Use mod vendor for vendored directory (backwards compatible)

1 files changed, 0 insertions, 1481 deletions

diff --git a/vendor/github.com/google/gops/internal/obj/x86/obj6.go b/vendor/github.com/google/gops/internal/obj/x86/obj6.go
deleted file mode 100644
index aad950bb..00000000
--- a/vendor/github.com/google/gops/internal/obj/x86/obj6.go
+++ /dev/null
@@ -1,1481 +0,0 @@
-// Inferno utils/6l/pass.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/pass.c
-//
-//	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 x86
-
-import (
-	"fmt"
-	"log"
-	"math"
-	"strings"
-
-	"github.com/google/gops/internal/obj"
-	"github.com/google/gops/internal/sys"
-)
-
-func CanUse1InsnTLS(ctxt *obj.Link) bool {
-	if isAndroid {
-		// For android, we use a disgusting hack that assumes
-		// the thread-local storage slot for g is allocated
-		// using pthread_key_create with a fixed offset
-		// (see src/runtime/cgo/gcc_android_amd64.c).
-		// This makes access to the TLS storage (for g) doable
-		// with 1 instruction.
-		return true
-	}
-
-	if ctxt.Arch.RegSize == 4 {
-		switch ctxt.Headtype {
-		case obj.Hlinux,
-			obj.Hnacl,
-			obj.Hplan9,
-			obj.Hwindows,
-			obj.Hwindowsgui:
-			return false
-		}
-
-		return true
-	}
-
-	switch ctxt.Headtype {
-	case obj.Hplan9, obj.Hwindows, obj.Hwindowsgui:
-		return false
-	case obj.Hlinux:
-		return !ctxt.Flag_shared
-	}
-
-	return true
-}
-
-func progedit(ctxt *obj.Link, p *obj.Prog) {
-	// Maintain information about code generation mode.
-	if ctxt.Mode == 0 {
-		ctxt.Mode = ctxt.Arch.RegSize * 8
-	}
-	p.Mode = int8(ctxt.Mode)
-
-	switch p.As {
-	case AMODE:
-		if p.From.Type == obj.TYPE_CONST || (p.From.Type == obj.TYPE_MEM && p.From.Reg == REG_NONE) {
-			switch int(p.From.Offset) {
-			case 16, 32, 64:
-				ctxt.Mode = int(p.From.Offset)
-			}
-		}
-		obj.Nopout(p)
-	}
-
-	// Thread-local storage references use the TLS pseudo-register.
-	// As a register, TLS refers to the thread-local storage base, and it
-	// can only be loaded into another register:
-	//
-	//         MOVQ TLS, AX
-	//
-	// An offset from the thread-local storage base is written off(reg)(TLS*1).
-	// Semantically it is off(reg), but the (TLS*1) annotation marks this as
-	// indexing from the loaded TLS base. This emits a relocation so that
-	// if the linker needs to adjust the offset, it can. For example:
-	//
-	//         MOVQ TLS, AX
-	//         MOVQ 0(AX)(TLS*1), CX // load g into CX
-	//
-	// On systems that support direct access to the TLS memory, this
-	// pair of instructions can be reduced to a direct TLS memory reference:
-	//
-	//         MOVQ 0(TLS), CX // load g into CX
-	//
-	// The 2-instruction and 1-instruction forms correspond to the two code
-	// sequences for loading a TLS variable in the local exec model given in "ELF
-	// Handling For Thread-Local Storage".
-	//
-	// We apply this rewrite on systems that support the 1-instruction form.
-	// The decision is made using only the operating system and the -shared flag,
-	// not the link mode. If some link modes on a particular operating system
-	// require the 2-instruction form, then all builds for that operating system
-	// will use the 2-instruction form, so that the link mode decision can be
-	// delayed to link time.
-	//
-	// In this way, all supported systems use identical instructions to
-	// access TLS, and they are rewritten appropriately first here in
-	// liblink and then finally using relocations in the linker.
-	//
-	// When -shared is passed, we leave the code in the 2-instruction form but
-	// assemble (and relocate) them in different ways to generate the initial
-	// exec code sequence. It's a bit of a fluke that this is possible without
-	// rewriting the instructions more comprehensively, and it only does because
-	// we only support a single TLS variable (g).
-
-	if CanUse1InsnTLS(ctxt) {
-		// Reduce 2-instruction sequence to 1-instruction sequence.
-		// Sequences like
-		//	MOVQ TLS, BX
-		//	... off(BX)(TLS*1) ...
-		// become
-		//	NOP
-		//	... off(TLS) ...
-		//
-		// TODO(rsc): Remove the Hsolaris special case. It exists only to
-		// guarantee we are producing byte-identical binaries as before this code.
-		// But it should be unnecessary.
-		if (p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_REG && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 && ctxt.Headtype != obj.Hsolaris {
-			obj.Nopout(p)
-		}
-		if p.From.Type == obj.TYPE_MEM && p.From.Index == REG_TLS && REG_AX <= p.From.Reg && p.From.Reg <= REG_R15 {
-			p.From.Reg = REG_TLS
-			p.From.Scale = 0
-			p.From.Index = REG_NONE
-		}
-
-		if p.To.Type == obj.TYPE_MEM && p.To.Index == REG_TLS && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
-			p.To.Reg = REG_TLS
-			p.To.Scale = 0
-			p.To.Index = REG_NONE
-		}
-	} else {
-		// load_g_cx, below, always inserts the 1-instruction sequence. Rewrite it
-		// as the 2-instruction sequence if necessary.
-		//	MOVQ 0(TLS), BX
-		// becomes
-		//	MOVQ TLS, BX
-		//	MOVQ 0(BX)(TLS*1), BX
-		if (p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_MEM && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
-			q := obj.Appendp(ctxt, p)
-			q.As = p.As
-			q.From = p.From
-			q.From.Type = obj.TYPE_MEM
-			q.From.Reg = p.To.Reg
-			q.From.Index = REG_TLS
-			q.From.Scale = 2 // TODO: use 1
-			q.To = p.To
-			p.From.Type = obj.TYPE_REG
-			p.From.Reg = REG_TLS
-			p.From.Index = REG_NONE
-			p.From.Offset = 0
-		}
-	}
-
-	// TODO: Remove.
