// cmd/7l/asm.c, cmd/7l/asmout.c, cmd/7l/optab.c, cmd/7l/span.c, cmd/ld/sub.c, cmd/ld/mod.c, from Vita Nuova.
// https://code.google.com/p/ken-cc/source/browse/
//
// 	Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// 	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// 	Portions Copyright © 1997-1999 Vita Nuova Limited
// 	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// 	Portions Copyright © 2004,2006 Bruce Ellis
// 	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// 	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// 	Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package arm64

import (
	"cmd/internal/obj"
	"fmt"
	"log"
	"math"
	"sort"
)

const (
	FuncAlign = 16
)

const (
	REGFROM = 1
)

type Optab struct {
	as    obj.As
	a1    uint8
	a2    uint8
	a3    uint8
	type_ int8
	size  int8
	param int16
	flag  int8
	scond uint16
}

var oprange [ALAST & obj.AMask][]Optab

var xcmp [C_NCLASS][C_NCLASS]bool

const (
	S32     = 0 << 31
	S64     = 1 << 31
	Sbit    = 1 << 29
	LSL0_32 = 2 << 13
	LSL0_64 = 3 << 13
)

func OPDP2(x uint32) uint32 {
	return 0<<30 | 0<<29 | 0xd6<<21 | x<<10
}

func OPDP3(sf uint32, op54 uint32, op31 uint32, o0 uint32) uint32 {
	return sf<<31 | op54<<29 | 0x1B<<24 | op31<<21 | o0<<15
}

func OPBcc(x uint32) uint32 {
	return 0x2A<<25 | 0<<24 | 0<<4 | x&15
}

func OPBLR(x uint32) uint32 {
	/* x=0, JMP; 1, CALL; 2, RET */
	return 0x6B<<25 | 0<<23 | x<<21 | 0x1F<<16 | 0<<10
}

func SYSOP(l uint32, op0 uint32, op1 uint32, crn uint32, crm uint32, op2 uint32, rt uint32) uint32 {
	return 0x354<<22 | l<<21 | op0<<19 | op1<<16 | crn&15<<12 | crm&15<<8 | op2<<5 | rt
}

func SYSHINT(x uint32) uint32 {
	return SYSOP(0, 0, 3, 2, 0, x, 0x1F)
}

func LDSTR12U(sz uint32, v uint32, opc uint32) uint32 {
	return sz<<30 | 7<<27 | v<<26 | 1<<24 | opc<<22
}

func LDSTR9S(sz uint32, v uint32, opc uint32) uint32 {
	return sz<<30 | 7<<27 | v<<26 | 0<<24 | opc<<22
}

func LD2STR(o uint32) uint32 {
	return o &^ (3 << 22)
}

func LDSTX(sz uint32, o2 uint32, l uint32, o1 uint32, o0 uint32) uint32 {
	return sz<<30 | 0x8<<24 | o2<<23 | l<<22 | o1<<21 | o0<<15
}

func FPCMP(m uint32, s uint32, type_ uint32, op uint32, op2 uint32) uint32 {
	return m<<31 | s<<29 | 0x1E<<24 | type_<<22 | 1<<21 | op<<14 | 8<<10 | op2
}

func FPCCMP(m uint32, s uint32, type_ uint32, op uint32) uint32 {
	return m<<31 | s<<29 | 0x1E<<24 | type_<<22 | 1<<21 | 1<<10 | op<<4
}

func FPOP1S(m uint32, s uint32, type_ uint32, op uint32) uint32 {
	return m<<31 | s<<29 | 0x1E<<24 | type_<<22 | 1<<21 | op<<15 | 0x10<<10
}

func FPOP2S(m uint32, s uint32, type_ uint32, op uint32) uint32 {
	return m<<31 | s<<29 | 0x1E<<24 | type_<<22 | 1<<21 | op<<12 | 2<<10
}

func FPCVTI(sf uint32, s uint32, type_ uint32, rmode uint32, op uint32) uint32 {
	return sf<<31 | s<<29 | 0x1E<<24 | type_<<22 | 1<<21 | rmode<<19 | op<<16 | 0<<10
}

func ADR(p uint32, o uint32, rt uint32) uint32 {
	return p<<31 | (o&3)<<29 | 0x10<<24 | ((o>>2)&0x7FFFF)<<5 | rt&31
}

func OPBIT(x uint32) uint32 {
	return 1<<30 | 0<<29 | 0xD6<<21 | 0<<16 | x<<10
}

const (
	LFROM = 1 << 0
	LTO   = 1 << 1
)

var optab = []Optab{
	/* struct Optab:
	OPCODE, from, prog->reg, to, type,size,param,flag,scond */
	{obj.ATEXT, C_ADDR, C_NONE, C_TEXTSIZE, 0, 0, 0, 0, 0},

	/* arithmetic operations */
	{AADD, C_REG, C_REG, C_REG, 1, 4, 0, 0, 0},
	{AADD, C_REG, C_NONE, C_REG, 1, 4, 0, 0, 0},
	{AADC, C_REG, C_REG, C_REG, 1, 4, 0, 0, 0},
	{AADC, C_REG, C_NONE, C_REG, 1, 4, 0, 0, 0},
	{ANEG, C_REG, C_NONE, C_REG, 25, 4, 0, 0, 0},
	{ANEG, C_NONE, C_NONE, C_REG, 25, 4, 0, 0, 0},
	{ANGC, C_REG, C_NONE, C_REG, 17, 4, 0, 0, 0},
	{ACMP, C_REG, C_REG, C_NONE, 1, 4, 0, 0, 0},
	{AADD, C_ADDCON, C_RSP, C_RSP, 2, 4, 0, 0, 0},
	{AADD, C_ADDCON, C_NONE, C_RSP, 2, 4, 0, 0, 0},
	{ACMP, C_ADDCON, C_RSP, C_NONE, 2, 4, 0, 0, 0},
	{AADD, C_MOVCON, C_RSP, C_RSP, 62, 8, 0, 0, 0},
	{AADD, C_MOVCON, C_NONE, C_RSP, 62, 8, 0, 0, 0},
	{ACMP, C_MOVCON, C_RSP, C_NONE, 62, 8, 0, 0, 0},
	{AADD, C_BITCON, C_RSP, C_RSP, 62, 8, 0, 0, 0},
	{AADD, C_BITCON, C_NONE, C_RSP, 62, 8, 0, 0, 0},
	{ACMP, C_BITCON, C_RSP, C_NONE, 62, 8, 0, 0, 0},
	{AADD, C_VCON, C_RSP, C_RSP, 13, 8, 0, LFROM, 0},
	{AADD, C_VCON, C_NONE, C_RSP, 13, 8, 0, LFROM, 0},
	{ACMP, C_VCON, C_REG, C_NONE, 13, 8, 0, LFROM, 0},
	{AADD, C_SHIFT, C_REG, C_REG, 3, 4, 0, 0, 0},
	{AADD, C_SHIFT, C_NONE, C_REG, 3, 4, 0, 0, 0},
	{AMVN, C_SHIFT, C_NONE, C_REG, 3, 4, 0, 0, 0},
	{ACMP, C_SHIFT, C_REG, C_NONE, 3, 4, 0, 0, 0},
	{ANEG, C_SHIFT, C_NONE, C_REG, 26, 4, 0, 0, 0},
	{AADD, C_REG, C_RSP, C_RSP, 27, 4, 0, 0, 0},
	{AADD, C_REG, C_NONE, C_RSP, 27, 4, 0, 0, 0},
	{ACMP, C_REG, C_RSP, C_NONE, 27, 4, 0, 0, 0},
	{AADD, C_EXTREG, C_RSP, C_RSP, 27, 4, 0, 0, 0},
	{AADD, C_EXTREG, C_NONE, C_RSP, 27, 4, 0, 0, 0},
	{AMVN, C_EXTREG, C_NONE, C_RSP, 27, 4, 0, 0, 0},
	{ACMP, C_EXTREG, C_RSP, C_NONE, 27, 4, 0, 0, 0},
	{AADD, C_REG, C_REG, C_REG, 1, 4, 0, 0, 0},
	{AADD, C_REG, C_NONE, C_REG, 1, 4, 0, 0, 0},

	/* logical operations */
	{AAND, C_REG, C_REG, C_REG, 1, 4, 0, 0, 0},
	{AAND, C_REG, C_NONE, C_REG, 1, 4, 0, 0, 0},
	{ABIC, C_REG, C_REG, C_REG, 1, 4, 0, 0, 0},
	{ABIC, C_REG, C_NONE, C_REG, 1, 4, 0, 0, 0},
	{AAND, C_BITCON, C_REG, C_REG, 53, 4, 0, 0, 0},
	{AAND, C_BITCON, C_NONE, C_REG, 53, 4, 0, 0, 0},
	{ABIC, C_BITCON, C_REG, C_REG, 53, 4, 0, 0, 0},
	{ABIC, C_BITCON, C_NONE, C_REG, 53, 4, 0, 0, 0},
	{AAND, C_MOVCON, C_REG, C_REG, 62, 8, 0, 0, 0},
	{AAND, C_MOVCON, C_NONE, C_REG, 62, 8, 0, 0, 0},
	{ABIC, C_MOVCON, C_REG, C_REG, 62, 8, 0, 0, 0},
	{ABIC, C_MOVCON, C_NONE, C_REG, 62, 8, 0, 0, 0},
	{AAND, C_VCON, C_REG, C_REG, 28, 8, 0, LFROM, 0},
	{AAND, C_VCON, C_NONE, C_REG, 28, 8, 0, LFROM, 0},
	{ABIC, C_VCON, C_REG, C_REG, 28, 8, 0, LFROM, 0},
	{ABIC, C_VCON, C_NONE, C_REG, 28, 8, 0, LFROM, 0},
	{AAND, C_SHIFT, C_REG, C_REG, 3, 4, 0, 0, 0},
	{AAND, C_SHIFT, C_NONE, C_REG, 3, 4, 0, 0, 0},
	{ABIC, C_SHIFT, C_REG, C_REG, 3, 4, 0, 0, 0},
	{ABIC, C_SHIFT, C_NONE, C_REG, 3, 4, 0, 0, 0},
	{AMOVD, C_RSP, C_NONE, C_RSP, 24, 4, 0, 0, 0},
	{AMVN, C_REG, C_NONE, C_REG, 24, 4, 0, 0, 0},
	{AMOVB, C_REG, C_NONE, C_REG, 45, 4, 0, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_REG, 45, 4, 0, 0, 0},
	{AMOVH, C_REG, C_NONE, C_REG, 45, 4, 0, 0, 0}, /* also MOVHU */
	{AMOVW, C_REG, C_NONE, C_REG, 45, 4, 0, 0, 0}, /* also MOVWU */
	/* TODO: MVN C_SHIFT */

	/* MOVs that become MOVK/MOVN/MOVZ/ADD/SUB/OR */
	{AMOVW, C_MOVCON, C_NONE, C_REG, 32, 4, 0, 0, 0},
	{AMOVD, C_MOVCON, C_NONE, C_REG, 32, 4, 0, 0, 0},

	// TODO: these don't work properly.
	// { AMOVW,		C_ADDCON,	C_NONE,	C_REG,		2, 4, 0 , 0},
	// { AMOVD,		C_ADDCON,	C_NONE,	C_REG,		2, 4, 0 , 0},
	{AMOVW, C_BITCON, C_NONE, C_REG, 32, 4, 0, 0, 0},
	{AMOVD, C_BITCON, C_NONE, C_REG, 32, 4, 0, 0, 0},

	{AMOVK, C_VCON, C_NONE, C_REG, 33, 4, 0, 0, 0},
	{AMOVD, C_AACON, C_NONE, C_REG, 4, 4, REGFROM, 0, 0},
	{ASDIV, C_REG, C_NONE, C_REG, 1, 4, 0, 0, 0},
	{ASDIV, C_REG, C_REG, C_REG, 1, 4, 0, 0, 0},
	{AB, C_NONE, C_NONE, C_SBRA, 5, 4, 0, 0, 0},
	{ABL, C_NONE, C_NONE, C_SBRA, 5, 4, 0, 0, 0},
	{AB, C_NONE, C_NONE, C_ZOREG, 6, 4, 0, 0, 0},
	{ABL, C_NONE, C_NONE, C_REG, 6, 4, 0, 0, 0},
	{ABL, C_REG, C_NONE, C_REG, 6, 4, 0, 0, 0},
	{ABL, C_NONE, C_NONE, C_ZOREG, 6, 4, 0, 0, 0},
	{obj.ARET, C_NONE, C_NONE, C_REG, 6, 4, 0, 0, 0},
	{obj.ARET, C_NONE, C_NONE, C_ZOREG, 6, 4, 0, 0, 0},
	{AADRP, C_SBRA, C_NONE, C_REG, 60, 4, 0, 0, 0},
	{AADR, C_SBRA, C_NONE, C_REG, 61, 4, 0, 0, 0},
	{ABFM, C_VCON, C_REG, C_REG, 42, 4, 0, 0, 0},
	{ABFI, C_VCON, C_REG, C_REG, 43, 4, 0, 0, 0},
	{AEXTR, C_VCON, C_REG, C_REG, 44, 4, 0, 0, 0},
	{ASXTB, C_REG, C_NONE, C_REG, 45, 4, 0, 0, 0},
	{ACLS, C_REG, C_NONE, C_REG, 46, 4, 0, 0, 0},
	{ABEQ, C_NONE, C_NONE, C_SBRA, 7, 4, 0, 0, 0},
	{ALSL, C_VCON, C_REG, C_REG, 8, 4, 0, 0, 0},
	{ALSL, C_VCON, C_NONE, C_REG, 8, 4, 0, 0, 0},
	{ALSL, C_REG, C_NONE, C_REG, 9, 4, 0, 0, 0},
	{ALSL, C_REG, C_REG, C_REG, 9, 4, 0, 0, 0},
	{ASVC, C_NONE, C_NONE, C_VCON, 10, 4, 0, 0, 0},
	{ASVC, C_NONE, C_NONE, C_NONE, 10, 4, 0, 0, 0},
	{ADWORD, C_NONE, C_NONE, C_VCON, 11, 8, 0, 0, 0},
	{ADWORD, C_NONE, C_NONE, C_LEXT, 11, 8, 0, 0, 0},
	{ADWORD, C_NONE, C_NONE, C_ADDR, 11, 8, 0, 0, 0},
	{ADWORD, C_NONE, C_NONE, C_LACON, 11, 8, 0, 0, 0},
	{AWORD, C_NONE, C_NONE, C_LCON, 14, 4, 0, 0, 0},
	{AWORD, C_NONE, C_NONE, C_LEXT, 14, 4, 0, 0, 0},
	{AWORD, C_NONE, C_NONE, C_ADDR, 14, 4, 0, 0, 0},
	{AMOVW, C_VCON, C_NONE, C_REG, 12, 4, 0, LFROM, 0},
	{AMOVW, C_VCONADDR, C_NONE, C_REG, 68, 8, 0, 0, 0},
	{AMOVD, C_VCON, C_NONE, C_REG, 12, 4, 0, LFROM, 0},
	{AMOVD, C_VCONADDR, C_NONE, C_REG, 68, 8, 0, 0, 0},
	{AMOVB, C_REG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AMOVH, C_REG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AMOVW, C_REG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AMOVD, C_REG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AMOVB, C_ADDR, C_NONE, C_REG, 65, 12, 0, 0, 0},
	{AMOVBU, C_ADDR, C_NONE, C_REG, 65, 12, 0, 0, 0},
	{AMOVH, C_ADDR, C_NONE, C_REG, 65, 12, 0, 0, 0},
	{AMOVW, C_ADDR, C_NONE, C_REG, 65, 12, 0, 0, 0},
	{AMOVD, C_ADDR, C_NONE, C_REG, 65, 12, 0, 0, 0},
	{AMOVD, C_GOTADDR, C_NONE, C_REG, 71, 8, 0, 0, 0},
	{AMOVD, C_TLS_LE, C_NONE, C_REG, 69, 4, 0, 0, 0},
	{AMOVD, C_TLS_IE, C_NONE, C_REG, 70, 8, 0, 0, 0},
	{AMUL, C_REG, C_REG, C_REG, 15, 4, 0, 0, 0},
	{AMUL, C_REG, C_NONE, C_REG, 15, 4, 0, 0, 0},
	{AMADD, C_REG, C_REG, C_REG, 15, 4, 0, 0, 0},
	{AREM, C_REG, C_REG, C_REG, 16, 8, 0, 0, 0},
	{AREM, C_REG, C_NONE, C_REG, 16, 8, 0, 0, 0},
	{ACSEL, C_COND, C_REG, C_REG, 18, 4, 0, 0, 0}, /* from3 optional */
	{ACSET, C_COND, C_NONE, C_REG, 18, 4, 0, 0, 0},
	{ACCMN, C_COND, C_REG, C_VCON, 19, 4, 0, 0, 0}, /* from3 either C_REG or C_VCON */

	/* scaled 12-bit unsigned displacement store */
	{AMOVB, C_REG, C_NONE, C_UAUTO4K, 20, 4, REGSP, 0, 0},
	{AMOVB, C_REG, C_NONE, C_UOREG4K, 20, 4, 0, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_UAUTO4K, 20, 4, REGSP, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_UOREG4K, 20, 4, 0, 0, 0},

	{AMOVH, C_REG, C_NONE, C_UAUTO8K, 20, 4, REGSP, 0, 0},
	{AMOVH, C_REG, C_NONE, C_ZOREG, 20, 4, 0, 0, 0},
	{AMOVH, C_REG, C_NONE, C_UOREG8K, 20, 4, 0, 0, 0},

	{AMOVW, C_REG, C_NONE, C_UAUTO16K, 20, 4, REGSP, 0, 0},
	{AMOVW, C_REG, C_NONE, C_ZOREG, 20, 4, 0, 0, 0},
	{AMOVW, C_REG, C_NONE, C_UOREG16K, 20, 4, 0, 0, 0},

	/* unscaled 9-bit signed displacement store */
	{AMOVB, C_REG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},
	{AMOVB, C_REG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},

	{AMOVH, C_REG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},
	{AMOVH, C_REG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},
	{AMOVW, C_REG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},
	{AMOVW, C_REG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},

	{AMOVD, C_REG, C_NONE, C_UAUTO32K, 20, 4, REGSP, 0, 0},
	{AMOVD, C_REG, C_NONE, C_ZOREG, 20, 4, 0, 0, 0},
	{AMOVD, C_REG, C_NONE, C_UOREG32K, 20, 4, 0, 0, 0},
	{AMOVD, C_REG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},
	{AMOVD, C_REG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},

