1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package arm64
6
7import (
8	"cmd/compile/internal/ir"
9	"cmd/compile/internal/objw"
10	"cmd/compile/internal/types"
11	"cmd/internal/obj"
12	"cmd/internal/obj/arm64"
13)
14
15func padframe(frame int64) int64 {
16	// arm64 requires that the frame size (not counting saved FP&LR)
17	// be 16 bytes aligned. If not, pad it.
18	if frame%16 != 0 {
19		frame += 16 - (frame % 16)
20	}
21	return frame
22}
23
24func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, _ *uint32) *obj.Prog {
25	if cnt == 0 {
26		return p
27	}
28	if cnt < int64(4*types.PtrSize) {
29		for i := int64(0); i < cnt; i += int64(types.PtrSize) {
30			p = pp.Append(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGZERO, 0, obj.TYPE_MEM, arm64.REGSP, 8+off+i)
31		}
32	} else if cnt <= int64(128*types.PtrSize) {
33		if cnt%(2*int64(types.PtrSize)) != 0 {
34			p = pp.Append(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGZERO, 0, obj.TYPE_MEM, arm64.REGSP, 8+off)
35			off += int64(types.PtrSize)
36			cnt -= int64(types.PtrSize)
37		}
38		p = pp.Append(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGSP, 0, obj.TYPE_REG, arm64.REG_R20, 0)
39		p = pp.Append(p, arm64.AADD, obj.TYPE_CONST, 0, 8+off, obj.TYPE_REG, arm64.REG_R20, 0)
40		p.Reg = arm64.REG_R20
41		p = pp.Append(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
42		p.To.Name = obj.NAME_EXTERN
43		p.To.Sym = ir.Syms.Duffzero
44		p.To.Offset = 4 * (64 - cnt/(2*int64(types.PtrSize)))
45	} else {
46		// Not using REGTMP, so this is async preemptible (async preemption clobbers REGTMP).
47		// We are at the function entry, where no register is live, so it is okay to clobber
48		// other registers
49		const rtmp = arm64.REG_R20
50		p = pp.Append(p, arm64.AMOVD, obj.TYPE_CONST, 0, 8+off-8, obj.TYPE_REG, rtmp, 0)
51		p = pp.Append(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGSP, 0, obj.TYPE_REG, arm64.REGRT1, 0)
52		p = pp.Append(p, arm64.AADD, obj.TYPE_REG, rtmp, 0, obj.TYPE_REG, arm64.REGRT1, 0)
53		p.Reg = arm64.REGRT1
54		p = pp.Append(p, arm64.AMOVD, obj.TYPE_CONST, 0, cnt, obj.TYPE_REG, rtmp, 0)
55		p = pp.Append(p, arm64.AADD, obj.TYPE_REG, rtmp, 0, obj.TYPE_REG, arm64.REGRT2, 0)
56		p.Reg = arm64.REGRT1
57		p = pp.Append(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGZERO, 0, obj.TYPE_MEM, arm64.REGRT1, int64(types.PtrSize))
58		p.Scond = arm64.C_XPRE
59		p1 := p
60		p = pp.Append(p, arm64.ACMP, obj.TYPE_REG, arm64.REGRT1, 0, obj.TYPE_NONE, 0, 0)
61		p.Reg = arm64.REGRT2
62		p = pp.Append(p, arm64.ABNE, obj.TYPE_NONE, 0, 0, obj.TYPE_BRANCH, 0, 0)
63		p.To.SetTarget(p1)
64	}
65
66	return p
67}
68
69func ginsnop(pp *objw.Progs) *obj.Prog {
70	p := pp.Prog(arm64.AHINT)
71	p.From.Type = obj.TYPE_CONST
72	return p
73}
74