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 oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
if oprange[AOR&obj.AMask] == nil {
buildop(ctxt)
}
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 = C_REG
}
//print("oplook %P %d %d %d\n", p, a1, a2, a3);
ops := oprange[p.As&obj.AMask]
c1 := &xcmp[a1]
c3 := &xcmp[a3]
for i := range ops {
op := &ops[i]
if int(op.a2) == a2 && 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", obj.Aconv(p.As), DRconv(a1), DRconv(a2), DRconv(a3))
prasm(p)
if ops == nil {
ops = optab
}
return &ops[0]
}
func progedit(ctxt *obj.Link, p *obj.Prog) {
p.From.Class = 0
p.To.Class = 0
// Rewrite B/BL to symbol as TYPE_BRANCH.
switch p.As {
case AB,
ABL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
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
}
}
// Replace TLS register fetches on older ARM processors.
switch p.As {
// Treat MRC 15, 0, <reg>, C13, C0, 3 specially.
case AMRC:
if p.To.Offset&0xffff0fff == 0xee1d0f70 {
// Because the instruction might be rewritten to a BL which returns in R0
// the register must be zero.
if p.To.Offset&0xf000 != 0 {
ctxt.Diag("%v: TLS MRC instruction must write to R0 as it might get translated into a BL instruction", p.Line())
}
if ctxt.Goarm < 7 {
// Replace it with BL runtime.read_tls_fallback(SB) for ARM CPUs that lack the tls extension.
if progedit_tlsfallback == nil {
progedit_tlsfallback = obj.Linklookup(ctxt, "runtime.read_tls_fallback", 0)
}
// MOVW LR, R11
p.As = AMOVW
p.From.Type = obj.TYPE_REG
p.From.Reg = REGLINK
p.To.Type = obj.TYPE_REG
p.To.Reg = REGTMP
// BL runtime.read_tls_fallback(SB)
p = obj.Appendp(ctxt, p)
p.As = ABL
p.To.Type = obj.TYPE_BRANCH
p.To.Sym = progedit_tlsfallback
p.To.Offset = 0
// MOVW R11, LR
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.From.Type = obj.TYPE_REG
p.From.Reg = REGTMP
p.To.Type = obj.TYPE_REG
p.To.Reg = REGLINK
break
}
}
// Otherwise, MRC/MCR instructions need no further treatment.
p.As = AWORD
}
// Rewrite float constants to values stored in memory.
switch p.As {
case AMOVF:
if p.From.Type == obj.TYPE_FCONST && chipfloat5(ctxt, p.From.Val.(float64)) < 0 && (chipzero5(ctxt, p.From.Val.(float64)) < 0 || p.Scond&C_SCOND != C_SCOND_NONE) {
f32 := float32(p.From.Val.(float64))
i32 := math.Float32bits(f32)
literal := fmt.Sprintf("$f32.%08x", i32)
s := obj.Linklookup(ctxt, literal, 0)
p.From.Type = obj.TYPE_MEM
p.From.Sym = s
p.From.Name = obj.NAME_EXTERN
p.From.Offset = 0
}
case AMOVD:
if p.From.Type == obj.TYPE_FCONST && chipfloat5(ctxt, p.From.Val.(float64)) < 0 && (chipzero5(ctxt, p.From.Val.(float64)) < 0 || p.Scond&C_SCOND != C_SCOND_NONE) {
i64 := math.Float64bits(p.From.Val.(float64))
literal := fmt.Sprintf("$f64.%016x", i64)
s := obj.Linklookup(ctxt, literal, 0)
p.From.Type = obj.TYPE_MEM
p.From.Sym = s
p.From.Name = obj.NAME_EXTERN
p.From.Offset = 0
}
}
if ctxt.Flag_dynlink {
rewriteToUseGot(ctxt, p)
}
}
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
autosize := int32(0)
ctxt.Cursym = cursym
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
softfloat(ctxt, cursym)
p := cursym.Text
autoffset := int32(p.To.Offset)
if autoffset < 0 {
autoffset = 0
}
cursym.Locals = autoffset
cursym.Args = p.To.Val.(int32)
/*
* find leaf subroutines
* strip NOPs
* expand RET
* expand BECOME pseudo
*/
var q1 *obj.Prog
var q *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
switch p.As {
case obj.ATEXT:
p.Mark |= LEAF
case obj.ARET:
break
case ADIV, ADIVU, AMOD, AMODU:
q = p
if ctxt.Sym_div == nil {
initdiv(ctxt)
}
cursym.Text.Mark &^= LEAF
continue
case obj.ANOP:
q1 = p.Link
q.Link = q1 /* q is non-nop */
if q1 != nil {
q1.Mark |= p.Mark
}
continue
case ABL,
ABX,
obj.ADUFFZERO,
obj.ADUFFCOPY:
cursym.Text.Mark &^= LEAF
fallthrough
case AB,
ABEQ,
ABNE,
ABCS,
ABHS,
ABCC,
ABLO,
ABMI,
ABPL,
ABVS,
ABVC,
ABHI,
ABLS,
ABGE,
ABLT,
ABGT,
ABLE:
q1 = p.Pcond
if q1 != nil {
for q1.As == obj.ANOP {
q1 = q1.Link
p.Pcond = q1
}
}
}
q = p
}
var p1 *obj.Prog
var p2 *obj.Prog
var q2 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
o := p.As
switch o {
case obj.ATEXT:
autosize = int32(p.To.Offset + 4)
if autosize <= 4 {
if cursym.Text.Mark&LEAF != 0 {
p.To.Offset = -4
autosize = 0
}
}
if autosize == 0 && cursym.Text.Mark&LEAF == 0 {
if ctxt.Debugvlog != 0 {
fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name)
ctxt.Bso.Flush()
}
cursym.Text.Mark |= LEAF
}
if cursym.Text.Mark&LEAF != 0 {
cursym.Leaf = true
if autosize == 0 {
break
}
}
if p.From3.Offset&obj.NOSPLIT == 0 {
p = stacksplit(ctxt, p, autosize) // emit split check
}
// MOVW.W R14,$-autosize(SP)
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.Scond |= C_WBIT
p.From.Type = obj.TYPE_REG
p.From.Reg = REGLINK
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(-autosize)
p.To.Reg = REGSP
p.Spadj = autosize
if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOVW g_panic(g), R1
// CMP $0, R1
// B.EQ end
// MOVW panic_argp(R1), R2
// ADD $(autosize+4), R13, R3
// CMP R2, R3
// B.NE end
// ADD $4, R13, R4
// MOVW R4, panic_argp(R1)
// end:
// NOP
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not an ARM NOP: it encodes to 0 instruction bytes.
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.From.Type = obj.TYPE_MEM
p.From.Reg = REGG
p.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R1
p = obj.Appendp(ctxt, p)
p.As = ACMP
p.From.Type = obj.TYPE_CONST
p.From.Offset = 0
p.Reg = REG_R1
p = obj.Appendp(ctxt, p)
p.As = ABEQ
p.To.Type = obj.TYPE_BRANCH
p1 = p
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_R1
p.From.Offset = 0 // Panic.argp
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(ctxt, p)
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(autosize) + 4
p.Reg = REG_R13
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R3
p = obj.Appendp(ctxt, p)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R2
p.Reg = REG_R3
p = obj.Appendp(ctxt, p)
p.As = ABNE
p.To.Type = obj.TYPE_BRANCH
p2 = p
p = obj.Appendp(ctxt, p)
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = 4
p.Reg = REG_R13
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R4
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R4
p.To.Type = obj.TYPE_MEM
p.To.Reg = REG_R1
p.To.Offset = 0 // Panic.argp
p = obj.Appendp(ctxt, p)
p.As = obj.ANOP
p1.Pcond = p
p2.Pcond = p
}
case obj.ARET:
nocache(p)
if cursym.Text.Mark&LEAF != 0 {
if autosize == 0 {
p.As = AB
p.From = obj.Addr{}
if p.To.Sym != nil { // retjmp
p.To.Type = obj.TYPE_BRANCH
} else {
p.To.Type = obj.TYPE_MEM
p.To.Offset = 0
p.To.Reg = REGLINK
}
break
}
}
p.As = AMOVW
p.Scond |= C_PBIT
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(autosize)
p.From.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REGPC
// If there are instructions following
// this ARET, they come from a branch
// with the same stackframe, so no spadj.
if p.To.Sym != nil { // retjmp
p.To.Reg = REGLINK
q2 = obj.Appendp(ctxt, p)
q2.As = AB
q2.To.Type = obj.TYPE_BRANCH
q2.To.Sym = p.To.Sym
p.To.Sym = nil
p = q2
}
case AADD:
if p.From.Type == obj.TYPE_CONST && p.From.Reg == 0 && p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP {
p.Spadj = int32(-p.From.Offset)
}
case ASUB:
if p.From.Type == obj.TYPE_CONST && p.From.Reg == 0 && p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP {
p.Spadj = int32(p.From.Offset)
}
case ADIV, ADIVU, AMOD, AMODU:
if cursym.Text.From3.Offset&obj.NOSPLIT != 0 {
ctxt.Diag("cannot divide in NOSPLIT function")
}
if ctxt.Debugdivmod != 0 {
break
}
if p.From.Type != obj.TYPE_REG {
break
}
if p.To.Type != obj.TYPE_REG {
break
}
// Make copy because we overwrite p below.
