Golang程序
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1011行
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24.29 KB
// cmd/7l/noop.c, cmd/7l/obj.c, cmd/ld/pass.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"
"cmd/internal/objabi"
"cmd/internal/sys"
"math"
)
var complements = []obj.As{
AADD: ASUB,
AADDW: ASUBW,
ASUB: AADD,
ASUBW: AADDW,
ACMP: ACMN,
ACMPW: ACMNW,
ACMN: ACMP,
ACMNW: ACMPW,
}
func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
// MOV g_stackguard(g), R1
p = obj.Appendp(p, c.newprog)
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.From.Reg = REGG
p.From.Offset = 2 * int64(c.ctxt.Arch.PtrSize) // G.stackguard0
if c.cursym.CFunc() {
p.From.Offset = 3 * int64(c.ctxt.Arch.PtrSize) // G.stackguard1
}
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R1
q := (*obj.Prog)(nil)
if framesize <= objabi.StackSmall {
// small stack: SP < stackguard
// MOV SP, R2
// CMP stackguard, R2
p = obj.Appendp(p, c.newprog)
p.As = AMOVD
p.From.Type = obj.TYPE_REG
p.From.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.Reg = REG_R2
} else if framesize <= objabi.StackBig {
// large stack: SP-framesize < stackguard-StackSmall
// SUB $(framesize-StackSmall), SP, R2
// CMP stackguard, R2
p = obj.Appendp(p, c.newprog)
p.As = ASUB
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(framesize) - objabi.StackSmall
p.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.Reg = REG_R2
} 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.
// CMP $StackPreempt, R1
// BEQ label_of_call_to_morestack
// ADD $StackGuard, SP, R2
// SUB R1, R2
// MOV $(framesize+(StackGuard-StackSmall)), R3
// CMP R3, R2
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_CONST
p.From.Offset = objabi.StackPreempt
p.Reg = REG_R1
p = obj.Appendp(p, c.newprog)
q = p
p.As = ABEQ
p.To.Type = obj.TYPE_BRANCH
p = obj.Appendp(p, c.newprog)
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(objabi.StackGuard)
p.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(p, c.newprog)
p.As = ASUB
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(p, c.newprog)
p.As = AMOVD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(framesize) + (int64(objabi.StackGuard) - objabi.StackSmall)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R3
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R3
p.Reg = REG_R2
}
// BLS do-morestack
bls := obj.Appendp(p, c.newprog)
bls.As = ABLS
bls.To.Type = obj.TYPE_BRANCH
var last *obj.Prog
for last = c.cursym.Func.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(last, c.newprog)
spfix.As = obj.ANOP
spfix.Spadj = -framesize
pcdata := c.ctxt.EmitEntryLiveness(c.cursym, spfix, c.newprog)
// MOV LR, R3
movlr := obj.Appendp(pcdata, c.newprog)
movlr.As = AMOVD
movlr.From.Type = obj.TYPE_REG
movlr.From.Reg = REGLINK
movlr.To.Type = obj.TYPE_REG
movlr.To.Reg = REG_R3
if q != nil {
q.Pcond = movlr
}
bls.Pcond = movlr
debug := movlr
if false {
debug = obj.Appendp(debug, c.newprog)
debug.As = AMOVD
debug.From.Type = obj.TYPE_CONST
debug.From.Offset = int64(framesize)
debug.To.Type = obj.TYPE_REG
debug.To.Reg = REGTMP
}
// BL runtime.morestack(SB)
call := obj.Appendp(debug, c.newprog)
call.As = ABL
call.To.Type = obj.TYPE_BRANCH
morestack := "runtime.morestack"
switch {
case c.cursym.CFunc():
morestack = "runtime.morestackc"
case !c.cursym.Func.Text.From.Sym.NeedCtxt():
morestack = "runtime.morestack_noctxt"
}
call.To.Sym = c.ctxt.Lookup(morestack)
// B start
jmp := obj.Appendp(call, c.newprog)
jmp.As = AB
jmp.To.Type = obj.TYPE_BRANCH
jmp.Pcond = c.cursym.Func.Text.Link
jmp.Spadj = +framesize
// placeholder for bls's jump target
// p = obj.Appendp(ctxt, p)
// p.As = obj.ANOP
return bls
}
func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
c := ctxt7{ctxt: ctxt, newprog: newprog}
p.From.Class = 0
p.To.Class = 0
// $0 results in C_ZCON, which matches both C_REG and various
// C_xCON, however the C_REG cases in asmout don't expect a
// constant, so they will use the register fields and assemble
// a R0. To prevent that, rewrite $0 as ZR.