	/* short displacement load */
	{AMOVB, C_UAUTO4K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVB, C_NSAUTO, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVB, C_ZOREG, C_NONE, C_REG, 21, 4, 0, 0, 0},
	{AMOVB, C_UOREG4K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVB, C_NSOREG, C_NONE, C_REG, 21, 4, REGSP, 0, 0},

	{AMOVBU, C_UAUTO4K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVBU, C_NSAUTO, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVBU, C_ZOREG, C_NONE, C_REG, 21, 4, 0, 0, 0},
	{AMOVBU, C_UOREG4K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVBU, C_NSOREG, C_NONE, C_REG, 21, 4, REGSP, 0, 0},

	{AMOVH, C_UAUTO8K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVH, C_NSAUTO, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVH, C_ZOREG, C_NONE, C_REG, 21, 4, 0, 0, 0},
	{AMOVH, C_UOREG8K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVH, C_NSOREG, C_NONE, C_REG, 21, 4, REGSP, 0, 0},

	{AMOVW, C_UAUTO16K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVW, C_NSAUTO, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVW, C_ZOREG, C_NONE, C_REG, 21, 4, 0, 0, 0},
	{AMOVW, C_UOREG16K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVW, C_NSOREG, C_NONE, C_REG, 21, 4, REGSP, 0, 0},

	{AMOVD, C_UAUTO32K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVD, C_NSAUTO, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVD, C_ZOREG, C_NONE, C_REG, 21, 4, 0, 0, 0},
	{AMOVD, C_UOREG32K, C_NONE, C_REG, 21, 4, REGSP, 0, 0},
	{AMOVD, C_NSOREG, C_NONE, C_REG, 21, 4, REGSP, 0, 0},

	/* long displacement store */
	{AMOVB, C_REG, C_NONE, C_LAUTO, 30, 8, REGSP, 0, 0},
	{AMOVB, C_REG, C_NONE, C_LOREG, 30, 8, 0, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_LAUTO, 30, 8, REGSP, 0, 0},
	{AMOVBU, C_REG, C_NONE, C_LOREG, 30, 8, 0, 0, 0},
	{AMOVH, C_REG, C_NONE, C_LAUTO, 30, 8, REGSP, 0, 0},
	{AMOVH, C_REG, C_NONE, C_LOREG, 30, 8, 0, 0, 0},
	{AMOVW, C_REG, C_NONE, C_LAUTO, 30, 8, REGSP, 0, 0},
	{AMOVW, C_REG, C_NONE, C_LOREG, 30, 8, 0, 0, 0},
	{AMOVD, C_REG, C_NONE, C_LAUTO, 30, 8, REGSP, 0, 0},
	{AMOVD, C_REG, C_NONE, C_LOREG, 30, 8, 0, 0, 0},

	/* long displacement load */
	{AMOVB, C_LAUTO, C_NONE, C_REG, 31, 8, REGSP, 0, 0},
	{AMOVB, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVB, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVBU, C_LAUTO, C_NONE, C_REG, 31, 8, REGSP, 0, 0},
	{AMOVBU, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVBU, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVH, C_LAUTO, C_NONE, C_REG, 31, 8, REGSP, 0, 0},
	{AMOVH, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVH, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVW, C_LAUTO, C_NONE, C_REG, 31, 8, REGSP, 0, 0},
	{AMOVW, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVW, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVD, C_LAUTO, C_NONE, C_REG, 31, 8, REGSP, 0, 0},
	{AMOVD, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},
	{AMOVD, C_LOREG, C_NONE, C_REG, 31, 8, 0, 0, 0},

	/* load long effective stack address (load int32 offset and add) */
	{AMOVD, C_LACON, C_NONE, C_REG, 34, 8, REGSP, LFROM, 0},

	/* pre/post-indexed load (unscaled, signed 9-bit offset) */
	{AMOVD, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPOST},
	{AMOVW, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPOST},
	{AMOVH, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPOST},
	{AMOVB, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPOST},
	{AMOVBU, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPOST},
	{AFMOVS, C_LOREG, C_NONE, C_FREG, 22, 4, 0, 0, C_XPOST},
	{AFMOVD, C_LOREG, C_NONE, C_FREG, 22, 4, 0, 0, C_XPOST},
	{AMOVD, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPRE},
	{AMOVW, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPRE},
	{AMOVH, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPRE},
	{AMOVB, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPRE},
	{AMOVBU, C_LOREG, C_NONE, C_REG, 22, 4, 0, 0, C_XPRE},
	{AFMOVS, C_LOREG, C_NONE, C_FREG, 22, 4, 0, 0, C_XPRE},
	{AFMOVD, C_LOREG, C_NONE, C_FREG, 22, 4, 0, 0, C_XPRE},

	/* pre/post-indexed store (unscaled, signed 9-bit offset) */
	{AMOVD, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AMOVW, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AMOVH, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AMOVB, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AMOVBU, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AFMOVS, C_FREG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AFMOVD, C_FREG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPOST},
	{AMOVD, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},
	{AMOVW, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},
	{AMOVH, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},
	{AMOVB, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},
	{AMOVBU, C_REG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},
	{AFMOVS, C_FREG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},
	{AFMOVD, C_FREG, C_NONE, C_LOREG, 23, 4, 0, 0, C_XPRE},

	/* pre/post-indexed load/store register pair
	   (unscaled, signed 10-bit quad-aligned offset) */
	{ALDP, C_LOREG, C_NONE, C_PAIR, 66, 4, 0, 0, C_XPRE},
	{ALDP, C_LOREG, C_NONE, C_PAIR, 66, 4, 0, 0, C_XPOST},
	{ASTP, C_PAIR, C_NONE, C_LOREG, 67, 4, 0, 0, C_XPRE},
	{ASTP, C_PAIR, C_NONE, C_LOREG, 67, 4, 0, 0, C_XPOST},

	/* special */
	{AMOVD, C_SPR, C_NONE, C_REG, 35, 4, 0, 0, 0},
	{AMRS, C_SPR, C_NONE, C_REG, 35, 4, 0, 0, 0},
	{AMOVD, C_REG, C_NONE, C_SPR, 36, 4, 0, 0, 0},
	{AMSR, C_REG, C_NONE, C_SPR, 36, 4, 0, 0, 0},
	{AMOVD, C_VCON, C_NONE, C_SPR, 37, 4, 0, 0, 0},
	{AMSR, C_VCON, C_NONE, C_SPR, 37, 4, 0, 0, 0},
	{AERET, C_NONE, C_NONE, C_NONE, 41, 4, 0, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_UAUTO16K, 20, 4, REGSP, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_ZOREG, 20, 4, 0, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_UOREG16K, 20, 4, 0, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_UAUTO32K, 20, 4, REGSP, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_NSAUTO, 20, 4, REGSP, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_ZOREG, 20, 4, 0, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_UOREG32K, 20, 4, 0, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_NSOREG, 20, 4, 0, 0, 0},
	{AFMOVS, C_UAUTO16K, C_NONE, C_FREG, 21, 4, REGSP, 0, 0},
	{AFMOVS, C_NSAUTO, C_NONE, C_FREG, 21, 4, REGSP, 0, 0},
	{AFMOVS, C_ZOREG, C_NONE, C_FREG, 21, 4, 0, 0, 0},
	{AFMOVS, C_UOREG16K, C_NONE, C_FREG, 21, 4, 0, 0, 0},
	{AFMOVS, C_NSOREG, C_NONE, C_FREG, 21, 4, 0, 0, 0},
	{AFMOVD, C_UAUTO32K, C_NONE, C_FREG, 21, 4, REGSP, 0, 0},
	{AFMOVD, C_NSAUTO, C_NONE, C_FREG, 21, 4, REGSP, 0, 0},
	{AFMOVD, C_ZOREG, C_NONE, C_FREG, 21, 4, 0, 0, 0},
	{AFMOVD, C_UOREG32K, C_NONE, C_FREG, 21, 4, 0, 0, 0},
	{AFMOVD, C_NSOREG, C_NONE, C_FREG, 21, 4, 0, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_LAUTO, 30, 8, REGSP, LTO, 0},
	{AFMOVS, C_FREG, C_NONE, C_LOREG, 30, 8, 0, LTO, 0},
	{AFMOVD, C_FREG, C_NONE, C_LAUTO, 30, 8, REGSP, LTO, 0},
	{AFMOVD, C_FREG, C_NONE, C_LOREG, 30, 8, 0, LTO, 0},
	{AFMOVS, C_LAUTO, C_NONE, C_FREG, 31, 8, REGSP, LFROM, 0},
	{AFMOVS, C_LOREG, C_NONE, C_FREG, 31, 8, 0, LFROM, 0},
	{AFMOVD, C_LAUTO, C_NONE, C_FREG, 31, 8, REGSP, LFROM, 0},
	{AFMOVD, C_LOREG, C_NONE, C_FREG, 31, 8, 0, LFROM, 0},
	{AFMOVS, C_FREG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AFMOVS, C_ADDR, C_NONE, C_FREG, 65, 12, 0, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_ADDR, 64, 12, 0, 0, 0},
	{AFMOVD, C_ADDR, C_NONE, C_FREG, 65, 12, 0, 0, 0},
	{AFADDS, C_FREG, C_NONE, C_FREG, 54, 4, 0, 0, 0},
	{AFADDS, C_FREG, C_FREG, C_FREG, 54, 4, 0, 0, 0},
	{AFADDS, C_FCON, C_NONE, C_FREG, 54, 4, 0, 0, 0},
	{AFADDS, C_FCON, C_FREG, C_FREG, 54, 4, 0, 0, 0},
	{AFMOVS, C_FCON, C_NONE, C_FREG, 54, 4, 0, 0, 0},
	{AFMOVS, C_FREG, C_NONE, C_FREG, 54, 4, 0, 0, 0},
	{AFMOVD, C_FCON, C_NONE, C_FREG, 54, 4, 0, 0, 0},
	{AFMOVD, C_FREG, C_NONE, C_FREG, 54, 4, 0, 0, 0},
	{AFCVTZSD, C_FREG, C_NONE, C_REG, 29, 4, 0, 0, 0},
	{ASCVTFD, C_REG, C_NONE, C_FREG, 29, 4, 0, 0, 0},
	{AFCMPS, C_FREG, C_FREG, C_NONE, 56, 4, 0, 0, 0},
	{AFCMPS, C_FCON, C_FREG, C_NONE, 56, 4, 0, 0, 0},
	{AFCCMPS, C_COND, C_REG, C_VCON, 57, 4, 0, 0, 0},
	{AFCSELD, C_COND, C_REG, C_FREG, 18, 4, 0, 0, 0},
	{AFCVTSD, C_FREG, C_NONE, C_FREG, 29, 4, 0, 0, 0},
	{ACLREX, C_NONE, C_NONE, C_VCON, 38, 4, 0, 0, 0},
	{ACLREX, C_NONE, C_NONE, C_NONE, 38, 4, 0, 0, 0},
	{ACBZ, C_REG, C_NONE, C_SBRA, 39, 4, 0, 0, 0},
	{ATBZ, C_VCON, C_REG, C_SBRA, 40, 4, 0, 0, 0},
	{ASYS, C_VCON, C_NONE, C_NONE, 50, 4, 0, 0, 0},
	{ASYS, C_VCON, C_REG, C_NONE, 50, 4, 0, 0, 0},
	{ASYSL, C_VCON, C_NONE, C_REG, 50, 4, 0, 0, 0},
	{ADMB, C_VCON, C_NONE, C_NONE, 51, 4, 0, 0, 0},
	{AHINT, C_VCON, C_NONE, C_NONE, 52, 4, 0, 0, 0},
	{ALDAR, C_ZOREG, C_NONE, C_REG, 58, 4, 0, 0, 0},
	{ALDXR, C_ZOREG, C_NONE, C_REG, 58, 4, 0, 0, 0},
	{ALDAXR, C_ZOREG, C_NONE, C_REG, 58, 4, 0, 0, 0},
	{ALDXP, C_ZOREG, C_REG, C_REG, 58, 4, 0, 0, 0},
	{ASTLR, C_REG, C_NONE, C_ZOREG, 59, 4, 0, 0, 0},  // to3=C_NONE
	{ASTXR, C_REG, C_NONE, C_ZOREG, 59, 4, 0, 0, 0},  // to3=C_REG
	{ASTLXR, C_REG, C_NONE, C_ZOREG, 59, 4, 0, 0, 0}, // to3=C_REG

	//	{ ASTXP,		C_REG, C_NONE,	C_ZOREG,		59, 4, 0 , 0}, // TODO(aram):

	{AAESD, C_VREG, C_NONE, C_VREG, 29, 4, 0, 0, 0},
	{ASHA1C, C_VREG, C_REG, C_VREG, 1, 4, 0, 0, 0},

	{obj.AUNDEF, C_NONE, C_NONE, C_NONE, 90, 4, 0, 0, 0},
	{obj.AUSEFIELD, C_ADDR, C_NONE, C_NONE, 0, 0, 0, 0, 0},
	{obj.APCDATA, C_VCON, C_NONE, C_VCON, 0, 0, 0, 0, 0},
	{obj.AFUNCDATA, C_VCON, C_NONE, C_ADDR, 0, 0, 0, 0, 0},
	{obj.ANOP, C_NONE, C_NONE, C_NONE, 0, 0, 0, 0, 0},
	{obj.ADUFFZERO, C_NONE, C_NONE, C_SBRA, 5, 4, 0, 0, 0}, // same as AB/ABL
	{obj.ADUFFCOPY, C_NONE, C_NONE, C_SBRA, 5, 4, 0, 0, 0}, // same as AB/ABL

	{obj.AXXX, C_NONE, C_NONE, C_NONE, 0, 4, 0, 0, 0},
}

/*
 * valid pstate field values, and value to use in instruction
 */
var pstatefield = []struct {
	a uint32
	b uint32
}{
	{REG_SPSel, 0<<16 | 4<<12 | 5<<5},
	{REG_DAIFSet, 3<<16 | 4<<12 | 6<<5},
	{REG_DAIFClr, 3<<16 | 4<<12 | 7<<5},
}

var pool struct {
	start uint32
	size  uint32
}

func prasm(p *obj.Prog) {
	fmt.Printf("%v\n", p)
}

func span7(ctxt *obj.Link, cursym *obj.LSym) {
	p := cursym.Text
	if p == nil || p.Link == nil { // handle external functions and ELF section symbols
		return
	}
	ctxt.Cursym = cursym
	ctxt.Autosize = int32(p.To.Offset&0xffffffff) + 8

	if oprange[AAND&obj.AMask] == nil {
		buildop(ctxt)
	}

	bflag := 1
	c := int64(0)
	p.Pc = c
	var m int
	var o *Optab
	for p = p.Link; p != nil; p = p.Link {
		ctxt.Curp = p
		if p.As == ADWORD && (c&7) != 0 {
			c += 4
		}
		p.Pc = c
		o = oplook(ctxt, p)
		m = int(o.size)
		if m == 0 {
			if p.As != obj.ANOP && p.As != obj.AFUNCDATA && p.As != obj.APCDATA && p.As != obj.AUSEFIELD {
				ctxt.Diag("zero-width instruction\n%v", p)
			}
			continue
		}

		switch o.flag & (LFROM | LTO) {
		case LFROM:
			addpool(ctxt, p, &p.From)

		case LTO:
			addpool(ctxt, p, &p.To)
			break
		}

		if p.As == AB || p.As == obj.ARET || p.As == AERET { /* TODO: other unconditional operations */
			checkpool(ctxt, p, 0)
		}
		c += int64(m)
		if ctxt.Blitrl != nil {
			checkpool(ctxt, p, 1)
		}
	}

	cursym.Size = c

	/*
	 * if any procedure is large enough to
	 * generate a large SBRA branch, then
	 * generate extra passes putting branches
	 * around jmps to fix. this is rare.
	 */
	for bflag != 0 {
		if ctxt.Debugvlog != 0 {
			fmt.Fprintf(ctxt.Bso, "%5.2f span1\n", obj.Cputime())
		}
		bflag = 0
		c = 0
		for p = cursym.Text.Link; p != nil; p = p.Link {
			if p.As == ADWORD && (c&7) != 0 {
				c += 4
			}
			p.Pc = c
			o = oplook(ctxt, p)

			/* very large branches */
			if o.type_ == 7 && p.Pcond != nil {
				otxt := p.Pcond.Pc - c
				if otxt <= -(1<<18)+10 || otxt >= (1<<18)-10 {
					q := ctxt.NewProg()
					q.Link = p.Link
					p.Link = q
					q.As = AB
					q.To.Type = obj.TYPE_BRANCH
					q.Pcond = p.Pcond
					p.Pcond = q
					q = ctxt.NewProg()
					q.Link = p.Link
					p.Link = q
					q.As = AB
					q.To.Type = obj.TYPE_BRANCH
					q.Pcond = q.Link.Link
					bflag = 1
				}
			}
			m = int(o.size)

			if m == 0 {
				if p.As != obj.ANOP && p.As != obj.AFUNCDATA && p.As != obj.APCDATA && p.As != obj.AUSEFIELD {
					ctxt.Diag("zero-width instruction\n%v", p)
				}
				continue
			}

			c += int64(m)
		}
	}

	c += -c & (FuncAlign - 1)
	cursym.Size = c

	/*
	 * lay out the code, emitting code and data relocations.
	 */
	cursym.Grow(cursym.Size)
	bp := cursym.P
	psz := int32(0)
	var i int
	var out [6]uint32
	for p := cursym.Text.Link; p != nil; p = p.Link {
		ctxt.Pc = p.Pc
		ctxt.Curp = p
		o = oplook(ctxt, p)

		// need to align DWORDs on 8-byte boundary. The ISA doesn't
		// require it, but the various 64-bit loads we generate assume it.
		if o.as == ADWORD && psz%8 != 0 {
			bp[3] = 0
			bp[2] = bp[3]
			bp[1] = bp[2]
			bp[0] = bp[1]
			bp = bp[4:]
			psz += 4
		}

		if int(o.size) > 4*len(out) {
			log.Fatalf("out array in span7 is too small, need at least %d for %v", o.size/4, p)
		}
		asmout(ctxt, p, o, out[:])
		for i = 0; i < int(o.size/4); i++ {
			ctxt.Arch.ByteOrder.PutUint32(bp, out[i])
			bp = bp[4:]
			psz += 4
		}
	}
}

