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[C++11] Add range based accessors for the Use-Def chain of a Value.

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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
Download Patch File Download Diff File Expand all files Collapse all files

27
lib/Analysis/IPA/GlobalsModRef.cpp
View File

@@ -252,33 +252,33 @@ bool GlobalsModRef::AnalyzeUsesOfPointer(Value *V,
GlobalValue *OkayStoreDest) {
if (!V->getType()->isPointerTy()) return true;
for (Value::use_iterator UI = V->use_begin(), E=V->use_end(); UI != E; ++UI) {
User *U = *UI;
if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
for (Use &U : V->uses()) {
User *I = U.getUser();
if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
Readers.push_back(LI->getParent()->getParent());
} else if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
if (V == SI->getOperand(1)) {
Writers.push_back(SI->getParent()->getParent());
} else if (SI->getOperand(1) != OkayStoreDest) {
return true; // Storing the pointer
}
} else if (Operator::getOpcode(U) == Instruction::GetElementPtr) {
if (AnalyzeUsesOfPointer(U, Readers, Writers))
} else if (Operator::getOpcode(I) == Instruction::GetElementPtr) {
if (AnalyzeUsesOfPointer(I, Readers, Writers))
return true;
} else if (Operator::getOpcode(U) == Instruction::BitCast) {
if (AnalyzeUsesOfPointer(U, Readers, Writers, OkayStoreDest))
} else if (Operator::getOpcode(I) == Instruction::BitCast) {
if (AnalyzeUsesOfPointer(I, Readers, Writers, OkayStoreDest))
return true;
} else if (CallSite CS = U) {
} else if (CallSite CS = I) {
// Make sure that this is just the function being called, not that it is
// passing into the function.
if (!CS.isCallee(UI)) {
if (!CS.isCallee(&U)) {
// Detect calls to free.
if (isFreeCall(U, TLI))
if (isFreeCall(I, TLI))
Writers.push_back(CS->getParent()->getParent());
else
return true; // Argument of an unknown call.
}
} else if (ICmpInst *ICI = dyn_cast<ICmpInst>(U)) {
} else if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) {
if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
return true; // Allow comparison against null.
} else {
@@ -303,8 +303,7 @@ bool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) {
// Walk the user list of the global. If we find anything other than a direct
// load or store, bail out.
for (Value::use_iterator I = GV->use_begin(), E = GV->use_end(); I != E; ++I){
User *U = *I;
for (User *U : GV->users()) {
if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
// The pointer loaded from the global can only be used in simple ways:
// we allow addressing of it and loading storing to it. We do *not* allow