if p.From.Type == obj.TYPE_CONST && p.From.Offset == 0 {
p.From.Type = obj.TYPE_REG
p.From.Reg = REGZERO
}
if p.To.Type == obj.TYPE_CONST && p.To.Offset == 0 {
p.To.Type = obj.TYPE_REG
p.To.Reg = REGZERO
}
// Rewrite BR/BL to symbol as TYPE_BRANCH.
switch p.As {
case AB,
ABL,
obj.ARET,
obj.ADUFFZERO,
obj.ADUFFCOPY:
if p.To.Sym != nil {
p.To.Type = obj.TYPE_BRANCH
}
break
}
// Rewrite float constants to values stored in memory.
switch p.As {
case AFMOVS:
if p.From.Type == obj.TYPE_FCONST {
f64 := p.From.Val.(float64)
f32 := float32(f64)
if c.chipfloat7(f64) > 0 {
break
}
if math.Float32bits(f32) == 0 {
p.From.Type = obj.TYPE_REG
p.From.Reg = REGZERO
break
}
p.From.Type = obj.TYPE_MEM
p.From.Sym = c.ctxt.Float32Sym(f32)
p.From.Name = obj.NAME_EXTERN
p.From.Offset = 0
}
case AFMOVD:
if p.From.Type == obj.TYPE_FCONST {
f64 := p.From.Val.(float64)
if c.chipfloat7(f64) > 0 {
break
}
if math.Float64bits(f64) == 0 {
p.From.Type = obj.TYPE_REG
p.From.Reg = REGZERO
break
}
p.From.Type = obj.TYPE_MEM
p.From.Sym = c.ctxt.Float64Sym(f64)
p.From.Name = obj.NAME_EXTERN
p.From.Offset = 0
}
break
}
// Rewrite negative immediates as positive immediates with
// complementary instruction.
switch p.As {
case AADD, ASUB, ACMP, ACMN:
if p.From.Type == obj.TYPE_CONST && p.From.Offset < 0 && p.From.Offset != -1<<63 {
p.From.Offset = -p.From.Offset
p.As = complements[p.As]
}
case AADDW, ASUBW, ACMPW, ACMNW:
if p.From.Type == obj.TYPE_CONST && p.From.Offset < 0 && int32(p.From.Offset) != -1<<31 {
p.From.Offset = -p.From.Offset
p.As = complements[p.As]
}
}
// For 32-bit logical instruction with constant,
// rewrite the high 32-bit to be a repetition of
// the low 32-bit, so that the BITCON test can be
// shared for both 32-bit and 64-bit. 32-bit ops
// will zero the high 32-bit of the destination
// register anyway.
if isANDWop(p.As) && p.From.Type == obj.TYPE_CONST {
v := p.From.Offset & 0xffffffff
p.From.Offset = v | v<<32
}
if c.ctxt.Flag_dynlink {
c.rewriteToUseGot(p)
}
}
// Rewrite p, if necessary, to access global data via the global offset table.