/*
 * when the first reference to the literal pool threatens
 * to go out of range of a 1Mb PC-relative offset
 * drop the pool now, and branch round it.
 */
func checkpool(ctxt *obj.Link, p *obj.Prog, skip int) {
	if pool.size >= 0xffff0 || !ispcdisp(int32(p.Pc+4+int64(pool.size)-int64(pool.start)+8)) {
		flushpool(ctxt, p, skip)
	} else if p.Link == nil {
		flushpool(ctxt, p, 2)
	}
}

func flushpool(ctxt *obj.Link, p *obj.Prog, skip int) {
	if ctxt.Blitrl != nil {
		if skip != 0 {
			if ctxt.Debugvlog != 0 && skip == 1 {
				fmt.Printf("note: flush literal pool at %#x: len=%d ref=%x\n", uint64(p.Pc+4), pool.size, pool.start)
			}
			q := ctxt.NewProg()
			q.As = AB
			q.To.Type = obj.TYPE_BRANCH
			q.Pcond = p.Link
			q.Link = ctxt.Blitrl
			q.Lineno = p.Lineno
			ctxt.Blitrl = q
		} else if p.Pc+int64(pool.size)-int64(pool.start) < maxPCDisp {
			return
		}

		// The line number for constant pool entries doesn't really matter.
		// We set it to the line number of the preceding instruction so that
		// there are no deltas to encode in the pc-line tables.
		for q := ctxt.Blitrl; q != nil; q = q.Link {
			q.Lineno = p.Lineno
		}

		ctxt.Elitrl.Link = p.Link
		p.Link = ctxt.Blitrl

		ctxt.Blitrl = nil /* BUG: should refer back to values until out-of-range */
		ctxt.Elitrl = nil
		pool.size = 0
		pool.start = 0
	}
}

/*
 * TODO: hash
 */
func addpool(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
	c := aclass(ctxt, a)
	lit := ctxt.Instoffset
	t := *ctxt.NewProg()
	t.As = AWORD
	sz := 4

	// MOVD foo(SB), R is actually
	//	MOVD addr, REGTMP
	//	MOVD REGTMP, R
	// where addr is the address of the DWORD containing the address of foo.
	if p.As == AMOVD || c == C_ADDR || c == C_VCON || int64(lit) != int64(int32(lit)) || uint64(lit) != uint64(uint32(lit)) {
		// conservative: don't know if we want signed or unsigned extension.
		// in case of ambiguity, store 64-bit
		t.As = ADWORD
		sz = 8
	}

	switch c {
	// TODO(aram): remove.
	default:
		if a.Name != obj.NAME_EXTERN {
			fmt.Printf("addpool: %v in %v shouldn't go to default case\n", DRconv(c), p)
		}

		t.To.Offset = a.Offset
		t.To.Sym = a.Sym
		t.To.Type = a.Type
		t.To.Name = a.Name

	/* This is here because MOV uint12<<12, R is disabled in optab.
	Because of this, we need to load the constant from memory. */
	case C_ADDCON:
		fallthrough

	case C_PSAUTO,
		C_PPAUTO,
		C_UAUTO4K,
		C_UAUTO8K,
		C_UAUTO16K,
		C_UAUTO32K,
		C_UAUTO64K,
		C_NSAUTO,
		C_NPAUTO,
		C_LAUTO,
		C_PPOREG,
		C_PSOREG,
		C_UOREG4K,
		C_UOREG8K,
		C_UOREG16K,
		C_UOREG32K,
		C_UOREG64K,
		C_NSOREG,
		C_NPOREG,
		C_LOREG,
		C_LACON,
		C_LCON,
		C_VCON:
		if a.Name == obj.NAME_EXTERN {
			fmt.Printf("addpool: %v in %v needs reloc\n", DRconv(c), p)
		}

		t.To.Type = obj.TYPE_CONST
		t.To.Offset = lit
		break
	}

	for q := ctxt.Blitrl; q != nil; q = q.Link { /* could hash on t.t0.offset */
		if q.To == t.To {
			p.Pcond = q
			return
		}
	}

	q := ctxt.NewProg()
	*q = t
	q.Pc = int64(pool.size)
	if ctxt.Blitrl == nil {
		ctxt.Blitrl = q
		pool.start = uint32(p.Pc)
	} else {
		ctxt.Elitrl.Link = q
	}
	ctxt.Elitrl = q
	pool.size = -pool.size & (FuncAlign - 1)
	pool.size += uint32(sz)
	p.Pcond = q
}

func regoff(ctxt *obj.Link, a *obj.Addr) uint32 {
	ctxt.Instoffset = 0
	aclass(ctxt, a)
	return uint32(ctxt.Instoffset)
}

// Maximum PC-relative displacement.
// The actual limit is ±2²⁰, but we are conservative
// to avoid needing to recompute the literal pool flush points
// as span-dependent jumps are enlarged.
const maxPCDisp = 512 * 1024

// ispcdisp reports whether v is a valid PC-relative displacement.
func ispcdisp(v int32) bool {
	return -maxPCDisp < v && v < maxPCDisp && v&3 == 0
}

func isaddcon(v int64) bool {
	/* uimm12 or uimm24? */
	if v < 0 {
		return false
	}
	if (v & 0xFFF) == 0 {
		v >>= 12
	}
	return v <= 0xFFF
}

// isbitcon returns whether a constant can be encoded into a logical instruction.
// bitcon has a binary form of repetition of a bit sequence of length 2, 4, 8, 16, 32, or 64,
// which itself is a rotate (w.r.t. the length of the unit) of a sequence of ones.
// special cases: 0 and -1 are not bitcon.
// this function needs to run against virtually all the constants, so it needs to be fast.
// for this reason, bitcon testing and bitcon encoding are separate functions.
func isbitcon(x uint64) bool {
	if x == 1<<64-1 || x == 0 {
		return false
	}
	// determine the period and sign-extend a unit to 64 bits
	switch {
	case x != x>>32|x<<32:
		// period is 64
		// nothing to do
	case x != x>>16|x<<48:
		// period is 32
		x = uint64(int64(int32(x)))
	case x != x>>8|x<<56:
		// period is 16
		x = uint64(int64(int16(x)))
	case x != x>>4|x<<60:
		// period is 8
		x = uint64(int64(int8(x)))
	default:
		// period is 4 or 2, always true
		// 0001, 0010, 0100, 1000 -- 0001 rotate
		// 0011, 0110, 1100, 1001 -- 0011 rotate
		// 0111, 1011, 1101, 1110 -- 0111 rotate
		// 0101, 1010             -- 01   rotate, repeat
		return true
	}
	return sequenceOfOnes(x) || sequenceOfOnes(^x)
}

// sequenceOfOnes tests whether a constant is a sequence of ones in binary, with leading and trailing zeros
func sequenceOfOnes(x uint64) bool {
	y := x & -x // lowest set bit of x. x is good iff x+y is a power of 2
	y += x
	return (y-1)&y == 0
}

// bitconEncode returns the encoding of a bitcon used in logical instructions
// x is known to be a bitcon
// a bitcon is a sequence of n ones at low bits (i.e. 1<<n-1), right rotated
// by R bits, and repeated with period of 64, 32, 16, 8, 4, or 2.
// it is encoded in logical instructions with 3 bitfields
// N (1 bit) : R (6 bits) : S (6 bits), where
// N=1           -- period=64
// N=0, S=0xxxxx -- period=32
// N=0, S=10xxxx -- period=16
// N=0, S=110xxx -- period=8
// N=0, S=1110xx -- period=4
// N=0, S=11110x -- period=2
// R is the shift amount, low bits of S = n-1
func bitconEncode(x uint64, mode int) uint32 {
	var period uint32
	// determine the period and sign-extend a unit to 64 bits
	switch {
	case x != x>>32|x<<32:
		period = 64
	case x != x>>16|x<<48:
		period = 32
		x = uint64(int64(int32(x)))
	case x != x>>8|x<<56:
		period = 16
		x = uint64(int64(int16(x)))
	case x != x>>4|x<<60:
		period = 8
		x = uint64(int64(int8(x)))
	case x != x>>2|x<<62:
		period = 4
		x = uint64(int64(x<<60) >> 60)
	default:
		period = 2
		x = uint64(int64(x<<62) >> 62)
	}
	neg := false
	if int64(x) < 0 {
		x = ^x
		neg = true
	}
	y := x & -x // lowest set bit of x.
	s := log2(y)
	n := log2(x+y) - s // x (or ^x) is a sequence of n ones left shifted by s bits
	if neg {
		// ^x is a sequence of n ones left shifted by s bits
		// adjust n, s for x
		s = n + s
		n = period - n
	}

	N := uint32(0)
	if mode == 64 && period == 64 {
		N = 1
	}
	R := (period - s) & (period - 1) & uint32(mode-1) // shift amount of right rotate
	S := (n - 1) | 63&^(period<<1-1)                  // low bits = #ones - 1, high bits encodes period
	return N<<22 | R<<16 | S<<10
}

func log2(x uint64) uint32 {
	if x == 0 {
		panic("log2 of 0")
	}
	n := uint32(0)
	if x >= 1<<32 {
		x >>= 32
		n += 32
	}
	if x >= 1<<16 {
		x >>= 16
		n += 16
	}
	if x >= 1<<8 {
		x >>= 8
		n += 8
	}
	if x >= 1<<4 {
		x >>= 4
		n += 4
	}
	if x >= 1<<2 {
		x >>= 2
		n += 2
	}
	if x >= 1<<1 {
		x >>= 1
		n += 1
	}
	return n
}

func autoclass(l int64) int {
	if l < 0 {
		if l >= -256 {
			return C_NSAUTO
		}
		if l >= -512 && (l&7) == 0 {
			return C_NPAUTO
		}
		return C_LAUTO
	}

	if l <= 255 {
		return C_PSAUTO
	}
	if l <= 504 && (l&7) == 0 {
		return C_PPAUTO
	}
	if l <= 4095 {
		return C_UAUTO4K
	}
	if l <= 8190 && (l&1) == 0 {
		return C_UAUTO8K
	}
	if l <= 16380 && (l&3) == 0 {
		return C_UAUTO16K
	}
	if l <= 32760 && (l&7) == 0 {
		return C_UAUTO32K
	}
	if l <= 65520 && (l&0xF) == 0 {
		return C_UAUTO64K
	}
	return C_LAUTO
}

func oregclass(l int64) int {
	if l == 0 {
		return C_ZOREG
	}
	return autoclass(l) - C_NPAUTO + C_NPOREG
}

/*
 * given an offset v and a class c (see above)
 * return the offset value to use in the instruction,
 * scaled if necessary
 */
func offsetshift(ctxt *obj.Link, v int64, c int) int64 {
	s := 0
	if c >= C_SEXT1 && c <= C_SEXT16 {
		s = c - C_SEXT1
	} else if c >= C_UAUTO4K && c <= C_UAUTO64K {
		s = c - C_UAUTO4K
	} else if c >= C_UOREG4K && c <= C_UOREG64K {
		s = c - C_UOREG4K
	}
	vs := v >> uint(s)
	if vs<<uint(s) != v {
		ctxt.Diag("odd offset: %d\n%v", v, ctxt.Curp)
	}
	return vs
}

/*
 * if v contains a single 16-bit value aligned
 * on a 16-bit field, and thus suitable for movk/movn,
 * return the field index 0 to 3; otherwise return -1
 */
func movcon(v int64) int {
	for s := 0; s < 64; s += 16 {
		if (uint64(v) &^ (uint64(0xFFFF) << uint(s))) == 0 {
			return s / 16
		}
	}
	return -1
}

func rclass(r int16) int {
	switch {
	case REG_R0 <= r && r <= REG_R30: // not 31
		return C_REG
	case r == REGZERO:
		return C_ZCON
	case REG_F0 <= r && r <= REG_F31:
		return C_FREG
	case REG_V0 <= r && r <= REG_V31:
		return C_VREG
	case COND_EQ <= r && r <= COND_NV:
		return C_COND
	case r == REGSP:
		return C_RSP
	case r&REG_EXT != 0:
		return C_EXTREG
	case r >= REG_SPECIAL:
		return C_SPR
	}
	return C_GOK
}

func aclass(ctxt *obj.Link, a *obj.Addr) int {
	switch a.Type {
	case obj.TYPE_NONE:
		return C_NONE

	case obj.TYPE_REG:
		return rclass(a.Reg)

	case obj.TYPE_REGREG:
		return C_PAIR

	case obj.TYPE_SHIFT:
		return C_SHIFT

	case obj.TYPE_MEM:
		switch a.Name {
		case obj.NAME_EXTERN, obj.NAME_STATIC:
			if a.Sym == nil {
				break
			}
			ctxt.Instoffset = a.Offset
			if a.Sym != nil { // use relocation
				if a.Sym.Type == obj.STLSBSS {
					if ctxt.Flag_shared {
						return C_TLS_IE
					} else {
						return C_TLS_LE
					}
				}
				return C_ADDR
			}
			return C_LEXT

		case obj.NAME_GOTREF:
			return C_GOTADDR

		case obj.NAME_AUTO:
			ctxt.Instoffset = int64(ctxt.Autosize) + a.Offset
			return autoclass(ctxt.Instoffset)

		case obj.NAME_PARAM:
			ctxt.Instoffset = int64(ctxt.Autosize) + a.Offset + 8
			return autoclass(ctxt.Instoffset)

		case obj.NAME_NONE:
			ctxt.Instoffset = a.Offset
			return oregclass(ctxt.Instoffset)
		}
		return C_GOK

	case obj.TYPE_FCONST:
		return C_FCON

	case obj.TYPE_TEXTSIZE:
		return C_TEXTSIZE

	case obj.TYPE_CONST, obj.TYPE_ADDR:
		switch a.Name {
		case obj.NAME_NONE:
			ctxt.Instoffset = a.Offset
			if a.Reg != 0 && a.Reg != REGZERO {
				goto aconsize
			}
			v := ctxt.Instoffset
			if v == 0 {
				return C_ZCON
			}
			if isaddcon(v) {
				if v <= 0xFFF {
					if isbitcon(uint64(v)) {
						return C_ABCON0
					}
					return C_ADDCON0
				}
				if isbitcon(uint64(v)) {
					return C_ABCON
				}
				return C_ADDCON
			}

			t := movcon(v)
			if t >= 0 {
				if isbitcon(uint64(v)) {
					return C_MBCON
				}
				return C_MOVCON
			}

			t = movcon(^v)
			if t >= 0 {
				if isbitcon(uint64(v)) {
					return C_MBCON
				}
				return C_MOVCON
			}

			if isbitcon(uint64(v)) {
				return C_BITCON
			}

			if uint64(v) == uint64(uint32(v)) || v == int64(int32(v)) {
				return C_LCON
			}
			return C_VCON

		case obj.NAME_EXTERN, obj.NAME_STATIC:
			if a.Sym == nil {
				break
			}
			if a.Sym.Type == obj.STLSBSS {
				ctxt.Diag("taking address of TLS variable is not supported")
			}
			ctxt.Instoffset = a.Offset
			return C_VCONADDR

		case obj.NAME_AUTO:
			ctxt.Instoffset = int64(ctxt.Autosize) + a.Offset
			goto aconsize

		case obj.NAME_PARAM:
			ctxt.Instoffset = int64(ctxt.Autosize) + a.Offset + 8
			goto aconsize
		}
		return C_GOK

	aconsize:
		if isaddcon(ctxt.Instoffset) {
			return C_AACON
		}
		return C_LACON

	case obj.TYPE_BRANCH:
		return C_SBRA
	}

	return C_GOK
}

func oclass(a *obj.Addr) int {
	return int(a.Class) - 1
}

func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
	a1 := int(p.Optab)
	if a1 != 0 {
		return &optab[a1-1]
	}
	a1 = int(p.From.Class)
	if a1 == 0 {
		a1 = aclass(ctxt, &p.From) + 1
		p.From.Class = int8(a1)
	}

	a1--
	a3 := int(p.To.Class)
	if a3 == 0 {
		a3 = aclass(ctxt, &p.To) + 1
		p.To.Class = int8(a3)
	}

	a3--
	a2 := C_NONE
	if p.Reg != 0 {
		a2 = rclass(p.Reg)
	}

	if false {
		fmt.Printf("oplook %v %d %d %d\n", obj.Aconv(p.As), a1, a2, a3)
		fmt.Printf("\t\t%d %d\n", p.From.Type, p.To.Type)
	}

	ops := oprange[p.As&obj.AMask]
	c1 := &xcmp[a1]
	c2 := &xcmp[a2]
	c3 := &xcmp[a3]
	c4 := &xcmp[p.Scond>>5]
	for i := range ops {
		op := &ops[i]
		if (int(op.a2) == a2 || c2[op.a2]) && c4[op.scond>>5] && c1[op.a1] && c3[op.a3] {
			p.Optab = uint16(cap(optab) - cap(ops) + i + 1)
			return op
		}
	}

	ctxt.Diag("illegal combination %v %v %v %v, %d %d", p, DRconv(a1), DRconv(a2), DRconv(a3), p.From.Type, p.To.Type)
	prasm(p)
	if ops == nil {
		ops = optab
	}
	return &ops[0]
}

func cmp(a int, b int) bool {
	if a == b {
		return true
	}
	switch a {
	case C_RSP:
		if b == C_REG {
			return true
		}

	case C_REG:
		if b == C_ZCON {
			return true
		}

	case C_ADDCON0:
		if b == C_ZCON || b == C_ABCON0 {
			return true
		}

	case C_ADDCON:
		if b == C_ZCON || b == C_ABCON0 || b == C_ADDCON0 || b == C_ABCON {
			return true
		}

	case C_BITCON:
		if b == C_ABCON0 || b == C_ABCON || b == C_MBCON {
			return true
		}

	case C_MOVCON:
		if b == C_MBCON || b == C_ZCON || b == C_ADDCON0 {
			return true
		}

	case C_LCON:
		if b == C_ZCON || b == C_BITCON || b == C_ADDCON || b == C_ADDCON0 || b == C_ABCON || b == C_ABCON0 || b == C_MBCON || b == C_MOVCON {
			return true
		}

	case C_VCON:
		return cmp(C_LCON, b)

	case C_LACON:
		if b == C_AACON {
			return true
		}

	case C_SEXT2:
		if b == C_SEXT1 {
			return true
		}

	case C_SEXT4:
		if b == C_SEXT1 || b == C_SEXT2 {
			return true
		}

	case C_SEXT8:
		if b >= C_SEXT1 && b <= C_SEXT4 {
			return true
		}

	case C_SEXT16:
		if b >= C_SEXT1 && b <= C_SEXT8 {
			return true
		}

	case C_LEXT:
		if b >= C_SEXT1 && b <= C_SEXT16 {
			return true
		}

	case C_PPAUTO:
		if b == C_PSAUTO {
			return true
		}

	case C_UAUTO4K:
		if b == C_PSAUTO || b == C_PPAUTO {
			return true
		}

	case C_UAUTO8K:
		return cmp(C_UAUTO4K, b)

	case C_UAUTO16K:
		return cmp(C_UAUTO8K, b)

