mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
1d961ba22d
Although I don't plan to bring over new assertions wholesale into the current qualification branch, it's entirely possible that various minor changes in main will use the new assertions; having this basic support in the release branch will simplify that. (This is why I'm adding the includes as a separate pass from rewriting the individual assertions)
96 lines
3.2 KiB
C++
96 lines
3.2 KiB
C++
//===--- FunctionOrder.cpp - Utility for function ordering ----------------===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
|
|
// Licensed under Apache License v2.0 with Runtime Library Exception
|
|
//
|
|
// See https://swift.org/LICENSE.txt for license information
|
|
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "swift/SILOptimizer/Analysis/FunctionOrder.h"
|
|
#include "swift/Basic/Assertions.h"
|
|
#include "swift/SIL/SILBasicBlock.h"
|
|
#include "swift/SIL/SILFunction.h"
|
|
#include "swift/SIL/SILInstruction.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/ADT/TinyPtrVector.h"
|
|
#include <algorithm>
|
|
|
|
using namespace swift;
|
|
|
|
/// Use Tarjan's strongly connected components (SCC) algorithm to find
|
|
/// the SCCs in the call graph.
|
|
void BottomUpFunctionOrder::DFS(SILFunction *Start) {
|
|
// Set the DFSNum for this node if we haven't already, and if we
|
|
// have, which indicates it's already been visited, return.
|
|
if (!DFSNum.insert(std::make_pair(Start, NextDFSNum)).second)
|
|
return;
|
|
|
|
assert(MinDFSNum.find(Start) == MinDFSNum.end() &&
|
|
"Function should not already have a minimum DFS number!");
|
|
|
|
MinDFSNum[Start] = NextDFSNum;
|
|
++NextDFSNum;
|
|
|
|
DFSStack.insert(Start);
|
|
|
|
// Visit all the instructions, looking for apply sites.
|
|
for (auto &B : *Start) {
|
|
for (auto &I : B) {
|
|
CalleeList callees;
|
|
if (auto FAS = FullApplySite::isa(&I)) {
|
|
callees = BCA->getCalleeList(FAS);
|
|
} else if (isa<StrongReleaseInst>(&I) || isa<ReleaseValueInst>(&I) ||
|
|
isa<DestroyValueInst>(&I)) {
|
|
callees = BCA->getDestructors(I.getOperand(0)->getType(), /*isExactType*/ false);
|
|
} else if (auto *bi = dyn_cast<BuiltinInst>(&I)) {
|
|
switch (bi->getBuiltinInfo().ID) {
|
|
case BuiltinValueKind::Once:
|
|
case BuiltinValueKind::OnceWithContext:
|
|
callees = BCA->getCalleeListOfValue(bi->getArguments()[1]);
|
|
break;
|
|
default:
|
|
continue;
|
|
}
|
|
} else {
|
|
continue;
|
|
}
|
|
|
|
for (auto *CalleeFn : callees) {
|
|
// If not yet visited, visit the callee.
|
|
if (DFSNum.find(CalleeFn) == DFSNum.end()) {
|
|
DFS(CalleeFn);
|
|
MinDFSNum[Start] = std::min(MinDFSNum[Start], MinDFSNum[CalleeFn]);
|
|
} else if (DFSStack.count(CalleeFn)) {
|
|
// If the callee is on the stack, it update our minimum DFS
|
|
// number based on it's DFS number.
|
|
MinDFSNum[Start] = std::min(MinDFSNum[Start], DFSNum[CalleeFn]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// If our DFS number is the minimum found, we've found a
|
|
// (potentially singleton) SCC, so pop the nodes off the stack and
|
|
// push the new SCC on our stack of SCCs.
|
|
if (DFSNum[Start] == MinDFSNum[Start]) {
|
|
SCC CurrentSCC;
|
|
|
|
SILFunction *Popped;
|
|
do {
|
|
Popped = DFSStack.pop_back_val();
|
|
CurrentSCC.push_back(Popped);
|
|
} while (Popped != Start);
|
|
|
|
TheSCCs.push_back(CurrentSCC);
|
|
}
|
|
}
|
|
|
|
void BottomUpFunctionOrder::FindSCCs(SILModule &M) {
|
|
for (auto &F : M)
|
|
DFS(&F);
|
|
}
|