func (c *ctxt7) rewriteToUseGot(p *obj.Prog) {
if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO {
// ADUFFxxx $offset
// becomes
// MOVD runtime.duffxxx@GOT, REGTMP
// ADD $offset, REGTMP
// CALL REGTMP
var sym *obj.LSym
if p.As == obj.ADUFFZERO {
sym = c.ctxt.Lookup("runtime.duffzero")
} else {
sym = c.ctxt.Lookup("runtime.duffcopy")
}
offset := p.To.Offset
p.As = AMOVD
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 = REGTMP
p.To.Name = obj.NAME_NONE
p.To.Offset = 0
p.To.Sym = nil
p1 := obj.Appendp(p, c.newprog)
p1.As = AADD
p1.From.Type = obj.TYPE_CONST
p1.From.Offset = offset
p1.To.Type = obj.TYPE_REG
p1.To.Reg = REGTMP
p2 := obj.Appendp(p1, c.newprog)
p2.As = obj.ACALL
p2.To.Type = obj.TYPE_REG
p2.To.Reg = REGTMP
}
// 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.From.Type == obj.TYPE_ADDR && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() {
// MOVD $sym, Rx becomes MOVD sym@GOT, Rx
// MOVD $sym+<off>, Rx becomes MOVD sym@GOT, Rx; ADD <off>, Rx
if p.As != AMOVD {
c.ctxt.Diag("do not know how to handle TYPE_ADDR in %v with -dynlink", p)
}
if p.To.Type != obj.TYPE_REG {
c.ctxt.Diag("do not know how to handle LEAQ-type insn to non-register in %v with -dynlink", p)
}
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_GOTREF
if p.From.Offset != 0 {
q := obj.Appendp(p, c.newprog)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = p.From.Offset
q.To = p.To
p.From.Offset = 0
}
}
if p.GetFrom3() != nil && p.GetFrom3().Name == obj.NAME_EXTERN {
c.ctxt.Diag("don't know how to handle %v with -dynlink", p)
}
var source *obj.Addr
// MOVx sym, Ry becomes MOVD sym@GOT, REGTMP; MOVx (REGTMP), Ry
// MOVx Ry, sym becomes MOVD sym@GOT, REGTMP; MOVD Ry, (REGTMP)
// 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() {
c.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.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ACALL || p.As == obj.ARET || p.As == obj.AJMP {
return
}
if source.Sym.Type == objabi.STLSBSS {
return
}
if source.Type != obj.TYPE_MEM {
c.ctxt.Diag("don't know how to handle %v with -dynlink", p)
}
p1 := obj.Appendp(p, c.newprog)
p2 := obj.Appendp(p1, c.newprog)
p1.As = AMOVD
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 = REGTMP
p2.As = p.As
p2.From = p.From
p2.To = p.To
if p.From.Name == obj.NAME_EXTERN {
p2.From.Reg = REGTMP
p2.From.Name = obj.NAME_NONE
p2.From.Sym = nil
} else if p.To.Name == obj.NAME_EXTERN {
p2.To.Reg = REGTMP
p2.To.Name = obj.NAME_NONE
p2.To.Sym = nil
} else {
return
}
obj.Nopout(p)
}
func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
if cursym.Func.Text == nil || cursym.Func.Text.Link == nil {
return
}
c := ctxt7{ctxt: ctxt, newprog: newprog, cursym: cursym}
p := c.cursym.Func.Text
textstksiz := p.To.Offset
if textstksiz == -8 {
// Historical way to mark NOFRAME.
p.From.Sym.Set(obj.AttrNoFrame, true)
textstksiz = 0
}
if textstksiz < 0 {
c.ctxt.Diag("negative frame size %d - did you mean NOFRAME?", textstksiz)
}
if p.From.Sym.NoFrame() {
if textstksiz != 0 {
c.ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz)
}
}
c.cursym.Func.Args = p.To.Val.(int32)
c.cursym.Func.Locals = int32(textstksiz)
/*
* find leaf subroutines
* strip NOPs
* expand RET
*/
q := (*obj.Prog)(nil)
var q1 *obj.Prog
for p := c.cursym.Func.Text; p != nil; p = p.Link {
switch p.As {
case obj.ATEXT:
p.Mark |= LEAF
case obj.ARET:
break
case obj.ANOP:
if p.Link != nil {
q1 = p.Link
q.Link = q1 /* q is non-nop */
q1.Mark |= p.Mark
}
continue
case ABL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
c.cursym.Func.Text.Mark &^= LEAF
fallthrough
case ACBNZ,
ACBZ,
ACBNZW,
ACBZW,
ATBZ,
ATBNZ,
AB,
ABEQ,
ABNE,
ABCS,
ABHS,
ABCC,
ABLO,
ABMI,
ABPL,
ABVS,
ABVC,
ABHI,
ABLS,
ABGE,
ABLT,
ABGT,
ABLE,
AADR, /* strange */
AADRP:
q1 = p.Pcond
if q1 != nil {
for q1.As == obj.ANOP {
q1 = q1.Link
p.Pcond = q1
}
}
break
}
q = p
}
var retjmp *obj.LSym
for p := c.cursym.Func.Text; p != nil; p = p.Link {
o := p.As
switch o {
case obj.ATEXT:
c.cursym.Func.Text = p
c.autosize = int32(textstksiz)
if p.Mark&LEAF != 0 && c.autosize == 0 {
// A leaf function with no locals has no frame.