	case C_UAUTO32K:
		return cmp(C_UAUTO16K, b)

	case C_UAUTO64K:
		return cmp(C_UAUTO32K, b)

	case C_NPAUTO:
		return cmp(C_NSAUTO, b)

	case C_LAUTO:
		return cmp(C_NPAUTO, b) || cmp(C_UAUTO64K, b)

	case C_PSOREG:
		if b == C_ZOREG {
			return true
		}

	case C_PPOREG:
		if b == C_ZOREG || b == C_PSOREG {
			return true
		}

	case C_UOREG4K:
		if b == C_ZOREG || b == C_PSAUTO || b == C_PSOREG || b == C_PPAUTO || b == C_PPOREG {
			return true
		}

	case C_UOREG8K:
		return cmp(C_UOREG4K, b)

	case C_UOREG16K:
		return cmp(C_UOREG8K, b)

	case C_UOREG32K:
		return cmp(C_UOREG16K, b)

	case C_UOREG64K:
		return cmp(C_UOREG32K, b)

	case C_NPOREG:
		return cmp(C_NSOREG, b)

	case C_LOREG:
		return cmp(C_NPOREG, b) || cmp(C_UOREG64K, b)

	case C_LBRA:
		if b == C_SBRA {
			return true
		}
	}

	return false
}

type ocmp []Optab

func (x ocmp) Len() int {
	return len(x)
}

func (x ocmp) Swap(i, j int) {
	x[i], x[j] = x[j], x[i]
}

func (x ocmp) Less(i, j int) bool {
	p1 := &x[i]
	p2 := &x[j]
	if p1.as != p2.as {
		return p1.as < p2.as
	}
	if p1.a1 != p2.a1 {
		return p1.a1 < p2.a1
	}
	if p1.a2 != p2.a2 {
		return p1.a2 < p2.a2
	}
	if p1.a3 != p2.a3 {
		return p1.a3 < p2.a3
	}
	if p1.scond != p2.scond {
		return p1.scond < p2.scond
	}
	return false
}

func oprangeset(a obj.As, t []Optab) {
	oprange[a&obj.AMask] = t
}

func buildop(ctxt *obj.Link) {
	var n int
	for i := 0; i < C_GOK; i++ {
		for n = 0; n < C_GOK; n++ {
			if cmp(n, i) {
				xcmp[i][n] = true
			}
		}
	}
	for n = 0; optab[n].as != obj.AXXX; n++ {
	}
	sort.Sort(ocmp(optab[:n]))
	for i := 0; i < n; i++ {
		r := optab[i].as
		start := i
		for optab[i].as == r {
			i++
		}
		t := optab[start:i]
		i--
		oprangeset(r, t)
		switch r {
		default:
			ctxt.Diag("unknown op in build: %v", obj.Aconv(r))
			log.Fatalf("bad code")

		case AADD:
			oprangeset(AADDS, t)
			oprangeset(ASUB, t)
			oprangeset(ASUBS, t)
			oprangeset(AADDW, t)
			oprangeset(AADDSW, t)
			oprangeset(ASUBW, t)
			oprangeset(ASUBSW, t)

		case AAND: /* logical immediate, logical shifted register */
			oprangeset(AANDS, t)

			oprangeset(AANDSW, t)
			oprangeset(AANDW, t)
			oprangeset(AEOR, t)
			oprangeset(AEORW, t)
			oprangeset(AORR, t)
			oprangeset(AORRW, t)

		case ABIC: /* only logical shifted register */
			oprangeset(ABICS, t)

			oprangeset(ABICSW, t)
			oprangeset(ABICW, t)
			oprangeset(AEON, t)
			oprangeset(AEONW, t)
			oprangeset(AORN, t)
			oprangeset(AORNW, t)

		case ANEG:
			oprangeset(ANEGS, t)
			oprangeset(ANEGSW, t)
			oprangeset(ANEGW, t)

		case AADC: /* rn=Rd */
			oprangeset(AADCW, t)

			oprangeset(AADCS, t)
			oprangeset(AADCSW, t)
			oprangeset(ASBC, t)
			oprangeset(ASBCW, t)
			oprangeset(ASBCS, t)
			oprangeset(ASBCSW, t)

		case ANGC: /* rn=REGZERO */
			oprangeset(ANGCW, t)

			oprangeset(ANGCS, t)
			oprangeset(ANGCSW, t)

		case ACMP:
			oprangeset(ACMPW, t)
			oprangeset(ACMN, t)
			oprangeset(ACMNW, t)

		case ATST:
			oprangeset(ATSTW, t)

			/* register/register, and shifted */
		case AMVN:
			oprangeset(AMVNW, t)

		case AMOVK:
			oprangeset(AMOVKW, t)
			oprangeset(AMOVN, t)
			oprangeset(AMOVNW, t)
			oprangeset(AMOVZ, t)
			oprangeset(AMOVZW, t)

		case ABEQ:
			oprangeset(ABNE, t)
			oprangeset(ABCS, t)
			oprangeset(ABHS, t)
			oprangeset(ABCC, t)
			oprangeset(ABLO, t)
			oprangeset(ABMI, t)
			oprangeset(ABPL, t)
			oprangeset(ABVS, t)
			oprangeset(ABVC, t)
			oprangeset(ABHI, t)
			oprangeset(ABLS, t)
			oprangeset(ABGE, t)
			oprangeset(ABLT, t)
			oprangeset(ABGT, t)
			oprangeset(ABLE, t)

		case ALSL:
			oprangeset(ALSLW, t)
			oprangeset(ALSR, t)
			oprangeset(ALSRW, t)
			oprangeset(AASR, t)
			oprangeset(AASRW, t)
			oprangeset(AROR, t)
			oprangeset(ARORW, t)

		case ACLS:
			oprangeset(ACLSW, t)
			oprangeset(ACLZ, t)
			oprangeset(ACLZW, t)
			oprangeset(ARBIT, t)
			oprangeset(ARBITW, t)
			oprangeset(AREV, t)
			oprangeset(AREVW, t)
			oprangeset(AREV16, t)
			oprangeset(AREV16W, t)
			oprangeset(AREV32, t)

		case ASDIV:
			oprangeset(ASDIVW, t)
			oprangeset(AUDIV, t)
			oprangeset(AUDIVW, t)
			oprangeset(ACRC32B, t)
			oprangeset(ACRC32CB, t)
			oprangeset(ACRC32CH, t)
			oprangeset(ACRC32CW, t)
			oprangeset(ACRC32CX, t)
			oprangeset(ACRC32H, t)
			oprangeset(ACRC32W, t)
			oprangeset(ACRC32X, t)

		case AMADD:
			oprangeset(AMADDW, t)
			oprangeset(AMSUB, t)
			oprangeset(AMSUBW, t)
			oprangeset(ASMADDL, t)
			oprangeset(ASMSUBL, t)
			oprangeset(AUMADDL, t)
			oprangeset(AUMSUBL, t)

		case AREM:
			oprangeset(AREMW, t)
			oprangeset(AUREM, t)
			oprangeset(AUREMW, t)

		case AMUL:
			oprangeset(AMULW, t)
			oprangeset(AMNEG, t)
			oprangeset(AMNEGW, t)
			oprangeset(ASMNEGL, t)
			oprangeset(ASMULL, t)
			oprangeset(ASMULH, t)
			oprangeset(AUMNEGL, t)
			oprangeset(AUMULH, t)
			oprangeset(AUMULL, t)

		case AMOVB:
			oprangeset(AMOVBU, t)

		case AMOVH:
			oprangeset(AMOVHU, t)

		case AMOVW:
			oprangeset(AMOVWU, t)

		case ABFM:
			oprangeset(ABFMW, t)
			oprangeset(ASBFM, t)
			oprangeset(ASBFMW, t)
			oprangeset(AUBFM, t)
			oprangeset(AUBFMW, t)

		case ABFI:
			oprangeset(ABFIW, t)
			oprangeset(ABFXIL, t)
			oprangeset(ABFXILW, t)
			oprangeset(ASBFIZ, t)
			oprangeset(ASBFIZW, t)
			oprangeset(ASBFX, t)
			oprangeset(ASBFXW, t)
			oprangeset(AUBFIZ, t)
			oprangeset(AUBFIZW, t)
			oprangeset(AUBFX, t)
			oprangeset(AUBFXW, t)

		case AEXTR:
			oprangeset(AEXTRW, t)

		case ASXTB:
			oprangeset(ASXTBW, t)
			oprangeset(ASXTH, t)
			oprangeset(ASXTHW, t)
			oprangeset(ASXTW, t)
			oprangeset(AUXTB, t)
			oprangeset(AUXTH, t)
			oprangeset(AUXTW, t)
			oprangeset(AUXTBW, t)
			oprangeset(AUXTHW, t)

		case ACCMN:
			oprangeset(ACCMNW, t)
			oprangeset(ACCMP, t)
			oprangeset(ACCMPW, t)

		case ACSEL:
			oprangeset(ACSELW, t)
			oprangeset(ACSINC, t)
			oprangeset(ACSINCW, t)
			oprangeset(ACSINV, t)
			oprangeset(ACSINVW, t)
			oprangeset(ACSNEG, t)
			oprangeset(ACSNEGW, t)

			// aliases Rm=Rn, !cond
			oprangeset(ACINC, t)

			oprangeset(ACINCW, t)
			oprangeset(ACINV, t)
			oprangeset(ACINVW, t)
			oprangeset(ACNEG, t)
			oprangeset(ACNEGW, t)

			// aliases, Rm=Rn=REGZERO, !cond
		case ACSET:
			oprangeset(ACSETW, t)

			oprangeset(ACSETM, t)
			oprangeset(ACSETMW, t)

		case AMOVD,
			AMOVBU,
			AB,
			ABL,
			AWORD,
			ADWORD,
			obj.ARET,
			obj.ATEXT,
			ASTP,
			ALDP:
			break

		case AERET:
			oprangeset(AWFE, t)
			oprangeset(AWFI, t)
			oprangeset(AYIELD, t)
			oprangeset(ASEV, t)
			oprangeset(ASEVL, t)
			oprangeset(ADRPS, t)

		case ACBZ:
			oprangeset(ACBZW, t)
			oprangeset(ACBNZ, t)
			oprangeset(ACBNZW, t)

		case ATBZ:
			oprangeset(ATBNZ, t)

		case AADR, AADRP:
			break

		case ACLREX:
			break

		case ASVC:
			oprangeset(AHLT, t)
			oprangeset(AHVC, t)
			oprangeset(ASMC, t)
			oprangeset(ABRK, t)
			oprangeset(ADCPS1, t)
			oprangeset(ADCPS2, t)
			oprangeset(ADCPS3, t)

		case AFADDS:
			oprangeset(AFADDD, t)
			oprangeset(AFSUBS, t)
			oprangeset(AFSUBD, t)
			oprangeset(AFMULS, t)
			oprangeset(AFMULD, t)
			oprangeset(AFNMULS, t)
			oprangeset(AFNMULD, t)
			oprangeset(AFDIVS, t)
			oprangeset(AFMAXD, t)
			oprangeset(AFMAXS, t)
			oprangeset(AFMIND, t)
			oprangeset(AFMINS, t)
			oprangeset(AFMAXNMD, t)
			oprangeset(AFMAXNMS, t)
			oprangeset(AFMINNMD, t)
			oprangeset(AFMINNMS, t)
			oprangeset(AFDIVD, t)

		case AFCVTSD:
			oprangeset(AFCVTDS, t)
			oprangeset(AFABSD, t)
			oprangeset(AFABSS, t)
			oprangeset(AFNEGD, t)
			oprangeset(AFNEGS, t)
			oprangeset(AFSQRTD, t)
			oprangeset(AFSQRTS, t)
			oprangeset(AFRINTNS, t)
			oprangeset(AFRINTND, t)
			oprangeset(AFRINTPS, t)
			oprangeset(AFRINTPD, t)
			oprangeset(AFRINTMS, t)
			oprangeset(AFRINTMD, t)
			oprangeset(AFRINTZS, t)
			oprangeset(AFRINTZD, t)
			oprangeset(AFRINTAS, t)
			oprangeset(AFRINTAD, t)
			oprangeset(AFRINTXS, t)
			oprangeset(AFRINTXD, t)
			oprangeset(AFRINTIS, t)
			oprangeset(AFRINTID, t)
			oprangeset(AFCVTDH, t)
			oprangeset(AFCVTHS, t)
			oprangeset(AFCVTHD, t)
			oprangeset(AFCVTSH, t)

		case AFCMPS:
			oprangeset(AFCMPD, t)
			oprangeset(AFCMPES, t)
			oprangeset(AFCMPED, t)

		case AFCCMPS:
			oprangeset(AFCCMPD, t)
			oprangeset(AFCCMPES, t)
			oprangeset(AFCCMPED, t)

		case AFCSELD:
			oprangeset(AFCSELS, t)

		case AFMOVS, AFMOVD:
			break

		case AFCVTZSD:
			oprangeset(AFCVTZSDW, t)
			oprangeset(AFCVTZSS, t)
			oprangeset(AFCVTZSSW, t)
			oprangeset(AFCVTZUD, t)
			oprangeset(AFCVTZUDW, t)
			oprangeset(AFCVTZUS, t)
			oprangeset(AFCVTZUSW, t)

		case ASCVTFD:
			oprangeset(ASCVTFS, t)
			oprangeset(ASCVTFWD, t)
			oprangeset(ASCVTFWS, t)
			oprangeset(AUCVTFD, t)
			oprangeset(AUCVTFS, t)
			oprangeset(AUCVTFWD, t)
			oprangeset(AUCVTFWS, t)

		case ASYS:
			oprangeset(AAT, t)
			oprangeset(ADC, t)
			oprangeset(AIC, t)
			oprangeset(ATLBI, t)

		case ASYSL, AHINT:
			break

		case ADMB:
			oprangeset(ADSB, t)
			oprangeset(AISB, t)

		case AMRS, AMSR:
			break

		case ALDAR:
			oprangeset(ALDARW, t)
			fallthrough

		case ALDXR:
			oprangeset(ALDXRB, t)
			oprangeset(ALDXRH, t)
			oprangeset(ALDXRW, t)

		case ALDAXR:
			oprangeset(ALDAXRW, t)

		case ALDXP:
			oprangeset(ALDXPW, t)

		case ASTLR:
			oprangeset(ASTLRW, t)

		case ASTXR:
			oprangeset(ASTXRB, t)
			oprangeset(ASTXRH, t)
			oprangeset(ASTXRW, t)

		case ASTLXR:
			oprangeset(ASTLXRW, t)

		case ASTXP:
			oprangeset(ASTXPW, t)

		case AAESD:
			oprangeset(AAESE, t)
			oprangeset(AAESMC, t)
			oprangeset(AAESIMC, t)
			oprangeset(ASHA1H, t)
			oprangeset(ASHA1SU1, t)
			oprangeset(ASHA256SU0, t)

		case ASHA1C:
			oprangeset(ASHA1P, t)
			oprangeset(ASHA1M, t)
			oprangeset(ASHA1SU0, t)
			oprangeset(ASHA256H, t)
			oprangeset(ASHA256H2, t)
			oprangeset(ASHA256SU1, t)

		case obj.ANOP,
			obj.AUNDEF,
			obj.AUSEFIELD,
			obj.AFUNCDATA,
			obj.APCDATA,
			obj.ADUFFZERO,
			obj.ADUFFCOPY:
			break
		}
	}
}

func chipfloat7(ctxt *obj.Link, e float64) int {
	ei := math.Float64bits(e)
	l := uint32(int32(ei))
	h := uint32(int32(ei >> 32))

	if l != 0 || h&0xffff != 0 {
		return -1
	}
	h1 := h & 0x7fc00000
	if h1 != 0x40000000 && h1 != 0x3fc00000 {
		return -1
	}
	n := 0

	// sign bit (a)
	if h&0x80000000 != 0 {
		n |= 1 << 7
	}

	// exp sign bit (b)
	if h1 == 0x3fc00000 {
		n |= 1 << 6
	}

	// rest of exp and mantissa (cd-efgh)
	n |= int((h >> 16) & 0x3f)