q1 := *p
if q1.Reg == REGTMP || q1.Reg == 0 && q1.To.Reg == REGTMP {
ctxt.Diag("div already using REGTMP: %v", p)
}
/* MOV m(g),REGTMP */
p.As = AMOVW
p.Lineno = q1.Lineno
p.From.Type = obj.TYPE_MEM
p.From.Reg = REGG
p.From.Offset = 6 * 4 // offset of g.m
p.Reg = 0
p.To.Type = obj.TYPE_REG
p.To.Reg = REGTMP
/* MOV a,m_divmod(REGTMP) */
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.Lineno = q1.Lineno
p.From.Type = obj.TYPE_REG
p.From.Reg = q1.From.Reg
p.To.Type = obj.TYPE_MEM
p.To.Reg = REGTMP
p.To.Offset = 8 * 4 // offset of m.divmod
/* MOV b,REGTMP */
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.Lineno = q1.Lineno
p.From.Type = obj.TYPE_REG
p.From.Reg = q1.Reg
if q1.Reg == 0 {
p.From.Reg = q1.To.Reg
}
p.To.Type = obj.TYPE_REG
p.To.Reg = REGTMP
p.To.Offset = 0
/* CALL appropriate */
p = obj.Appendp(ctxt, p)
p.As = ABL
p.Lineno = q1.Lineno
p.To.Type = obj.TYPE_BRANCH
switch o {
case ADIV:
p.To.Sym = ctxt.Sym_div
case ADIVU:
p.To.Sym = ctxt.Sym_divu
case AMOD:
p.To.Sym = ctxt.Sym_mod
case AMODU:
p.To.Sym = ctxt.Sym_modu
}
/* MOV REGTMP, b */
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.Lineno = q1.Lineno
p.From.Type = obj.TYPE_REG
p.From.Reg = REGTMP
p.From.Offset = 0
p.To.Type = obj.TYPE_REG
p.To.Reg = q1.To.Reg
case AMOVW:
if (p.Scond&C_WBIT != 0) && p.To.Type == obj.TYPE_MEM && p.To.Reg == REGSP {
p.Spadj = int32(-p.To.Offset)
}
if (p.Scond&C_PBIT != 0) && p.From.Type == obj.TYPE_MEM && p.From.Reg == REGSP && p.To.Reg != REGPC {
p.Spadj = int32(-p.From.Offset)
}
if p.From.Type == obj.TYPE_ADDR && p.From.Reg == REGSP && p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP {
p.Spadj = int32(-p.From.Offset)
}
}
}
}
// Rewrite p, if necessary, to access global data via the global offset table.
func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog) {
if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO {
// ADUFFxxx $offset
// becomes
// MOVW runtime.duffxxx@GOT, R9
// ADD $offset, R9
// CALL (R9)
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 = AMOVW
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_R9
p.To.Name = obj.NAME_NONE
p.To.Offset = 0
p.To.Sym = nil
p1 := obj.Appendp(ctxt, p)
p1.As = AADD
p1.From.Type = obj.TYPE_CONST
p1.From.Offset = offset
p1.To.Type = obj.TYPE_REG
p1.To.Reg = REG_R9
p2 := obj.Appendp(ctxt, p1)
p2.As = obj.ACALL
p2.To.Type = obj.TYPE_MEM
p2.To.Reg = REG_R9
return
}
// 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 {
// MOVW $sym, Rx becomes MOVW sym@GOT, Rx
// MOVW $sym+<off>, Rx becomes MOVW sym@GOT, Rx; ADD <off>, Rx
if p.As != AMOVW {
ctxt.Diag("do not know how to handle TYPE_ADDR in %v with -dynlink", p)
}
if p.To.Type != obj.TYPE_REG {
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(ctxt, p)
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.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 MOVW sym@GOT, R9; MOVx (R9), Ry
// MOVx Ry, sym becomes MOVW sym@GOT, R9; MOVx Ry, (R9)
// 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.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ACALL || p.As == obj.ARET || p.As == obj.AJMP {
return
}
if source.Sym.Type == obj.STLSBSS {
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 = AMOVW
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_R9
p2.As = p.As
p2.From = p.From
p2.To = p.To
if p.From.Name == obj.NAME_EXTERN {
p2.From.Reg = REG_R9
p2.From.Name = obj.NAME_NONE
p2.From.Sym = nil
} else if p.To.Name == obj.NAME_EXTERN {
p2.To.Reg = REG_R9
p2.To.Name = obj.NAME_NONE
p2.To.Sym = nil
} else {
return
}
obj.Nopout(p)
}
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
// TODO(minux): add morestack short-cuts with small fixed frame-size.
ctxt.Cursym = cursym
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
p := cursym.Text
textstksiz := p.To.Offset
if textstksiz == -8 {
// Compatibility hack.
p.From3.Offset |= obj.NOFRAME
textstksiz = 0
}
if textstksiz%8 != 0 {
ctxt.Diag("frame size %d not a multiple of 8", textstksiz)
}
if p.From3.Offset&obj.NOFRAME != 0 {
if textstksiz != 0 {
ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz)
}
}
cursym.Args = p.To.Val.(int32)
cursym.Locals = int32(textstksiz)
/*
* find leaf subroutines
* strip NOPs
* expand RET
* expand BECOME pseudo
*/
if ctxt.Debugvlog != 0 {
fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
}
ctxt.Bso.Flush()
var q *obj.Prog
var q1 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
switch p.As {
/* too hard, just leave alone */
case obj.ATEXT:
q = p
p.Mark |= LABEL | LEAF | SYNC
if p.Link != nil {
p.Link.Mark |= LABEL
}
case ANOR:
q = p
if p.To.Type == obj.TYPE_REG {
if p.To.Reg == REGZERO {
p.Mark |= LABEL | SYNC
}
}
case ASYNC,
AWORD:
q = p
p.Mark |= LABEL | SYNC
continue
case AMOVW, AMOVWZ, AMOVD:
q = p
if p.From.Reg >= REG_RESERVED || p.To.Reg >= REG_RESERVED {
p.Mark |= LABEL | SYNC
}
continue
case AFABS,
AFADD,
AFDIV,
AFMADD,
AFMOVD,
AFMOVS,
AFMSUB,
AFMUL,
AFNABS,
AFNEG,
AFNMADD,
AFNMSUB,
ALEDBR,
ALDEBR,
AFSUB:
q = p
p.Mark |= FLOAT
continue
case ABL,
ABCL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
cursym.Text.Mark &^= LEAF
fallthrough
case ABC,
ABEQ,
ABGE,
ABGT,
ABLE,
ABLT,
ABNE,
ABR,
ABVC,
ABVS,
ACMPBEQ,
ACMPBGE,
ACMPBGT,
ACMPBLE,
ACMPBLT,
ACMPBNE,
ACMPUBEQ,
ACMPUBGE,
ACMPUBGT,
ACMPUBLE,
ACMPUBLT,
ACMPUBNE:
p.Mark |= BRANCH
q = p
q1 = p.Pcond
if q1 != nil {
for q1.As == obj.ANOP {
q1 = q1.Link
p.Pcond = q1
}
if q1.Mark&LEAF == 0 {
q1.Mark |= LABEL
}
} else {
p.Mark |= LABEL
}
q1 = p.Link
if q1 != nil {
q1.Mark |= LABEL
}
continue
case AFCMPO, AFCMPU:
q = p
p.Mark |= FCMP | FLOAT
continue
case obj.ARET:
q = p
if p.Link != nil {
p.Link.Mark |= LABEL
}
continue
case obj.ANOP:
q1 = p.Link
q.Link = q1 /* q is non-nop */
q1.Mark |= p.Mark
continue
default:
q = p
continue
}
}
autosize := int32(0)
var p1 *obj.Prog
var p2 *obj.Prog
var pLast *obj.Prog
var pPre *obj.Prog
var pPreempt *obj.Prog
wasSplit := false
for p := cursym.Text; p != nil; p = p.Link {
pLast = p
switch p.As {
case obj.ATEXT:
autosize = int32(textstksiz)
if p.Mark&LEAF != 0 && autosize == 0 && p.From3.Offset&obj.NOFRAME == 0 {
// A leaf function with no locals has no frame.
p.From3.Offset |= obj.NOFRAME
}
if p.From3.Offset&obj.NOFRAME == 0 {
// If there is a stack frame at all, it includes
// space to save the LR.
autosize += int32(ctxt.FixedFrameSize())
}
p.To.Offset = int64(autosize)
q = p
if p.From3.Offset&obj.NOSPLIT == 0 {
p, pPreempt = stacksplitPre(ctxt, p, autosize) // emit pre part of split check
pPre = p
wasSplit = true //need post part of split
}
if autosize != 0 {
q = obj.Appendp(ctxt, p)
q.As = AMOVD
q.From.Type = obj.TYPE_ADDR
q.From.Offset = int64(-autosize)
q.From.Reg = REGSP // not actually needed - REGSP is assumed if no reg is provided
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = autosize
} else if cursym.Text.Mark&LEAF == 0 {
// A very few functions that do not return to their caller
// (e.g. gogo) are not identified as leaves but still have
// no frame.
cursym.Text.Mark |= LEAF
}
if cursym.Text.Mark&LEAF != 0 {
cursym.Leaf = true
break
}
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_LR
q.To.Type = obj.TYPE_MEM
q.To.Reg = REGSP
q.To.Offset = 0
if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOVD g_panic(g), R3
// CMP R0, R3
// BEQ end
// MOVD panic_argp(R3), R4
// ADD $(autosize+8), R1, R5
// CMP R4, R5
// BNE end
// ADD $8, R1, R6
// MOVD R6, panic_argp(R3)
// end:
// NOP
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not a s390x NOP: it encodes to 0 instruction bytes.
