Source file src/pkg/cmd/compile/internal/arm64/ggen.go

     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 arm64
     6	
     7	import (
     8		"cmd/compile/internal/gc"
     9		"cmd/internal/obj"
    10		"cmd/internal/obj/arm64"
    11		"cmd/internal/objabi"
    12	)
    13	
    14	var darwin = objabi.GOOS == "darwin"
    15	
    16	func padframe(frame int64) int64 {
    17		// arm64 requires that the frame size (not counting saved FP&LR)
    18		// be 16 bytes aligned. If not, pad it.
    19		if frame%16 != 0 {
    20			frame += 16 - (frame % 16)
    21		}
    22		return frame
    23	}
    24	
    25	func zerorange(pp *gc.Progs, p *obj.Prog, off, cnt int64, _ *uint32) *obj.Prog {
    26		if cnt == 0 {
    27			return p
    28		}
    29		if cnt < int64(4*gc.Widthptr) {
    30			for i := int64(0); i < cnt; i += int64(gc.Widthptr) {
    31				p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGZERO, 0, obj.TYPE_MEM, arm64.REGSP, 8+off+i)
    32			}
    33		} else if cnt <= int64(128*gc.Widthptr) && !darwin { // darwin ld64 cannot handle BR26 reloc with non-zero addend
    34			if cnt%(2*int64(gc.Widthptr)) != 0 {
    35				p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGZERO, 0, obj.TYPE_MEM, arm64.REGSP, 8+off)
    36				off += int64(gc.Widthptr)
    37				cnt -= int64(gc.Widthptr)
    38			}
    39			p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGSP, 0, obj.TYPE_REG, arm64.REG_R20, 0)
    40			p = pp.Appendpp(p, arm64.AADD, obj.TYPE_CONST, 0, 8+off, obj.TYPE_REG, arm64.REG_R20, 0)
    41			p.Reg = arm64.REG_R20
    42			p = pp.Appendpp(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
    43			p.To.Name = obj.NAME_EXTERN
    44			p.To.Sym = gc.Duffzero
    45			p.To.Offset = 4 * (64 - cnt/(2*int64(gc.Widthptr)))
    46		} else {
    47			p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_CONST, 0, 8+off-8, obj.TYPE_REG, arm64.REGTMP, 0)
    48			p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGSP, 0, obj.TYPE_REG, arm64.REGRT1, 0)
    49			p = pp.Appendpp(p, arm64.AADD, obj.TYPE_REG, arm64.REGTMP, 0, obj.TYPE_REG, arm64.REGRT1, 0)
    50			p.Reg = arm64.REGRT1
    51			p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_CONST, 0, cnt, obj.TYPE_REG, arm64.REGTMP, 0)
    52			p = pp.Appendpp(p, arm64.AADD, obj.TYPE_REG, arm64.REGTMP, 0, obj.TYPE_REG, arm64.REGRT2, 0)
    53			p.Reg = arm64.REGRT1
    54			p = pp.Appendpp(p, arm64.AMOVD, obj.TYPE_REG, arm64.REGZERO, 0, obj.TYPE_MEM, arm64.REGRT1, int64(gc.Widthptr))
    55			p.Scond = arm64.C_XPRE
    56			p1 := p
    57			p = pp.Appendpp(p, arm64.ACMP, obj.TYPE_REG, arm64.REGRT1, 0, obj.TYPE_NONE, 0, 0)
    58			p.Reg = arm64.REGRT2
    59			p = pp.Appendpp(p, arm64.ABNE, obj.TYPE_NONE, 0, 0, obj.TYPE_BRANCH, 0, 0)
    60			gc.Patch(p, p1)
    61		}
    62	
    63		return p
    64	}
    65	
    66	func zeroAuto(pp *gc.Progs, n *gc.Node) {
    67		// Note: this code must not clobber any registers.
    68		sym := n.Sym.Linksym()
    69		size := n.Type.Size()
    70		for i := int64(0); i < size; i += 8 {
    71			p := pp.Prog(arm64.AMOVD)
    72			p.From.Type = obj.TYPE_REG
    73			p.From.Reg = arm64.REGZERO
    74			p.To.Type = obj.TYPE_MEM
    75			p.To.Name = obj.NAME_AUTO
    76			p.To.Reg = arm64.REGSP
    77			p.To.Offset = n.Xoffset + i
    78			p.To.Sym = sym
    79		}
    80	}
    81	
    82	func ginsnop(pp *gc.Progs) *obj.Prog {
    83		p := pp.Prog(arm64.AHINT)
    84		p.From.Type = obj.TYPE_CONST
    85		return p
    86	}
    87	

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