-	if (ctxt.Headtype == obj.Hwindows || ctxt.Headtype == obj.Hwindowsgui) && p.Mode == 64 || ctxt.Headtype == obj.Hplan9 {
-		if p.From.Scale == 1 && p.From.Index == REG_TLS {
-			p.From.Scale = 2
-		}
-		if p.To.Scale == 1 && p.To.Index == REG_TLS {
-			p.To.Scale = 2
-		}
-	}
-
-	// Rewrite 0 to $0 in 3rd argument to CMPPS etc.
-	// That's what the tables expect.
-	switch p.As {
-	case ACMPPD, ACMPPS, ACMPSD, ACMPSS:
-		if p.To.Type == obj.TYPE_MEM && p.To.Name == obj.NAME_NONE && p.To.Reg == REG_NONE && p.To.Index == REG_NONE && p.To.Sym == nil {
-			p.To.Type = obj.TYPE_CONST
-		}
-	}
-
-	// Rewrite CALL/JMP/RET to symbol as TYPE_BRANCH.
-	switch p.As {
-	case obj.ACALL, obj.AJMP, obj.ARET:
-		if p.To.Type == obj.TYPE_MEM && (p.To.Name == obj.NAME_EXTERN || p.To.Name == obj.NAME_STATIC) && p.To.Sym != nil {
-			p.To.Type = obj.TYPE_BRANCH
-		}
-	}
-
-	// Rewrite MOVL/MOVQ $XXX(FP/SP) as LEAL/LEAQ.
-	if p.From.Type == obj.TYPE_ADDR && (ctxt.Arch.Family == sys.AMD64 || p.From.Name != obj.NAME_EXTERN && p.From.Name != obj.NAME_STATIC) {
-		switch p.As {
-		case AMOVL:
-			p.As = ALEAL
-			p.From.Type = obj.TYPE_MEM
-		case AMOVQ:
-			p.As = ALEAQ
-			p.From.Type = obj.TYPE_MEM
-		}
-	}
-
-	if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
-		if p.From3 != nil {
-			nacladdr(ctxt, p, p.From3)
-		}
-		nacladdr(ctxt, p, &p.From)
-		nacladdr(ctxt, p, &p.To)
-	}
-
-	// Rewrite float constants to values stored in memory.
-	switch p.As {
-	// Convert AMOVSS $(0), Xx to AXORPS Xx, Xx
-	case AMOVSS:
-		if p.From.Type == obj.TYPE_FCONST {
-			//  f == 0 can't be used here due to -0, so use Float64bits
-			if f := p.From.Val.(float64); math.Float64bits(f) == 0 {
-				if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
-					p.As = AXORPS
-					p.From = p.To
-					break
-				}
-			}
-		}
-		fallthrough
-
-	case AFMOVF,
-		AFADDF,
-		AFSUBF,
-		AFSUBRF,
-		AFMULF,
-		AFDIVF,
-		AFDIVRF,
-		AFCOMF,
-		AFCOMFP,
-		AADDSS,
-		ASUBSS,
-		AMULSS,
-		ADIVSS,
-		ACOMISS,
-		AUCOMISS:
-		if p.From.Type == obj.TYPE_FCONST {
-			f32 := float32(p.From.Val.(float64))
-			i32 := math.Float32bits(f32)
-			literal := fmt.Sprintf("$f32.%08x", i32)
-			s := obj.Linklookup(ctxt, literal, 0)
-			p.From.Type = obj.TYPE_MEM
-			p.From.Name = obj.NAME_EXTERN
-			p.From.Sym = s
-			p.From.Sym.Set(obj.AttrLocal, true)
-			p.From.Offset = 0
-		}
-
-	case AMOVSD:
-		// Convert AMOVSD $(0), Xx to AXORPS Xx, Xx
-		if p.From.Type == obj.TYPE_FCONST {
-			//  f == 0 can't be used here due to -0, so use Float64bits
-			if f := p.From.Val.(float64); math.Float64bits(f) == 0 {
-				if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
-					p.As = AXORPS
-					p.From = p.To
-					break
-				}
-			}
-		}
-		fallthrough
-
-	case AFMOVD,
-		AFADDD,
-		AFSUBD,
-		AFSUBRD,
-		AFMULD,
-		AFDIVD,
-		AFDIVRD,
-		AFCOMD,
-		AFCOMDP,
-		AADDSD,
-		ASUBSD,
-		AMULSD,
-		ADIVSD,
-		ACOMISD,
-		AUCOMISD:
-		if p.From.Type == obj.TYPE_FCONST {
-			i64 := math.Float64bits(p.From.Val.(float64))
-			literal := fmt.Sprintf("$f64.%016x", i64)
-			s := obj.Linklookup(ctxt, literal, 0)
-			p.From.Type = obj.TYPE_MEM
-			p.From.Name = obj.NAME_EXTERN
-			p.From.Sym = s
-			p.From.Sym.Set(obj.AttrLocal, true)
-			p.From.Offset = 0
-		}
-	}
-
-	if ctxt.Flag_dynlink {
-		rewriteToUseGot(ctxt, p)
-	}
-
-	if ctxt.Flag_shared && p.Mode == 32 {
-		rewriteToPcrel(ctxt, p)
-	}
-}
-
-// Rewrite p, if necessary, to access global data via the global offset table.
-func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog) {
-	var add, lea, mov obj.As
-	var reg int16
-	if p.Mode == 64 {
-		add = AADDQ
-		lea = ALEAQ
-		mov = AMOVQ
-		reg = REG_R15
-	} else {
-		add = AADDL
-		lea = ALEAL
-		mov = AMOVL
-		reg = REG_CX
-		if p.As == ALEAL && p.To.Reg != p.From.Reg && p.To.Reg != p.From.Index {
-			// Special case: clobber the destination register with
-			// the PC so we don't have to clobber CX.
-			// The SSA backend depends on CX not being clobbered across LEAL.
-			// See cmd/compile/internal/ssa/gen/386.rules (search for Flag_shared).