p.From.Sym.Set(obj.AttrNoFrame, true)
}
if !p.From.Sym.NoFrame() {
// If there is a stack frame at all, it includes
// space to save the LR.
c.autosize += 8
}
if c.autosize != 0 {
extrasize := int32(0)
if c.autosize%16 == 8 {
// Allocate extra 8 bytes on the frame top to save FP
extrasize = 8
} else if c.autosize&(16-1) == 0 {
// Allocate extra 16 bytes to save FP for the old frame whose size is 8 mod 16
extrasize = 16
} else {
c.ctxt.Diag("%v: unaligned frame size %d - must be 16 aligned", p, c.autosize-8)
}
c.autosize += extrasize
c.cursym.Func.Locals += extrasize
// low 32 bits for autosize
// high 32 bits for extrasize
p.To.Offset = int64(c.autosize) | int64(extrasize)<<32
} else {
// NOFRAME
p.To.Offset = 0
}
if c.autosize == 0 && c.cursym.Func.Text.Mark&LEAF == 0 {
if c.ctxt.Debugvlog {
c.ctxt.Logf("save suppressed in: %s\n", c.cursym.Func.Text.From.Sym.Name)
}
c.cursym.Func.Text.Mark |= LEAF
}
if cursym.Func.Text.Mark&LEAF != 0 {
cursym.Set(obj.AttrLeaf, true)
if p.From.Sym.NoFrame() {
break
}
}
if !p.From.Sym.NoSplit() {
p = c.stacksplit(p, c.autosize) // emit split check
}
aoffset := c.autosize
if aoffset > 0xF0 {
aoffset = 0xF0
}
// Frame is non-empty. Make sure to save link register, even if
// it is a leaf function, so that traceback works.
q = p
if c.autosize > aoffset {
// Frame size is too large for a MOVD.W instruction.
// Store link register before decrementing SP, so if a signal comes
// during the execution of the function prologue, the traceback
// code will not see a half-updated stack frame.
q = obj.Appendp(q, c.newprog)
q.Pos = p.Pos
q.As = ASUB
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(c.autosize)
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REGTMP
q = obj.Appendp(q, c.newprog)
q.Pos = p.Pos
q.As = AMOVD
q.From.Type = obj.TYPE_REG
q.From.Reg = REGLINK
q.To.Type = obj.TYPE_MEM
q.To.Reg = REGTMP
q1 = obj.Appendp(q, c.newprog)
q1.Pos = p.Pos
q1.As = AMOVD
q1.From.Type = obj.TYPE_REG
q1.From.Reg = REGTMP
q1.To.Type = obj.TYPE_REG
q1.To.Reg = REGSP
q1.Spadj = c.autosize
} else {
// small frame, update SP and save LR in a single MOVD.W instruction
q1 = obj.Appendp(q, c.newprog)
q1.As = AMOVD
q1.Pos = p.Pos
q1.From.Type = obj.TYPE_REG
q1.From.Reg = REGLINK
q1.To.Type = obj.TYPE_MEM
q1.Scond = C_XPRE
q1.To.Offset = int64(-aoffset)
q1.To.Reg = REGSP
q1.Spadj = aoffset
}
if objabi.Framepointer_enabled(objabi.GOOS, objabi.GOARCH) {
q1 = obj.Appendp(q1, c.newprog)
q1.Pos = p.Pos
q1.As = AMOVD
q1.From.Type = obj.TYPE_REG
q1.From.Reg = REGFP
q1.To.Type = obj.TYPE_MEM
q1.To.Reg = REGSP
q1.To.Offset = -8
q1 = obj.Appendp(q1, c.newprog)
q1.Pos = p.Pos
q1.As = ASUB
q1.From.Type = obj.TYPE_CONST
q1.From.Offset = 8
q1.Reg = REGSP
q1.To.Type = obj.TYPE_REG
q1.To.Reg = REGFP
}
if c.cursym.Func.Text.From.Sym.Wrapper() {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOV g_panic(g), R1
// CBNZ checkargp
// end:
// NOP
// ... function body ...