	//print("match %.8lux %.8lux %d\n", l, h, n);
	return n
}

/* form offset parameter to SYS; special register number */
func SYSARG5(op0 int, op1 int, Cn int, Cm int, op2 int) int {
	return op0<<19 | op1<<16 | Cn<<12 | Cm<<8 | op2<<5
}

func SYSARG4(op1 int, Cn int, Cm int, op2 int) int {
	return SYSARG5(0, op1, Cn, Cm, op2)
}

func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
	o1 := uint32(0)
	o2 := uint32(0)
	o3 := uint32(0)
	o4 := uint32(0)
	o5 := uint32(0)
	if false { /*debug['P']*/
		fmt.Printf("%x: %v\ttype %d\n", uint32(p.Pc), p, o.type_)
	}
	switch o.type_ {
	default:
		ctxt.Diag("unknown asm %d", o.type_)
		prasm(p)

	case 0: /* pseudo ops */
		break

	case 1: /* op Rm,[Rn],Rd; default Rn=Rd -> op Rm<<0,[Rn,]Rd (shifted register) */
		o1 = oprrr(ctxt, p.As)

		rf := int(p.From.Reg)
		rt := int(p.To.Reg)
		r := int(p.Reg)
		if p.To.Type == obj.TYPE_NONE {
			rt = REGZERO
		}
		if r == 0 {
			r = rt
		}
		o1 |= (uint32(rf&31) << 16) | (uint32(r&31) << 5) | uint32(rt&31)

	case 2: /* add/sub $(uimm12|uimm24)[,R],R; cmp $(uimm12|uimm24),R */
		o1 = opirr(ctxt, p.As)

		rt := int(p.To.Reg)
		if p.To.Type == obj.TYPE_NONE {
			if (o1 & Sbit) == 0 {
				ctxt.Diag("ineffective ZR destination\n%v", p)
			}
			rt = REGZERO
		}

		r := int(p.Reg)
		if r == 0 {
			r = rt
		}
		v := int32(regoff(ctxt, &p.From))
		o1 = oaddi(ctxt, int32(o1), v, r, rt)

	case 3: /* op R<<n[,R],R (shifted register) */
		o1 = oprrr(ctxt, p.As)

		o1 |= uint32(p.From.Offset) /* includes reg, op, etc */
		rt := int(p.To.Reg)
		if p.To.Type == obj.TYPE_NONE {
			rt = REGZERO
		}
		r := int(p.Reg)
		if p.As == AMVN || p.As == AMVNW {
			r = REGZERO
		} else if r == 0 {
			r = rt
		}
		o1 |= (uint32(r&31) << 5) | uint32(rt&31)

	case 4: /* mov $addcon, R; mov $recon, R; mov $racon, R */
		o1 = opirr(ctxt, p.As)

		rt := int(p.To.Reg)
		r := int(o.param)
		if r == 0 {
			r = REGZERO
		} else if r == REGFROM {
			r = int(p.From.Reg)
		}
		if r == 0 {
			r = REGSP
		}
		v := int32(regoff(ctxt, &p.From))
		if (v & 0xFFF000) != 0 {
			v >>= 12
			o1 |= 1 << 22 /* shift, by 12 */
		}

		o1 |= ((uint32(v) & 0xFFF) << 10) | (uint32(r&31) << 5) | uint32(rt&31)

	case 5: /* b s; bl s */
		o1 = opbra(ctxt, p.As)

		if p.To.Sym == nil {
			o1 |= uint32(brdist(ctxt, p, 0, 26, 2))
			break
		}

		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 4
		rel.Sym = p.To.Sym
		rel.Add = p.To.Offset
		rel.Type = obj.R_CALLARM64

	case 6: /* b ,O(R); bl ,O(R) */
		o1 = opbrr(ctxt, p.As)

		o1 |= uint32(p.To.Reg&31) << 5
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 0
		rel.Type = obj.R_CALLIND

	case 7: /* beq s */
		o1 = opbra(ctxt, p.As)

		o1 |= uint32(brdist(ctxt, p, 0, 19, 2) << 5)

	case 8: /* lsl $c,[R],R -> ubfm $(W-1)-c,$(-c MOD (W-1)),Rn,Rd */
		rt := int(p.To.Reg)

		rf := int(p.Reg)
		if rf == 0 {
			rf = rt
		}
		v := int32(p.From.Offset)
		switch p.As {
		case AASR:
			o1 = opbfm(ctxt, ASBFM, int(v), 63, rf, rt)

		case AASRW:
			o1 = opbfm(ctxt, ASBFMW, int(v), 31, rf, rt)

		case ALSL:
			o1 = opbfm(ctxt, AUBFM, int((64-v)&63), int(63-v), rf, rt)

		case ALSLW:
			o1 = opbfm(ctxt, AUBFMW, int((32-v)&31), int(31-v), rf, rt)

		case ALSR:
			o1 = opbfm(ctxt, AUBFM, int(v), 63, rf, rt)

		case ALSRW:
			o1 = opbfm(ctxt, AUBFMW, int(v), 31, rf, rt)

		case AROR:
			o1 = opextr(ctxt, AEXTR, v, rf, rf, rt)

		case ARORW:
			o1 = opextr(ctxt, AEXTRW, v, rf, rf, rt)

		default:
			ctxt.Diag("bad shift $con\n%v", ctxt.Curp)
			break
		}

	case 9: /* lsl Rm,[Rn],Rd -> lslv Rm, Rn, Rd */
		o1 = oprrr(ctxt, p.As)

		r := int(p.Reg)
		if r == 0 {
			r = int(p.To.Reg)
		}
		o1 |= (uint32(p.From.Reg&31) << 16) | (uint32(r&31) << 5) | uint32(p.To.Reg&31)

	case 10: /* brk/hvc/.../svc [$con] */
		o1 = opimm(ctxt, p.As)

		if p.To.Type != obj.TYPE_NONE {
			o1 |= uint32((p.To.Offset & 0xffff) << 5)
		}

	case 11: /* dword */
		aclass(ctxt, &p.To)

		o1 = uint32(ctxt.Instoffset)
		o2 = uint32(ctxt.Instoffset >> 32)
		if p.To.Sym != nil {
			rel := obj.Addrel(ctxt.Cursym)
			rel.Off = int32(ctxt.Pc)
			rel.Siz = 8
			rel.Sym = p.To.Sym
			rel.Add = p.To.Offset
			rel.Type = obj.R_ADDR
			o2 = 0
			o1 = o2
		}

	case 12: /* movT $vcon, reg */
		o1 = omovlit(ctxt, p.As, p, &p.From, int(p.To.Reg))

	case 13: /* addop $vcon, [R], R (64 bit literal); cmp $lcon,R -> addop $lcon,R, ZR */
		o1 = omovlit(ctxt, AMOVD, p, &p.From, REGTMP)

		if !(o1 != 0) {
			break
		}
		rt := int(p.To.Reg)
		if p.To.Type == obj.TYPE_NONE {
			rt = REGZERO
		}
		r := int(p.Reg)
		if r == 0 {
			r = rt
		}
		if p.To.Type != obj.TYPE_NONE && (p.To.Reg == REGSP || r == REGSP) {
			o2 = opxrrr(ctxt, p.As)
			o2 |= REGTMP & 31 << 16
			o2 |= LSL0_64
		} else {
			o2 = oprrr(ctxt, p.As)
			o2 |= REGTMP & 31 << 16 /* shift is 0 */
		}

		o2 |= uint32(r&31) << 5
		o2 |= uint32(rt & 31)

	case 14: /* word */
		if aclass(ctxt, &p.To) == C_ADDR {
			ctxt.Diag("address constant needs DWORD\n%v", p)
		}
		o1 = uint32(ctxt.Instoffset)
		if p.To.Sym != nil {
			// This case happens with words generated
			// in the PC stream as part of the literal pool.
			rel := obj.Addrel(ctxt.Cursym)

			rel.Off = int32(ctxt.Pc)
			rel.Siz = 4
			rel.Sym = p.To.Sym
			rel.Add = p.To.Offset
			rel.Type = obj.R_ADDR
			o1 = 0
		}

	case 15: /* mul/mneg/umulh/umull r,[r,]r; madd/msub Rm,Rn,Ra,Rd */
		o1 = oprrr(ctxt, p.As)

		rf := int(p.From.Reg)
		rt := int(p.To.Reg)
		var r int
		var ra int
		if p.From3Type() == obj.TYPE_REG {
			r = int(p.From3.Reg)
			ra = int(p.Reg)
			if ra == 0 {
				ra = REGZERO
			}
		} else {
			r = int(p.Reg)
			if r == 0 {
				r = rt
			}
			ra = REGZERO
		}

		o1 |= (uint32(rf&31) << 16) | (uint32(ra&31) << 10) | (uint32(r&31) << 5) | uint32(rt&31)

	case 16: /* XremY R[,R],R -> XdivY; XmsubY */
		o1 = oprrr(ctxt, p.As)

		rf := int(p.From.Reg)
		rt := int(p.To.Reg)
		r := int(p.Reg)
		if r == 0 {
			r = rt
		}
		o1 |= (uint32(rf&31) << 16) | (uint32(r&31) << 5) | REGTMP&31
		o2 = oprrr(ctxt, AMSUBW)
		o2 |= o1 & (1 << 31) /* same size */
		o2 |= (uint32(rf&31) << 16) | (uint32(r&31) << 10) | (REGTMP & 31 << 5) | uint32(rt&31)

	case 17: /* op Rm,[Rn],Rd; default Rn=ZR */
		o1 = oprrr(ctxt, p.As)

		rf := int(p.From.Reg)
		rt := int(p.To.Reg)
		r := int(p.Reg)
		if p.To.Type == obj.TYPE_NONE {
			rt = REGZERO
		}
		if r == 0 {
			r = REGZERO
		}
		o1 |= (uint32(rf&31) << 16) | (uint32(r&31) << 5) | uint32(rt&31)

	case 18: /* csel cond,Rn,Rm,Rd; cinc/cinv/cneg cond,Rn,Rd; cset cond,Rd */
		o1 = oprrr(ctxt, p.As)

		cond := int(p.From.Reg)
		r := int(p.Reg)
		var rf int
		if r != 0 {
			if p.From3Type() == obj.TYPE_NONE {
				/* CINC/CINV/CNEG */
				rf = r

				cond ^= 1
			} else {
				rf = int(p.From3.Reg) /* CSEL */
			}
		} else {
			/* CSET */
			if p.From3Type() != obj.TYPE_NONE {
				ctxt.Diag("invalid combination\n%v", p)
			}
			rf = REGZERO
			r = rf
			cond ^= 1
		}

		rt := int(p.To.Reg)
		o1 |= (uint32(rf&31) << 16) | (uint32(cond&31) << 12) | (uint32(r&31) << 5) | uint32(rt&31)

	case 19: /* CCMN cond, (Rm|uimm5),Rn, uimm4 -> ccmn Rn,Rm,uimm4,cond */
		nzcv := int(p.To.Offset)

		cond := int(p.From.Reg)
		var rf int
		if p.From3.Type == obj.TYPE_REG {
			o1 = oprrr(ctxt, p.As)
			rf = int(p.From3.Reg) /* Rm */
		} else {
			o1 = opirr(ctxt, p.As)
			rf = int(p.From3.Offset & 0x1F)
		}

		o1 |= (uint32(rf&31) << 16) | (uint32(cond) << 12) | (uint32(p.Reg&31) << 5) | uint32(nzcv)

	case 20: /* movT R,O(R) -> strT */
		v := int32(regoff(ctxt, &p.To))

		r := int(p.To.Reg)
		if r == 0 {
			r = int(o.param)
		}
		if v < 0 { /* unscaled 9-bit signed */
			o1 = olsr9s(ctxt, int32(opstr9(ctxt, p.As)), v, r, int(p.From.Reg))
		} else {
			v = int32(offsetshift(ctxt, int64(v), int(o.a3)))
			o1 = olsr12u(ctxt, int32(opstr12(ctxt, p.As)), v, r, int(p.From.Reg))
		}

	case 21: /* movT O(R),R -> ldrT */
		v := int32(regoff(ctxt, &p.From))

		r := int(p.From.Reg)
		if r == 0 {
			r = int(o.param)
		}
		if v < 0 { /* unscaled 9-bit signed */
			o1 = olsr9s(ctxt, int32(opldr9(ctxt, p.As)), v, r, int(p.To.Reg))
		} else {
			v = int32(offsetshift(ctxt, int64(v), int(o.a1)))

			//print("offset=%lld v=%ld a1=%d\n", instoffset, v, o->a1);
			o1 = olsr12u(ctxt, int32(opldr12(ctxt, p.As)), v, r, int(p.To.Reg))
		}

	case 22: /* movT (R)O!,R; movT O(R)!, R -> ldrT */
		v := int32(p.From.Offset)

		if v < -256 || v > 255 {
			ctxt.Diag("offset out of range\n%v", p)
		}
		o1 = opldrpp(ctxt, p.As)
		if o.scond == C_XPOST {
			o1 |= 1 << 10
		} else {
			o1 |= 3 << 10
		}
		o1 |= ((uint32(v) & 0x1FF) << 12) | (uint32(p.From.Reg&31) << 5) | uint32(p.To.Reg&31)

	case 23: /* movT R,(R)O!; movT O(R)!, R -> strT */
		v := int32(p.To.Offset)

		if v < -256 || v > 255 {
			ctxt.Diag("offset out of range\n%v", p)
		}
		o1 = LD2STR(opldrpp(ctxt, p.As))
		if o.scond == C_XPOST {
			o1 |= 1 << 10
		} else {
			o1 |= 3 << 10
		}
		o1 |= ((uint32(v) & 0x1FF) << 12) | (uint32(p.To.Reg&31) << 5) | uint32(p.From.Reg&31)

	case 24: /* mov/mvn Rs,Rd -> add $0,Rs,Rd or orr Rs,ZR,Rd */
		rf := int(p.From.Reg)
		rt := int(p.To.Reg)
		s := rf == REGSP || rt == REGSP
		if p.As == AMVN || p.As == AMVNW {
			if s {
				ctxt.Diag("illegal SP reference\n%v", p)
			}
			o1 = oprrr(ctxt, p.As)
			o1 |= (uint32(rf&31) << 16) | (REGZERO & 31 << 5) | uint32(rt&31)
		} else if s {
			o1 = opirr(ctxt, p.As)
			o1 |= (uint32(rf&31) << 5) | uint32(rt&31)
		} else {
			o1 = oprrr(ctxt, p.As)
			o1 |= (uint32(rf&31) << 16) | (REGZERO & 31 << 5) | uint32(rt&31)
		}

	case 25: /* negX Rs, Rd -> subX Rs<<0, ZR, Rd */
		o1 = oprrr(ctxt, p.As)

		rf := int(p.From.Reg)
		if rf == C_NONE {
			rf = int(p.To.Reg)
		}
		rt := int(p.To.Reg)
		o1 |= (uint32(rf&31) << 16) | (REGZERO & 31 << 5) | uint32(rt&31)

	case 26: /* negX Rm<<s, Rd -> subX Rm<<s, ZR, Rd */
		o1 = oprrr(ctxt, p.As)

		o1 |= uint32(p.From.Offset) /* includes reg, op, etc */
		rt := int(p.To.Reg)
		o1 |= (REGZERO & 31 << 5) | uint32(rt&31)

	case 27: /* op Rm<<n[,Rn],Rd (extended register) */
		o1 = opxrrr(ctxt, p.As)

		if (p.From.Reg-obj.RBaseARM64)&REG_EXT != 0 {
			ctxt.Diag("extended register not implemented\n%v", p)
			// o1 |= uint32(p.From.Offset) /* includes reg, op, etc */
		} else {
			o1 |= uint32(p.From.Reg&31) << 16
		}
		rt := int(p.To.Reg)
		if p.To.Type == obj.TYPE_NONE {
			rt = REGZERO
		}
		r := int(p.Reg)
		if r == 0 {
			r = rt
		}
		o1 |= (uint32(r&31) << 5) | uint32(rt&31)

	case 28: /* logop $vcon, [R], R (64 bit literal) */
		o1 = omovlit(ctxt, AMOVD, p, &p.From, REGTMP)

		if !(o1 != 0) {
			break
		}
		r := int(p.Reg)
		if r == 0 {
			r = int(p.To.Reg)
		}
		o2 = oprrr(ctxt, p.As)
		o2 |= REGTMP & 31 << 16 /* shift is 0 */
		o2 |= uint32(r&31) << 5
		o2 |= uint32(p.To.Reg & 31)

	case 29: /* op Rn, Rd */
		o1 = oprrr(ctxt, p.As)

		o1 |= uint32(p.From.Reg&31)<<5 | uint32(p.To.Reg&31)

	case 30: /* movT R,L(R) -> strT */
		s := movesize(o.as)

		if s < 0 {
			ctxt.Diag("unexpected long move, op %v tab %v\n%v", obj.Aconv(p.As), obj.Aconv(o.as), p)
		}
		v := int32(regoff(ctxt, &p.To))
		if v < 0 {
			ctxt.Diag("negative large offset\n%v", p)
		}
		if (v & ((1 << uint(s)) - 1)) != 0 {
			ctxt.Diag("misaligned offset\n%v", p)
		}
		hi := v - (v & (0xFFF << uint(s)))
		if (hi & 0xFFF) != 0 {
			ctxt.Diag("internal: miscalculated offset %d [%d]\n%v", v, s, p)
		}

		//fprint(2, "v=%ld (%#lux) s=%d hi=%ld (%#lux) v'=%ld (%#lux)\n", v, v, s, hi, hi, ((v-hi)>>s)&0xFFF, ((v-hi)>>s)&0xFFF);
		r := int(p.To.Reg)

		if r == 0 {
			r = int(o.param)
		}
		o1 = oaddi(ctxt, int32(opirr(ctxt, AADD)), hi, r, REGTMP)
		o2 = olsr12u(ctxt, int32(opstr12(ctxt, p.As)), ((v-hi)>>uint(s))&0xFFF, REGTMP, int(p.From.Reg))

	case 31: /* movT L(R), R -> ldrT */
		s := movesize(o.as)

		if s < 0 {
			ctxt.Diag("unexpected long move, op %v tab %v\n%v", obj.Aconv(p.As), obj.Aconv(o.as), p)
		}
		v := int32(regoff(ctxt, &p.From))
		if v < 0 {
			ctxt.Diag("negative large offset\n%v", p)
		}
		if (v & ((1 << uint(s)) - 1)) != 0 {
			ctxt.Diag("misaligned offset\n%v", p)
		}
		hi := v - (v & (0xFFF << uint(s)))
		if (hi & 0xFFF) != 0 {
			ctxt.Diag("internal: miscalculated offset %d [%d]\n%v", v, s, p)
		}