-			reg = p.To.Reg
-		}
-	}
-
-	if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO {
-		//     ADUFFxxx $offset
-		// becomes
-		//     $MOV runtime.duffxxx@GOT, $reg
-		//     $ADD $offset, $reg
-		//     CALL $reg
-		var sym *obj.LSym
-		if p.As == obj.ADUFFZERO {
-			sym = obj.Linklookup(ctxt, "runtime.duffzero", 0)
-		} else {
-			sym = obj.Linklookup(ctxt, "runtime.duffcopy", 0)
-		}
-		offset := p.To.Offset
-		p.As = mov
-		p.From.Type = obj.TYPE_MEM
-		p.From.Name = obj.NAME_GOTREF
-		p.From.Sym = sym
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = reg
-		p.To.Offset = 0
-		p.To.Sym = nil
-		p1 := obj.Appendp(ctxt, p)
-		p1.As = add
-		p1.From.Type = obj.TYPE_CONST
-		p1.From.Offset = offset
-		p1.To.Type = obj.TYPE_REG
-		p1.To.Reg = reg
-		p2 := obj.Appendp(ctxt, p1)
-		p2.As = obj.ACALL
-		p2.To.Type = obj.TYPE_REG
-		p2.To.Reg = reg
-	}
-
-	// We only care about global data: NAME_EXTERN means a global
-	// symbol in the Go sense, and p.Sym.Local is true for a few
-	// internally defined symbols.
-	if p.As == lea && p.From.Type == obj.TYPE_MEM && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() {
-		// $LEA sym, Rx becomes $MOV $sym, Rx which will be rewritten below
-		p.As = mov
-		p.From.Type = obj.TYPE_ADDR
-	}
-	if p.From.Type == obj.TYPE_ADDR && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() {
-		// $MOV $sym, Rx becomes $MOV sym@GOT, Rx
-		// $MOV $sym+<off>, Rx becomes $MOV sym@GOT, Rx; $LEA <off>(Rx), Rx
-		// On 386 only, more complicated things like PUSHL $sym become $MOV sym@GOT, CX; PUSHL CX
-		cmplxdest := false
-		pAs := p.As
-		var dest obj.Addr
-		if p.To.Type != obj.TYPE_REG || pAs != mov {
-			if p.Mode == 64 {
-				ctxt.Diag("do not know how to handle LEA-type insn to non-register in %v with -dynlink", p)
-			}
-			cmplxdest = true
-			dest = p.To
-			p.As = mov
-			p.To.Type = obj.TYPE_REG
-			p.To.Reg = reg
-			p.To.Sym = nil
-			p.To.Name = obj.NAME_NONE
-		}
-		p.From.Type = obj.TYPE_MEM
-		p.From.Name = obj.NAME_GOTREF
-		q := p
-		if p.From.Offset != 0 {
-			q = obj.Appendp(ctxt, p)
-			q.As = lea
-			q.From.Type = obj.TYPE_MEM
-			q.From.Reg = p.To.Reg
-			q.From.Offset = p.From.Offset
-			q.To = p.To
-			p.From.Offset = 0
-		}
-		if cmplxdest {
-			q = obj.Appendp(ctxt, q)
-			q.As = pAs
-			q.To = dest
-			q.From.Type = obj.TYPE_REG
-			q.From.Reg = reg
-		}
-	}
-	if p.From3 != nil && p.From3.Name == obj.NAME_EXTERN {
-		ctxt.Diag("don't know how to handle %v with -dynlink", p)
-	}
-	var source *obj.Addr
-	// MOVx sym, Ry becomes $MOV sym@GOT, R15; MOVx (R15), Ry
-	// MOVx Ry, sym becomes $MOV sym@GOT, R15; MOVx Ry, (R15)
-	// An addition may be inserted between the two MOVs if there is an offset.
-	if p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() {
-		if p.To.Name == obj.NAME_EXTERN && !p.To.Sym.Local() {
-			ctxt.Diag("cannot handle NAME_EXTERN on both sides in %v with -dynlink", p)
-		}
-		source = &p.From
-	} else if p.To.Name == obj.NAME_EXTERN && !p.To.Sym.Local() {
-		source = &p.To
-	} else {
-		return
-	}
-	if p.As == obj.ACALL {
-		// When dynlinking on 386, almost any call might end up being a call
-		// to a PLT, so make sure the GOT pointer is loaded into BX.
-		// RegTo2 is set on the replacement call insn to stop it being
-		// processed when it is in turn passed to progedit.
-		if p.Mode == 64 || (p.To.Sym != nil && p.To.Sym.Local()) || p.RegTo2 != 0 {
-			return
-		}
-		p1 := obj.Appendp(ctxt, p)
-		p2 := obj.Appendp(ctxt, p1)
-
-		p1.As = ALEAL
-		p1.From.Type = obj.TYPE_MEM
-		p1.From.Name = obj.NAME_STATIC
-		p1.From.Sym = obj.Linklookup(ctxt, "_GLOBAL_OFFSET_TABLE_", 0)
-		p1.To.Type = obj.TYPE_REG
-		p1.To.Reg = REG_BX
-
-		p2.As = p.As
-		p2.Scond = p.Scond
-		p2.From = p.From
-		p2.From3 = p.From3
-		p2.Reg = p.Reg
-		p2.To = p.To
-		// p.To.Type was set to TYPE_BRANCH above, but that makes checkaddr
-		// in ../pass.go complain, so set it back to TYPE_MEM here, until p2
-		// itself gets passed to progedit.
