// as2variant returns the variant (V_*) flags of instruction as.
func as2variant(as obj.As) int {
for i, v := range varianttable[as&obj.AMask] {
if v&obj.AMask == as&obj.AMask {
return i
}
}
gc.Fatalf("as2variant: instruction %v is not a variant of itself", obj.Aconv(as&obj.AMask))
return 0
}
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]
}
/*
* shortprop eliminates redundant zero/sign extensions.
*
* MOVBS x, R
* <no use R>
* MOVBS R, R'
*
* changed to
*
* MOVBS x, R
* ...
* MOVB R, R' (compiled to mov)
*
* MOVBS above can be a MOVBS, MOVBU, MOVHS or MOVHU.
*/
func shortprop(r *gc.Flow) bool {
p := r.Prog
r1 := findpre(r, &p.From)
if r1 == nil {
return false
}
p1 := r1.Prog
if p1.As == p.As {
// Two consecutive extensions.
goto gotit
}
if p1.As == arm.AMOVW && isdconst(&p1.From) && p1.From.Offset >= 0 && p1.From.Offset < 128 {
// Loaded an immediate.
goto gotit
}
return false
gotit:
if gc.Debug['P'] != 0 {
fmt.Printf("shortprop\n%v\n%v", p1, p)
}
switch p.As {
case arm.AMOVBS,
arm.AMOVBU:
p.As = arm.AMOVB
case arm.AMOVHS,
arm.AMOVHU:
p.As = arm.AMOVH
}
if gc.Debug['P'] != 0 {
fmt.Printf(" => %v\n", obj.Aconv(p.As))
}
return true
}
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 1 if v only used
// 2 if v is set and used in one address (read-alter-rewrite;
// can't substitute)
// 3 if v is only set
// 4 if v is set in one address and used in another (so addresses
// can be rewritten independently)
// 0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
if p.From3Type() != obj.TYPE_NONE {
// never generates a from3
fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
}
switch p.As {
default:
fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
return 2
case obj.ANOP, /* read p->from, write p->to */
mips.AMOVV,
mips.AMOVF,
mips.AMOVD,
mips.AMOVH,
mips.AMOVHU,
mips.AMOVB,
mips.AMOVBU,
mips.AMOVW,
mips.AMOVWU,
mips.AMOVFD,
mips.AMOVDF,
mips.AMOVDW,
mips.AMOVWD,
mips.AMOVFW,
mips.AMOVWF,
mips.AMOVDV,
mips.AMOVVD,
mips.AMOVFV,
mips.AMOVVF,
mips.ATRUNCFV,
mips.ATRUNCDV,
mips.ATRUNCFW,
mips.ATRUNCDW:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
// Update only indirect uses of v in p->to
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
// Fix up implicit from
if p.From.Type == obj.TYPE_NONE {
p.From = p.To
}
if copyau(&p.From, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau(&p.To, v) {
// p->to only indirectly uses v
return 1
}
return 0
case mips.ASGT, /* read p->from, read p->reg, write p->to */
mips.ASGTU,
mips.AADD,
mips.AADDU,
mips.ASUB,
mips.ASUBU,
mips.ASLL,
mips.ASRL,
mips.ASRA,
mips.AOR,
mips.ANOR,
mips.AAND,
mips.AXOR,
mips.AADDV,
mips.AADDVU,
mips.ASUBV,
mips.ASUBVU,
mips.ASLLV,
mips.ASRLV,
mips.ASRAV,
mips.AADDF,
mips.AADDD,
mips.ASUBF,
mips.ASUBD,
mips.AMULF,
mips.AMULD,
mips.ADIVF,
mips.ADIVD:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
// Update only indirect uses of v in p->to
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
if p.Reg == 0 {
// Fix up implicit reg (e.g., ADD
// R3,R4 -> ADD R3,R4,R4) so we can
// update reg and to separately.
