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author | Chandler Carruth <chandlerc@gmail.com> | 2014-03-09 03:16:01 +0000 |
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committer | Chandler Carruth <chandlerc@gmail.com> | 2014-03-09 03:16:01 +0000 |
commit | 36b699f2b139a30a2dfa4448223d6985b55daa8a (patch) | |
tree | d6844c991f0c06de4b66a2615259607d8349e5b3 /lib/Transforms/ObjCARC/ObjCARCContract.cpp | |
parent | b033b03c23fb3ae066937b2ec09eb9d7a3f1d522 (diff) | |
download | llvm-36b699f2b139a30a2dfa4448223d6985b55daa8a.tar.gz llvm-36b699f2b139a30a2dfa4448223d6985b55daa8a.tar.bz2 llvm-36b699f2b139a30a2dfa4448223d6985b55daa8a.tar.xz |
[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
Diffstat (limited to 'lib/Transforms/ObjCARC/ObjCARCContract.cpp')
-rw-r--r-- | lib/Transforms/ObjCARC/ObjCARCContract.cpp | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/lib/Transforms/ObjCARC/ObjCARCContract.cpp b/lib/Transforms/ObjCARC/ObjCARCContract.cpp index b1dc2ec533..1412181766 100644 --- a/lib/Transforms/ObjCARC/ObjCARCContract.cpp +++ b/lib/Transforms/ObjCARC/ObjCARCContract.cpp @@ -440,17 +440,17 @@ bool ObjCARCContract::runOnFunction(Function &F) { // 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 @@ bool ObjCARCContract::runOnFunction(Function &F) { 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); } |