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/ObjCARC/ObjCARCContract.cpp | 13 ++++++------ llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp | 23 ++++++++-------------- llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp | 7 +++---- 3 files changed, 17 insertions(+), 26 deletions(-) (limited to 'llvm/lib/Transforms/ObjCARC') diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp index b1dc2ec5339..1412181766c 100644 --- a/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp +++ b/llvm/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(Inst)->getArgOperand(0); + Value *Arg = cast(Inst)->getArgOperand(0); for (;;) { // If we're compiling bugpointed code, don't get in trouble. if (!isa(Arg) && !isa(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); } diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp index 4e2cf59d184..eed3cb23ca0 100644 --- a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp +++ b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp @@ -163,12 +163,9 @@ static const Value *FindSingleUseIdentifiedObject(const Value *Arg) { // If we found an identifiable object but it has multiple uses, but they are // trivial uses, we can still consider this to be a single-use value. if (IsObjCIdentifiedObject(Arg)) { - for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end(); - UI != UE; ++UI) { - const User *U = *UI; + for (const User *U : Arg->users()) if (!U->use_empty() || StripPointerCastsAndObjCCalls(U) != Arg) return 0; - } return Arg; } @@ -1266,13 +1263,11 @@ ObjCARCOpt::OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV, Users.push_back(Ptr); do { Ptr = Users.pop_back_val(); - for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end(); - UI != UE; ++UI) { - const User *I = *UI; - if (isa(I) || GetBasicInstructionClass(I) == IC_RetainRV) + for (const User *U : Ptr->users()) { + if (isa(U) || GetBasicInstructionClass(U) == IC_RetainRV) return; - if (isa(I)) - Users.push_back(I); + if (isa(U)) + Users.push_back(U); } } while (!Users.empty()); @@ -2787,9 +2782,8 @@ void ObjCARCOpt::OptimizeWeakCalls(Function &F) { CallInst *Call = cast(Inst); Value *Arg = Call->getArgOperand(0); if (AllocaInst *Alloca = dyn_cast(Arg)) { - for (Value::use_iterator UI = Alloca->use_begin(), - UE = Alloca->use_end(); UI != UE; ++UI) { - const Instruction *UserInst = cast(*UI); + for (User *U : Alloca->users()) { + const Instruction *UserInst = cast(U); switch (GetBasicInstructionClass(UserInst)) { case IC_InitWeak: case IC_StoreWeak: @@ -2800,8 +2794,7 @@ void ObjCARCOpt::OptimizeWeakCalls(Function &F) { } } Changed = true; - for (Value::use_iterator UI = Alloca->use_begin(), - UE = Alloca->use_end(); UI != UE; ) { + for (auto UI = Alloca->user_begin(), UE = Alloca->user_end(); UI != UE;) { CallInst *UserInst = cast(*UI++); switch (GetBasicInstructionClass(UserInst)) { case IC_InitWeak: diff --git a/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp b/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp index ae3c6282cf8..22be6fdf45f 100644 --- a/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp +++ b/llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp @@ -79,11 +79,10 @@ static bool IsStoredObjCPointer(const Value *P) { Visited.insert(P); do { P = Worklist.pop_back_val(); - for (Value::const_use_iterator UI = P->use_begin(), UE = P->use_end(); - UI != UE; ++UI) { - const User *Ur = *UI; + for (const Use &U : P->uses()) { + const User *Ur = U.getUser(); if (isa(Ur)) { - if (UI.getOperandNo() == 0) + if (U.getOperandNo() == 0) // The pointer is stored. return true; // The pointed is stored through. -- cgit v1.2.3