github.com/sanprasirt/go@v0.0.0-20170607001320-a027466e4b6d/src/cmd/compile/internal/mips64/ggen.go (about)

     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  
     5  package mips64
     6  
     7  import (
     8  	"cmd/compile/internal/gc"
     9  	"cmd/internal/obj"
    10  	"cmd/internal/obj/mips"
    11  )
    12  
    13  func zerorange(pp *gc.Progs, p *obj.Prog, off, cnt int64, _ *uint32) *obj.Prog {
    14  	if cnt == 0 {
    15  		return p
    16  	}
    17  	if cnt < int64(4*gc.Widthptr) {
    18  		for i := int64(0); i < cnt; i += int64(gc.Widthptr) {
    19  			p = pp.Appendpp(p, mips.AMOVV, obj.TYPE_REG, mips.REGZERO, 0, obj.TYPE_MEM, mips.REGSP, 8+off+i)
    20  		}
    21  	} else if cnt <= int64(128*gc.Widthptr) {
    22  		p = pp.Appendpp(p, mips.AADDV, obj.TYPE_CONST, 0, 8+off-8, obj.TYPE_REG, mips.REGRT1, 0)
    23  		p.Reg = mips.REGSP
    24  		p = pp.Appendpp(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
    25  		p.To.Name = obj.NAME_EXTERN
    26  		p.To.Sym = gc.Duffzero
    27  		p.To.Offset = 8 * (128 - cnt/int64(gc.Widthptr))
    28  	} else {
    29  		//	ADDV	$(8+frame+lo-8), SP, r1
    30  		//	ADDV	$cnt, r1, r2
    31  		// loop:
    32  		//	MOVV	R0, (Widthptr)r1
    33  		//	ADDV	$Widthptr, r1
    34  		//	BNE		r1, r2, loop
    35  		p = pp.Appendpp(p, mips.AADDV, obj.TYPE_CONST, 0, 8+off-8, obj.TYPE_REG, mips.REGRT1, 0)
    36  		p.Reg = mips.REGSP
    37  		p = pp.Appendpp(p, mips.AADDV, obj.TYPE_CONST, 0, cnt, obj.TYPE_REG, mips.REGRT2, 0)
    38  		p.Reg = mips.REGRT1
    39  		p = pp.Appendpp(p, mips.AMOVV, obj.TYPE_REG, mips.REGZERO, 0, obj.TYPE_MEM, mips.REGRT1, int64(gc.Widthptr))
    40  		p1 := p
    41  		p = pp.Appendpp(p, mips.AADDV, obj.TYPE_CONST, 0, int64(gc.Widthptr), obj.TYPE_REG, mips.REGRT1, 0)
    42  		p = pp.Appendpp(p, mips.ABNE, obj.TYPE_REG, mips.REGRT1, 0, obj.TYPE_BRANCH, 0, 0)
    43  		p.Reg = mips.REGRT2
    44  		gc.Patch(p, p1)
    45  	}
    46  
    47  	return p
    48  }
    49  
    50  func zeroAuto(pp *gc.Progs, n *gc.Node) {
    51  	// Note: this code must not clobber any registers.
    52  	sym := n.Sym.Linksym()
    53  	size := n.Type.Size()
    54  	for i := int64(0); i < size; i += 8 {
    55  		p := pp.Prog(mips.AMOVV)
    56  		p.From.Type = obj.TYPE_REG
    57  		p.From.Reg = mips.REGZERO
    58  		p.To.Type = obj.TYPE_MEM
    59  		p.To.Name = obj.NAME_AUTO
    60  		p.To.Reg = mips.REGSP
    61  		p.To.Offset = n.Xoffset + i
    62  		p.To.Sym = sym
    63  	}
    64  }
    65  
    66  func ginsnop(pp *gc.Progs) {
    67  	p := pp.Prog(mips.ANOR)
    68  	p.From.Type = obj.TYPE_REG
    69  	p.From.Reg = mips.REG_R0
    70  	p.To.Type = obj.TYPE_REG
    71  	p.To.Reg = mips.REG_R0
    72  }