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REGG
q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R0
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ABEQ
q.To.Type = obj.TYPE_BRANCH
p1 = q
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REG_R3
q.From.Offset = 0 // Panic.argp
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R4
q = obj.Appendp(ctxt, q)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(autosize) + ctxt.FixedFrameSize()
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R5
q = obj.Appendp(ctxt, q)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R4
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R5
q = obj.Appendp(ctxt, q)
q.As = ABNE
q.To.Type = obj.TYPE_BRANCH
p2 = q
q = obj.Appendp(ctxt, q)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = ctxt.FixedFrameSize()
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R6
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R6
q.To.Type = obj.TYPE_MEM
q.To.Reg = REG_R3
q.To.Offset = 0 // Panic.argp
q = obj.Appendp(ctxt, q)
q.As = obj.ANOP
p1.Pcond = q
p2.Pcond = q
}
case obj.ARET:
if p.From.Type == obj.TYPE_CONST {
ctxt.Diag("using BECOME (%v) is not supported!", p)
break
}
retTarget := p.To.Sym
if cursym.Text.Mark&LEAF != 0 {
if autosize == 0 {
p.As = ABR
p.From = obj.Addr{}
if retTarget == nil {
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_LR
} else {
p.To.Type = obj.TYPE_BRANCH
p.To.Sym = retTarget
}
p.Mark |= BRANCH
break
}
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(autosize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REGSP
p.Spadj = -autosize
q = obj.Appendp(ctxt, p)
q.As = ABR
q.From = obj.Addr{}
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_LR
q.Mark |= BRANCH
q.Spadj = autosize
break
}
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.From.Reg = REGSP
p.From.Offset = 0
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_LR
q = p
if autosize != 0 {
q = obj.Appendp(ctxt, q)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(autosize)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = -autosize
}
q = obj.Appendp(ctxt, q)
q.As = ABR
q.From = obj.Addr{}
if retTarget == nil {
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_LR
} else {
q.To.Type = obj.TYPE_BRANCH
q.To.Sym = retTarget
}
q.Mark |= BRANCH
q.Spadj = autosize
case AADD:
if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
p.Spadj = int32(-p.From.Offset)
}
}
}
if wasSplit {
pLast = stacksplitPost(ctxt, pLast, pPre, pPreempt) // emit post part of split check
}
}
// Rewrite p, if necessary, to access global data via the global offset table.
func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog) {
// At the moment EXRL instructions are not emitted by the compiler and only reference local symbols in
// assembly code.
if p.As == AEXRL {
return
}
// 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.To.Type != obj.TYPE_REG || p.As != AMOVD {
ctxt.Diag("do not know how to handle LEA-type insn to non-register in %v with -dynlink", p)
}
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 = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = p.From.Offset
q.To = p.To
p.From.Offset = 0
}
}
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
// MOVD sym, Ry becomes MOVD sym@GOT, REGTMP; MOVD (REGTMP), Ry
// MOVD 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 {
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 == obj.STLSBSS {
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 = 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) {
ctxt.Cursym = cursym
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
p := cursym.Text
textstksiz := p.To.Offset
aoffset := int32(textstksiz)
cursym.Args = p.To.Val.(int32)
cursym.Locals = int32(textstksiz)
/*
* find leaf subroutines
* strip NOPs
* expand RET
*/
ctxt.Bso.Flush()
q := (*obj.Prog)(nil)
var q1 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
switch p.As {
case obj.ATEXT:
p.Mark |= LEAF
case obj.ARET:
break
case obj.ANOP:
q1 = p.Link
q.Link = q1 /* q is non-nop */
q1.Mark |= p.Mark
continue
case ABL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
cursym.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 q2 *obj.Prog
var retjmp *obj.LSym
for p := cursym.Text; p != nil; p = p.Link {
o := p.As
switch o {
case obj.ATEXT:
cursym.Text = p
if textstksiz < 0 {
ctxt.Autosize = 0
} else {
ctxt.Autosize = int32(textstksiz + 8)
}
if (cursym.Text.Mark&LEAF != 0) && ctxt.Autosize <= 8 {
ctxt.Autosize = 0
} else if ctxt.Autosize&(16-1) != 0 {
// The frame includes an LR.
// If the frame size is 8, it's only an LR,
// so there's no potential for breaking references to
// local variables by growing the frame size,
// because there are no local variables.
// But otherwise, if there is a non-empty locals section,
// the author of the code is responsible for making sure
// that the frame size is 8 mod 16.
if ctxt.Autosize == 8 {
ctxt.Autosize += 8
cursym.Locals += 8
} else {
ctxt.Diag("%v: unaligned frame size %d - must be 8 mod 16 (or 0)", p, ctxt.Autosize-8)
}
}
p.To.Offset = int64(ctxt.Autosize) - 8
if ctxt.Autosize == 0 && !(cursym.Text.Mark&LEAF != 0) {
if ctxt.Debugvlog != 0 {
fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Text.From.Sym.Name)
}
ctxt.Bso.Flush()
cursym.Text.Mark |= LEAF
}
if !(p.From3.Offset&obj.NOSPLIT != 0) {
p = stacksplit(ctxt, p, ctxt.Autosize) // emit split check
}
aoffset = ctxt.Autosize
if aoffset > 0xF0 {
aoffset = 0xF0
}
if cursym.Text.Mark&LEAF != 0 {
cursym.Leaf = true
if ctxt.Autosize == 0 {
break
}
aoffset = 0
}
q = p
if ctxt.Autosize > aoffset {
q = ctxt.NewProg()
q.As = ASUB
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(ctxt.Autosize) - int64(aoffset)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = int32(q.From.Offset)
q.Link = p.Link
p.Link = q
if cursym.Text.Mark&LEAF != 0 {
break
}
}
q1 = ctxt.NewProg()
q1.As = AMOVD
q1.Lineno = p.Lineno
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.Link = q.Link
q1.Spadj = aoffset
q.Link = q1
if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOV g_panic(g), R1
// CMP ZR, R1
// BEQ end
// MOV panic_argp(R1), R2
// ADD $(autosize+8), RSP, R3
// CMP R2, R3
// BNE end
// ADD $8, RSP, R4
// MOVD R4, panic_argp(R1)
// end:
// NOP
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not a ARM64 NOP: it encodes to 0 instruction bytes.
q = q1
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REGG
q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R1
q = obj.Appendp(ctxt, q)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REGZERO
q.Reg = REG_R1
q = obj.Appendp(ctxt, q)
q.As = ABEQ
q.To.Type = obj.TYPE_BRANCH
q1 = q
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REG_R1
q.From.Offset = 0 // Panic.argp
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R2
q = obj.Appendp(ctxt, q)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(ctxt.Autosize) + 8
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R2
q.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ABNE
q.To.Type = obj.TYPE_BRANCH
q2 = q
q = obj.Appendp(ctxt, q)
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
q = obj.Appendp(ctxt, q)
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
q = obj.Appendp(ctxt, q)
q.As = obj.ANOP
q1.Pcond = q
q2.Pcond = q
}
case obj.ARET:
nocache(p)
if p.From.Type == obj.TYPE_CONST {
ctxt.Diag("using BECOME (%v) is not supported!", p)
break
}
retjmp = p.To.Sym
p.To = obj.Addr{}
if cursym.Text.Mark&LEAF != 0 {
if ctxt.Autosize != 0 {
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(ctxt.Autosize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REGSP
p.Spadj = -ctxt.Autosize
}
} else {
/* want write-back pre-indexed SP+autosize -> SP, loading REGLINK*/
aoffset = ctxt.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 ctxt.Autosize > aoffset {
q = ctxt.NewProg()
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(ctxt.Autosize) - int64(aoffset)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Link = p.Link
q.Spadj = int32(-q.From.Offset)
q.Lineno = p.Lineno
p.Link = q
p = q
}
}
if p.As != obj.ARET {
q = ctxt.NewProg()
q.Lineno = p.Lineno
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 = +ctxt.Autosize
break
}
p.As = obj.ARET
p.To.Type = obj.TYPE_MEM
p.To.Offset = 0
p.To.Reg = REGLINK
p.Spadj = +ctxt.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)
}
}
break
}
}
}
// 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 == 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_CX
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_CX
}
}
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 preprocess(ctxt *obj.Link, cursym *obj.LSym) {
// TODO(minux): add morestack short-cuts with small fixed frame-size.
ctxt.Cursym = cursym
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
p := cursym.Text
textstksiz := p.To.Offset
if textstksiz == -8 {
// Compatibility hack.
