1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#if ENABLE(B3_JIT)
29
30#include "CPU.h"
31#include "Options.h"
32
33namespace JSC { namespace B3 { namespace Air {
34
35class Code;
36
37// This implements the Poletto and Sarkar register allocator called "linear scan":
38// http://dl.acm.org/citation.cfm?id=330250
39//
40// This is not Air's primary register allocator. We use it only when running at optLevel<2.
41// That's not the default level. This register allocator is optimized primarily for running
42// quickly. It's expected that improvements to this register allocator should focus on improving
43// its execution time without much regard for the quality of generated code. If you want good
44// code, use graph coloring.
45//
46// For Air's primary register allocator, see AirAllocateRegistersByGraphColoring.h|cpp.
47//
48// This also does stack allocation as an afterthought. It does not do any spill coalescing.
49void allocateRegistersAndStackByLinearScan(Code&);
50
51} } } // namespace JSC::B3::Air
52
53#endif // ENABLE(B3_JIT)
54