p.Reg = p.To.Reg
}
if copyau(&p.From, v) {
return 4
}
if copyau1(p, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
if copyau(&p.To, v) {
return 1
}
return 0
case obj.ACHECKNIL, /* read p->from */
mips.ABEQ, /* read p->from, read p->reg */
mips.ABNE,
mips.ABGTZ,
mips.ABGEZ,
mips.ABLTZ,
mips.ABLEZ,
mips.ACMPEQD,
mips.ACMPEQF,
mips.ACMPGED,
mips.ACMPGEF,
mips.ACMPGTD,
mips.ACMPGTF,
mips.ABFPF,
mips.ABFPT,
mips.AMUL,
mips.AMULU,
mips.ADIV,
mips.ADIVU,
mips.AMULV,
mips.AMULVU,
mips.ADIVV,
mips.ADIVVU:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
return 0
case mips.AJMP: /* read p->to */
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 1
}
return 0
case mips.ARET: /* funny */
if s != nil {
return 0
}
// All registers die at this point, so claim
// everything is set (and not used).
return 3
case mips.AJAL: /* funny */
if v.Type == obj.TYPE_REG {
// TODO(rsc): REG_R0 and REG_F0 used to be
// (when register numbers started at 0) exregoffset and exfregoffset,
// which are unset entirely.
// It's strange that this handles R0 and F0 differently from the other
// registers. Possible failure to optimize?
if mips.REG_R0 < v.Reg && v.Reg <= mips.REG_R31 {
return 2
}
if v.Reg == mips.REGARG {
return 2
}
if mips.REG_F0 < v.Reg && v.Reg <= mips.REG_F31 {
return 2
}
}
if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
return 2
}
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 4
}
return 3
// R0 is zero, used by DUFFZERO, cannot be substituted.
// R1 is ptr to memory, used and set, cannot be substituted.
case obj.ADUFFZERO:
if v.Type == obj.TYPE_REG {
if v.Reg == 0 {
return 1
}
if v.Reg == 1 {
return 2
}
}
return 0
// R1, R2 are ptr to src, dst, used and set, cannot be substituted.
// R3 is scratch, set by DUFFCOPY, cannot be substituted.
case obj.ADUFFCOPY:
if v.Type == obj.TYPE_REG {
if v.Reg == 1 || v.Reg == 2 {
return 2
}
if v.Reg == 3 {
return 3
}
}
return 0
case obj.ATEXT: /* funny */
if v.Type == obj.TYPE_REG {
if v.Reg == mips.REGARG {
return 3
}
}
return 0
case obj.APCDATA,
obj.AFUNCDATA,
obj.AVARDEF,
obj.AVARKILL,
obj.AVARLIVE,
obj.AUSEFIELD:
return 0
}
}
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 1 if v only used
// 2 if v is set and used in one address (read-alter-rewrite;
// can't substitute)
// 3 if v is only set
// 4 if v is set in one address and used in another (so addresses
// can be rewritten independently)
// 0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
if p.From3Type() != obj.TYPE_NONE {
// 9g never generates a from3
fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
}
switch p.As {
default:
fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
return 2
case obj.ANOP, /* read p->from, write p->to */
ppc64.AMOVH,
ppc64.AMOVHZ,
ppc64.AMOVB,
ppc64.AMOVBZ,
ppc64.AMOVW,
ppc64.AMOVWZ,
ppc64.AMOVD,
ppc64.ANEG,
ppc64.ANEGCC,
ppc64.AADDME,
ppc64.AADDMECC,
ppc64.AADDZE,
ppc64.AADDZECC,
ppc64.ASUBME,
ppc64.ASUBMECC,
ppc64.ASUBZE,
ppc64.ASUBZECC,
ppc64.AFCTIW,
ppc64.AFCTIWZ,
ppc64.AFCTID,
ppc64.AFCTIDZ,
ppc64.AFCFID,
ppc64.AFCFIDCC,
ppc64.AFCFIDU,
ppc64.AFCFIDUCC,
ppc64.AFMOVS,
ppc64.AFMOVD,
ppc64.AFRSP,
ppc64.AFNEG,
ppc64.AFNEGCC,
ppc64.AFSQRT:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
// Update only indirect uses of v in p->to
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
// Fix up implicit from
if p.From.Type == obj.TYPE_NONE {
p.From = p.To
}
if copyau(&p.From, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau(&p.To, v) {