p.From3.Offset |= obj.NOFRAME
textstksiz = 0
}
if textstksiz%8 != 0 {
ctxt.Diag("frame size %d not a multiple of 8", textstksiz)
}
if p.From3.Offset&obj.NOFRAME != 0 {
if textstksiz != 0 {
ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz)
}
}
cursym.Args = p.To.Val.(int32)
cursym.Locals = int32(textstksiz)
/*
* find leaf subroutines
* strip NOPs
* expand RET
* expand BECOME pseudo
*/
if ctxt.Debugvlog != 0 {
fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
}
ctxt.Bso.Flush()
var q *obj.Prog
var q1 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
switch p.As {
/* too hard, just leave alone */
case obj.ATEXT:
q = p
p.Mark |= LABEL | LEAF | SYNC
if p.Link != nil {
p.Link.Mark |= LABEL
}
case ANOR:
q = p
if p.To.Type == obj.TYPE_REG {
if p.To.Reg == REGZERO {
p.Mark |= LABEL | SYNC
}
}
case ALWAR,
ALBAR,
ASTBCCC,
ASTWCCC,
AECIWX,
AECOWX,
AEIEIO,
AICBI,
AISYNC,
ATLBIE,
ATLBIEL,
ASLBIA,
ASLBIE,
ASLBMFEE,
ASLBMFEV,
ASLBMTE,
ADCBF,
ADCBI,
ADCBST,
ADCBT,
ADCBTST,
ADCBZ,
ASYNC,
ATLBSYNC,
APTESYNC,
ALWSYNC,
ATW,
AWORD,
ARFI,
ARFCI,
ARFID,
AHRFID:
q = p
p.Mark |= LABEL | SYNC
continue
case AMOVW, AMOVWZ, AMOVD:
q = p
if p.From.Reg >= REG_SPECIAL || p.To.Reg >= REG_SPECIAL {
p.Mark |= LABEL | SYNC
}
continue
case AFABS,
AFABSCC,
AFADD,
AFADDCC,
AFCTIW,
AFCTIWCC,
AFCTIWZ,
AFCTIWZCC,
AFDIV,
AFDIVCC,
AFMADD,
AFMADDCC,
AFMOVD,
AFMOVDU,
/* case AFMOVDS: */
AFMOVS,
AFMOVSU,
/* case AFMOVSD: */
AFMSUB,
AFMSUBCC,
AFMUL,
AFMULCC,
AFNABS,
AFNABSCC,
AFNEG,
AFNEGCC,
AFNMADD,
AFNMADDCC,
AFNMSUB,
AFNMSUBCC,
AFRSP,
AFRSPCC,
AFSUB,
AFSUBCC:
q = p
p.Mark |= FLOAT
continue
case ABL,
ABCL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
cursym.Text.Mark &^= LEAF
fallthrough
case ABC,
ABEQ,
ABGE,
ABGT,
ABLE,
ABLT,
ABNE,
ABR,
ABVC,
ABVS:
p.Mark |= BRANCH
q = p
q1 = p.Pcond
if q1 != nil {
for q1.As == obj.ANOP {
q1 = q1.Link
p.Pcond = q1
}
if q1.Mark&LEAF == 0 {
q1.Mark |= LABEL
}
} else {
p.Mark |= LABEL
}
q1 = p.Link
if q1 != nil {
q1.Mark |= LABEL
}
continue
case AFCMPO, AFCMPU:
q = p
p.Mark |= FCMP | FLOAT
continue
case obj.ARET:
q = p
if p.Link != nil {
p.Link.Mark |= LABEL
}
continue
case obj.ANOP:
q1 = p.Link
q.Link = q1 /* q is non-nop */
q1.Mark |= p.Mark
continue
default:
q = p
continue
}
}
autosize := int32(0)
var aoffset int
var mov obj.As
var p1 *obj.Prog
var p2 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
o := p.As
switch o {
case obj.ATEXT:
mov = AMOVD
aoffset = 0
autosize = int32(textstksiz)
if p.Mark&LEAF != 0 && autosize == 0 && p.From3.Offset&obj.NOFRAME == 0 {
// A leaf function with no locals has no frame.
p.From3.Offset |= obj.NOFRAME
}
if p.From3.Offset&obj.NOFRAME == 0 {
// If there is a stack frame at all, it includes
// space to save the LR.
autosize += int32(ctxt.FixedFrameSize())
}
p.To.Offset = int64(autosize)
q = p
if ctxt.Flag_shared && cursym.Name != "runtime.duffzero" && cursym.Name != "runtime.duffcopy" && cursym.Name != "runtime.stackBarrier" {
// When compiling Go into PIC, all functions must start
// with instructions to load the TOC pointer into r2:
//
// addis r2, r12, .TOC.-func@ha
// addi r2, r2, .TOC.-func@l+4
//
// We could probably skip this prologue in some situations
// but it's a bit subtle. However, it is both safe and
// necessary to leave the prologue off duffzero and
// duffcopy as we rely on being able to jump to a specific
// instruction offset for them, and stackBarrier is only
// ever called from an overwritten LR-save slot on the
// stack (when r12 will not be remotely the right thing)
// but fortunately does not access global data.
//
// These are AWORDS because there is no (afaict) way to
// generate the addis instruction except as part of the
// load of a large constant, and in that case there is no
// way to use r12 as the source.
q = obj.Appendp(ctxt, q)
q.As = AWORD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = 0x3c4c0000
q = obj.Appendp(ctxt, q)
q.As = AWORD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = 0x38420000
rel := obj.Addrel(ctxt.Cursym)
rel.Off = 0
rel.Siz = 8
rel.Sym = obj.Linklookup(ctxt, ".TOC.", 0)
rel.Type = obj.R_ADDRPOWER_PCREL
}
if cursym.Text.From3.Offset&obj.NOSPLIT == 0 {
q = stacksplit(ctxt, q, autosize) // emit split check
}
if autosize != 0 {
/* use MOVDU to adjust R1 when saving R31, if autosize is small */
if cursym.Text.Mark&LEAF == 0 && autosize >= -BIG && autosize <= BIG {
mov = AMOVDU
aoffset = int(-autosize)
} else {
q = obj.Appendp(ctxt, q)
q.As = AADD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(-autosize)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = +autosize
}
} else if cursym.Text.Mark&LEAF == 0 {
// A very few functions that do not return to their caller
// (e.g. gogo) are not identified as leaves but still have
// no frame.
cursym.Text.Mark |= LEAF
}
if cursym.Text.Mark&LEAF != 0 {
cursym.Leaf = true
break
}
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_LR
q.To.Type = obj.TYPE_REG
q.To.Reg = REGTMP
q = obj.Appendp(ctxt, q)
q.As = mov
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_REG
q.From.Reg = REGTMP
q.To.Type = obj.TYPE_MEM
q.To.Offset = int64(aoffset)
q.To.Reg = REGSP
if q.As == AMOVDU {
q.Spadj = int32(-aoffset)
}
if ctxt.Flag_shared {
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R2
q.To.Type = obj.TYPE_MEM
q.To.Reg = REGSP
q.To.Offset = 24
}
if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOVD g_panic(g), R3
// CMP R0, R3
// BEQ end
// MOVD panic_argp(R3), R4
// ADD $(autosize+8), R1, R5
// CMP R4, R5
// BNE end
// ADD $8, R1, R6
// MOVD R6, panic_argp(R3)
// end:
// NOP
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not a ppc64 NOP: it encodes to 0 instruction bytes.
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REGG
q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R0
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ABEQ
q.To.Type = obj.TYPE_BRANCH
p1 = q
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_MEM
q.From.Reg = REG_R3
q.From.Offset = 0 // Panic.argp
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R4
q = obj.Appendp(ctxt, q)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(autosize) + ctxt.FixedFrameSize()
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R5
q = obj.Appendp(ctxt, q)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R4
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R5
q = obj.Appendp(ctxt, q)
q.As = ABNE
q.To.Type = obj.TYPE_BRANCH
p2 = q
q = obj.Appendp(ctxt, q)
q.As = AADD
q.From.Type = obj.TYPE_CONST
q.From.Offset = ctxt.FixedFrameSize()
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R6
q = obj.Appendp(ctxt, q)
q.As = AMOVD
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R6
q.To.Type = obj.TYPE_MEM
q.To.Reg = REG_R3
q.To.Offset = 0 // Panic.argp
q = obj.Appendp(ctxt, q)
q.As = obj.ANOP
p1.Pcond = q
p2.Pcond = q
}
case obj.ARET:
if p.From.Type == obj.TYPE_CONST {
ctxt.Diag("using BECOME (%v) is not supported!", p)
break
}
retTarget := p.To.Sym
if cursym.Text.Mark&LEAF != 0 {
if autosize == 0 {
p.As = ABR
p.From = obj.Addr{}
if retTarget == nil {
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_LR
} else {
p.To.Type = obj.TYPE_BRANCH
p.To.Sym = retTarget
}
p.Mark |= BRANCH
break
}
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(autosize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REGSP
p.Spadj = -autosize
q = ctxt.NewProg()
q.As = ABR
q.Lineno = p.Lineno
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_LR
q.Mark |= BRANCH
q.Spadj = +autosize
q.Link = p.Link
p.Link = q
break
}
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.From.Offset = 0
p.From.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REGTMP
q = ctxt.NewProg()
q.As = AMOVD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_REG
q.From.Reg = REGTMP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_LR
q.Link = p.Link
p.Link = q
p = q
if false {
// Debug bad returns
q = ctxt.NewProg()
q.As = AMOVD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_MEM
q.From.Offset = 0
q.From.Reg = REGTMP
q.To.Type = obj.TYPE_REG
q.To.Reg = REGTMP
q.Link = p.Link
p.Link = q
p = q
}
if autosize != 0 {
q = ctxt.NewProg()
q.As = AADD
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(autosize)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = -autosize
q.Link = p.Link
p.Link = q
}
q1 = ctxt.NewProg()
q1.As = ABR
q1.Lineno = p.Lineno
if retTarget == nil {
q1.To.Type = obj.TYPE_REG
q1.To.Reg = REG_LR
} else {
q1.To.Type = obj.TYPE_BRANCH
q1.To.Sym = retTarget
}
q1.Mark |= BRANCH
q1.Spadj = +autosize
q1.Link = q.Link
q.Link = q1
case AADD:
if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
p.Spadj = int32(-p.From.Offset)
}
}
}
}
func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
o1 := uint32(0)
o2 := uint32(0)
o3 := uint32(0)
o4 := uint32(0)
switch o.type_ {
default:
ctxt.Diag("unknown type %d %v", o.type_)
prasm(p)
case 0: /* pseudo ops */
break
case 1: /* mov r1,r2 ==> OR r1,r0,r2 */
a := AOR
if p.As == AMOVW {
a = AADDU // sign-extended to high 32 bits
}
o1 = OP_RRR(oprrr(ctxt, a), uint32(p.From.Reg), uint32(REGZERO), uint32(p.To.Reg))
case 2: /* add/sub r1,[r2],r3 */
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o1 = OP_RRR(oprrr(ctxt, p.As), uint32(p.From.Reg), uint32(r), uint32(p.To.Reg))
case 3: /* mov $soreg, r ==> or/add $i,o,r */
v := regoff(ctxt, &p.From)
r := int(p.From.Reg)
if r == 0 {
r = int(o.param)
}
a := AADDVU
if o.a1 == C_ANDCON {
a = AOR
}
o1 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(r), uint32(p.To.Reg))
case 4: /* add $scon,[r1],r2 */
v := regoff(ctxt, &p.From)
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o1 = OP_IRR(opirr(ctxt, p.As), uint32(v), uint32(r), uint32(p.To.Reg))
case 5: /* syscall */
o1 = oprrr(ctxt, p.As)
case 6: /* beq r1,[r2],sbra */
v := int32(0)
if p.Pcond == nil {
v = int32(-4) >> 2
} else {
v = int32(p.Pcond.Pc-p.Pc-4) >> 2
}
if (v<<16)>>16 != v {
ctxt.Diag("short branch too far\n%v", p)
}
o1 = OP_IRR(opirr(ctxt, p.As), uint32(v), uint32(p.From.Reg), uint32(p.Reg))
// for ABFPT and ABFPF only: always fill delay slot with 0
// see comments in func preprocess for details.