-		p2.To.Type = obj.TYPE_MEM
-		p2.RegTo2 = 1
-
-		obj.Nopout(p)
-		return
-
-	}
-	if p.As == obj.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ARET || p.As == obj.AJMP {
-		return
-	}
-	if source.Type != obj.TYPE_MEM {
-		ctxt.Diag("don't know how to handle %v with -dynlink", p)
-	}
-	p1 := obj.Appendp(ctxt, p)
-	p2 := obj.Appendp(ctxt, p1)
-
-	p1.As = mov
-	p1.From.Type = obj.TYPE_MEM
-	p1.From.Sym = source.Sym
-	p1.From.Name = obj.NAME_GOTREF
-	p1.To.Type = obj.TYPE_REG
-	p1.To.Reg = reg
-
-	p2.As = p.As
-	p2.From = p.From
-	p2.To = p.To
-	if p.From.Name == obj.NAME_EXTERN {
-		p2.From.Reg = reg
-		p2.From.Name = obj.NAME_NONE
-		p2.From.Sym = nil
-	} else if p.To.Name == obj.NAME_EXTERN {
-		p2.To.Reg = reg
-		p2.To.Name = obj.NAME_NONE
-		p2.To.Sym = nil
-	} else {
-		return
-	}
-	obj.Nopout(p)
-}
-
-func rewriteToPcrel(ctxt *obj.Link, p *obj.Prog) {
-	// RegTo2 is set on the instructions we insert here so they don't get
-	// processed twice.
-	if p.RegTo2 != 0 {
-		return
-	}
-	if p.As == obj.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ACALL || p.As == obj.ARET || p.As == obj.AJMP {
-		return
-	}
-	// Any Prog (aside from the above special cases) with an Addr with Name ==
-	// NAME_EXTERN, NAME_STATIC or NAME_GOTREF has a CALL __x86.get_pc_thunk.XX
-	// inserted before it.
-	isName := func(a *obj.Addr) bool {
-		if a.Sym == nil || (a.Type != obj.TYPE_MEM && a.Type != obj.TYPE_ADDR) || a.Reg != 0 {
-			return false
-		}
-		if a.Sym.Type == obj.STLSBSS {
-			return false
-		}
-		return a.Name == obj.NAME_EXTERN || a.Name == obj.NAME_STATIC || a.Name == obj.NAME_GOTREF
-	}
-
-	if isName(&p.From) && p.From.Type == obj.TYPE_ADDR {
-		// Handle things like "MOVL $sym, (SP)" or "PUSHL $sym" by rewriting
-		// to "MOVL $sym, CX; MOVL CX, (SP)" or "MOVL $sym, CX; PUSHL CX"
-		// respectively.
-		if p.To.Type != obj.TYPE_REG {
-			q := obj.Appendp(ctxt, p)
-			q.As = p.As
-			q.From.Type = obj.TYPE_REG
-			q.From.Reg = REG_CX
-			q.To = p.To
-			p.As = AMOVL
-			p.To.Type = obj.TYPE_REG
-			p.To.Reg = REG_CX
-			p.To.Sym = nil
-			p.To.Name = obj.NAME_NONE
-		}
-	}
-
-	if !isName(&p.From) && !isName(&p.To) && (p.From3 == nil || !isName(p.From3)) {
-		return
-	}
-	var dst int16 = REG_CX
-	if (p.As == ALEAL || p.As == AMOVL) && p.To.Reg != p.From.Reg && p.To.Reg != p.From.Index {
-		dst = p.To.Reg
-		// Why?  See the comment near the top of rewriteToUseGot above.
-		// AMOVLs might be introduced by the GOT rewrites.
-	}
-	q := obj.Appendp(ctxt, p)
-	q.RegTo2 = 1
-	r := obj.Appendp(ctxt, q)
-	r.RegTo2 = 1
-	q.As = obj.ACALL
-	q.To.Sym = obj.Linklookup(ctxt, "__x86.get_pc_thunk."+strings.ToLower(Rconv(int(dst))), 0)
-	q.To.Type = obj.TYPE_MEM
-	q.To.Name = obj.NAME_EXTERN
-	q.To.Sym.Set(obj.AttrLocal, true)
-	r.As = p.As
-	r.Scond = p.Scond
-	r.From = p.From
-	r.From3 = p.From3
-	r.Reg = p.Reg
-	r.To = p.To
-	if isName(&p.From) {
-		r.From.Reg = dst
-	}
-	if isName(&p.To) {
-		r.To.Reg = dst
-	}
-	if p.From3 != nil && isName(p.From3) {
-		r.From3.Reg = dst
-	}
-	obj.Nopout(p)
-}
-
-func nacladdr(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
-	if p.As == ALEAL || p.As == ALEAQ {
-		return
-	}
-
-	if a.Reg == REG_BP {
-		ctxt.Diag("invalid address: %v", p)
-		return
-	}
-
-	if a.Reg == REG_TLS {
-		a.Reg = REG_BP
-	}
-	if a.Type == obj.TYPE_MEM && a.Name == obj.NAME_NONE {
-		switch a.Reg {
-		// all ok
-		case REG_BP, REG_SP, REG_R15:
-			break
-
-		default:
-			if a.Index != REG_NONE {
-				ctxt.Diag("invalid address %v", p)
-			}
-			a.Index = a.Reg
-			if a.Index != REG_NONE {
-				a.Scale = 1
-			}
-			a.Reg = REG_R15
-		}
-	}
-}
-
-func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
-	if ctxt.Headtype == obj.Hplan9 && ctxt.Plan9privates == nil {
-		ctxt.Plan9privates = obj.Linklookup(ctxt, "_privates", 0)
-	}
-
-	ctxt.Cursym = cursym
-
-	if cursym.Text == nil || cursym.Text.Link == nil {
-		return
-	}
-
-	p := cursym.Text
-	autoffset := int32(p.To.Offset)
-	if autoffset < 0 {
-		autoffset = 0
-	}
-
-	var bpsize int
-	if p.Mode == 64 && ctxt.Framepointer_enabled && autoffset > 0 && p.From3.Offset&obj.NOFRAME == 0 {
-		// Make room for to save a base pointer. If autoffset == 0,
-		// this might do something special like a tail jump to
-		// another function, so in that case we omit this.
-		bpsize = ctxt.Arch.PtrSize
-		autoffset += int32(bpsize)
-		p.To.Offset += int64(bpsize)
-	} else {
-		bpsize = 0
-	}
-
-	textarg := int64(p.To.Val.(int32))
-	cursym.Args = int32(textarg)
-	cursym.Locals = int32(p.To.Offset)
-
-	// TODO(rsc): Remove.
-	if p.Mode == 32 && cursym.Locals < 0 {
-		cursym.Locals = 0
-	}
-
-	// TODO(rsc): Remove 'p.Mode == 64 &&'.