// checkargp:
// MOV panic_argp(R1), R2
// ADD $(autosize+8), RSP, R3
// CMP R2, R3
// BNE end
// ADD $8, RSP, R4
// MOVD R4, panic_argp(R1)
// B end
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not an ARM64 NOP: it encodes to 0 instruction bytes.
q = q1
// MOV g_panic(g), R1
q = obj.Appendp(q, c.newprog)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REGG
q.From.Offset = 4 * int64(c.ctxt.Arch.PtrSize) // G.panic
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R1
// CBNZ R1, checkargp
cbnz := obj.Appendp(q, c.newprog)
cbnz.As = ACBNZ
cbnz.From.Type = obj.TYPE_REG
cbnz.From.Reg = REG_R1
cbnz.To.Type = obj.TYPE_BRANCH
// Empty branch target at the top of the function body
end := obj.Appendp(cbnz, c.newprog)
end.As = obj.ANOP
// find the end of the function
var last *obj.Prog
for last = end; last.Link != nil; last = last.Link {
}
// MOV panic_argp(R1), R2
mov := obj.Appendp(last, c.newprog)
mov.As = AMOVD
mov.From.Type = obj.TYPE_MEM
mov.From.Reg = REG_R1
mov.From.Offset = 0 // Panic.argp
mov.To.Type = obj.TYPE_REG
mov.To.Reg = REG_R2
// CBNZ branches to the MOV above
cbnz.Pcond = mov
// ADD $(autosize+8), SP, R3
q = obj.Appendp(mov, c.newprog)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(c.autosize) + 8
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
// CMP R2, R3
q = obj.Appendp(q, c.newprog)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R2
q.Reg = REG_R3
// BNE end
q = obj.Appendp(q, c.newprog)
q.As = ABNE
q.To.Type = obj.TYPE_BRANCH
q.Pcond = end
// ADD $8, SP, R4
q = obj.Appendp(q, c.newprog)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = 8
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R4
// MOV R4, panic_argp(R1)
q = obj.Appendp(q, c.newprog)
q.As = AMOVD
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R4
q.To.Type = obj.TYPE_MEM
q.To.Reg = REG_R1
q.To.Offset = 0 // Panic.argp
// B end
q = obj.Appendp(q, c.newprog)
q.As = AB
q.To.Type = obj.TYPE_BRANCH
q.Pcond = end
}
case obj.ARET:
nocache(p)
if p.From.Type == obj.TYPE_CONST {
c.ctxt.Diag("using BECOME (%v) is not supported!", p)
break
}
retjmp = p.To.Sym
p.To = obj.Addr{}
if c.cursym.Func.Text.Mark&LEAF != 0 {
if c.autosize != 0 {
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(c.autosize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REGSP
p.Spadj = -c.autosize
if objabi.Framepointer_enabled(objabi.GOOS, objabi.GOARCH) {
p = obj.Appendp(p, c.newprog)
p.As = ASUB
p.From.Type = obj.TYPE_CONST
p.From.Offset = 8
p.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REGFP
}
}
} else {
/* want write-back pre-indexed SP+autosize -> SP, loading REGLINK*/
if objabi.Framepointer_enabled(objabi.GOOS, objabi.GOARCH) {
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.From.Reg = REGSP
p.From.Offset = -8
p.To.Type = obj.TYPE_REG
p.To.Reg = REGFP
p = obj.Appendp(p, c.newprog)
}
aoffset := c.autosize
if aoffset > 0xF0 {
aoffset = 0xF0
}
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.Scond = C_XPOST
p.From.Offset = int64(aoffset)
p.From.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REGLINK
p.Spadj = -aoffset
if c.autosize > aoffset {
q = newprog()