// p->to only indirectly uses v
return 1
}
return 0
case ppc64.AMOVBU, /* rar p->from, write p->to or read p->from, rar p->to */
ppc64.AMOVBZU,
ppc64.AMOVHU,
ppc64.AMOVHZU,
ppc64.AMOVWZU,
ppc64.AMOVDU:
if p.From.Type == obj.TYPE_MEM {
if copyas(&p.From, v) {
// No s!=nil check; need to fail
// anyway in that case
return 2
}
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyas(&p.To, v) {
return 3
}
} else if p.To.Type == obj.TYPE_MEM {
if copyas(&p.To, v) {
return 2
}
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
return 1
}
} else {
fmt.Printf("copyu: bad %v\n", p)
}
return 0
case ppc64.ARLWMI, /* read p->from, read p->reg, rar p->to */
ppc64.ARLWMICC:
if copyas(&p.To, v) {
return 2
}
fallthrough
/* fall through */
case ppc64.AADD,
/* read p->from, read p->reg, write p->to */
ppc64.AADDC,
ppc64.AADDE,
ppc64.ASUB,
ppc64.ASLW,
ppc64.ASRW,
ppc64.ASRAW,
ppc64.ASLD,
ppc64.ASRD,
ppc64.ASRAD,
ppc64.AOR,
ppc64.AORCC,
ppc64.AORN,
ppc64.AORNCC,
ppc64.AAND,
ppc64.AANDCC,
ppc64.AANDN,
ppc64.AANDNCC,
ppc64.ANAND,
ppc64.ANANDCC,
ppc64.ANOR,
ppc64.ANORCC,
ppc64.AXOR,
ppc64.AMULHW,
ppc64.AMULHWU,
ppc64.AMULLW,
ppc64.AMULLD,
ppc64.ADIVW,
ppc64.ADIVD,
ppc64.ADIVWU,
ppc64.ADIVDU,
ppc64.AREM,
ppc64.AREMU,
ppc64.AREMD,
ppc64.AREMDU,
ppc64.ARLWNM,
ppc64.ARLWNMCC,
ppc64.AFADDS,
ppc64.AFADD,
ppc64.AFSUBS,
ppc64.AFSUB,
ppc64.AFMULS,
ppc64.AFMUL,
ppc64.AFDIVS,
ppc64.AFDIV:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
// Update only indirect uses of v in p->to
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
if p.Reg == 0 {
// Fix up implicit reg (e.g., ADD
// R3,R4 -> ADD R3,R4,R4) so we can
// update reg and to separately.
p.Reg = p.To.Reg
}
if copyau(&p.From, v) {
return 4
}
if copyau1(p, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
if copyau(&p.To, v) {
return 1
}
return 0
case ppc64.ABEQ,
ppc64.ABGT,
ppc64.ABGE,
ppc64.ABLT,
ppc64.ABLE,
ppc64.ABNE,
ppc64.ABVC,
ppc64.ABVS:
return 0
case obj.ACHECKNIL, /* read p->from */
ppc64.ACMP, /* read p->from, read p->to */
ppc64.ACMPU,
ppc64.ACMPW,
ppc64.ACMPWU,
ppc64.AFCMPO,
ppc64.AFCMPU:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
return 1
}
if copyau(&p.To, v) {
return 1
}
return 0
// 9g never generates a branch to a GPR (this isn't
// even a normal instruction; liblink turns it in to a
// mov and a branch).
case ppc64.ABR: /* read p->to */
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 1
}
return 0
case obj.ARET: /* funny */
if s != nil {
return 0
}
// All registers die at this point, so claim
// everything is set (and not used).
return 3
case ppc64.ABL: /* funny */
if v.Type == obj.TYPE_REG {
// TODO(rsc): REG_R0 and REG_F0 used to be
// (when register numbers started at 0) exregoffset and exfregoffset,
// which are unset entirely.
// It's strange that this handles R0 and F0 differently from the other
// registers. Possible failure to optimize?
if ppc64.REG_R0 < v.Reg && v.Reg <= ppc64.REGEXT {
return 2
}
if v.Reg == ppc64.REGARG {
return 2
}
if ppc64.REG_F0 < v.Reg && v.Reg <= ppc64.FREGEXT {
return 2
}
}
if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
return 2
}
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 4
}
return 3
// R0 is zero, used by DUFFZERO, cannot be substituted.
// R3 is ptr to memory, used and set, cannot be substituted.
case obj.ADUFFZERO:
if v.Type == obj.TYPE_REG {
if v.Reg == 0 {
return 1
}
if v.Reg == 3 {
return 2
}
}
return 0
// R3, R4 are ptr to src, dst, used and set, cannot be substituted.