o2 = 0
case 7: /* mov r, soreg ==> sw o(r) */
r := int(p.To.Reg)
if r == 0 {
r = int(o.param)
}
v := regoff(ctxt, &p.To)
o1 = OP_IRR(opirr(ctxt, p.As), uint32(v), uint32(r), uint32(p.From.Reg))
case 8: /* mov soreg, r ==> lw o(r) */
r := int(p.From.Reg)
if r == 0 {
r = int(o.param)
}
v := regoff(ctxt, &p.From)
o1 = OP_IRR(opirr(ctxt, -p.As), uint32(v), uint32(r), uint32(p.To.Reg))
case 9: /* sll r1,[r2],r3 */
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o1 = OP_RRR(oprrr(ctxt, p.As), uint32(r), uint32(p.From.Reg), uint32(p.To.Reg))
case 10: /* add $con,[r1],r2 ==> mov $con, t; add t,[r1],r2 */
v := regoff(ctxt, &p.From)
a := AOR
if v < 0 {
a = AADDU
}
o1 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(0), uint32(REGTMP))
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o2 = OP_RRR(oprrr(ctxt, p.As), uint32(REGTMP), uint32(r), uint32(p.To.Reg))
case 11: /* jmp lbra */
v := int32(0)
if aclass(ctxt, &p.To) == C_SBRA && p.To.Sym == nil && p.As == AJMP {
// use PC-relative branch for short branches
// BEQ R0, R0, sbra
if p.Pcond == nil {
v = int32(-4) >> 2
} else {
v = int32(p.Pcond.Pc-p.Pc-4) >> 2
}
if (v<<16)>>16 == v {
o1 = OP_IRR(opirr(ctxt, ABEQ), uint32(v), uint32(REGZERO), uint32(REGZERO))
break
}
}
if p.Pcond == nil {
v = int32(p.Pc) >> 2
} else {
v = int32(p.Pcond.Pc) >> 2
}
o1 = OP_JMP(opirr(ctxt, p.As), uint32(v))
if p.To.Sym == nil {
p.To.Sym = ctxt.Cursym.Text.From.Sym
p.To.Offset = p.Pcond.Pc
}
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc)
rel.Siz = 4
rel.Sym = p.To.Sym
rel.Add = p.To.Offset
if p.As == AJAL {
rel.Type = obj.R_CALLMIPS
} else {
rel.Type = obj.R_JMPMIPS
}
case 12: /* movbs r,r */
v := 16
if p.As == AMOVB {
v = 24
}
o1 = OP_SRR(opirr(ctxt, ASLL), uint32(v), uint32(p.From.Reg), uint32(p.To.Reg))
o2 = OP_SRR(opirr(ctxt, ASRA), uint32(v), uint32(p.To.Reg), uint32(p.To.Reg))
case 13: /* movbu r,r */
if p.As == AMOVBU {
o1 = OP_IRR(opirr(ctxt, AAND), uint32(0xff), uint32(p.From.Reg), uint32(p.To.Reg))
} else {
o1 = OP_IRR(opirr(ctxt, AAND), uint32(0xffff), uint32(p.From.Reg), uint32(p.To.Reg))
}
case 14: /* movwu r,r */
o1 = OP_SRR(opirr(ctxt, -ASLLV), uint32(0), uint32(p.From.Reg), uint32(p.To.Reg))
o2 = OP_SRR(opirr(ctxt, -ASRLV), uint32(0), uint32(p.To.Reg), uint32(p.To.Reg))
case 16: /* sll $c,[r1],r2 */
v := regoff(ctxt, &p.From)
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
/* OP_SRR will use only the low 5 bits of the shift value */
if v >= 32 && vshift(p.As) {
o1 = OP_SRR(opirr(ctxt, -p.As), uint32(v-32), uint32(r), uint32(p.To.Reg))
} else {
o1 = OP_SRR(opirr(ctxt, p.As), uint32(v), uint32(r), uint32(p.To.Reg))
}
case 18: /* jmp [r1],0(r2) */
r := int(p.Reg)
if r == 0 {
r = int(o.param)
}
o1 = OP_RRR(oprrr(ctxt, p.As), uint32(0), uint32(p.To.Reg), uint32(r))
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc)
rel.Siz = 0
rel.Type = obj.R_CALLIND
case 19: /* mov $lcon,r ==> lu+or */
v := regoff(ctxt, &p.From)
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(v>>16), uint32(REGZERO), uint32(p.To.Reg))
o2 = OP_IRR(opirr(ctxt, AOR), uint32(v), uint32(p.To.Reg), uint32(p.To.Reg))
case 20: /* mov lo/hi,r */
a := OP(2, 0) /* mfhi */
if p.From.Reg == REG_LO {
a = OP(2, 2) /* mflo */
}
o1 = OP_RRR(a, uint32(REGZERO), uint32(REGZERO), uint32(p.To.Reg))
case 21: /* mov r,lo/hi */
a := OP(2, 1) /* mthi */
if p.To.Reg == REG_LO {
a = OP(2, 3) /* mtlo */
}
o1 = OP_RRR(a, uint32(REGZERO), uint32(p.From.Reg), uint32(REGZERO))
case 22: /* mul r1,r2 */
o1 = OP_RRR(oprrr(ctxt, p.As), uint32(p.From.Reg), uint32(p.Reg), uint32(REGZERO))
case 23: /* add $lcon,r1,r2 ==> lu+or+add */
v := regoff(ctxt, &p.From)
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(v>>16), uint32(REGZERO), uint32(REGTMP))
o2 = OP_IRR(opirr(ctxt, AOR), uint32(v), uint32(REGTMP), uint32(REGTMP))
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o3 = OP_RRR(oprrr(ctxt, p.As), uint32(REGTMP), uint32(r), uint32(p.To.Reg))
case 24: /* mov $ucon,r ==> lu r */
v := regoff(ctxt, &p.From)
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(v>>16), uint32(REGZERO), uint32(p.To.Reg))
case 25: /* add/and $ucon,[r1],r2 ==> lu $con,t; add t,[r1],r2 */
v := regoff(ctxt, &p.From)
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(v>>16), uint32(REGZERO), uint32(REGTMP))
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o2 = OP_RRR(oprrr(ctxt, p.As), uint32(REGTMP), uint32(r), uint32(p.To.Reg))
case 26: /* mov $lsext/auto/oreg,r ==> lu+or+add */
v := regoff(ctxt, &p.From)
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(v>>16), uint32(REGZERO), uint32(REGTMP))
o2 = OP_IRR(opirr(ctxt, AOR), uint32(v), uint32(REGTMP), uint32(REGTMP))
r := int(p.From.Reg)
if r == 0 {
r = int(o.param)
}
o3 = OP_RRR(oprrr(ctxt, AADDVU), uint32(REGTMP), uint32(r), uint32(p.To.Reg))
case 27: /* mov [sl]ext/auto/oreg,fr ==> lwc1 o(r) */
v := regoff(ctxt, &p.From)
r := int(p.From.Reg)
if r == 0 {
r = int(o.param)
}
a := -AMOVF
if p.As == AMOVD {
a = -AMOVD
}
switch o.size {
case 12:
o1 = OP_IRR(opirr(ctxt, ALUI), uint32((v+1<<15)>>16), uint32(REGZERO), uint32(REGTMP))
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(r), uint32(REGTMP), uint32(REGTMP))
o3 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(REGTMP), uint32(p.To.Reg))
case 4:
o1 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(r), uint32(p.To.Reg))
}
case 28: /* mov fr,[sl]ext/auto/oreg ==> swc1 o(r) */
v := regoff(ctxt, &p.To)
r := int(p.To.Reg)
if r == 0 {
r = int(o.param)
}
a := AMOVF
if p.As == AMOVD {
a = AMOVD
}
switch o.size {
case 12:
o1 = OP_IRR(opirr(ctxt, ALUI), uint32((v+1<<15)>>16), uint32(REGZERO), uint32(REGTMP))
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(r), uint32(REGTMP), uint32(REGTMP))
o3 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(REGTMP), uint32(p.From.Reg))
case 4:
o1 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(r), uint32(p.From.Reg))
}
case 30: /* movw r,fr */
a := SP(2, 1) | (4 << 21) /* mtc1 */
o1 = OP_RRR(a, uint32(p.From.Reg), uint32(0), uint32(p.To.Reg))
case 31: /* movw fr,r */
a := SP(2, 1) | (0 << 21) /* mtc1 */
o1 = OP_RRR(a, uint32(p.To.Reg), uint32(0), uint32(p.From.Reg))
case 32: /* fadd fr1,[fr2],fr3 */
r := int(p.Reg)
if r == 0 {
r = int(p.To.Reg)
}
o1 = OP_FRRR(oprrr(ctxt, p.As), uint32(p.From.Reg), uint32(r), uint32(p.To.Reg))
case 33: /* fabs fr1, fr3 */
o1 = OP_FRRR(oprrr(ctxt, p.As), uint32(0), uint32(p.From.Reg), uint32(p.To.Reg))
case 34: /* mov $con,fr ==> or/add $i,t; mov t,fr */
v := regoff(ctxt, &p.From)
a := AADDU
if o.a1 == C_ANDCON {
a = AOR
}
o1 = OP_IRR(opirr(ctxt, a), uint32(v), uint32(0), uint32(REGTMP))
o2 = OP_RRR(SP(2, 1)|(4<<21), uint32(REGTMP), uint32(0), uint32(p.To.Reg)) /* mtc1 */
case 35: /* mov r,lext/auto/oreg ==> sw o(REGTMP) */
v := regoff(ctxt, &p.To)
r := int(p.To.Reg)
if r == 0 {
r = int(o.param)
}
o1 = OP_IRR(opirr(ctxt, ALUI), uint32((v+1<<15)>>16), uint32(REGZERO), uint32(REGTMP))