		//fprint(2, "v=%ld (%#lux) s=%d hi=%ld (%#lux) v'=%ld (%#lux)\n", v, v, s, hi, hi, ((v-hi)>>s)&0xFFF, ((v-hi)>>s)&0xFFF);
		r := int(p.From.Reg)

		if r == 0 {
			r = int(o.param)
		}
		o1 = oaddi(ctxt, int32(opirr(ctxt, AADD)), hi, r, REGTMP)
		o2 = olsr12u(ctxt, int32(opldr12(ctxt, p.As)), ((v-hi)>>uint(s))&0xFFF, REGTMP, int(p.To.Reg))

	case 32: /* mov $con, R -> movz/movn */
		o1 = omovconst(ctxt, p.As, p, &p.From, int(p.To.Reg))

	case 33: /* movk $uimm16 << pos */
		o1 = opirr(ctxt, p.As)

		d := p.From.Offset
		if (d >> 16) != 0 {
			ctxt.Diag("requires uimm16\n%v", p)
		}
		s := 0
		if p.From3Type() != obj.TYPE_NONE {
			if p.From3.Type != obj.TYPE_CONST {
				ctxt.Diag("missing bit position\n%v", p)
			}
			s = int(p.From3.Offset / 16)
			if (s*16&0xF) != 0 || s >= 4 || (o1&S64) == 0 && s >= 2 {
				ctxt.Diag("illegal bit position\n%v", p)
			}
		}

		rt := int(p.To.Reg)
		o1 |= uint32(((d & 0xFFFF) << 5) | int64((uint32(s)&3)<<21) | int64(rt&31))

	case 34: /* mov $lacon,R */
		o1 = omovlit(ctxt, AMOVD, p, &p.From, REGTMP)

		if !(o1 != 0) {
			break
		}
		o2 = opxrrr(ctxt, AADD)
		o2 |= REGTMP & 31 << 16
		o2 |= LSL0_64
		r := int(p.From.Reg)
		if r == 0 {
			r = int(o.param)
		}
		o2 |= uint32(r&31) << 5
		o2 |= uint32(p.To.Reg & 31)

	case 35: /* mov SPR,R -> mrs */
		o1 = oprrr(ctxt, AMRS)

		v := int32(p.From.Offset)
		if (o1 & uint32(v&^(3<<19))) != 0 {
			ctxt.Diag("MRS register value overlap\n%v", p)
		}
		o1 |= uint32(v)
		o1 |= uint32(p.To.Reg & 31)

	case 36: /* mov R,SPR */
		o1 = oprrr(ctxt, AMSR)

		v := int32(p.To.Offset)
		if (o1 & uint32(v&^(3<<19))) != 0 {
			ctxt.Diag("MSR register value overlap\n%v", p)
		}
		o1 |= uint32(v)
		o1 |= uint32(p.From.Reg & 31)

	case 37: /* mov $con,PSTATEfield -> MSR [immediate] */
		if (uint64(p.From.Offset) &^ uint64(0xF)) != 0 {
			ctxt.Diag("illegal immediate for PSTATE field\n%v", p)
		}
		o1 = opirr(ctxt, AMSR)
		o1 |= uint32((p.From.Offset & 0xF) << 8) /* Crm */
		v := int32(0)
		for i := 0; i < len(pstatefield); i++ {
			if int64(pstatefield[i].a) == p.To.Offset {
				v = int32(pstatefield[i].b)
				break
			}
		}

		if v == 0 {
			ctxt.Diag("illegal PSTATE field for immediate move\n%v", p)
		}
		o1 |= uint32(v)

	case 38: /* clrex [$imm] */
		o1 = opimm(ctxt, p.As)

		if p.To.Type == obj.TYPE_NONE {
			o1 |= 0xF << 8
		} else {
			o1 |= uint32((p.To.Offset & 0xF) << 8)
		}

	case 39: /* cbz R, rel */
		o1 = opirr(ctxt, p.As)

		o1 |= uint32(p.From.Reg & 31)
		o1 |= uint32(brdist(ctxt, p, 0, 19, 2) << 5)

	case 40: /* tbz */
		o1 = opirr(ctxt, p.As)

		v := int32(p.From.Offset)
		if v < 0 || v > 63 {
			ctxt.Diag("illegal bit number\n%v", p)
		}
		o1 |= ((uint32(v) & 0x20) << (31 - 5)) | ((uint32(v) & 0x1F) << 19)
		o1 |= uint32(brdist(ctxt, p, 0, 14, 2) << 5)
		o1 |= uint32(p.Reg)

	case 41: /* eret, nop, others with no operands */
		o1 = op0(ctxt, p.As)

	case 42: /* bfm R,r,s,R */
		o1 = opbfm(ctxt, p.As, int(p.From.Offset), int(p.From3.Offset), int(p.Reg), int(p.To.Reg))

	case 43: /* bfm aliases */
		r := int(p.From.Offset)

		s := int(p.From3.Offset)
		rf := int(p.Reg)
		rt := int(p.To.Reg)
		if rf == 0 {
			rf = rt
		}
		switch p.As {
		case ABFI:
			o1 = opbfm(ctxt, ABFM, 64-r, s-1, rf, rt)

		case ABFIW:
			o1 = opbfm(ctxt, ABFMW, 32-r, s-1, rf, rt)

		case ABFXIL:
			o1 = opbfm(ctxt, ABFM, r, r+s-1, rf, rt)

		case ABFXILW:
			o1 = opbfm(ctxt, ABFMW, r, r+s-1, rf, rt)

		case ASBFIZ:
			o1 = opbfm(ctxt, ASBFM, 64-r, s-1, rf, rt)

		case ASBFIZW:
			o1 = opbfm(ctxt, ASBFMW, 32-r, s-1, rf, rt)

		case ASBFX:
			o1 = opbfm(ctxt, ASBFM, r, r+s-1, rf, rt)

		case ASBFXW:
			o1 = opbfm(ctxt, ASBFMW, r, r+s-1, rf, rt)

		case AUBFIZ:
			o1 = opbfm(ctxt, AUBFM, 64-r, s-1, rf, rt)

		case AUBFIZW:
			o1 = opbfm(ctxt, AUBFMW, 32-r, s-1, rf, rt)

		case AUBFX:
			o1 = opbfm(ctxt, AUBFM, r, r+s-1, rf, rt)

		case AUBFXW:
			o1 = opbfm(ctxt, AUBFMW, r, r+s-1, rf, rt)

		default:
			ctxt.Diag("bad bfm alias\n%v", ctxt.Curp)
			break
		}

	case 44: /* extr $b, Rn, Rm, Rd */
		o1 = opextr(ctxt, p.As, int32(p.From.Offset), int(p.From3.Reg), int(p.Reg), int(p.To.Reg))

	case 45: /* sxt/uxt[bhw] R,R; movT R,R -> sxtT R,R */
		rf := int(p.From.Reg)

		rt := int(p.To.Reg)
		as := p.As
		if rf == REGZERO {
			as = AMOVWU /* clearer in disassembly */
		}
		switch as {
		case AMOVB, ASXTB:
			o1 = opbfm(ctxt, ASBFM, 0, 7, rf, rt)

		case AMOVH, ASXTH:
			o1 = opbfm(ctxt, ASBFM, 0, 15, rf, rt)

		case AMOVW, ASXTW:
			o1 = opbfm(ctxt, ASBFM, 0, 31, rf, rt)

		case AMOVBU, AUXTB:
			o1 = opbfm(ctxt, AUBFM, 0, 7, rf, rt)

		case AMOVHU, AUXTH:
			o1 = opbfm(ctxt, AUBFM, 0, 15, rf, rt)

		case AMOVWU:
			o1 = oprrr(ctxt, as) | (uint32(rf&31) << 16) | (REGZERO & 31 << 5) | uint32(rt&31)

		case AUXTW:
			o1 = opbfm(ctxt, AUBFM, 0, 31, rf, rt)

		case ASXTBW:
			o1 = opbfm(ctxt, ASBFMW, 0, 7, rf, rt)

		case ASXTHW:
			o1 = opbfm(ctxt, ASBFMW, 0, 15, rf, rt)

		case AUXTBW:
			o1 = opbfm(ctxt, AUBFMW, 0, 7, rf, rt)

		case AUXTHW:
			o1 = opbfm(ctxt, AUBFMW, 0, 15, rf, rt)

		default:
			ctxt.Diag("bad sxt %v", obj.Aconv(as))
			break
		}

	case 46: /* cls */
		o1 = opbit(ctxt, p.As)

		o1 |= uint32(p.From.Reg&31) << 5
		o1 |= uint32(p.To.Reg & 31)

	case 47: /* movT R,V(R) -> strT (huge offset) */
		o1 = omovlit(ctxt, AMOVW, p, &p.To, REGTMP)

		if !(o1 != 0) {
			break
		}
		r := int(p.To.Reg)
		if r == 0 {
			r = int(o.param)
		}
		o2 = olsxrr(ctxt, p.As, REGTMP, r, int(p.From.Reg))

	case 48: /* movT V(R), R -> ldrT (huge offset) */
		o1 = omovlit(ctxt, AMOVW, p, &p.From, REGTMP)

		if !(o1 != 0) {
			break
		}
		r := int(p.From.Reg)
		if r == 0 {
			r = int(o.param)
		}
		o2 = olsxrr(ctxt, p.As, REGTMP, r, int(p.To.Reg))

	case 50: /* sys/sysl */
		o1 = opirr(ctxt, p.As)

		if (p.From.Offset &^ int64(SYSARG4(0x7, 0xF, 0xF, 0x7))) != 0 {
			ctxt.Diag("illegal SYS argument\n%v", p)
		}
		o1 |= uint32(p.From.Offset)
		if p.To.Type == obj.TYPE_REG {
			o1 |= uint32(p.To.Reg & 31)
		} else if p.Reg != 0 {
			o1 |= uint32(p.Reg & 31)
		} else {
			o1 |= 0x1F
		}

	case 51: /* dmb */
		o1 = opirr(ctxt, p.As)

		if p.From.Type == obj.TYPE_CONST {
			o1 |= uint32((p.From.Offset & 0xF) << 8)
		}

	case 52: /* hint */
		o1 = opirr(ctxt, p.As)

		o1 |= uint32((p.From.Offset & 0x7F) << 5)

	case 53: /* and/or/eor/bic/... $bitcon, Rn, Rd */
		a := p.As
		rt := int(p.To.Reg)
		r := int(p.Reg)
		if r == 0 {
			r = rt
		}
		mode := 64
		v := uint64(p.From.Offset)
		switch p.As {
		case AANDW, AORRW, AEORW, AANDSW:
			mode = 32
		case ABIC, AORN, AEON, ABICS:
			v = ^v
		case ABICW, AORNW, AEONW, ABICSW:
			v = ^v
			mode = 32
		}
		o1 = opirr(ctxt, a)
		o1 |= bitconEncode(v, mode) | uint32(r&31)<<5 | uint32(rt&31)

	case 54: /* floating point arith */
		o1 = oprrr(ctxt, p.As)

		var rf int
		if p.From.Type == obj.TYPE_CONST {
			rf = chipfloat7(ctxt, p.From.Val.(float64))
			if rf < 0 || true {
				ctxt.Diag("invalid floating-point immediate\n%v", p)
				rf = 0
			}

			rf |= (1 << 3)
		} else {
			rf = int(p.From.Reg)
		}
		rt := int(p.To.Reg)
		r := int(p.Reg)
		if (o1&(0x1F<<24)) == (0x1E<<24) && (o1&(1<<11)) == 0 { /* monadic */
			r = rf
			rf = 0
		} else if r == 0 {
			r = rt
		}
		o1 |= (uint32(rf&31) << 16) | (uint32(r&31) << 5) | uint32(rt&31)

	case 56: /* floating point compare */
		o1 = oprrr(ctxt, p.As)

		var rf int
		if p.From.Type == obj.TYPE_CONST {
			o1 |= 8 /* zero */
			rf = 0
		} else {
			rf = int(p.From.Reg)
		}
		rt := int(p.Reg)
		o1 |= uint32(rf&31)<<16 | uint32(rt&31)<<5

	case 57: /* floating point conditional compare */
		o1 = oprrr(ctxt, p.As)

		cond := int(p.From.Reg)
		nzcv := int(p.To.Offset)
		if nzcv&^0xF != 0 {
			ctxt.Diag("implausible condition\n%v", p)
		}
		rf := int(p.Reg)
		if p.From3 == nil || p.From3.Reg < REG_F0 || p.From3.Reg > REG_F31 {
			ctxt.Diag("illegal FCCMP\n%v", p)
			break
		}
		rt := int(p.From3.Reg)
		o1 |= uint32(rf&31)<<16 | uint32(cond)<<12 | uint32(rt&31)<<5 | uint32(nzcv)

	case 58: /* ldar/ldxr/ldaxr */
		o1 = opload(ctxt, p.As)

		o1 |= 0x1F << 16
		o1 |= uint32(p.From.Reg) << 5
		if p.Reg != 0 {
			o1 |= uint32(p.Reg) << 10
		} else {
			o1 |= 0x1F << 10
		}
		o1 |= uint32(p.To.Reg & 31)

	case 59: /* stxr/stlxr */
		o1 = opstore(ctxt, p.As)

		if p.RegTo2 != obj.REG_NONE {
			o1 |= uint32(p.RegTo2&31) << 16
		} else {
			o1 |= 0x1F << 16
		}

		// TODO(aram): add support for STXP
		o1 |= uint32(p.To.Reg&31) << 5

		o1 |= uint32(p.From.Reg & 31)

	case 60: /* adrp label,r */
		d := brdist(ctxt, p, 12, 21, 0)

		o1 = ADR(1, uint32(d), uint32(p.To.Reg))

	case 61: /* adr label, r */
		d := brdist(ctxt, p, 0, 21, 0)

		o1 = ADR(0, uint32(d), uint32(p.To.Reg))

	case 62: /* op $movcon, [R], R -> mov $movcon, REGTMP + op REGTMP, [R], R */
		if p.Reg == REGTMP {
			ctxt.Diag("cannot use REGTMP as source: %v\n", p)
		}
		o1 = omovconst(ctxt, AMOVD, p, &p.From, REGTMP)

		rt := int(p.To.Reg)
		if p.To.Type == obj.TYPE_NONE {
			rt = REGZERO
		}
		r := int(p.Reg)
		if r == 0 {
			r = rt
		}
		if p.To.Type != obj.TYPE_NONE && (p.To.Reg == REGSP || r == REGSP) {
			o2 = opxrrr(ctxt, p.As)
			o2 |= REGTMP & 31 << 16
			o2 |= LSL0_64
		} else {
			o2 = oprrr(ctxt, p.As)
			o2 |= REGTMP & 31 << 16 /* shift is 0 */
		}
		o2 |= uint32(r&31) << 5
		o2 |= uint32(rt & 31)

		/* reloc ops */
	case 64: /* movT R,addr -> adrp + add + movT R, (REGTMP) */
		o1 = ADR(1, 0, REGTMP)
		o2 = opirr(ctxt, AADD) | REGTMP&31<<5 | REGTMP&31
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 8
		rel.Sym = p.To.Sym
		rel.Add = p.To.Offset
		rel.Type = obj.R_ADDRARM64
		o3 = olsr12u(ctxt, int32(opstr12(ctxt, p.As)), 0, REGTMP, int(p.From.Reg))

	case 65: /* movT addr,R -> adrp + add + movT (REGTMP), R */
		o1 = ADR(1, 0, REGTMP)
		o2 = opirr(ctxt, AADD) | REGTMP&31<<5 | REGTMP&31
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 8
		rel.Sym = p.From.Sym
		rel.Add = p.From.Offset
		rel.Type = obj.R_ADDRARM64
		o3 = olsr12u(ctxt, int32(opldr12(ctxt, p.As)), 0, REGTMP, int(p.To.Reg))

	case 66: /* ldp O(R)!, (r1, r2); ldp (R)O!, (r1, r2) */
		v := int32(p.From.Offset)

		if v < -512 || v > 504 {
			ctxt.Diag("offset out of range\n%v", p)
		}
		if o.scond == C_XPOST {
			o1 |= 1 << 23
		} else {
			o1 |= 3 << 23
		}
		o1 |= 1 << 22
		o1 |= uint32(int64(2<<30|5<<27|((uint32(v)/8)&0x7f)<<15) | p.To.Offset<<10 | int64(uint32(p.From.Reg&31)<<5) | int64(p.To.Reg&31))

	case 67: /* stp (r1, r2), O(R)!; stp (r1, r2), (R)O! */
		v := int32(p.To.Offset)

		if v < -512 || v > 504 {
			ctxt.Diag("offset out of range\n%v", p)
		}
		if o.scond == C_XPOST {
			o1 |= 1 << 23
		} else {
			o1 |= 3 << 23
		}
		o1 |= uint32(int64(2<<30|5<<27|((uint32(v)/8)&0x7f)<<15) | p.From.Offset<<10 | int64(uint32(p.To.Reg&31)<<5) | int64(p.From.Reg&31))

	case 68: /* movT $vconaddr(SB), reg -> adrp + add + reloc */
		if p.As == AMOVW {
			ctxt.Diag("invalid load of 32-bit address: %v", p)
		}
		o1 = ADR(1, 0, uint32(p.To.Reg))
		o2 = opirr(ctxt, AADD) | uint32(p.To.Reg&31)<<5 | uint32(p.To.Reg&31)
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 8
		rel.Sym = p.From.Sym
		rel.Add = p.From.Offset
		rel.Type = obj.R_ADDRARM64

	case 69: /* LE model movd $tlsvar, reg -> movz reg, 0 + reloc */
		o1 = opirr(ctxt, AMOVZ)
		o1 |= uint32(p.To.Reg & 31)
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 4
		rel.Sym = p.From.Sym
		rel.Type = obj.R_ARM64_TLS_LE
		if p.From.Offset != 0 {
			ctxt.Diag("invalid offset on MOVW $tlsvar")
		}

	case 70: /* IE model movd $tlsvar, reg -> adrp REGTMP, 0; ldr reg, [REGTMP, #0] + relocs */
		o1 = ADR(1, 0, REGTMP)
		o2 = olsr12u(ctxt, int32(opldr12(ctxt, AMOVD)), 0, REGTMP, int(p.To.Reg))
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 8
		rel.Sym = p.From.Sym
		rel.Add = 0
		rel.Type = obj.R_ARM64_TLS_IE
		if p.From.Offset != 0 {
			ctxt.Diag("invalid offset on MOVW $tlsvar")
		}

	case 71: /* movd sym@GOT, reg -> adrp REGTMP, #0; ldr reg, [REGTMP, #0] + relocs */
		o1 = ADR(1, 0, REGTMP)
		o2 = olsr12u(ctxt, int32(opldr12(ctxt, AMOVD)), 0, REGTMP, int(p.To.Reg))
		rel := obj.Addrel(ctxt.Cursym)
		rel.Off = int32(ctxt.Pc)
		rel.Siz = 8
		rel.Sym = p.From.Sym
		rel.Add = 0
		rel.Type = obj.R_ARM64_GOTPCREL

