncomingBlock(U);
}
return 0;
}
@ -502,7 +500,7 @@ emitCallAndSwitchStatement(Function *newFunction, BasicBlock *codeReplacer,
LoadInst *load = new LoadInst(Output, outputs[i]->getName()+".reload");
Reloads.push_back(load);
codeReplacer->getInstList().push_back(load);
std::vector<User*> Users(outputs[i]->use_begin(), outputs[i]->use_end());
std::vector<User*> Users(outputs[i]->user_begin(), outputs[i]->user_end());
for (unsigned u = 0, e = Users.size(); u != e; ++u) {
Instruction *inst = cast<Instruction>(Users[u]);
if (!Blocks.count(inst->getParent()))