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 arm
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/arm"
13)
14
15func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, r0 *uint32) *obj.Prog {
16	if cnt == 0 {
17		return p
18	}
19	if *r0 == 0 {
20		p = pp.Append(p, arm.AMOVW, obj.TYPE_CONST, 0, 0, obj.TYPE_REG, arm.REG_R0, 0)
21		*r0 = 1
22	}
23
24	if cnt < int64(4*types.PtrSize) {
25		for i := int64(0); i < cnt; i += int64(types.PtrSize) {
26			p = pp.Append(p, arm.AMOVW, obj.TYPE_REG, arm.REG_R0, 0, obj.TYPE_MEM, arm.REGSP, 4+off+i)
27		}
28	} else if cnt <= int64(128*types.PtrSize) {
29		p = pp.Append(p, arm.AADD, obj.TYPE_CONST, 0, 4+off, obj.TYPE_REG, arm.REG_R1, 0)
30		p.Reg = arm.REGSP
31		p = pp.Append(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
32		p.To.Name = obj.NAME_EXTERN
33		p.To.Sym = ir.Syms.Duffzero
34		p.To.Offset = 4 * (128 - cnt/int64(types.PtrSize))
35	} else {
36		p = pp.Append(p, arm.AADD, obj.TYPE_CONST, 0, 4+off, obj.TYPE_REG, arm.REG_R1, 0)
37		p.Reg = arm.REGSP
38		p = pp.Append(p, arm.AADD, obj.TYPE_CONST, 0, cnt, obj.TYPE_REG, arm.REG_R2, 0)
39		p.Reg = arm.REG_R1
40		p = pp.Append(p, arm.AMOVW, obj.TYPE_REG, arm.REG_R0, 0, obj.TYPE_MEM, arm.REG_R1, 4)
41		p1 := p
42		p.Scond |= arm.C_PBIT
43		p = pp.Append(p, arm.ACMP, obj.TYPE_REG, arm.REG_R1, 0, obj.TYPE_NONE, 0, 0)
44		p.Reg = arm.REG_R2
45		p = pp.Append(p, arm.ABNE, obj.TYPE_NONE, 0, 0, obj.TYPE_BRANCH, 0, 0)
46		p.To.SetTarget(p1)
47	}
48
49	return p
50}
51
52func ginsnop(pp *objw.Progs) *obj.Prog {
53	p := pp.Prog(arm.AAND)
54	p.From.Type = obj.TYPE_REG
55	p.From.Reg = arm.REG_R0
56	p.To.Type = obj.TYPE_REG
57	p.To.Reg = arm.REG_R0
58	p.Scond = arm.C_SCOND_EQ
59	return p
60}
61