-	if p.Mode == 64 && autoffset < obj.StackSmall && p.From3Offset()&obj.NOSPLIT == 0 {
-		leaf := true
-	LeafSearch:
-		for q := p; q != nil; q = q.Link {
-			switch q.As {
-			case obj.ACALL:
-				// Treat common runtime calls that take no arguments
-				// the same as duffcopy and duffzero.
-				if !isZeroArgRuntimeCall(q.To.Sym) {
-					leaf = false
-					break LeafSearch
-				}
-				fallthrough
-			case obj.ADUFFCOPY, obj.ADUFFZERO:
-				if autoffset >= obj.StackSmall-8 {
-					leaf = false
-					break LeafSearch
-				}
-			}
-		}
-
-		if leaf {
-			p.From3.Offset |= obj.NOSPLIT
-		}
-	}
-
-	if p.From3Offset()&obj.NOSPLIT == 0 || p.From3Offset()&obj.WRAPPER != 0 {
-		p = obj.Appendp(ctxt, p)
-		p = load_g_cx(ctxt, p) // load g into CX
-	}
-
-	if cursym.Text.From3Offset()&obj.NOSPLIT == 0 {
-		p = stacksplit(ctxt, p, autoffset, int32(textarg)) // emit split check
-	}
-
-	if autoffset != 0 {
-		if autoffset%int32(ctxt.Arch.RegSize) != 0 {
-			ctxt.Diag("unaligned stack size %d", autoffset)
-		}
-		p = obj.Appendp(ctxt, p)
-		p.As = AADJSP
-		p.From.Type = obj.TYPE_CONST
-		p.From.Offset = int64(autoffset)
-		p.Spadj = autoffset
-	}
-
-	deltasp := autoffset
-
-	if bpsize > 0 {
-		// Save caller's BP
-		p = obj.Appendp(ctxt, p)
-
-		p.As = AMOVQ
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_BP
-		p.To.Type = obj.TYPE_MEM
-		p.To.Reg = REG_SP
-		p.To.Scale = 1
-		p.To.Offset = int64(autoffset) - int64(bpsize)
-
-		// Move current frame to BP
-		p = obj.Appendp(ctxt, p)
-
-		p.As = ALEAQ
-		p.From.Type = obj.TYPE_MEM
-		p.From.Reg = REG_SP
-		p.From.Scale = 1
-		p.From.Offset = int64(autoffset) - int64(bpsize)
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_BP
-	}
-
-	if cursym.Text.From3Offset()&obj.WRAPPER != 0 {
-		// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
-		//
-		//	MOVQ g_panic(CX), BX
-		//	TESTQ BX, BX
-		//	JEQ end
-		//	LEAQ (autoffset+8)(SP), DI
-		//	CMPQ panic_argp(BX), DI
-		//	JNE end
-		//	MOVQ SP, panic_argp(BX)
-		// end:
-		//	NOP
-		//
-		// The NOP is needed to give the jumps somewhere to land.
-		// It is a liblink NOP, not an x86 NOP: it encodes to 0 instruction bytes.
-
-		p = obj.Appendp(ctxt, p)
-
-		p.As = AMOVQ
-		p.From.Type = obj.TYPE_MEM
-		p.From.Reg = REG_CX
-		p.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_BX
-		if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
-			p.As = AMOVL
-			p.From.Type = obj.TYPE_MEM
-			p.From.Reg = REG_R15
-			p.From.Scale = 1
-			p.From.Index = REG_CX
-		}
-		if p.Mode == 32 {
-			p.As = AMOVL
-		}
-
-		p = obj.Appendp(ctxt, p)
-		p.As = ATESTQ
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_BX
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_BX
-		if ctxt.Headtype == obj.Hnacl || p.Mode == 32 {
-			p.As = ATESTL
-		}
-
-		p = obj.Appendp(ctxt, p)
-		p.As = AJEQ
-		p.To.Type = obj.TYPE_BRANCH
-		p1 := p
-
-		p = obj.Appendp(ctxt, p)
-		p.As = ALEAQ
-		p.From.Type = obj.TYPE_MEM
-		p.From.Reg = REG_SP
-		p.From.Offset = int64(autoffset) + int64(ctxt.Arch.RegSize)
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_DI
-		if ctxt.Headtype == obj.Hnacl || p.Mode == 32 {
-			p.As = ALEAL
-		}
-
-		p = obj.Appendp(ctxt, p)
-		p.As = ACMPQ
-		p.From.Type = obj.TYPE_MEM
-		p.From.Reg = REG_BX
-		p.From.Offset = 0 // Panic.argp
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_DI
-		if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
-			p.As = ACMPL
-			p.From.Type = obj.TYPE_MEM
-			p.From.Reg = REG_R15
-			p.From.Scale = 1
-			p.From.Index = REG_BX
-		}
-		if p.Mode == 32 {
-			p.As = ACMPL
-		}
-
-		p = obj.Appendp(ctxt, p)
-		p.As = AJNE
-		p.To.Type = obj.TYPE_BRANCH
-		p2 := p
-
-		p = obj.Appendp(ctxt, p)
-		p.As = AMOVQ
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_SP
-		p.To.Type = obj.TYPE_MEM
-		p.To.Reg = REG_BX
-		p.To.Offset = 0 // Panic.argp
-		if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
-			p.As = AMOVL
-			p.To.Type = obj.TYPE_MEM
-			p.To.Reg = REG_R15
-			p.To.Scale = 1
-			p.To.Index = REG_BX
-		}
-		if p.Mode == 32 {
-			p.As = AMOVL
-		}
-
-		p = obj.Appendp(ctxt, p)
-		p.As = obj.ANOP
-		p1.Pcond = p
-		p2.Pcond = p
-	}
-
-	for ; p != nil; p = p.Link {
-		pcsize := int(p.Mode) / 8
-		switch p.From.Name {
-		case obj.NAME_AUTO:
-			p.From.Offset += int64(deltasp) - int64(bpsize)
-		case obj.NAME_PARAM:
-			p.From.Offset += int64(deltasp) + int64(pcsize)
-		}
-		if p.From3 != nil {
-			switch p.From3.Name {
-			case obj.NAME_AUTO:
-				p.From3.Offset += int64(deltasp) - int64(bpsize)
-			case obj.NAME_PARAM:
-				p.From3.Offset += int64(deltasp) + int64(pcsize)
-			}
-		}
-		switch p.To.Name {
-		case obj.NAME_AUTO:
-			p.To.Offset += int64(deltasp) - int64(bpsize)
-		case obj.NAME_PARAM:
-			p.To.Offset += int64(deltasp) + int64(pcsize)
-		}
-
-		switch p.As {
-		default:
-			continue
-
-		case APUSHL, APUSHFL:
-			deltasp += 4
-			p.Spadj = 4
-			continue
-
-		case APUSHQ, APUSHFQ:
-			deltasp += 8
-			p.Spadj = 8
-			continue
-
-		case APUSHW, APUSHFW:
-			deltasp += 2
-			p.Spadj = 2
-			continue
-
-		case APOPL, APOPFL:
-			deltasp -= 4
-			p.Spadj = -4
-			continue
-
-		case APOPQ, APOPFQ:
-			deltasp -= 8
-			p.Spadj = -8
-			continue
-
-		case APOPW, APOPFW:
-			deltasp -= 2
-			p.Spadj = -2
-			continue
-
-		case obj.ARET:
-			// do nothing
-		}
-
-		if autoffset != deltasp {
-			ctxt.Diag("unbalanced PUSH/POP")
-		}
-
-		if autoffset != 0 {
-			if bpsize > 0 {
-				// Restore caller's BP
-				p.As = AMOVQ
-
-				p.From.Type = obj.TYPE_MEM
-				p.From.Reg = REG_SP
-				p.From.Scale = 1
-				p.From.Offset = int64(autoffset) - int64(bpsize)
-				p.To.Type = obj.TYPE_REG
-				p.To.Reg = REG_BP
-				p = obj.Appendp(ctxt, p)
-			}
-
-			p.As = AADJSP
-			p.From.Type = obj.TYPE_CONST
-			p.From.Offset = int64(-autoffset)
-			p.Spadj = -autoffset
-			p = obj.Appendp(ctxt, p)
-			p.As = obj.ARET
-
-			// If there are instructions following
-			// this ARET, they come from a branch
-			// with the same stackframe, so undo
-			// the cleanup.
-			p.Spadj = +autoffset
-		}
-
-		if p.To.Sym != nil { // retjmp
-			p.As = obj.AJMP
-		}
-	}
-}
-
-func isZeroArgRuntimeCall(s *obj.LSym) bool {
-	if s == nil {
-		return false
-	}
-	switch s.Name {
-	case "runtime.panicindex", "runtime.panicslice", "runtime.panicdivide":
-		return true
-	}
-	return false
-}
-
-func indir_cx(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
-	if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
-		a.Type = obj.TYPE_MEM
-		a.Reg = REG_R15
-		a.Index = REG_CX
-		a.Scale = 1
-		return
-	}
-
-	a.Type = obj.TYPE_MEM
-	a.Reg = REG_CX
-}
-
-// Append code to p to load g into cx.
-// Overwrites p with the first instruction (no first appendp).
-// Overwriting p is unusual but it lets use this in both the
-// prologue (caller must call appendp first) and in the epilogue.
-// Returns last new instruction.
-func load_g_cx(ctxt *obj.Link, p *obj.Prog) *obj.Prog {
-	p.As = AMOVQ
-	if ctxt.Arch.PtrSize == 4 {
-		p.As = AMOVL
-	}
-	p.From.Type = obj.TYPE_MEM
-	p.From.Reg = REG_TLS
-	p.From.Offset = 0
-	p.To.Type = obj.TYPE_REG
-	p.To.Reg = REG_CX
-
-	next := p.Link
-	progedit(ctxt, p)
-	for p.Link != next {
-		p = p.Link
-	}
-
-	if p.From.Index == REG_TLS {
-		p.From.Scale = 2
-	}
-
-	return p
-}
-
-// Append code to p to check for stack split.
-// Appends to (does not overwrite) p.
-// Assumes g is in CX.
-// Returns last new instruction.
-func stacksplit(ctxt *obj.Link, p *obj.Prog, framesize int32, textarg int32) *obj.Prog {
-	cmp := ACMPQ
-	lea := ALEAQ
-	mov := AMOVQ
-	sub := ASUBQ
-
-	if ctxt.Headtype == obj.Hnacl || p.Mode == 32 {
-		cmp = ACMPL
-		lea = ALEAL
-		mov = AMOVL
-		sub = ASUBL
-	}
-
-	var q1 *obj.Prog
-	if framesize <= obj.StackSmall {
-		// small stack: SP <= stackguard
-		//	CMPQ SP, stackguard
-		p = obj.Appendp(ctxt, p)
-
-		p.As = cmp
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_SP
-		indir_cx(ctxt, p, &p.To)
-		p.To.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
-		if ctxt.Cursym.CFunc() {
-			p.To.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
-		}
-	} else if framesize <= obj.StackBig {
-		// large stack: SP-framesize <= stackguard-StackSmall
-		//	LEAQ -xxx(SP), AX
-		//	CMPQ AX, stackguard
-		p = obj.Appendp(ctxt, p)
-
-		p.As = lea
-		p.From.Type = obj.TYPE_MEM
-		p.From.Reg = REG_SP
-		p.From.Offset = -(int64(framesize) - obj.StackSmall)
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_AX
-
-		p = obj.Appendp(ctxt, p)
-		p.As = cmp
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_AX
-		indir_cx(ctxt, p, &p.To)
-		p.To.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
-		if ctxt.Cursym.CFunc() {
-			p.To.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
-		}
-	} else {
-		// Such a large stack we need to protect against wraparound.
-		// If SP is close to zero:
-		//	SP-stackguard+StackGuard <= framesize + (StackGuard-StackSmall)
-		// The +StackGuard on both sides is required to keep the left side positive:
-		// SP is allowed to be slightly below stackguard. See stack.h.
-		//
-		// Preemption sets stackguard to StackPreempt, a very large value.