// R5 is scratch, set by DUFFCOPY, cannot be substituted.
case obj.ADUFFCOPY:
if v.Type == obj.TYPE_REG {
if v.Reg == 3 || v.Reg == 4 {
return 2
}
if v.Reg == 5 {
return 3
}
}
return 0
case obj.ATEXT: /* funny */
if v.Type == obj.TYPE_REG {
if v.Reg == ppc64.REGARG {
return 3
}
}
return 0
case obj.APCDATA,
obj.AFUNCDATA,
obj.AVARDEF,
obj.AVARKILL,
obj.AVARLIVE,
obj.AUSEFIELD:
return 0
}
}
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 1 if v only used
// 2 if v is set and used in one address (read-alter-rewrite;
// can't substitute)
// 3 if v is only set
// 4 if v is set in one address and used in another (so addresses
// can be rewritten independently)
// 0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
if p.From3Type() != obj.TYPE_NONE {
// 7g never generates a from3
fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
}
if p.RegTo2 != obj.REG_NONE {
// 7g never generates a to2
fmt.Printf("copyu: RegTo2 (%v) not implemented\n", obj.Rconv(int(p.RegTo2)))
}
switch p.As {
default:
fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
return 2
case obj.ANOP, /* read p->from, write p->to */
arm64.ANEG,
arm64.AFNEGD,
arm64.AFNEGS,
arm64.AFSQRTD,
arm64.AFCVTZSD,
arm64.AFCVTZSS,
arm64.AFCVTZSDW,
arm64.AFCVTZSSW,
arm64.AFCVTZUD,
arm64.AFCVTZUS,
arm64.AFCVTZUDW,
arm64.AFCVTZUSW,
arm64.AFCVTSD,
arm64.AFCVTDS,
arm64.ASCVTFD,
arm64.ASCVTFS,
arm64.ASCVTFWD,
arm64.ASCVTFWS,
arm64.AUCVTFD,
arm64.AUCVTFS,
arm64.AUCVTFWD,
arm64.AUCVTFWS,
arm64.AMOVB,
arm64.AMOVBU,
arm64.AMOVH,
arm64.AMOVHU,
arm64.AMOVW,
arm64.AMOVWU,
arm64.AMOVD,
arm64.AFMOVS,
arm64.AFMOVD:
if p.Scond == 0 {
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
// Update only indirect uses of v in p->to
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
// Fix up implicit from
if p.From.Type == obj.TYPE_NONE {
p.From = p.To
}
if copyau(&p.From, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau(&p.To, v) {
// p->to only indirectly uses v
return 1
}
return 0
}
/* rar p->from, write p->to or read p->from, rar p->to */
if p.From.Type == obj.TYPE_MEM {
if copyas(&p.From, v) {
// No s!=nil check; need to fail
// anyway in that case
return 2
}
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyas(&p.To, v) {
return 3
}
} else if p.To.Type == obj.TYPE_MEM {
if copyas(&p.To, v) {
return 2
}
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
return 1
}
} else {
fmt.Printf("copyu: bad %v\n", p)
}
return 0
case arm64.AADD, /* read p->from, read p->reg, write p->to */
arm64.AADDS,
arm64.ASUB,
arm64.AADC,
arm64.AAND,
arm64.AORR,
arm64.AEOR,
arm64.AROR,
arm64.AMUL,
arm64.ASMULL,
arm64.AUMULL,
arm64.ASMULH,
arm64.AUMULH,
arm64.ASDIV,
arm64.AUDIV,
arm64.ALSL,
arm64.ALSR,
arm64.AASR,
arm64.AFADDD,
arm64.AFADDS,
arm64.AFSUBD,
arm64.AFSUBS,
arm64.AFMULD,
arm64.AFMULS,
arm64.AFDIVD,
arm64.AFDIVS:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
// Update only indirect uses of v in p->to
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
if p.Reg == 0 {
// Fix up implicit reg (e.g., ADD
// R3,R4 -> ADD R3,R4,R4) so we can
// update reg and to separately.
