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Diffstat (limited to 'llvm/lib/Analysis/OrderedBasicBlock.cpp')
-rw-r--r-- | llvm/lib/Analysis/OrderedBasicBlock.cpp | 111 |
1 files changed, 0 insertions, 111 deletions
diff --git a/llvm/lib/Analysis/OrderedBasicBlock.cpp b/llvm/lib/Analysis/OrderedBasicBlock.cpp deleted file mode 100644 index 48f2a4020c666..0000000000000 --- a/llvm/lib/Analysis/OrderedBasicBlock.cpp +++ /dev/null @@ -1,111 +0,0 @@ -//===- OrderedBasicBlock.cpp --------------------------------- -*- C++ -*-===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file implements the OrderedBasicBlock class. OrderedBasicBlock -// maintains an interface where clients can query if one instruction comes -// before another in a BasicBlock. Since BasicBlock currently lacks a reliable -// way to query relative position between instructions one can use -// OrderedBasicBlock to do such queries. OrderedBasicBlock is lazily built on a -// source BasicBlock and maintains an internal Instruction -> Position map. A -// OrderedBasicBlock instance should be discarded whenever the source -// BasicBlock changes. -// -// It's currently used by the CaptureTracker in order to find relative -// positions of a pair of instructions inside a BasicBlock. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Analysis/OrderedBasicBlock.h" -#include "llvm/IR/Instruction.h" -using namespace llvm; - -OrderedBasicBlock::OrderedBasicBlock(const BasicBlock *BasicB) - : NextInstPos(0), BB(BasicB) { - LastInstFound = BB->end(); -} - -/// Given no cached results, find if \p A comes before \p B in \p BB. -/// Cache and number out instruction while walking \p BB. -bool OrderedBasicBlock::comesBefore(const Instruction *A, - const Instruction *B) { - const Instruction *Inst = nullptr; - assert(!(LastInstFound == BB->end() && NextInstPos != 0) && - "Instruction supposed to be in NumberedInsts"); - assert(A->getParent() == BB && "Instruction supposed to be in the block!"); - assert(B->getParent() == BB && "Instruction supposed to be in the block!"); - - // Start the search with the instruction found in the last lookup round. - auto II = BB->begin(); - auto IE = BB->end(); - if (LastInstFound != IE) - II = std::next(LastInstFound); - - // Number all instructions up to the point where we find 'A' or 'B'. - for (; II != IE; ++II) { - Inst = cast<Instruction>(II); - NumberedInsts[Inst] = NextInstPos++; - if (Inst == A || Inst == B) - break; - } - - assert(II != IE && "Instruction not found?"); - assert((Inst == A || Inst == B) && "Should find A or B"); - LastInstFound = II; - return Inst != B; -} - -/// Find out whether \p A dominates \p B, meaning whether \p A -/// comes before \p B in \p BB. This is a simplification that considers -/// cached instruction positions and ignores other basic blocks, being -/// only relevant to compare relative instructions positions inside \p BB. -bool OrderedBasicBlock::dominates(const Instruction *A, const Instruction *B) { - assert(A->getParent() == B->getParent() && - "Instructions must be in the same basic block!"); - assert(A->getParent() == BB && "Instructions must be in the tracked block!"); - - // First we lookup the instructions. If they don't exist, lookup will give us - // back ::end(). If they both exist, we compare the numbers. Otherwise, if NA - // exists and NB doesn't, it means NA must come before NB because we would - // have numbered NB as well if it didn't. The same is true for NB. If it - // exists, but NA does not, NA must come after it. If neither exist, we need - // to number the block and cache the results (by calling comesBefore). - auto NAI = NumberedInsts.find(A); - auto NBI = NumberedInsts.find(B); - if (NAI != NumberedInsts.end() && NBI != NumberedInsts.end()) - return NAI->second < NBI->second; - if (NAI != NumberedInsts.end()) - return true; - if (NBI != NumberedInsts.end()) - return false; - - return comesBefore(A, B); -} - -void OrderedBasicBlock::eraseInstruction(const Instruction *I) { - if (LastInstFound != BB->end() && I == &*LastInstFound) { - if (LastInstFound == BB->begin()) { - LastInstFound = BB->end(); - NextInstPos = 0; - } else - LastInstFound--; - } - - NumberedInsts.erase(I); -} - -void OrderedBasicBlock::replaceInstruction(const Instruction *Old, - const Instruction *New) { - auto OI = NumberedInsts.find(Old); - if (OI == NumberedInsts.end()) - return; - - NumberedInsts.insert({New, OI->second}); - if (LastInstFound != BB->end() && Old == &*LastInstFound) - LastInstFound = New->getIterator(); - NumberedInsts.erase(Old); -} |