-		// That breaks the math above, so we have to check for that explicitly.
-		//	MOVQ	stackguard, CX
-		//	CMPQ	CX, $StackPreempt
-		//	JEQ	label-of-call-to-morestack
-		//	LEAQ	StackGuard(SP), AX
-		//	SUBQ	CX, AX
-		//	CMPQ	AX, $(framesize+(StackGuard-StackSmall))
-
-		p = obj.Appendp(ctxt, p)
-
-		p.As = mov
-		indir_cx(ctxt, p, &p.From)
-		p.From.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
-		if ctxt.Cursym.CFunc() {
-			p.From.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
-		}
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_SI
-
-		p = obj.Appendp(ctxt, p)
-		p.As = cmp
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_SI
-		p.To.Type = obj.TYPE_CONST
-		p.To.Offset = obj.StackPreempt
-		if p.Mode == 32 {
-			p.To.Offset = int64(uint32(obj.StackPreempt & (1<<32 - 1)))
-		}
-
-		p = obj.Appendp(ctxt, p)
-		p.As = AJEQ
-		p.To.Type = obj.TYPE_BRANCH
-		q1 = p
-
-		p = obj.Appendp(ctxt, p)
-		p.As = lea
-		p.From.Type = obj.TYPE_MEM
-		p.From.Reg = REG_SP
-		p.From.Offset = obj.StackGuard
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_AX
-
-		p = obj.Appendp(ctxt, p)
-		p.As = sub
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_SI
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_AX
-
-		p = obj.Appendp(ctxt, p)
-		p.As = cmp
-		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_AX
-		p.To.Type = obj.TYPE_CONST
-		p.To.Offset = int64(framesize) + (obj.StackGuard - obj.StackSmall)
-	}
-
-	// common
-	jls := obj.Appendp(ctxt, p)
-	jls.As = AJLS
-	jls.To.Type = obj.TYPE_BRANCH
-
-	var last *obj.Prog
-	for last = ctxt.Cursym.Text; last.Link != nil; last = last.Link {
-	}
-
-	// Now we are at the end of the function, but logically
-	// we are still in function prologue. We need to fix the
-	// SP data and PCDATA.
-	spfix := obj.Appendp(ctxt, last)
-	spfix.As = obj.ANOP
-	spfix.Spadj = -framesize
-
-	pcdata := obj.Appendp(ctxt, spfix)
-	pcdata.Lineno = ctxt.Cursym.Text.Lineno
-	pcdata.Mode = ctxt.Cursym.Text.Mode
-	pcdata.As = obj.APCDATA
-	pcdata.From.Type = obj.TYPE_CONST
-	pcdata.From.Offset = obj.PCDATA_StackMapIndex
-	pcdata.To.Type = obj.TYPE_CONST
-	pcdata.To.Offset = -1 // pcdata starts at -1 at function entry
-
-	call := obj.Appendp(ctxt, pcdata)
-	call.Lineno = ctxt.Cursym.Text.Lineno
-	call.Mode = ctxt.Cursym.Text.Mode
-	call.As = obj.ACALL
-	call.To.Type = obj.TYPE_BRANCH
-	call.To.Name = obj.NAME_EXTERN
-	morestack := "runtime.morestack"
-	switch {
-	case ctxt.Cursym.CFunc():
-		morestack = "runtime.morestackc"
-	case ctxt.Cursym.Text.From3Offset()&obj.NEEDCTXT == 0:
-		morestack = "runtime.morestack_noctxt"
-	}
-	call.To.Sym = obj.Linklookup(ctxt, morestack, 0)
-	// When compiling 386 code for dynamic linking, the call needs to be adjusted
-	// to follow PIC rules. This in turn can insert more instructions, so we need
-	// to keep track of the start of the call (where the jump will be to) and the
-	// end (which following instructions are appended to).
-	callend := call
-	progedit(ctxt, callend)
-	for ; callend.Link != nil; callend = callend.Link {
-		progedit(ctxt, callend.Link)
-	}
-
-	jmp := obj.Appendp(ctxt, callend)
-	jmp.As = obj.AJMP
-	jmp.To.Type = obj.TYPE_BRANCH
-	jmp.Pcond = ctxt.Cursym.Text.Link
-	jmp.Spadj = +framesize
-
-	jls.Pcond = call
-	if q1 != nil {
-		q1.Pcond = call
-	}
-
-	return jls
-}
-
-func follow(ctxt *obj.Link, s *obj.LSym) {
-	ctxt.Cursym = s
-
-	firstp := ctxt.NewProg()
-	lastp := firstp
-	xfol(ctxt, s.Text, &lastp)
-	lastp.Link = nil
-	s.Text = firstp.Link
-}
-
-func nofollow(a obj.As) bool {
-	switch a {
-	case obj.AJMP,
-		obj.ARET,
-		AIRETL,
-		AIRETQ,
-		AIRETW,
-		ARETFL,
-		ARETFQ,
-		ARETFW,
-		obj.AUNDEF:
-		return true
-	}
-
-	return false
-}
-
-func pushpop(a obj.As) bool {
-	switch a {
-	case APUSHL,
-		APUSHFL,
-		APUSHQ,
-		APUSHFQ,
-		APUSHW,
-		APUSHFW,
-		APOPL,
-		APOPFL,
-		APOPQ,
-		APOPFQ,
-		APOPW,
-		APOPFW:
-		return true
-	}
-
-	return false
-}
-
-func relinv(a obj.As) obj.As {
-	switch a {
-	case AJEQ:
-		return AJNE
-	case AJNE:
-		return AJEQ
-	case AJLE:
-		return AJGT
-	case AJLS:
-		return AJHI
-	case AJLT:
-		return AJGE
-	case AJMI:
-		return AJPL
-	case AJGE:
-		return AJLT
-	case AJPL:
-		return AJMI
-	case AJGT:
-		return AJLE
-	case AJHI:
-		return AJLS
-	case AJCS:
-		return AJCC
-	case AJCC:
-		return AJCS
-	case AJPS:
-		return AJPC
-	case AJPC:
-		return AJPS
-	case AJOS:
-		return AJOC
-	case AJOC:
-		return AJOS
-	}
-
-	log.Fatalf("unknown relation: %s", a)
-	return 0
-}
-
-func xfol(ctxt *obj.Link, p *obj.Prog, last **obj.Prog) {
-	var q *obj.Prog
-	var i int
-	var a obj.As
-
-loop:
-	if p == nil {
-		return
-	}
-	if p.As == obj.AJMP {
-		q = p.Pcond
-		if q != nil && q.As != obj.ATEXT {
-			/* mark instruction as done and continue layout at target of jump */
-			p.Mark |= DONE
-
-			p = q
-			if p.Mark&DONE == 0 {
-				goto loop
-			}
-		}
-	}
-
-	if p.Mark&DONE != 0 {
-		/*
-		 * p goes here, but already used it elsewhere.
