From cdf4788401afff02e12279fc1fded94d6180639c Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Sun, 9 Mar 2014 03:16:01 +0000 Subject: [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 --- llvm/lib/Transforms/Scalar/StructurizeCFG.cpp | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-) (limited to 'llvm/lib/Transforms/Scalar/StructurizeCFG.cpp') diff --git a/llvm/lib/Transforms/Scalar/StructurizeCFG.cpp b/llvm/lib/Transforms/Scalar/StructurizeCFG.cpp index 8d4aaca8c2d..8fd22681e5f 100644 --- a/llvm/lib/Transforms/Scalar/StructurizeCFG.cpp +++ b/llvm/lib/Transforms/Scalar/StructurizeCFG.cpp @@ -325,16 +325,10 @@ Value *StructurizeCFG::invert(Value *Condition) { if (Instruction *Inst = dyn_cast(Condition)) { // Third: Check all the users for an invert BasicBlock *Parent = Inst->getParent(); - for (Value::use_iterator I = Condition->use_begin(), - E = Condition->use_end(); I != E; ++I) { - - Instruction *User = dyn_cast(*I); - if (!User || User->getParent() != Parent) - continue; - - if (match(*I, m_Not(m_Specific(Condition)))) - return *I; - } + for (User *U : Condition->users()) + if (Instruction *I = dyn_cast(U)) + if (I->getParent() == Parent && match(I, m_Not(m_Specific(Condition)))) + return I; // Last option: Create a new instruction return BinaryOperator::CreateNot(Condition, "", Parent->getTerminator()); @@ -834,16 +828,14 @@ void StructurizeCFG::rebuildSSA() { II != IE; ++II) { bool Initialized = false; - for (Use *I = &II->use_begin().getUse(), *Next; I; I = Next) { - - Next = I->getNext(); - - Instruction *User = cast(I->getUser()); + for (auto I = II->use_begin(), E = II->use_end(); I != E;) { + Use &U = *I++; + Instruction *User = cast(U.getUser()); if (User->getParent() == BB) { continue; } else if (PHINode *UserPN = dyn_cast(User)) { - if (UserPN->getIncomingBlock(*I) == BB) + if (UserPN->getIncomingBlock(U) == BB) continue; } @@ -857,7 +849,7 @@ void StructurizeCFG::rebuildSSA() { Updater.AddAvailableValue(BB, II); Initialized = true; } - Updater.RewriteUseAfterInsertions(*I); + Updater.RewriteUseAfterInsertions(U); } } } -- cgit v1.2.3