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(r), uint32(REGTMP), uint32(REGTMP))
o3 = OP_IRR(opirr(ctxt, p.As), uint32(v), uint32(REGTMP), uint32(p.From.Reg))
case 36: /* mov lext/auto/oreg,r ==> lw o(REGTMP) */
v := regoff(ctxt, &p.From)
r := int(p.From.Reg)
if r == 0 {
r = int(o.param)
}
o1 = OP_IRR(opirr(ctxt, ALUI), uint32((v+1<<15)>>16), uint32(REGZERO), uint32(REGTMP))
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(r), uint32(REGTMP), uint32(REGTMP))
o3 = OP_IRR(opirr(ctxt, -p.As), uint32(v), uint32(REGTMP), uint32(p.To.Reg))
case 37: /* movw r,mr */
a := SP(2, 0) | (4 << 21) /* mtc0 */
if p.As == AMOVV {
a = SP(2, 0) | (5 << 21) /* dmtc0 */
}
o1 = OP_RRR(a, uint32(p.From.Reg), uint32(0), uint32(p.To.Reg))
case 38: /* movw mr,r */
a := SP(2, 0) | (0 << 21) /* mfc0 */
if p.As == AMOVV {
a = SP(2, 0) | (1 << 21) /* dmfc0 */
}
o1 = OP_RRR(a, uint32(p.To.Reg), uint32(0), uint32(p.From.Reg))
case 40: /* word */
o1 = uint32(regoff(ctxt, &p.From))
case 41: /* movw f,fcr */
o1 = OP_RRR(SP(2, 1)|(2<<21), uint32(REGZERO), uint32(0), uint32(p.To.Reg)) /* mfcc1 */
o2 = OP_RRR(SP(2, 1)|(6<<21), uint32(p.From.Reg), uint32(0), uint32(p.To.Reg)) /* mtcc1 */
case 42: /* movw fcr,r */
o1 = OP_RRR(SP(2, 1)|(2<<21), uint32(p.To.Reg), uint32(0), uint32(p.From.Reg)) /* mfcc1 */
case 47: /* movv r,fr */
a := SP(2, 1) | (5 << 21) /* dmtc1 */
o1 = OP_RRR(a, uint32(p.From.Reg), uint32(0), uint32(p.To.Reg))
case 48: /* movv fr,r */
a := SP(2, 1) | (1 << 21) /* dmtc1 */
o1 = OP_RRR(a, uint32(p.To.Reg), uint32(0), uint32(p.From.Reg))
case 49: /* undef */
o1 = 52 /* trap -- teq r0, r0 */
/* relocation operations */
case 50: /* mov r,addr ==> lu + add REGSB, REGTMP + sw o(REGTMP) */
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(0), uint32(REGZERO), uint32(REGTMP))
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_ADDRMIPSU
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(REGSB), uint32(REGTMP), uint32(REGTMP))
o3 = OP_IRR(opirr(ctxt, p.As), uint32(0), uint32(REGTMP), uint32(p.From.Reg))
rel2 := obj.Addrel(ctxt.Cursym)
rel2.Off = int32(ctxt.Pc + 8)
rel2.Siz = 4
rel2.Sym = p.To.Sym
rel2.Add = p.To.Offset
rel2.Type = obj.R_ADDRMIPS
case 51: /* mov addr,r ==> lu + add REGSB, REGTMP + lw o(REGTMP) */
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(0), uint32(REGZERO), uint32(REGTMP))
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc)
rel.Siz = 4
rel.Sym = p.From.Sym
rel.Add = p.From.Offset
rel.Type = obj.R_ADDRMIPSU
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(REGSB), uint32(REGTMP), uint32(REGTMP))
o3 = OP_IRR(opirr(ctxt, -p.As), uint32(0), uint32(REGTMP), uint32(p.To.Reg))
rel2 := obj.Addrel(ctxt.Cursym)
rel2.Off = int32(ctxt.Pc + 8)
rel2.Siz = 4
rel2.Sym = p.From.Sym
rel2.Add = p.From.Offset
rel2.Type = obj.R_ADDRMIPS
case 52: /* mov $lext, r ==> lu + add REGSB, r + add */
o1 = OP_IRR(opirr(ctxt, ALUI), uint32(0), uint32(REGZERO), uint32(p.To.Reg))
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc)
rel.Siz = 4
rel.Sym = p.From.Sym
rel.Add = p.From.Offset
rel.Type = obj.R_ADDRMIPSU
o2 = OP_RRR(oprrr(ctxt, AADDVU), uint32(REGSB), uint32(p.To.Reg), uint32(p.To.Reg))
o3 = OP_IRR(opirr(ctxt, AADDVU), uint32(0), uint32(p.To.Reg), uint32(p.To.Reg))
rel2 := obj.Addrel(ctxt.Cursym)
rel2.Off = int32(ctxt.Pc + 8)
rel2.Siz = 4
rel2.Sym = p.From.Sym
rel2.Add = p.From.Offset
rel2.Type = obj.R_ADDRMIPS
case 53: /* mov r, tlsvar ==> rdhwr + sw o(r3) */
// clobbers R3 !
// load thread pointer with RDHWR, R3 is used for fast kernel emulation on Linux
o1 = (037<<26 + 073) | (29 << 11) | (3 << 16) // rdhwr $29, r3
o2 = OP_IRR(opirr(ctxt, p.As), uint32(0), uint32(REG_R3), uint32(p.From.Reg))
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc + 4)
rel.Siz = 4
rel.Sym = p.To.Sym
rel.Add = p.To.Offset
rel.Type = obj.R_ADDRMIPSTLS
case 54: /* mov tlsvar, r ==> rdhwr + lw o(r3) */
// clobbers R3 !
o1 = (037<<26 + 073) | (29 << 11) | (3 << 16) // rdhwr $29, r3
o2 = OP_IRR(opirr(ctxt, -p.As), uint32(0), uint32(REG_R3), uint32(p.To.Reg))
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc + 4)
rel.Siz = 4
rel.Sym = p.From.Sym
rel.Add = p.From.Offset
rel.Type = obj.R_ADDRMIPSTLS
case 55: /* mov $tlsvar, r ==> rdhwr + add */
// clobbers R3 !
o1 = (037<<26 + 073) | (29 << 11) | (3 << 16) // rdhwr $29, r3
o2 = OP_IRR(opirr(ctxt, AADDVU), uint32(0), uint32(REG_R3), uint32(p.To.Reg))
rel := obj.Addrel(ctxt.Cursym)
rel.Off = int32(ctxt.Pc + 4)
rel.Siz = 4
rel.Sym = p.From.Sym
rel.Add = p.From.Offset
rel.Type = obj.R_ADDRMIPSTLS
}
out[0] = o1
out[1] = o2
out[2] = o3
out[3] = o4
return
}
func buildop(ctxt *obj.Link) {
var n int
for i := 0; i < C_NCLASS; i++ {
for n = 0; n < C_NCLASS; 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
r0 := r & obj.AMask
start := i
for optab[i].as == r {
i++
}
oprange[r0] = optab[start:i]
i--
switch r {
default:
ctxt.Diag("unknown op in build: %v", obj.Aconv(r))
log.Fatalf("bad code")
case AABSF:
opset(AMOVFD, r0)
opset(AMOVDF, r0)
opset(AMOVWF, r0)
opset(AMOVFW, r0)
opset(AMOVWD, r0)
opset(AMOVDW, r0)
opset(ANEGF, r0)
opset(ANEGD, r0)
opset(AABSD, r0)
opset(ATRUNCDW, r0)
opset(ATRUNCFW, r0)
opset(ATRUNCDV, r0)
opset(ATRUNCFV, r0)
opset(AMOVVF, r0)
opset(AMOVFV, r0)
opset(AMOVVD, r0)
opset(AMOVDV, r0)
case AADD:
opset(ASGT, r0)
opset(ASGTU, r0)
opset(AADDU, r0)
opset(AADDV, r0)
opset(AADDVU, r0)
case AADDF:
opset(ADIVF, r0)
opset(ADIVD, r0)
opset(AMULF, r0)
opset(AMULD, r0)
opset(ASUBF, r0)
opset(ASUBD, r0)
opset(AADDD, r0)
case AAND:
opset(AOR, r0)
opset(AXOR, r0)
case ABEQ:
opset(ABNE, r0)
case ABLEZ:
opset(ABGEZ, r0)
opset(ABGEZAL, r0)
opset(ABLTZ, r0)
opset(ABLTZAL, r0)
opset(ABGTZ, r0)
case AMOVB:
opset(AMOVH, r0)
case AMOVBU:
opset(AMOVHU, r0)
case AMUL:
opset(AREM, r0)
opset(AREMU, r0)
opset(ADIVU, r0)
opset(AMULU, r0)
opset(ADIV, r0)
opset(ADIVV, r0)
opset(ADIVVU, r0)
opset(AMULV, r0)
opset(AMULVU, r0)
opset(AREMV, r0)
opset(AREMVU, r0)
case ASLL:
opset(ASRL, r0)
opset(ASRA, r0)
opset(ASLLV, r0)
opset(ASRAV, r0)
opset(ASRLV, r0)
case ASUB:
opset(ASUBU, r0)
opset(ASUBV, r0)
opset(ASUBVU, r0)
opset(ANOR, r0)
case ASYSCALL:
opset(ATLBP, r0)
opset(ATLBR, r0)
opset(ATLBWI, r0)
opset(ATLBWR, r0)
case ACMPEQF:
opset(ACMPGTF, r0)
opset(ACMPGTD, r0)
opset(ACMPGEF, r0)
opset(ACMPGED, r0)
opset(ACMPEQD, r0)
case ABFPT:
opset(ABFPF, r0)
case AMOVWL:
opset(AMOVWR, r0)
opset(AMOVVR, r0)
opset(AMOVVL, r0)
case AMOVW,
AMOVD,
AMOVF,
AMOVV,
ABREAK,
ARFE,
AJAL,
AJMP,
AMOVWU,
AWORD,
obj.ANOP,
obj.ATEXT,
obj.AUNDEF,
obj.AUSEFIELD,
obj.AFUNCDATA,
obj.APCDATA,
obj.ADUFFZERO,
obj.ADUFFCOPY:
break
}
}
}
func span0(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 + 8)
if oprange[AOR&obj.AMask] == nil {
buildop(ctxt)
}
c := int64(0)
p.Pc = c
var m int
var o *Optab
for p = p.Link; p != nil; p = p.Link {
ctxt.Curp = p
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
}
c += int64(m)
}
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.
