mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-23 03:02:36 +01:00
68092989f3
This file lists every pass in LLVM, and is included by Pass.h, which is very popular. Every time we add, remove, or rename a pass in LLVM, it caused lots of recompilation. I found this fact by looking at this table, which is sorted by the number of times a file was changed over the last 100,000 git commits multiplied by the number of object files that depend on it in the current checkout: recompiles touches affected_files header 342380 95 3604 llvm/include/llvm/ADT/STLExtras.h 314730 234 1345 llvm/include/llvm/InitializePasses.h 307036 118 2602 llvm/include/llvm/ADT/APInt.h 213049 59 3611 llvm/include/llvm/Support/MathExtras.h 170422 47 3626 llvm/include/llvm/Support/Compiler.h 162225 45 3605 llvm/include/llvm/ADT/Optional.h 158319 63 2513 llvm/include/llvm/ADT/Triple.h 140322 39 3598 llvm/include/llvm/ADT/StringRef.h 137647 59 2333 llvm/include/llvm/Support/Error.h 131619 73 1803 llvm/include/llvm/Support/FileSystem.h Before this change, touching InitializePasses.h would cause 1345 files to recompile. After this change, touching it only causes 550 compiles in an incremental rebuild. Reviewers: bkramer, asbirlea, bollu, jdoerfert Differential Revision: https://reviews.llvm.org/D70211
91 lines
2.7 KiB
C++
91 lines
2.7 KiB
C++
//===- FlattenCFGPass.cpp - CFG Flatten Pass ----------------------===//
|
|
//
|
|
// 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 flattening of CFG.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Analysis/AliasAnalysis.h"
|
|
#include "llvm/IR/CFG.h"
|
|
#include "llvm/IR/ValueHandle.h"
|
|
#include "llvm/InitializePasses.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Transforms/Scalar.h"
|
|
#include "llvm/Transforms/Utils/Local.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "flattencfg"
|
|
|
|
namespace {
|
|
struct FlattenCFGPass : public FunctionPass {
|
|
static char ID; // Pass identification, replacement for typeid
|
|
public:
|
|
FlattenCFGPass() : FunctionPass(ID) {
|
|
initializeFlattenCFGPassPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
bool runOnFunction(Function &F) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.addRequired<AAResultsWrapperPass>();
|
|
}
|
|
|
|
private:
|
|
AliasAnalysis *AA;
|
|
};
|
|
}
|
|
|
|
char FlattenCFGPass::ID = 0;
|
|
INITIALIZE_PASS_BEGIN(FlattenCFGPass, "flattencfg", "Flatten the CFG", false,
|
|
false)
|
|
INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
|
|
INITIALIZE_PASS_END(FlattenCFGPass, "flattencfg", "Flatten the CFG", false,
|
|
false)
|
|
|
|
// Public interface to the FlattenCFG pass
|
|
FunctionPass *llvm::createFlattenCFGPass() { return new FlattenCFGPass(); }
|
|
|
|
/// iterativelyFlattenCFG - Call FlattenCFG on all the blocks in the function,
|
|
/// iterating until no more changes are made.
|
|
static bool iterativelyFlattenCFG(Function &F, AliasAnalysis *AA) {
|
|
bool Changed = false;
|
|
bool LocalChange = true;
|
|
|
|
// Use block handles instead of iterating over function blocks directly
|
|
// to avoid using iterators invalidated by erasing blocks.
|
|
std::vector<WeakVH> Blocks;
|
|
Blocks.reserve(F.size());
|
|
for (auto &BB : F)
|
|
Blocks.push_back(&BB);
|
|
|
|
while (LocalChange) {
|
|
LocalChange = false;
|
|
|
|
// Loop over all of the basic blocks and try to flatten them.
|
|
for (WeakVH &BlockHandle : Blocks) {
|
|
// Skip blocks erased by FlattenCFG.
|
|
if (auto *BB = cast_or_null<BasicBlock>(BlockHandle))
|
|
if (FlattenCFG(BB, AA))
|
|
LocalChange = true;
|
|
}
|
|
Changed |= LocalChange;
|
|
}
|
|
return Changed;
|
|
}
|
|
|
|
bool FlattenCFGPass::runOnFunction(Function &F) {
|
|
AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
|
|
bool EverChanged = false;
|
|
// iterativelyFlattenCFG can make some blocks dead.
|
|
while (iterativelyFlattenCFG(F, AA)) {
|
|
removeUnreachableBlocks(F);
|
|
EverChanged = true;
|
|
}
|
|
return EverChanged;
|
|
}
|