-		 * copy up to 4 instructions or else branch to other copy.
-		 */
-		i = 0
-		q = p
-		for ; i < 4; i, q = i+1, q.Link {
-			if q == nil {
-				break
-			}
-			if q == *last {
-				break
-			}
-			a = q.As
-			if a == obj.ANOP {
-				i--
-				continue
-			}
-
-			if nofollow(a) || pushpop(a) {
-				break // NOTE(rsc): arm does goto copy
-			}
-			if q.Pcond == nil || q.Pcond.Mark&DONE != 0 {
-				continue
-			}
-			if a == obj.ACALL || a == ALOOP {
-				continue
-			}
-			for {
-				if p.As == obj.ANOP {
-					p = p.Link
-					continue
-				}
-
-				q = obj.Copyp(ctxt, p)
-				p = p.Link
-				q.Mark |= DONE
-				(*last).Link = q
-				*last = q
-				if q.As != a || q.Pcond == nil || q.Pcond.Mark&DONE != 0 {
-					continue
-				}
-
-				q.As = relinv(q.As)
-				p = q.Pcond
-				q.Pcond = q.Link
-				q.Link = p
-				xfol(ctxt, q.Link, last)
-				p = q.Link
-				if p.Mark&DONE != 0 {
-					return
-				}
-				goto loop
-				/* */
-			}
-		}
-		q = ctxt.NewProg()
-		q.As = obj.AJMP
-		q.Lineno = p.Lineno
-		q.To.Type = obj.TYPE_BRANCH
-		q.To.Offset = p.Pc
-		q.Pcond = p
-		p = q
-	}
-
-	/* emit p */
-	p.Mark |= DONE
-
-	(*last).Link = p
-	*last = p
-	a = p.As
-
-	/* continue loop with what comes after p */
-	if nofollow(a) {
-		return
-	}
-	if p.Pcond != nil && a != obj.ACALL {
-		/*
-		 * some kind of conditional branch.
-		 * recurse to follow one path.
-		 * continue loop on the other.
-		 */
-		q = obj.Brchain(ctxt, p.Pcond)
-		if q != nil {
-			p.Pcond = q
-		}
-		q = obj.Brchain(ctxt, p.Link)
-		if q != nil {
-			p.Link = q
-		}
-		if p.From.Type == obj.TYPE_CONST {
-			if p.From.Offset == 1 {
-				/*
-				 * expect conditional jump to be taken.
-				 * rewrite so that's the fall-through case.
-				 */
-				p.As = relinv(a)
-
-				q = p.Link
-				p.Link = p.Pcond
-				p.Pcond = q
-			}
-		} else {
-			q = p.Link
-			if q.Mark&DONE != 0 {
-				if a != ALOOP {
-					p.As = relinv(a)
-					p.Link = p.Pcond
-					p.Pcond = q
-				}
-			}
-		}
-
-		xfol(ctxt, p.Link, last)
-		if p.Pcond.Mark&DONE != 0 {
-			return
-		}
-		p = p.Pcond
-		goto loop
-	}
-
-	p = p.Link
-	goto loop
-}
-
-var unaryDst = map[obj.As]bool{
-	ABSWAPL:    true,
-	ABSWAPQ:    true,
-	ACMPXCHG8B: true,
-	ADECB:      true,
-	ADECL:      true,
-	ADECQ:      true,
-	ADECW:      true,
-	AINCB:      true,
-	AINCL:      true,
-	AINCQ:      true,
-	AINCW:      true,
-	ANEGB:      true,
-	ANEGL:      true,
-	ANEGQ:      true,
-	ANEGW:      true,
-	ANOTB:      true,
-	ANOTL:      true,
-	ANOTQ:      true,
-	ANOTW:      true,
-	APOPL:      true,
-	APOPQ:      true,
-	APOPW:      true,
-	ASETCC:     true,
-	ASETCS:     true,
-	ASETEQ:     true,
-	ASETGE:     true,
-	ASETGT:     true,
-	ASETHI:     true,
-	ASETLE:     true,
-	ASETLS:     true,
-	ASETLT:     true,
-	ASETMI:     true,
-	ASETNE:     true,
-	ASETOC:     true,
-	ASETOS:     true,
-	ASETPC:     true,
-	ASETPL:     true,
-	ASETPS:     true,
-	AFFREE:     true,
-	AFLDENV:    true,
-	AFSAVE:     true,
-	AFSTCW:     true,
-	AFSTENV:    true,
-	AFSTSW:     true,
-	AFXSAVE:    true,
-	AFXSAVE64:  true,
-	ASTMXCSR:   true,
-}
-
-var Linkamd64 = obj.LinkArch{
-	Arch:       sys.ArchAMD64,
-	Preprocess: preprocess,
-	Assemble:   span6,
-	Follow:     follow,
-	Progedit:   progedit,
-	UnaryDst:   unaryDst,
-}
-
-var Linkamd64p32 = obj.LinkArch{
-	Arch:       sys.ArchAMD64P32,
-	Preprocess: preprocess,
-	Assemble:   span6,
-	Follow:     follow,
-	Progedit:   progedit,
-	UnaryDst:   unaryDst,
-}
-
-var Link386 = obj.LinkArch{
-	Arch:       sys.Arch386,
-	Preprocess: preprocess,
-	Assemble:   span6,
-	Follow:     follow,
-	Progedit:   progedit,
-	UnaryDst:   unaryDst,
-}