*/
bflag := 1
var otxt int64
var q *obj.Prog
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 {
p.Pc = c
o = oplook(ctxt, p)
// very large conditional branches
if o.type_ == 6 && p.Pcond != nil {
otxt = p.Pcond.Pc - c
if otxt < -(1<<17)+10 || otxt >= (1<<17)-10 {
q = ctxt.NewProg()
q.Link = p.Link
p.Link = q
q.As = AJMP
q.Lineno = p.Lineno
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 = AJMP
q.Lineno = p.Lineno
q.To.Type = obj.TYPE_BRANCH
q.Pcond = q.Link.Link
addnop(ctxt, p.Link)
addnop(ctxt, p)
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)
}
cursym.Size = c
}
c += -c & (FuncAlign - 1)
cursym.Size = c
/*
* lay out the code, emitting code and data relocations.
*/
cursym.Grow(cursym.Size)
bp := cursym.P
var i int32
var out [4]uint32
for p := cursym.Text.Link; p != nil; p = p.Link {
ctxt.Pc = p.Pc
ctxt.Curp = p
o = oplook(ctxt, p)
if int(o.size) > 4*len(out) {
log.Fatalf("out array in span0 is too small, need at least %d for %v", o.size/4, p)
}
asmout(ctxt, p, o, out[:])
for i = 0; i < int32(o.size/4); i++ {
ctxt.Arch.ByteOrder.PutUint32(bp, out[i])
bp = bp[4:]
}
}
}
func opirr(ctxt *obj.Link, a obj.As) uint32 {
switch a {
case AADD:
return SP(1, 0)
case AADDU:
return SP(1, 1)
case ASGT:
return SP(1, 2)
case ASGTU:
return SP(1, 3)
case AAND:
return SP(1, 4)
case AOR:
return SP(1, 5)
case AXOR:
return SP(1, 6)
case ALUI:
return SP(1, 7)
case ASLL:
return OP(0, 0)
case ASRL:
return OP(0, 2)
case ASRA:
return OP(0, 3)
case AADDV:
return SP(3, 0)
case AADDVU:
return SP(3, 1)
case AJMP:
return SP(0, 2)
case AJAL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
return SP(0, 3)
case ABEQ:
return SP(0, 4)
case -ABEQ:
return SP(2, 4) /* likely */
case ABNE:
return SP(0, 5)
case -ABNE:
return SP(2, 5) /* likely */
case ABGEZ:
return SP(0, 1) | BCOND(0, 1)
case -ABGEZ:
return SP(0, 1) | BCOND(0, 3) /* likely */
case ABGEZAL:
return SP(0, 1) | BCOND(2, 1)
case -ABGEZAL:
return SP(0, 1) | BCOND(2, 3) /* likely */
case ABGTZ:
return SP(0, 7)
case -ABGTZ:
return SP(2, 7) /* likely */
case ABLEZ:
return SP(0, 6)
case -ABLEZ:
return SP(2, 6) /* likely */
case ABLTZ:
return SP(0, 1) | BCOND(0, 0)
case -ABLTZ:
return SP(0, 1) | BCOND(0, 2) /* likely */
case ABLTZAL:
return SP(0, 1) | BCOND(2, 0)
case -ABLTZAL:
return SP(0, 1) | BCOND(2, 2) /* likely */
case ABFPT:
return SP(2, 1) | (257 << 16)
case -ABFPT:
return SP(2, 1) | (259 << 16) /* likely */
case ABFPF:
return SP(2, 1) | (256 << 16)
case -ABFPF:
return SP(2, 1) | (258 << 16) /* likely */
case AMOVB,
AMOVBU:
return SP(5, 0)
case AMOVH,
AMOVHU:
return SP(5, 1)
case AMOVW,
AMOVWU:
return SP(5, 3)
case AMOVV:
return SP(7, 7)
case AMOVF:
return SP(7, 1)
case AMOVD:
return SP(7, 5)
case AMOVWL:
return SP(5, 2)
case AMOVWR:
return SP(5, 6)
case AMOVVL:
return SP(5, 4)
case AMOVVR:
return SP(5, 5)
case ABREAK:
return SP(5, 7)
case -AMOVWL:
return SP(4, 2)
case -AMOVWR:
return SP(4, 6)
case -AMOVVL:
return SP(3, 2)
case -AMOVVR:
return SP(3, 3)
case -AMOVB:
return SP(4, 0)
case -AMOVBU:
return SP(4, 4)
case -AMOVH:
return SP(4, 1)
case -AMOVHU:
return SP(4, 5)
case -AMOVW:
return SP(4, 3)
case -AMOVWU:
return SP(4, 7)
case -AMOVV:
return SP(6, 7)
case -AMOVF:
return SP(6, 1)
case -AMOVD:
return SP(6, 5)
case ASLLV:
return OP(7, 0)
case ASRLV:
return OP(7, 2)
case ASRAV:
return OP(7, 3)
case -ASLLV:
return OP(7, 4)
case -ASRLV:
return OP(7, 6)
case -ASRAV:
return OP(7, 7)
}
if a < 0 {
ctxt.Diag("bad irr opcode -%v", obj.Aconv(-a))
} else {
ctxt.Diag("bad irr opcode %v", obj.Aconv(a))
}
return 0
}
func oprrr(ctxt *obj.Link, a obj.As) uint32 {
switch a {
case AADD:
return OP(4, 0)
case AADDU:
return OP(4, 1)
case ASGT:
return OP(5, 2)
case ASGTU:
return OP(5, 3)
case AAND:
return OP(4, 4)
case AOR:
return OP(4, 5)
case AXOR:
return OP(4, 6)
case ASUB:
return OP(4, 2)
case ASUBU:
return OP(4, 3)
case ANOR:
return OP(4, 7)
case ASLL:
return OP(0, 4)
case ASRL:
return OP(0, 6)
case ASRA:
return OP(0, 7)
case ASLLV:
return OP(2, 4)
case ASRLV:
return OP(2, 6)
case ASRAV:
return OP(2, 7)
case AADDV:
return OP(5, 4)
case AADDVU:
return OP(5, 5)
case ASUBV:
return OP(5, 6)
case ASUBVU:
return OP(5, 7)
case AREM,
ADIV:
return OP(3, 2)
case AREMU,
ADIVU:
return OP(3, 3)
case AMUL:
return OP(3, 0)
case AMULU:
return OP(3, 1)
case AREMV,
ADIVV:
return OP(3, 6)
case AREMVU,
ADIVVU:
return OP(3, 7)
case AMULV:
return OP(3, 4)
case AMULVU:
return OP(3, 5)
case AJMP:
return OP(1, 0)
case AJAL:
return OP(1, 1)
case ABREAK:
return OP(1, 5)
case ASYSCALL:
return OP(1, 4)
case ATLBP:
return MMU(1, 0)
case ATLBR:
return MMU(0, 1)
case ATLBWI:
return MMU(0, 2)
case ATLBWR:
return MMU(0, 6)
case ARFE:
return MMU(2, 0)
case ADIVF:
return FPF(0, 3)
case ADIVD:
return FPD(0, 3)
case AMULF:
return FPF(0, 2)
case AMULD:
return FPD(0, 2)
case ASUBF:
return FPF(0, 1)
case ASUBD:
return FPD(0, 1)
case AADDF:
return FPF(0, 0)
case AADDD:
return FPD(0, 0)
case ATRUNCFV:
return FPF(1, 1)
case ATRUNCDV:
return FPD(1, 1)
case ATRUNCFW:
return FPF(1, 5)
case ATRUNCDW:
return FPD(1, 5)
case AMOVFV:
return FPF(4, 5)
case AMOVDV:
return FPD(4, 5)
case AMOVVF:
return FPV(4, 0)
case AMOVVD:
return FPV(4, 1)
case AMOVFW:
return FPF(4, 4)
case AMOVDW:
return FPD(4, 4)
case AMOVWF:
return FPW(4, 0)
case AMOVDF:
return FPD(4, 0)
case AMOVWD:
return FPW(4, 1)
case AMOVFD:
return FPF(4, 1)
case AABSF:
return FPF(0, 5)
case AABSD:
return FPD(0, 5)
case AMOVF:
return FPF(0, 6)
case AMOVD:
return FPD(0, 6)
case ANEGF:
return FPF(0, 7)
case ANEGD:
return FPD(0, 7)
case ACMPEQF:
return FPF(6, 2)
case ACMPEQD:
return FPD(6, 2)
case ACMPGTF:
return FPF(7, 4)
case ACMPGTD:
return FPD(7, 4)
case ACMPGEF:
return FPF(7, 6)
case ACMPGED:
return FPD(7, 6)
}
if a < 0 {
ctxt.Diag("bad rrr opcode -%v", obj.Aconv(-a))
} else {
ctxt.Diag("bad rrr opcode %v", obj.Aconv(a))
}
return 0
}
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
// TODO(minux): add morestack short-cuts with small fixed frame-size.
