From 36b699f2b139a30a2dfa4448223d6985b55daa8a 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. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CodeGenPrepare.cpp | 78 ++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 44 deletions(-) (limited to 'lib/CodeGen/CodeGenPrepare.cpp') diff --git a/lib/CodeGen/CodeGenPrepare.cpp b/lib/CodeGen/CodeGenPrepare.cpp index e02d47834a..89351b95e9 100644 --- a/lib/CodeGen/CodeGenPrepare.cpp +++ b/lib/CodeGen/CodeGenPrepare.cpp @@ -336,16 +336,15 @@ bool CodeGenPrepare::CanMergeBlocks(const BasicBlock *BB, // don't mess around with them. BasicBlock::const_iterator BBI = BB->begin(); while (const PHINode *PN = dyn_cast(BBI++)) { - for (Value::const_use_iterator UI = PN->use_begin(), E = PN->use_end(); - UI != E; ++UI) { - const Instruction *User = cast(*UI); - if (User->getParent() != DestBB || !isa(User)) + for (const User *U : PN->users()) { + const Instruction *UI = cast(U); + if (UI->getParent() != DestBB || !isa(UI)) return false; // If User is inside DestBB block and it is a PHINode then check // incoming value. If incoming value is not from BB then this is // a complex condition (e.g. preheaders) we want to avoid here. - if (User->getParent() == DestBB) { - if (const PHINode *UPN = dyn_cast(User)) + if (UI->getParent() == DestBB) { + if (const PHINode *UPN = dyn_cast(UI)) for (unsigned I = 0, E = UPN->getNumIncomingValues(); I != E; ++I) { Instruction *Insn = dyn_cast(UPN->getIncomingValue(I)); if (Insn && Insn->getParent() == BB && @@ -474,7 +473,7 @@ static bool SinkCast(CastInst *CI) { DenseMap InsertedCasts; bool MadeChange = false; - for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end(); + for (Value::user_iterator UI = CI->user_begin(), E = CI->user_end(); UI != E; ) { Use &TheUse = UI.getUse(); Instruction *User = cast(*UI); @@ -483,7 +482,7 @@ static bool SinkCast(CastInst *CI) { // appropriate predecessor block. BasicBlock *UserBB = User->getParent(); if (PHINode *PN = dyn_cast(User)) { - UserBB = PN->getIncomingBlock(UI); + UserBB = PN->getIncomingBlock(TheUse); } // Preincrement use iterator so we don't invalidate it. @@ -567,7 +566,7 @@ static bool OptimizeCmpExpression(CmpInst *CI) { DenseMap InsertedCmps; bool MadeChange = false; - for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end(); + for (Value::user_iterator UI = CI->user_begin(), E = CI->user_end(); UI != E; ) { Use &TheUse = UI.getUse(); Instruction *User = cast(*UI); @@ -1143,11 +1142,9 @@ class TypePromotionTransaction { DEBUG(dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *New << "\n"); // Record the original uses. - for (Value::use_iterator UseIt = Inst->use_begin(), - EndIt = Inst->use_end(); - UseIt != EndIt; ++UseIt) { - Instruction *Use = cast(*UseIt); - OriginalUses.push_back(InstructionAndIdx(Use, UseIt.getOperandNo())); + for (Use &U : Inst->uses()) { + Instruction *UserI = cast(U.getUser()); + OriginalUses.push_back(InstructionAndIdx(UserI, U.getOperandNo())); } // Now, we can replace the uses. Inst->replaceAllUsesWith(New); @@ -2115,23 +2112,22 @@ static bool FindAllMemoryUses(Instruction *I, return true; // Loop over all the uses, recursively processing them. - for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); - UI != E; ++UI) { - User *U = *UI; + for (Use &U : I->uses()) { + Instruction *UserI = cast(U.getUser()); - if (LoadInst *LI = dyn_cast(U)) { - MemoryUses.push_back(std::make_pair(LI, UI.getOperandNo())); + if (LoadInst *LI = dyn_cast(UserI)) { + MemoryUses.push_back(std::make_pair(LI, U.getOperandNo())); continue; } - if (StoreInst *SI = dyn_cast(U)) { - unsigned opNo = UI.getOperandNo(); + if (StoreInst *SI = dyn_cast(UserI)) { + unsigned opNo = U.getOperandNo(); if (opNo == 0) return true; // Storing addr, not into addr. MemoryUses.push_back(std::make_pair(SI, opNo)); continue; } - if (CallInst *CI = dyn_cast(U)) { + if (CallInst *CI = dyn_cast(UserI)) { InlineAsm *IA = dyn_cast(CI->getCalledValue()); if (!IA) return true; @@ -2141,8 +2137,7 @@ static bool FindAllMemoryUses(Instruction *I, continue; } - if (FindAllMemoryUses(cast(U), MemoryUses, ConsideredInsts, - TLI)) + if (FindAllMemoryUses(UserI, MemoryUses, ConsideredInsts, TLI)) return true; } @@ -2603,12 +2598,11 @@ bool CodeGenPrepare::OptimizeExtUses(Instruction *I) { return false; bool DefIsLiveOut = false; - for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); - UI != E; ++UI) { - Instruction *User = cast(*UI); + for (User *U : I->users()) { + Instruction *UI = cast(U); // Figure out which BB this ext is used in. - BasicBlock *UserBB = User->getParent(); + BasicBlock *UserBB = UI->getParent(); if (UserBB == DefBB) continue; DefIsLiveOut = true; break; @@ -2617,14 +2611,13 @@ bool CodeGenPrepare::OptimizeExtUses(Instruction *I) { return false; // Make sure none of the uses are PHI nodes. - for (Value::use_iterator UI = Src->use_begin(), E = Src->use_end(); - UI != E; ++UI) { - Instruction *User = cast(*UI); - BasicBlock *UserBB = User->getParent(); + for (User *U : Src->users()) { + Instruction *UI = cast(U); + BasicBlock *UserBB = UI->getParent(); if (UserBB == DefBB) continue; // Be conservative. We don't want this xform to end up introducing // reloads just before load / store instructions. - if (isa(User) || isa(User) || isa(User)) + if (isa(UI) || isa(UI) || isa(UI)) return false; } @@ -2632,10 +2625,8 @@ bool CodeGenPrepare::OptimizeExtUses(Instruction *I) { DenseMap InsertedTruncs; bool MadeChange = false; - for (Value::use_iterator UI = Src->use_begin(), E = Src->use_end(); - UI != E; ++UI) { - Use &TheUse = UI.getUse(); - Instruction *User = cast(*UI); + for (Use &U : Src->uses()) { + Instruction *User = cast(U.getUser()); // Figure out which BB this ext is used in. BasicBlock *UserBB = User->getParent(); @@ -2651,7 +2642,7 @@ bool CodeGenPrepare::OptimizeExtUses(Instruction *I) { } // Replace a use of the {s|z}ext source with a use of the result. - TheUse = InsertedTrunc; + U = InsertedTrunc; ++NumExtUses; MadeChange = true; } @@ -2779,16 +2770,15 @@ bool CodeGenPrepare::OptimizeShuffleVectorInst(ShuffleVectorInst *SVI) { DenseMap InsertedShuffles; bool MadeChange = false; - for (Value::use_iterator UI = SVI->use_begin(), E = SVI->use_end(); - UI != E; ++UI) { - Instruction *User = cast(*UI); + for (User *U : SVI->users()) { + Instruction *UI = cast(U); // Figure out which BB this ext is used in. - BasicBlock *UserBB = User->getParent(); + BasicBlock *UserBB = UI->getParent(); if (UserBB == DefBB) continue; // For now only apply this when the splat is used by a shift instruction. - if (!User->isShift()) continue; + if (!UI->isShift()) continue; // Everything checks out, sink the shuffle if the user's block doesn't // already have a copy. @@ -2801,7 +2791,7 @@ bool CodeGenPrepare::OptimizeShuffleVectorInst(ShuffleVectorInst *SVI) { SVI->getOperand(2), "", InsertPt); } - User->replaceUsesOfWith(SVI, InsertedShuffle); + UI->replaceUsesOfWith(SVI, InsertedShuffle); MadeChange = true; } -- cgit v1.2.3