	// This is supposed to be something that stops execution.
	// It's not supposed to be reached, ever, but if it is, we'd
	// like to be able to tell how we got there. Assemble as
	// 0xbea71700 which is guaranteed to raise undefined instruction
	// exception.
	case 90:
		o1 = 0xbea71700

		break
	}

	out[0] = o1
	out[1] = o2
	out[2] = o3
	out[3] = o4
	out[4] = o5
	return
}

/*
 * basic Rm op Rn -> Rd (using shifted register with 0)
 * also op Rn -> Rt
 * also Rm*Rn op Ra -> Rd
 */
func oprrr(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case AADC:
		return S64 | 0<<30 | 0<<29 | 0xd0<<21 | 0<<10

	case AADCW:
		return S32 | 0<<30 | 0<<29 | 0xd0<<21 | 0<<10

	case AADCS:
		return S64 | 0<<30 | 1<<29 | 0xd0<<21 | 0<<10

	case AADCSW:
		return S32 | 0<<30 | 1<<29 | 0xd0<<21 | 0<<10

	case ANGC, ASBC:
		return S64 | 1<<30 | 0<<29 | 0xd0<<21 | 0<<10

	case ANGCS, ASBCS:
		return S64 | 1<<30 | 1<<29 | 0xd0<<21 | 0<<10

	case ANGCW, ASBCW:
		return S32 | 1<<30 | 0<<29 | 0xd0<<21 | 0<<10

	case ANGCSW, ASBCSW:
		return S32 | 1<<30 | 1<<29 | 0xd0<<21 | 0<<10

	case AADD:
		return S64 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case AADDW:
		return S32 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case ACMN, AADDS:
		return S64 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case ACMNW, AADDSW:
		return S32 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case ASUB:
		return S64 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case ASUBW:
		return S32 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case ACMP, ASUBS:
		return S64 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case ACMPW, ASUBSW:
		return S32 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 0<<21 | 0<<10

	case AAND:
		return S64 | 0<<29 | 0xA<<24

	case AANDW:
		return S32 | 0<<29 | 0xA<<24

	case AMOVD, AORR:
		return S64 | 1<<29 | 0xA<<24

		//	case AMOVW:
	case AMOVWU, AORRW:
		return S32 | 1<<29 | 0xA<<24

	case AEOR:
		return S64 | 2<<29 | 0xA<<24

	case AEORW:
		return S32 | 2<<29 | 0xA<<24

	case AANDS:
		return S64 | 3<<29 | 0xA<<24

	case AANDSW:
		return S32 | 3<<29 | 0xA<<24

	case ABIC:
		return S64 | 0<<29 | 0xA<<24 | 1<<21

	case ABICW:
		return S32 | 0<<29 | 0xA<<24 | 1<<21

	case ABICS:
		return S64 | 3<<29 | 0xA<<24 | 1<<21

	case ABICSW:
		return S32 | 3<<29 | 0xA<<24 | 1<<21

	case AEON:
		return S64 | 2<<29 | 0xA<<24 | 1<<21

	case AEONW:
		return S32 | 2<<29 | 0xA<<24 | 1<<21

	case AMVN, AORN:
		return S64 | 1<<29 | 0xA<<24 | 1<<21

	case AMVNW, AORNW:
		return S32 | 1<<29 | 0xA<<24 | 1<<21

	case AASR:
		return S64 | OPDP2(10) /* also ASRV */

	case AASRW:
		return S32 | OPDP2(10)

	case ALSL:
		return S64 | OPDP2(8)

	case ALSLW:
		return S32 | OPDP2(8)

	case ALSR:
		return S64 | OPDP2(9)

	case ALSRW:
		return S32 | OPDP2(9)

	case AROR:
		return S64 | OPDP2(11)

	case ARORW:
		return S32 | OPDP2(11)

	case ACCMN:
		return S64 | 0<<30 | 1<<29 | 0xD2<<21 | 0<<11 | 0<<10 | 0<<4 /* cond<<12 | nzcv<<0 */

	case ACCMNW:
		return S32 | 0<<30 | 1<<29 | 0xD2<<21 | 0<<11 | 0<<10 | 0<<4

	case ACCMP:
		return S64 | 1<<30 | 1<<29 | 0xD2<<21 | 0<<11 | 0<<10 | 0<<4 /* imm5<<16 | cond<<12 | nzcv<<0 */

	case ACCMPW:
		return S32 | 1<<30 | 1<<29 | 0xD2<<21 | 0<<11 | 0<<10 | 0<<4

	case ACRC32B:
		return S32 | OPDP2(16)

	case ACRC32H:
		return S32 | OPDP2(17)

	case ACRC32W:
		return S32 | OPDP2(18)

	case ACRC32X:
		return S64 | OPDP2(19)

	case ACRC32CB:
		return S32 | OPDP2(20)

	case ACRC32CH:
		return S32 | OPDP2(21)

	case ACRC32CW:
		return S32 | OPDP2(22)

	case ACRC32CX:
		return S64 | OPDP2(23)

	case ACSEL:
		return S64 | 0<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 0<<10

	case ACSELW:
		return S32 | 0<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 0<<10

	case ACSET:
		return S64 | 0<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 1<<10

	case ACSETW:
		return S32 | 0<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 1<<10

	case ACSETM:
		return S64 | 1<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 0<<10

	case ACSETMW:
		return S32 | 1<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 0<<10

	case ACINC, ACSINC:
		return S64 | 0<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 1<<10

	case ACINCW, ACSINCW:
		return S32 | 0<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 1<<10

	case ACINV, ACSINV:
		return S64 | 1<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 0<<10

	case ACINVW, ACSINVW:
		return S32 | 1<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 0<<10

	case ACNEG, ACSNEG:
		return S64 | 1<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 1<<10

	case ACNEGW, ACSNEGW:
		return S32 | 1<<30 | 0<<29 | 0xD4<<21 | 0<<11 | 1<<10

	case AMUL, AMADD:
		return S64 | 0<<29 | 0x1B<<24 | 0<<21 | 0<<15

	case AMULW, AMADDW:
		return S32 | 0<<29 | 0x1B<<24 | 0<<21 | 0<<15

	case AMNEG, AMSUB:
		return S64 | 0<<29 | 0x1B<<24 | 0<<21 | 1<<15

	case AMNEGW, AMSUBW:
		return S32 | 0<<29 | 0x1B<<24 | 0<<21 | 1<<15

	case AMRS:
		return SYSOP(1, 2, 0, 0, 0, 0, 0)

	case AMSR:
		return SYSOP(0, 2, 0, 0, 0, 0, 0)

	case ANEG:
		return S64 | 1<<30 | 0<<29 | 0xB<<24 | 0<<21

	case ANEGW:
		return S32 | 1<<30 | 0<<29 | 0xB<<24 | 0<<21

	case ANEGS:
		return S64 | 1<<30 | 1<<29 | 0xB<<24 | 0<<21

	case ANEGSW:
		return S32 | 1<<30 | 1<<29 | 0xB<<24 | 0<<21

	case AREM, ASDIV:
		return S64 | OPDP2(3)

	case AREMW, ASDIVW:
		return S32 | OPDP2(3)

	case ASMULL, ASMADDL:
		return OPDP3(1, 0, 1, 0)

	case ASMNEGL, ASMSUBL:
		return OPDP3(1, 0, 1, 1)

	case ASMULH:
		return OPDP3(1, 0, 2, 0)

	case AUMULL, AUMADDL:
		return OPDP3(1, 0, 5, 0)

	case AUMNEGL, AUMSUBL:
		return OPDP3(1, 0, 5, 1)

	case AUMULH:
		return OPDP3(1, 0, 6, 0)

	case AUREM, AUDIV:
		return S64 | OPDP2(2)

	case AUREMW, AUDIVW:
		return S32 | OPDP2(2)

	case AAESE:
		return 0x4E<<24 | 2<<20 | 8<<16 | 4<<12 | 2<<10

	case AAESD:
		return 0x4E<<24 | 2<<20 | 8<<16 | 5<<12 | 2<<10

	case AAESMC:
		return 0x4E<<24 | 2<<20 | 8<<16 | 6<<12 | 2<<10

	case AAESIMC:
		return 0x4E<<24 | 2<<20 | 8<<16 | 7<<12 | 2<<10

	case ASHA1C:
		return 0x5E<<24 | 0<<12

	case ASHA1P:
		return 0x5E<<24 | 1<<12

	case ASHA1M:
		return 0x5E<<24 | 2<<12

	case ASHA1SU0:
		return 0x5E<<24 | 3<<12

	case ASHA256H:
		return 0x5E<<24 | 4<<12

	case ASHA256H2:
		return 0x5E<<24 | 5<<12

	case ASHA256SU1:
		return 0x5E<<24 | 6<<12

	case ASHA1H:
		return 0x5E<<24 | 2<<20 | 8<<16 | 0<<12 | 2<<10

	case ASHA1SU1:
		return 0x5E<<24 | 2<<20 | 8<<16 | 1<<12 | 2<<10

	case ASHA256SU0:
		return 0x5E<<24 | 2<<20 | 8<<16 | 2<<12 | 2<<10

	case AFCVTZSD:
		return FPCVTI(1, 0, 1, 3, 0)

	case AFCVTZSDW:
		return FPCVTI(0, 0, 1, 3, 0)

	case AFCVTZSS:
		return FPCVTI(1, 0, 0, 3, 0)

	case AFCVTZSSW:
		return FPCVTI(0, 0, 0, 3, 0)

	case AFCVTZUD:
		return FPCVTI(1, 0, 1, 3, 1)

	case AFCVTZUDW:
		return FPCVTI(0, 0, 1, 3, 1)

	case AFCVTZUS:
		return FPCVTI(1, 0, 0, 3, 1)

	case AFCVTZUSW:
		return FPCVTI(0, 0, 0, 3, 1)

	case ASCVTFD:
		return FPCVTI(1, 0, 1, 0, 2)

	case ASCVTFS:
		return FPCVTI(1, 0, 0, 0, 2)

	case ASCVTFWD:
		return FPCVTI(0, 0, 1, 0, 2)

	case ASCVTFWS:
		return FPCVTI(0, 0, 0, 0, 2)

	case AUCVTFD:
		return FPCVTI(1, 0, 1, 0, 3)

	case AUCVTFS:
		return FPCVTI(1, 0, 0, 0, 3)

	case AUCVTFWD:
		return FPCVTI(0, 0, 1, 0, 3)

	case AUCVTFWS:
		return FPCVTI(0, 0, 0, 0, 3)

	case AFADDS:
		return FPOP2S(0, 0, 0, 2)

	case AFADDD:
		return FPOP2S(0, 0, 1, 2)

	case AFSUBS:
		return FPOP2S(0, 0, 0, 3)

	case AFSUBD:
		return FPOP2S(0, 0, 1, 3)

	case AFMULS:
		return FPOP2S(0, 0, 0, 0)

	case AFMULD:
		return FPOP2S(0, 0, 1, 0)

	case AFDIVS:
		return FPOP2S(0, 0, 0, 1)

	case AFDIVD:
		return FPOP2S(0, 0, 1, 1)

	case AFMAXS:
		return FPOP2S(0, 0, 0, 4)

	case AFMINS:
		return FPOP2S(0, 0, 0, 5)

	case AFMAXD:
		return FPOP2S(0, 0, 1, 4)

	case AFMIND:
		return FPOP2S(0, 0, 1, 5)

	case AFMAXNMS:
		return FPOP2S(0, 0, 0, 6)

	case AFMAXNMD:
		return FPOP2S(0, 0, 1, 6)

	case AFMINNMS:
		return FPOP2S(0, 0, 0, 7)

	case AFMINNMD:
		return FPOP2S(0, 0, 1, 7)

	case AFNMULS:
		return FPOP2S(0, 0, 0, 8)

	case AFNMULD:
		return FPOP2S(0, 0, 1, 8)

	case AFCMPS:
		return FPCMP(0, 0, 0, 0, 0)

	case AFCMPD:
		return FPCMP(0, 0, 1, 0, 0)

	case AFCMPES:
		return FPCMP(0, 0, 0, 0, 16)

	case AFCMPED:
		return FPCMP(0, 0, 1, 0, 16)

	case AFCCMPS:
		return FPCCMP(0, 0, 0, 0)

	case AFCCMPD:
		return FPCCMP(0, 0, 1, 0)

	case AFCCMPES:
		return FPCCMP(0, 0, 0, 1)

	case AFCCMPED:
		return FPCCMP(0, 0, 1, 1)

	case AFCSELS:
		return 0x1E<<24 | 0<<22 | 1<<21 | 3<<10

	case AFCSELD:
		return 0x1E<<24 | 1<<22 | 1<<21 | 3<<10

	case AFMOVS:
		return FPOP1S(0, 0, 0, 0)

	case AFABSS:
		return FPOP1S(0, 0, 0, 1)

	case AFNEGS:
		return FPOP1S(0, 0, 0, 2)

	case AFSQRTS:
		return FPOP1S(0, 0, 0, 3)

	case AFCVTSD:
		return FPOP1S(0, 0, 0, 5)

	case AFCVTSH:
		return FPOP1S(0, 0, 0, 7)

	case AFRINTNS:
		return FPOP1S(0, 0, 0, 8)

	case AFRINTPS:
		return FPOP1S(0, 0, 0, 9)

	case AFRINTMS:
		return FPOP1S(0, 0, 0, 10)

	case AFRINTZS:
		return FPOP1S(0, 0, 0, 11)

	case AFRINTAS:
		return FPOP1S(0, 0, 0, 12)

	case AFRINTXS:
		return FPOP1S(0, 0, 0, 14)

	case AFRINTIS:
		return FPOP1S(0, 0, 0, 15)

	case AFMOVD:
		return FPOP1S(0, 0, 1, 0)

	case AFABSD:
		return FPOP1S(0, 0, 1, 1)

	case AFNEGD:
		return FPOP1S(0, 0, 1, 2)

	case AFSQRTD:
		return FPOP1S(0, 0, 1, 3)

	case AFCVTDS:
		return FPOP1S(0, 0, 1, 4)

	case AFCVTDH:
		return FPOP1S(0, 0, 1, 7)

	case AFRINTND:
		return FPOP1S(0, 0, 1, 8)

	case AFRINTPD:
		return FPOP1S(0, 0, 1, 9)

	case AFRINTMD:
		return FPOP1S(0, 0, 1, 10)

	case AFRINTZD:
		return FPOP1S(0, 0, 1, 11)

	case AFRINTAD:
		return FPOP1S(0, 0, 1, 12)

	case AFRINTXD:
		return FPOP1S(0, 0, 1, 14)

	case AFRINTID:
		return FPOP1S(0, 0, 1, 15)

	case AFCVTHS:
		return FPOP1S(0, 0, 3, 4)

	case AFCVTHD:
		return FPOP1S(0, 0, 3, 5)
	}

	ctxt.Diag("bad rrr %d %v", a, obj.Aconv(a))
	prasm(ctxt.Curp)
	return 0
}

/*
 * imm -> Rd
 * imm op Rn -> Rd
 */
func opirr(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	/* op $addcon, Rn, Rd */
	case AMOVD, AADD:
		return S64 | 0<<30 | 0<<29 | 0x11<<24

	case ACMN, AADDS:
		return S64 | 0<<30 | 1<<29 | 0x11<<24

	case AMOVW, AADDW:
		return S32 | 0<<30 | 0<<29 | 0x11<<24

	case ACMNW, AADDSW:
		return S32 | 0<<30 | 1<<29 | 0x11<<24

	case ASUB:
		return S64 | 1<<30 | 0<<29 | 0x11<<24

	case ACMP, ASUBS:
		return S64 | 1<<30 | 1<<29 | 0x11<<24

	case ASUBW:
		return S32 | 1<<30 | 0<<29 | 0x11<<24

	case ACMPW, ASUBSW:
		return S32 | 1<<30 | 1<<29 | 0x11<<24

		/* op $imm(SB), Rd; op label, Rd */
	case AADR:
		return 0<<31 | 0x10<<24

	case AADRP:
		return 1<<31 | 0x10<<24

		/* op $bimm, Rn, Rd */
	case AAND, ABIC:
		return S64 | 0<<29 | 0x24<<23

	case AANDW, ABICW:
		return S32 | 0<<29 | 0x24<<23 | 0<<22

	case AORR, AORN:
		return S64 | 1<<29 | 0x24<<23

	case AORRW, AORNW:
		return S32 | 1<<29 | 0x24<<23 | 0<<22

	case AEOR, AEON:
		return S64 | 2<<29 | 0x24<<23

	case AEORW, AEONW:
		return S32 | 2<<29 | 0x24<<23 | 0<<22

	case AANDS, ABICS:
		return S64 | 3<<29 | 0x24<<23

	case AANDSW, ABICSW:
		return S32 | 3<<29 | 0x24<<23 | 0<<22

	case AASR:
		return S64 | 0<<29 | 0x26<<23 /* alias of SBFM */

	case AASRW:
		return S32 | 0<<29 | 0x26<<23 | 0<<22

		/* op $width, $lsb, Rn, Rd */
	case ABFI:
		return S64 | 2<<29 | 0x26<<23 | 1<<22
		/* alias of BFM */

	case ABFIW:
		return S32 | 2<<29 | 0x26<<23 | 0<<22

		/* op $imms, $immr, Rn, Rd */
	case ABFM:
		return S64 | 1<<29 | 0x26<<23 | 1<<22

	case ABFMW:
		return S32 | 1<<29 | 0x26<<23 | 0<<22

	case ASBFM:
		return S64 | 0<<29 | 0x26<<23 | 1<<22

	case ASBFMW:
		return S32 | 0<<29 | 0x26<<23 | 0<<22

	case AUBFM:
		return S64 | 2<<29 | 0x26<<23 | 1<<22

	case AUBFMW:
		return S32 | 2<<29 | 0x26<<23 | 0<<22

	case ABFXIL:
		return S64 | 1<<29 | 0x26<<23 | 1<<22 /* alias of BFM */

	case ABFXILW:
		return S32 | 1<<29 | 0x26<<23 | 0<<22

	case AEXTR:
		return S64 | 0<<29 | 0x27<<23 | 1<<22 | 0<<21

	case AEXTRW:
		return S32 | 0<<29 | 0x27<<23 | 0<<22 | 0<<21

	case ACBNZ:
		return S64 | 0x1A<<25 | 1<<24

	case ACBNZW:
		return S32 | 0x1A<<25 | 1<<24

	case ACBZ:
		return S64 | 0x1A<<25 | 0<<24

	case ACBZW:
		return S32 | 0x1A<<25 | 0<<24

	case ACCMN:
		return S64 | 0<<30 | 1<<29 | 0xD2<<21 | 1<<11 | 0<<10 | 0<<4 /* imm5<<16 | cond<<12 | nzcv<<0 */

	case ACCMNW:
		return S32 | 0<<30 | 1<<29 | 0xD2<<21 | 1<<11 | 0<<10 | 0<<4

	case ACCMP:
		return S64 | 1<<30 | 1<<29 | 0xD2<<21 | 1<<11 | 0<<10 | 0<<4 /* imm5<<16 | cond<<12 | nzcv<<0 */

	case ACCMPW:
		return S32 | 1<<30 | 1<<29 | 0xD2<<21 | 1<<11 | 0<<10 | 0<<4

	case AMOVK:
		return S64 | 3<<29 | 0x25<<23

	case AMOVKW:
		return S32 | 3<<29 | 0x25<<23

	case AMOVN:
		return S64 | 0<<29 | 0x25<<23

	case AMOVNW:
		return S32 | 0<<29 | 0x25<<23

	case AMOVZ:
		return S64 | 2<<29 | 0x25<<23

	case AMOVZW:
		return S32 | 2<<29 | 0x25<<23

	case AMSR:
		return SYSOP(0, 0, 0, 4, 0, 0, 0x1F) /* MSR (immediate) */

	case AAT,
		ADC,
		AIC,
		ATLBI,
		ASYS:
		return SYSOP(0, 1, 0, 0, 0, 0, 0)

	case ASYSL:
		return SYSOP(1, 1, 0, 0, 0, 0, 0)

	case ATBZ:
		return 0x36 << 24

	case ATBNZ:
		return 0x37 << 24

	case ADSB:
		return SYSOP(0, 0, 3, 3, 0, 4, 0x1F)

	case ADMB:
		return SYSOP(0, 0, 3, 3, 0, 5, 0x1F)

	case AISB:
		return SYSOP(0, 0, 3, 3, 0, 6, 0x1F)

	case AHINT:
		return SYSOP(0, 0, 3, 2, 0, 0, 0x1F)
	}

	ctxt.Diag("bad irr %v", obj.Aconv(a))
	prasm(ctxt.Curp)
	return 0
}

func opbit(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ACLS:
		return S64 | OPBIT(5)

