diff options
author | Chandler Carruth <chandlerc@gmail.com> | 2014-03-09 03:16:01 +0000 |
---|---|---|
committer | Chandler Carruth <chandlerc@gmail.com> | 2014-03-09 03:16:01 +0000 |
commit | 36b699f2b139a30a2dfa4448223d6985b55daa8a (patch) | |
tree | d6844c991f0c06de4b66a2615259607d8349e5b3 /lib/Transforms/IPO/FunctionAttrs.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/IPO/FunctionAttrs.cpp')
-rw-r--r-- | lib/Transforms/IPO/FunctionAttrs.cpp | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp index cb565d0814..7add0d576a 100644 --- a/lib/Transforms/IPO/FunctionAttrs.cpp +++ b/lib/Transforms/IPO/FunctionAttrs.cpp @@ -421,14 +421,12 @@ determinePointerReadAttrs(Argument *A, bool IsRead = false; // We don't need to track IsWritten. If A is written to, return immediately. - for (Value::use_iterator UI = A->use_begin(), UE = A->use_end(); - UI != UE; ++UI) { + for (Use &U : A->uses()) { if (Count++ >= 20) return Attribute::None; - Use *U = &UI.getUse(); - Visited.insert(U); - Worklist.push_back(U); + Visited.insert(&U); + Worklist.push_back(&U); } while (!Worklist.empty()) { @@ -443,12 +441,9 @@ determinePointerReadAttrs(Argument *A, case Instruction::Select: case Instruction::AddrSpaceCast: // The original value is not read/written via this if the new value isn't. - for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end(); - UI != UE; ++UI) { - Use *U = &UI.getUse(); - if (Visited.insert(U)) - Worklist.push_back(U); - } + for (Use &UU : I->uses()) + if (Visited.insert(&UU)) + Worklist.push_back(&UU); break; case Instruction::Call: |