shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity

[BOLT] Speed up dataflow analysis with RPO (#183704)

Browse Source
This commit is contained in:
Haibo Jiang 2026-03-10 08:46:01 +08:00 committed by GitHub
parent c6bde8318e
commit 2c2126603c
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 33 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
bolt/include/bolt/Passes/DataflowAnalysis.h
View File

@ -11,6 +11,7 @@
#include "bolt/Core/BinaryContext.h"
#include "bolt/Core/BinaryFunction.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/Support/Errc.h"
#include <optional>
#include <queue>
@ -332,23 +333,41 @@ public:
}
std::queue<BinaryBasicBlock *> Worklist;
// TODO: Pushing this in a DFS ordering will greatly speed up the dataflow
// performance.
DenseSet<BinaryBasicBlock *> BBs;
if (!Backward) {
for (BinaryBasicBlock &BB : Func) {
Worklist.push(&BB);
MCInst *Prev = nullptr;
for (MCInst &Inst : BB) {
PrevPoint[&Inst] = Prev ? ProgramPoint(Prev) : ProgramPoint(&BB);
Prev = &Inst;
}
llvm::ReversePostOrderTraversal<BinaryFunction *> RPOT(&Func);
for (BinaryBasicBlock *BB : RPOT) {
Worklist.push(BB);
BBs.insert(BB);
}
} else {
for (BinaryBasicBlock &BB : llvm::reverse(Func)) {
Worklist.push(&BB);
MCInst *Prev = nullptr;
for (MCInst &Inst : llvm::reverse(BB)) {
PrevPoint[&Inst] = Prev ? ProgramPoint(Prev) : ProgramPoint(&BB);
for (BinaryBasicBlock *BB : post_order(&Func)) {
Worklist.push(BB);
BBs.insert(BB);
}
}
// Reverse post-order and post-order will leave unreachable basic
// blocks. Here will identify and add them to the worklist.
if (BBs.size() != Func.size()) {
for (BinaryBasicBlock &BB : Func) {
if (!BBs.count(&BB)) {
Worklist.push(&BB);
BBs.insert(&BB);
}
}
}
for (auto *BB : BBs) {
MCInst *Prev = nullptr;
if (!Backward) {
for (MCInst &Inst : *BB) {
PrevPoint[&Inst] = Prev ? ProgramPoint(Prev) : ProgramPoint(BB);
Prev = &Inst;
}
} else {
for (MCInst &Inst : llvm::reverse(*BB)) {
PrevPoint[&Inst] = Prev ? ProgramPoint(Prev) : ProgramPoint(BB);
Prev = &Inst;
}
}