	case ACLSW:
		return S32 | OPBIT(5)

	case ACLZ:
		return S64 | OPBIT(4)

	case ACLZW:
		return S32 | OPBIT(4)

	case ARBIT:
		return S64 | OPBIT(0)

	case ARBITW:
		return S32 | OPBIT(0)

	case AREV:
		return S64 | OPBIT(3)

	case AREVW:
		return S32 | OPBIT(2)

	case AREV16:
		return S64 | OPBIT(1)

	case AREV16W:
		return S32 | OPBIT(1)

	case AREV32:
		return S64 | OPBIT(2)

	default:
		ctxt.Diag("bad bit op\n%v", ctxt.Curp)
		return 0
	}
}

/*
 * add/subtract extended register
 */
func opxrrr(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case AADD:
		return S64 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64

	case AADDW:
		return S32 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32

	case ACMN, AADDS:
		return S64 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64

	case ACMNW, AADDSW:
		return S32 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32

	case ASUB:
		return S64 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64

	case ASUBW:
		return S32 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32

	case ACMP, ASUBS:
		return S64 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64

	case ACMPW, ASUBSW:
		return S32 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32
	}

	ctxt.Diag("bad opxrrr %v\n%v", obj.Aconv(a), ctxt.Curp)
	return 0
}

func opimm(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ASVC:
		return 0xD4<<24 | 0<<21 | 1 /* imm16<<5 */

	case AHVC:
		return 0xD4<<24 | 0<<21 | 2

	case ASMC:
		return 0xD4<<24 | 0<<21 | 3

	case ABRK:
		return 0xD4<<24 | 1<<21 | 0

	case AHLT:
		return 0xD4<<24 | 2<<21 | 0

	case ADCPS1:
		return 0xD4<<24 | 5<<21 | 1

	case ADCPS2:
		return 0xD4<<24 | 5<<21 | 2

	case ADCPS3:
		return 0xD4<<24 | 5<<21 | 3

	case ACLREX:
		return SYSOP(0, 0, 3, 3, 0, 2, 0x1F)
	}

	ctxt.Diag("bad imm %v", obj.Aconv(a))
	prasm(ctxt.Curp)
	return 0
}

func brdist(ctxt *obj.Link, p *obj.Prog, preshift int, flen int, shift int) int64 {
	v := int64(0)
	t := int64(0)
	if p.Pcond != nil {
		v = (p.Pcond.Pc >> uint(preshift)) - (ctxt.Pc >> uint(preshift))
		if (v & ((1 << uint(shift)) - 1)) != 0 {
			ctxt.Diag("misaligned label\n%v", p)
		}
		v >>= uint(shift)
		t = int64(1) << uint(flen-1)
		if v < -t || v >= t {
			ctxt.Diag("branch too far %#x vs %#x [%p]\n%v\n%v", v, t, ctxt.Blitrl, p, p.Pcond)
			panic("branch too far")
		}
	}

	return v & ((t << 1) - 1)
}

/*
 * pc-relative branches
 */
func opbra(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ABEQ:
		return OPBcc(0x0)

	case ABNE:
		return OPBcc(0x1)

	case ABCS:
		return OPBcc(0x2)

	case ABHS:
		return OPBcc(0x2)

	case ABCC:
		return OPBcc(0x3)

	case ABLO:
		return OPBcc(0x3)

	case ABMI:
		return OPBcc(0x4)

	case ABPL:
		return OPBcc(0x5)

	case ABVS:
		return OPBcc(0x6)

	case ABVC:
		return OPBcc(0x7)

	case ABHI:
		return OPBcc(0x8)

	case ABLS:
		return OPBcc(0x9)

	case ABGE:
		return OPBcc(0xa)

	case ABLT:
		return OPBcc(0xb)

	case ABGT:
		return OPBcc(0xc)

	case ABLE:
		return OPBcc(0xd) /* imm19<<5 | cond */

	case AB:
		return 0<<31 | 5<<26 /* imm26 */

	case obj.ADUFFZERO,
		ABL:
		return 1<<31 | 5<<26
	}

	ctxt.Diag("bad bra %v", obj.Aconv(a))
	prasm(ctxt.Curp)
	return 0
}

func opbrr(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ABL:
		return OPBLR(1) /* BLR */

	case AB:
		return OPBLR(0) /* BR */

	case obj.ARET:
		return OPBLR(2) /* RET */
	}

	ctxt.Diag("bad brr %v", obj.Aconv(a))
	prasm(ctxt.Curp)
	return 0
}

func op0(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ADRPS:
		return 0x6B<<25 | 5<<21 | 0x1F<<16 | 0x1F<<5

	case AERET:
		return 0x6B<<25 | 4<<21 | 0x1F<<16 | 0<<10 | 0x1F<<5

	// case ANOP:
	// 	return SYSHINT(0)

	case AYIELD:
		return SYSHINT(1)

	case AWFE:
		return SYSHINT(2)

	case AWFI:
		return SYSHINT(3)

	case ASEV:
		return SYSHINT(4)

	case ASEVL:
		return SYSHINT(5)
	}

	ctxt.Diag("bad op0 %v", obj.Aconv(a))
	prasm(ctxt.Curp)
	return 0
}

/*
 * register offset
 */
func opload(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ALDAR:
		return LDSTX(3, 1, 1, 0, 1) | 0x1F<<10

	case ALDARW:
		return LDSTX(2, 1, 1, 0, 1) | 0x1F<<10

	case ALDARB:
		return LDSTX(0, 1, 1, 0, 1) | 0x1F<<10

	case ALDARH:
		return LDSTX(1, 1, 1, 0, 1) | 0x1F<<10

	case ALDAXP:
		return LDSTX(3, 0, 1, 1, 1)

	case ALDAXPW:
		return LDSTX(2, 0, 1, 1, 1)

	case ALDAXR:
		return LDSTX(3, 0, 1, 0, 1) | 0x1F<<10

	case ALDAXRW:
		return LDSTX(2, 0, 1, 0, 1) | 0x1F<<10

	case ALDAXRB:
		return LDSTX(0, 0, 1, 0, 1) | 0x1F<<10

	case ALDAXRH:
		return LDSTX(1, 0, 1, 0, 1) | 0x1F<<10

	case ALDXR:
		return LDSTX(3, 0, 1, 0, 0) | 0x1F<<10

	case ALDXRB:
		return LDSTX(0, 0, 1, 0, 0) | 0x1F<<10

	case ALDXRH:
		return LDSTX(1, 0, 1, 0, 0) | 0x1F<<10

	case ALDXRW:
		return LDSTX(2, 0, 1, 0, 0) | 0x1F<<10

	case ALDXP:
		return LDSTX(3, 0, 1, 1, 0)

	case ALDXPW:
		return LDSTX(2, 0, 1, 1, 0)

	case AMOVNP:
		return S64 | 0<<30 | 5<<27 | 0<<26 | 0<<23 | 1<<22

	case AMOVNPW:
		return S32 | 0<<30 | 5<<27 | 0<<26 | 0<<23 | 1<<22
	}

	ctxt.Diag("bad opload %v\n%v", obj.Aconv(a), ctxt.Curp)
	return 0
}

func opstore(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case ASTLR:
		return LDSTX(3, 1, 0, 0, 1) | 0x1F<<10

	case ASTLRB:
		return LDSTX(0, 1, 0, 0, 1) | 0x1F<<10

	case ASTLRH:
		return LDSTX(1, 1, 0, 0, 1) | 0x1F<<10

	case ASTLP:
		return LDSTX(3, 0, 0, 1, 1)

	case ASTLPW:
		return LDSTX(2, 0, 0, 1, 1)

	case ASTLRW:
		return LDSTX(2, 1, 0, 0, 1) | 0x1F<<10

	case ASTLXP:
		return LDSTX(2, 0, 0, 1, 1)

	case ASTLXPW:
		return LDSTX(3, 0, 0, 1, 1)

	case ASTLXR:
		return LDSTX(3, 0, 0, 0, 1) | 0x1F<<10

	case ASTLXRB:
		return LDSTX(0, 0, 0, 0, 1) | 0x1F<<10

	case ASTLXRH:
		return LDSTX(1, 0, 0, 0, 1) | 0x1F<<10

	case ASTLXRW:
		return LDSTX(2, 0, 0, 0, 1) | 0x1F<<10

	case ASTXR:
		return LDSTX(3, 0, 0, 0, 0) | 0x1F<<10

	case ASTXRB:
		return LDSTX(0, 0, 0, 0, 0) | 0x1F<<10

	case ASTXRH:
		return LDSTX(1, 0, 0, 0, 0) | 0x1F<<10

	case ASTXP:
		return LDSTX(3, 0, 0, 1, 0)

	case ASTXPW:
		return LDSTX(2, 0, 0, 1, 0)

	case ASTXRW:
		return LDSTX(2, 0, 0, 0, 0) | 0x1F<<10

	case AMOVNP:
		return S64 | 0<<30 | 5<<27 | 0<<26 | 0<<23 | 1<<22

	case AMOVNPW:
		return S32 | 0<<30 | 5<<27 | 0<<26 | 0<<23 | 1<<22
	}

	ctxt.Diag("bad opstore %v\n%v", obj.Aconv(a), ctxt.Curp)
	return 0
}

/*
 * load/store register (unsigned immediate) C3.3.13
 *	these produce 64-bit values (when there's an option)
 */
func olsr12u(ctxt *obj.Link, o int32, v int32, b int, r int) uint32 {
	if v < 0 || v >= (1<<12) {
		ctxt.Diag("offset out of range: %d\n%v", v, ctxt.Curp)
	}
	o |= (v & 0xFFF) << 10
	o |= int32(b&31) << 5
	o |= int32(r & 31)
	return uint32(o)
}

func opldr12(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case AMOVD:
		return LDSTR12U(3, 0, 1) /* imm12<<10 | Rn<<5 | Rt */

	case AMOVW:
		return LDSTR12U(2, 0, 2)

	case AMOVWU:
		return LDSTR12U(2, 0, 1)

	case AMOVH:
		return LDSTR12U(1, 0, 2)

	case AMOVHU:
		return LDSTR12U(1, 0, 1)

	case AMOVB:
		return LDSTR12U(0, 0, 2)

	case AMOVBU:
		return LDSTR12U(0, 0, 1)

	case AFMOVS:
		return LDSTR12U(2, 1, 1)

	case AFMOVD:
		return LDSTR12U(3, 1, 1)
	}

	ctxt.Diag("bad opldr12 %v\n%v", obj.Aconv(a), ctxt.Curp)
	return 0
}

func opstr12(ctxt *obj.Link, a obj.As) uint32 {
	return LD2STR(opldr12(ctxt, a))
}

/*
 * load/store register (unscaled immediate) C3.3.12
 */
func olsr9s(ctxt *obj.Link, o int32, v int32, b int, r int) uint32 {
	if v < -256 || v > 255 {
		ctxt.Diag("offset out of range: %d\n%v", v, ctxt.Curp)
	}
	o |= (v & 0x1FF) << 12
	o |= int32(b&31) << 5
	o |= int32(r & 31)
	return uint32(o)
}

func opldr9(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case AMOVD:
		return LDSTR9S(3, 0, 1) /* simm9<<12 | Rn<<5 | Rt */

	case AMOVW:
		return LDSTR9S(2, 0, 2)

	case AMOVWU:
		return LDSTR9S(2, 0, 1)

	case AMOVH:
		return LDSTR9S(1, 0, 2)

	case AMOVHU:
		return LDSTR9S(1, 0, 1)

	case AMOVB:
		return LDSTR9S(0, 0, 2)

	case AMOVBU:
		return LDSTR9S(0, 0, 1)

	case AFMOVS:
		return LDSTR9S(2, 1, 1)

	case AFMOVD:
		return LDSTR9S(3, 1, 1)
	}

	ctxt.Diag("bad opldr9 %v\n%v", obj.Aconv(a), ctxt.Curp)
	return 0
}

func opstr9(ctxt *obj.Link, a obj.As) uint32 {
	return LD2STR(opldr9(ctxt, a))
}

func opldrpp(ctxt *obj.Link, a obj.As) uint32 {
	switch a {
	case AMOVD:
		return 3<<30 | 7<<27 | 0<<26 | 0<<24 | 1<<22 /* simm9<<12 | Rn<<5 | Rt */

	case AMOVW:
		return 2<<30 | 7<<27 | 0<<26 | 0<<24 | 2<<22

	case AMOVWU:
		return 2<<30 | 7<<27 | 0<<26 | 0<<24 | 1<<22

	case AMOVH:
		return 1<<30 | 7<<27 | 0<<26 | 0<<24 | 2<<22

	case AMOVHU:
		return 1<<30 | 7<<27 | 0<<26 | 0<<24 | 1<<22

	case AMOVB:
		return 0<<30 | 7<<27 | 0<<26 | 0<<24 | 2<<22

	case AMOVBU:
		return 0<<30 | 7<<27 | 0<<26 | 0<<24 | 1<<22
	}

	ctxt.Diag("bad opldr %v\n%v", obj.Aconv(a), ctxt.Curp)
	return 0
}

/*
 * load/store register (extended register)
 */
func olsxrr(ctxt *obj.Link, as obj.As, rt int, r1 int, r2 int) uint32 {
	ctxt.Diag("need load/store extended register\n%v", ctxt.Curp)
	return 0xffffffff
}

func oaddi(ctxt *obj.Link, o1 int32, v int32, r int, rt int) uint32 {
	if (v & 0xFFF000) != 0 {
		if v&0xFFF != 0 {
			ctxt.Diag("%v misuses oaddi", ctxt.Curp)
		}
		v >>= 12
		o1 |= 1 << 22
	}

	o1 |= ((v & 0xFFF) << 10) | (int32(r&31) << 5) | int32(rt&31)
	return uint32(o1)
}

/*
 * load a a literal value into dr
 */
func omovlit(ctxt *obj.Link, as obj.As, p *obj.Prog, a *obj.Addr, dr int) uint32 {
	var o1 int32
	if p.Pcond == nil { /* not in literal pool */
		aclass(ctxt, a)
		fmt.Fprintf(ctxt.Bso, "omovlit add %d (%#x)\n", ctxt.Instoffset, uint64(ctxt.Instoffset))

		/* TODO: could be clever, and use general constant builder */
		o1 = int32(opirr(ctxt, AADD))

		v := int32(ctxt.Instoffset)
		if v != 0 && (v&0xFFF) == 0 {
			v >>= 12
			o1 |= 1 << 22 /* shift, by 12 */
		}

		o1 |= ((v & 0xFFF) << 10) | (REGZERO & 31 << 5) | int32(dr&31)
	} else {
		fp := 0
		w := 0 /* default: 32 bit, unsigned */
		switch as {
		case AFMOVS:
			fp = 1

		case AFMOVD:
			fp = 1
			w = 1 /* 64 bit simd&fp */

		case AMOVD:
			if p.Pcond.As == ADWORD {
				w = 1 /* 64 bit */
			} else if p.Pcond.To.Offset < 0 {
				w = 2 /* sign extend */
			}

		case AMOVB, AMOVH, AMOVW:
			w = 2 /* 32 bit, sign-extended to 64 */
			break
		}

		v := int32(brdist(ctxt, p, 0, 19, 2))
		o1 = (int32(w) << 30) | (int32(fp) << 26) | (3 << 27)
		o1 |= (v & 0x7FFFF) << 5
		o1 |= int32(dr & 31)
	}

	return uint32(o1)
}

// load a constant (MOVCON or BITCON) in a into rt
func omovconst(ctxt *obj.Link, as obj.As, p *obj.Prog, a *obj.Addr, rt int) (o1 uint32) {
	if c := oclass(a); c == C_BITCON || c == C_ABCON || c == C_ABCON0 {
		// or $bitcon, REGZERO, rt
		mode := 64
		var as1 obj.As
		switch as {
		case AMOVW:
			as1 = AORRW
			mode = 32
		case AMOVD:
			as1 = AORR
		}
		o1 = opirr(ctxt, as1)
		o1 |= bitconEncode(uint64(a.Offset), mode) | uint32(REGZERO&31)<<5 | uint32(rt&31)
		return o1
	}

	r := 32
	if as == AMOVD {
		r = 64
	}
	d := a.Offset
	s := movcon(d)
	if s < 0 || s >= r {
		d = ^d
		s = movcon(d)
		if s < 0 || s >= r {
			ctxt.Diag("impossible move wide: %#x\n%v", uint64(a.Offset), p)
		}
		if as == AMOVD {
			o1 = opirr(ctxt, AMOVN)
		} else {
			o1 = opirr(ctxt, AMOVNW)
		}
	} else {
		if as == AMOVD {
			o1 = opirr(ctxt, AMOVZ)
		} else {
			o1 = opirr(ctxt, AMOVZW)
		}
	}
	o1 |= uint32((((d >> uint(s*16)) & 0xFFFF) << 5) | int64((uint32(s)&3)<<21) | int64(rt&31))
	return o1
}

func opbfm(ctxt *obj.Link, a obj.As, r int, s int, rf int, rt int) uint32 {
	var c uint32
	o := opirr(ctxt, a)
	if (o & (1 << 31)) == 0 {
		c = 32
	} else {
		c = 64
	}
	if r < 0 || uint32(r) >= c {
		ctxt.Diag("illegal bit number\n%v", ctxt.Curp)
	}
	o |= (uint32(r) & 0x3F) << 16
	if s < 0 || uint32(s) >= c {
		ctxt.Diag("illegal bit number\n%v", ctxt.Curp)
	}
	o |= (uint32(s) & 0x3F) << 10
	o |= (uint32(rf&31) << 5) | uint32(rt&31)
	return o
}

func opextr(ctxt *obj.Link, a obj.As, v int32, rn int, rm int, rt int) uint32 {
	var c uint32
	o := opirr(ctxt, a)
	if (o & (1 << 31)) != 0 {
		c = 63
	} else {
		c = 31
	}
	if v < 0 || uint32(v) > c {
		ctxt.Diag("illegal bit number\n%v", ctxt.Curp)
	}
	o |= uint32(v) << 10
	o |= uint32(rn&31) << 5
	o |= uint32(rm&31) << 16
	o |= uint32(rt & 31)
	return o
}

/*
 * size in log2(bytes)
 */
func movesize(a obj.As) int {
	switch a {
	case AMOVD:
		return 3

	case AMOVW, AMOVWU:
		return 2

	case AMOVH, AMOVHU:
		return 1

	case AMOVB, AMOVBU:
		return 0

	case AFMOVS:
		return 2

	case AFMOVD:
		return 3

	default:
		return -1
	}
}