ctxt.Cursym = cursym
// a switch for enabling/disabling instruction scheduling
nosched := true
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
p := cursym.Text
textstksiz := p.To.Offset
cursym.Args = p.To.Val.(int32)
cursym.Locals = int32(textstksiz)
/*
* find leaf subroutines
* strip NOPs
* expand RET
* expand BECOME pseudo
*/
if ctxt.Debugvlog != 0 {
fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
}
ctxt.Bso.Flush()
var q *obj.Prog
var q1 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
switch p.As {
/* too hard, just leave alone */
case obj.ATEXT:
q = p
p.Mark |= LABEL | LEAF | SYNC
if p.Link != nil {
p.Link.Mark |= LABEL
}
/* too hard, just leave alone */
case AMOVW,
AMOVV:
q = p
if p.To.Type == obj.TYPE_REG && p.To.Reg >= REG_SPECIAL {
p.Mark |= LABEL | SYNC
break
}
if p.From.Type == obj.TYPE_REG && p.From.Reg >= REG_SPECIAL {
p.Mark |= LABEL | SYNC
}
/* too hard, just leave alone */
case ASYSCALL,
AWORD,
ATLBWR,
ATLBWI,
ATLBP,
ATLBR:
q = p
p.Mark |= LABEL | SYNC
case ANOR:
q = p
if p.To.Type == obj.TYPE_REG {
if p.To.Reg == REGZERO {
p.Mark |= LABEL | SYNC
}
}
case ABGEZAL,
ABLTZAL,
AJAL,
obj.ADUFFZERO,
obj.ADUFFCOPY:
cursym.Text.Mark &^= LEAF
fallthrough
case AJMP,
ABEQ,
ABGEZ,
ABGTZ,
ABLEZ,
ABLTZ,
ABNE,
ABFPT, ABFPF:
if p.As == ABFPT || p.As == ABFPF {
// We don't treat ABFPT and ABFPF as branches here,
// so that we will always fill nop (0x0) in their
// delay slot during assembly.
// This is to workaround a kernel FPU emulator bug
// where it uses the user stack to simulate the
// instruction in the delay slot if it's not 0x0,
// and somehow that leads to SIGSEGV when the kernel
// jump to the stack.
p.Mark |= SYNC
} else {
p.Mark |= BRANCH
}
q = p
q1 = p.Pcond
if q1 != nil {
for q1.As == obj.ANOP {
q1 = q1.Link
p.Pcond = q1
}
if q1.Mark&LEAF == 0 {
q1.Mark |= LABEL
}
}
//else {
// p.Mark |= LABEL
//}
q1 = p.Link
if q1 != nil {
q1.Mark |= LABEL
}
continue
case ARET:
q = p
if p.Link != nil {
p.Link.Mark |= LABEL
}
continue
case obj.ANOP:
q1 = p.Link
q.Link = q1 /* q is non-nop */
q1.Mark |= p.Mark
continue
default:
q = p
continue
}
}
autosize := int32(0)
var p1 *obj.Prog
var p2 *obj.Prog
for p := cursym.Text; p != nil; p = p.Link {
o := p.As
switch o {
case obj.ATEXT:
autosize = int32(textstksiz + 8)
if (p.Mark&LEAF != 0) && autosize <= 8 {
autosize = 0
} else if autosize&4 != 0 {
autosize += 4
}
p.To.Offset = int64(autosize) - 8
if p.From3.Offset&obj.NOSPLIT == 0 {
p = stacksplit(ctxt, p, autosize) // emit split check
}
q = p
if autosize != 0 {
q = obj.Appendp(ctxt, p)
q.As = AADDV
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(-autosize)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = +autosize
} else if cursym.Text.Mark&LEAF == 0 {
if cursym.Text.From3.Offset&obj.NOSPLIT != 0 {
if ctxt.Debugvlog != 0 {
fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name)
ctxt.Bso.Flush()
}
cursym.Text.Mark |= LEAF
}
}
if cursym.Text.Mark&LEAF != 0 {
cursym.Leaf = true
break
}
q = obj.Appendp(ctxt, q)
q.As = AMOVV
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_REG
q.From.Reg = REGLINK
q.To.Type = obj.TYPE_MEM
q.To.Offset = int64(0)
q.To.Reg = REGSP
if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOVV g_panic(g), R1
// BEQ R1, end
// MOVV panic_argp(R1), R2
// ADDV $(autosize+8), R29, R3
// BNE R2, R3, end
// ADDV $8, R29, R2
// MOVV R2, panic_argp(R1)
// end:
// NOP
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not an mips NOP: it encodes to 0 instruction bytes.
q = obj.Appendp(ctxt, q)
q.As = AMOVV
q.From.Type = obj.TYPE_MEM
q.From.Reg = REGG
q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R1
q = obj.Appendp(ctxt, q)
q.As = ABEQ
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R1
q.To.Type = obj.TYPE_BRANCH
q.Mark |= BRANCH
p1 = q
q = obj.Appendp(ctxt, q)
q.As = AMOVV
q.From.Type = obj.TYPE_MEM
q.From.Reg = REG_R1
q.From.Offset = 0 // Panic.argp
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R2
q = obj.Appendp(ctxt, q)
q.As = AADDV
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(autosize) + 8
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R3
q = obj.Appendp(ctxt, q)
q.As = ABNE
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R2
q.Reg = REG_R3
q.To.Type = obj.TYPE_BRANCH
q.Mark |= BRANCH
p2 = q
q = obj.Appendp(ctxt, q)
q.As = AADDV
q.From.Type = obj.TYPE_CONST
q.From.Offset = 8
q.Reg = REGSP
q.To.Type = obj.TYPE_REG
q.To.Reg = REG_R2
q = obj.Appendp(ctxt, q)
q.As = AMOVV
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R2
q.To.Type = obj.TYPE_MEM
q.To.Reg = REG_R1
q.To.Offset = 0 // Panic.argp
q = obj.Appendp(ctxt, q)
q.As = obj.ANOP
p1.Pcond = q
p2.Pcond = q
}
case ARET:
if p.From.Type == obj.TYPE_CONST {
ctxt.Diag("using BECOME (%v) is not supported!", p)
break
}
if p.To.Sym != nil { // retjmp
p.As = AJMP
p.To.Type = obj.TYPE_BRANCH
break
}
if cursym.Text.Mark&LEAF != 0 {
if autosize == 0 {
p.As = AJMP
p.From = obj.Addr{}
p.To.Type = obj.TYPE_MEM
p.To.Offset = 0
p.To.Reg = REGLINK
p.Mark |= BRANCH
break
}
p.As = AADDV
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(autosize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REGSP
p.Spadj = -autosize
q = ctxt.NewProg()
q.As = AJMP
q.Lineno = p.Lineno
q.To.Type = obj.TYPE_MEM
q.To.Offset = 0
q.To.Reg = REGLINK
q.Mark |= BRANCH
q.Spadj = +autosize
q.Link = p.Link
p.Link = q
break
}
p.As = AMOVV
p.From.Type = obj.TYPE_MEM
p.From.Offset = 0
p.From.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R4
if false {
// Debug bad returns
q = ctxt.NewProg()
q.As = AMOVV
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_MEM
q.From.Offset = 0
q.From.Reg = REG_R4
q.To.Type = obj.TYPE_REG
q.To.Reg = REGTMP
q.Link = p.Link
p.Link = q
p = q
}
if autosize != 0 {
q = ctxt.NewProg()
q.As = AADDV
q.Lineno = p.Lineno
q.From.Type = obj.TYPE_CONST
q.From.Offset = int64(autosize)
q.To.Type = obj.TYPE_REG
q.To.Reg = REGSP
q.Spadj = -autosize
q.Link = p.Link
p.Link = q
}
q1 = ctxt.NewProg()
q1.As = AJMP
q1.Lineno = p.Lineno
q1.To.Type = obj.TYPE_MEM
q1.To.Offset = 0
q1.To.Reg = REG_R4
q1.Mark |= BRANCH
q1.Spadj = +autosize
q1.Link = q.Link
q.Link = q1
case AADDV,
AADDVU:
if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
p.Spadj = int32(-p.From.Offset)
}
}
}
if nosched {
// if we don't do instruction scheduling, simply add
// NOP after each branch instruction.
for p = cursym.Text; p != nil; p = p.Link {
if p.Mark&BRANCH != 0 {
addnop(ctxt, p)
}
}
return
}
// instruction scheduling
q = nil // p - 1
q1 = cursym.Text // top of block
o := 0 // count of instructions
for p = cursym.Text; p != nil; p = p1 {
p1 = p.Link
o++
if p.Mark&NOSCHED != 0 {
if q1 != p {
sched(ctxt, q1, q)
}
for ; p != nil; p = p.Link {
if p.Mark&NOSCHED == 0 {
break
}
q = p
}
p1 = p
q1 = p
o = 0
continue
}
if p.Mark&(LABEL|SYNC) != 0 {
if q1 != p {
sched(ctxt, q1, q)
}
q1 = p
o = 1
}
if p.Mark&(BRANCH|SYNC) != 0 {
sched(ctxt, q1, p)
q1 = p1
o = 0
}
if o >= NSCHED {
sched(ctxt, q1, p)
q1 = p1
o = 0
}
q = p
}
}