mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
42 lines
1.5 KiB
C++
42 lines
1.5 KiB
C++
//===--- BasicBlockUtils.cpp - Utilities for SILBasicBlock ----------------===//
|
|
//
|
|
// 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/SIL/BasicBlockUtils.h"
|
|
#include "swift/SIL/SILFunction.h"
|
|
#include "swift/SIL/SILBasicBlock.h"
|
|
|
|
using namespace swift;
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DeadEndBlocks
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
void DeadEndBlocks::compute() {
|
|
assert(ReachableBlocks.empty() && "Computed twice");
|
|
|
|
// First step: find blocks which end up in a no-return block (terminated by
|
|
// an unreachable instruction).
|
|
// Search for function-exiting blocks, i.e. return and throw.
|
|
for (const SILBasicBlock &BB : *F) {
|
|
const TermInst *TI = BB.getTerminator();
|
|
if (TI->isFunctionExiting())
|
|
ReachableBlocks.insert(&BB);
|
|
}
|
|
// Propagate the reachability up the control flow graph.
|
|
unsigned Idx = 0;
|
|
while (Idx < ReachableBlocks.size()) {
|
|
const SILBasicBlock *BB = ReachableBlocks[Idx++];
|
|
for (SILBasicBlock *Pred : BB->getPredecessorBlocks())
|
|
ReachableBlocks.insert(Pred);
|
|
}
|
|
}
|