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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x86
import (
"cmd/compile/internal/gc"
"cmd/internal/obj"
"cmd/internal/obj/x86"
)
func zerorange(pp *gc.Progs, p *obj.Prog, off, cnt int64, ax *uint32) *obj.Prog {
if cnt == 0 {
return p
}
if *ax == 0 {
p = pp.Appendpp(p, x86.AMOVL, obj.TYPE_CONST, 0, 0, obj.TYPE_REG, x86.REG_AX, 0)
*ax = 1
}
if cnt <= int64(4*gc.Widthreg) {
for i := int64(0); i < cnt; i += int64(gc.Widthreg) {
p = pp.Appendpp(p, x86.AMOVL, obj.TYPE_REG, x86.REG_AX, 0, obj.TYPE_MEM, x86.REG_SP, off+i)
}
} else if cnt <= int64(128*gc.Widthreg) {
p = pp.Appendpp(p, x86.ALEAL, obj.TYPE_MEM, x86.REG_SP, off, obj.TYPE_REG, x86.REG_DI, 0)
p = pp.Appendpp(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_ADDR, 0, 1*(128-cnt/int64(gc.Widthreg)))
p.To.Sym = gc.Duffzero
} else {
p = pp.Appendpp(p, x86.AMOVL, obj.TYPE_CONST, 0, cnt/int64(gc.Widthreg), obj.TYPE_REG, x86.REG_CX, 0)
p = pp.Appendpp(p, x86.ALEAL, obj.TYPE_MEM, x86.REG_SP, off, obj.TYPE_REG, x86.REG_DI, 0)
p = pp.Appendpp(p, x86.AREP, obj.TYPE_NONE, 0, 0, obj.TYPE_NONE, 0, 0)
p = pp.Appendpp(p, x86.ASTOSL, obj.TYPE_NONE, 0, 0, obj.TYPE_NONE, 0, 0)
}
return p
}
func ginsnop(pp *gc.Progs) *obj.Prog {
// See comment in ../amd64/ggen.go.
p := pp.Prog(x86.AXCHGL)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
p.To.Type = obj.TYPE_REG
p.To.Reg = x86.REG_AX
return p
}
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