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(c.autosize) - int64(aoffset)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Link = p.Link
q.Spadj = int32(-q.From.Offset)
q.Pos = p.Pos
p.Link = q
p = q
}
}
if p.As != obj.ARET {
q = newprog()
q.Pos = p.Pos
q.Link = p.Link
p.Link = q
p = q
}
if retjmp != nil { // retjmp
p.As = AB
p.To.Type = obj.TYPE_BRANCH
p.To.Sym = retjmp
p.Spadj = +c.autosize
break
}
p.As = obj.ARET
p.To.Type = obj.TYPE_MEM
p.To.Offset = 0
p.To.Reg = REGLINK
p.Spadj = +c.autosize
case AADD, ASUB:
if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
if p.As == AADD {
p.Spadj = int32(-p.From.Offset)
} else {
p.Spadj = int32(+p.From.Offset)
}
}
case obj.AGETCALLERPC:
if cursym.Leaf() {
/* MOVD LR, Rd */
p.As = AMOVD
p.From.Type = obj.TYPE_REG
p.From.Reg = REGLINK
} else {
/* MOVD (RSP), Rd */
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.From.Reg = REGSP
}
case obj.ADUFFCOPY:
if objabi.Framepointer_enabled(objabi.GOOS, objabi.GOARCH) {
// ADR ret_addr, R27
// STP (FP, R27), -24(SP)
// SUB 24, SP, FP
// DUFFCOPY
// ret_addr:
// SUB 8, SP, FP
q1 := p
// copy DUFFCOPY from q1 to q4
q4 := obj.Appendp(p, c.newprog)
q4.Pos = p.Pos
q4.As = obj.ADUFFCOPY
q4.To = p.To
q1.As = AADR
q1.From.Type = obj.TYPE_BRANCH
q1.To.Type = obj.TYPE_REG
q1.To.Reg = REG_R27
q2 := obj.Appendp(q1, c.newprog)
q2.Pos = p.Pos
q2.As = ASTP
q2.From.Type = obj.TYPE_REGREG
q2.From.Reg = REGFP
q2.From.Offset = int64(REG_R27)
q2.To.Type = obj.TYPE_MEM
q2.To.Reg = REGSP
q2.To.Offset = -24
// maintaine FP for DUFFCOPY
q3 := obj.Appendp(q2, c.newprog)
q3.Pos = p.Pos
q3.As = ASUB
q3.From.Type = obj.TYPE_CONST
q3.From.Offset = 24
q3.Reg = REGSP
q3.To.Type = obj.TYPE_REG
q3.To.Reg = REGFP
q5 := obj.Appendp(q4, c.newprog)
q5.Pos = p.Pos
q5.As = ASUB
q5.From.Type = obj.TYPE_CONST
q5.From.Offset = 8
q5.Reg = REGSP
q5.To.Type = obj.TYPE_REG
q5.To.Reg = REGFP
q1.Pcond = q5
p = q5
}
case obj.ADUFFZERO:
if objabi.Framepointer_enabled(objabi.GOOS, objabi.GOARCH) {
// ADR ret_addr, R27
// STP (FP, R27), -24(SP)
// SUB 24, SP, FP
// DUFFZERO
// ret_addr:
// SUB 8, SP, FP
q1 := p
// copy DUFFZERO from q1 to q4
q4 := obj.Appendp(p, c.newprog)
q4.Pos = p.Pos
q4.As = obj.ADUFFZERO
q4.To = p.To
q1.As = AADR
q1.From.Type = obj.TYPE_BRANCH
q1.To.Type = obj.TYPE_REG
q1.To.Reg = REG_R27
q2 := obj.Appendp(q1, c.newprog)
q2.Pos = p.Pos
q2.As = ASTP
q2.From.Type = obj.TYPE_REGREG
q2.From.Reg = REGFP
q2.From.Offset = int64(REG_R27)
q2.To.Type = obj.TYPE_MEM
q2.To.Reg = REGSP
q2.To.Offset = -24
// maintaine FP for DUFFZERO
q3 := obj.Appendp(q2, c.newprog)
q3.Pos = p.Pos
q3.As = ASUB
q3.From.Type = obj.TYPE_CONST
q3.From.Offset = 24
q3.Reg = REGSP
q3.To.Type = obj.TYPE_REG
q3.To.Reg = REGFP
q5 := obj.Appendp(q4, c.newprog)
q5.Pos = p.Pos
q5.As = ASUB
q5.From.Type = obj.TYPE_CONST
q5.From.Offset = 8
q5.Reg = REGSP
q5.To.Type = obj.TYPE_REG
q5.To.Reg = REGFP
q1.Pcond = q5
p = q5
}
}
}
}
func nocache(p *obj.Prog) {
p.Optab = 0
p.From.Class = 0
p.To.Class = 0
}
var unaryDst = map[obj.As]bool{
AWORD: true,
ADWORD: true,
ABL: true,
AB: true,
ACLREX: true,
}
var Linkarm64 = obj.LinkArch{
Arch: sys.ArchARM64,
Init: buildop,
Preprocess: preprocess,
Assemble: span7,
Progedit: progedit,
UnaryDst: unaryDst,
DWARFRegisters: ARM64DWARFRegisters,
}