p.Reg = p.To.Reg
}
if copyau(&p.From, v) {
return 4
}
if copyau1(p, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
if copyau(&p.To, v) {
return 1
}
return 0
case arm64.ABEQ,
arm64.ABNE,
arm64.ABGE,
arm64.ABLT,
arm64.ABGT,
arm64.ABLE,
arm64.ABLO,
arm64.ABLS,
arm64.ABHI,
arm64.ABHS:
return 0
case obj.ACHECKNIL, /* read p->from */
arm64.ACMP, /* read p->from, read p->reg */
arm64.AFCMPD,
arm64.AFCMPS:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
return 0
case arm64.AB: /* read p->to */
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 1
}
return 0
case obj.ARET: /* funny */
if s != nil {
return 0
}
// All registers die at this point, so claim
// everything is set (and not used).
return 3
case arm64.ABL: /* funny */
if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
return 2
}
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 4
}
return 3
// R31 is zero, used by DUFFZERO, cannot be substituted.
// R16 is ptr to memory, used and set, cannot be substituted.
case obj.ADUFFZERO:
if v.Type == obj.TYPE_REG {
if v.Reg == 31 {
return 1
}
if v.Reg == 16 {
return 2
}
}
return 0
// R16, R17 are ptr to src, dst, used and set, cannot be substituted.
// R27 is scratch, set by DUFFCOPY, cannot be substituted.
case obj.ADUFFCOPY:
if v.Type == obj.TYPE_REG {
if v.Reg == 16 || v.Reg == 17 {
return 2
}
if v.Reg == 27 {
return 3
}
}
return 0
case arm64.AHINT,
obj.ATEXT,
obj.APCDATA,
obj.AFUNCDATA,
obj.AVARDEF,
obj.AVARKILL,
obj.AVARLIVE,
obj.AUSEFIELD:
return 0
}
}
func peep(firstp *obj.Prog) {
g := gc.Flowstart(firstp, nil)
if g == nil {
return
}
gactive = 0
var p *obj.Prog
var r *gc.Flow
var t int
loop1:
if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
gc.Dumpit("loop1", g.Start, 0)
}
t = 0
for r = g.Start; r != nil; r = r.Link {
p = r.Prog
// TODO(minux) Handle smaller moves. arm and amd64
// distinguish between moves that *must* sign/zero
// extend and moves that don't care so they
// can eliminate moves that don't care without
// breaking moves that do care. This might let us
// simplify or remove the next peep loop, too.
if p.As == arm64.AMOVD || p.As == arm64.AFMOVD {
if regtyp(&p.To) {
// Try to eliminate reg->reg moves
if regtyp(&p.From) {
if p.From.Type == p.To.Type {
if copyprop(r) {
excise(r)
t++
} else if subprop(r) && copyprop(r) {
excise(r)
t++
}
}
}
}
}
}
if t != 0 {
goto loop1
}
/*
* look for MOVB x,R; MOVB R,R (for small MOVs not handled above)
*/
var p1 *obj.Prog
var r1 *gc.Flow
for r := g.Start; r != nil; r = r.Link {
p = r.Prog
switch p.As {
default:
continue
case arm64.AMOVH,
arm64.AMOVHU,
arm64.AMOVB,
arm64.AMOVBU,
arm64.AMOVW,
arm64.AMOVWU:
if p.To.Type != obj.TYPE_REG {
continue
}
}
r1 = r.Link
if r1 == nil {
continue
}
p1 = r1.Prog
if p1.As != p.As {
continue
}
if p1.From.Type != obj.TYPE_REG || p1.From.Reg != p.To.Reg {
continue
}
if p1.To.Type != obj.TYPE_REG || p1.To.Reg != p.To.Reg {
continue
}
excise(r1)
}
if gc.Debug['D'] > 1 {
goto ret /* allow following code improvement to be suppressed */
}
// MOVD $c, R'; ADD R', R (R' unused) -> ADD $c, R
for r := g.Start; r != nil; r = r.Link {
p = r.Prog
switch p.As {
default:
continue
case arm64.AMOVD:
if p.To.Type != obj.TYPE_REG {
continue
}
if p.From.Type != obj.TYPE_CONST {
continue
}
if p.From.Offset < 0 || 4096 <= p.From.Offset {
continue
}
}
r1 = r.Link
if r1 == nil {
continue
}
p1 = r1.Prog
if p1.As != arm64.AADD && p1.As != arm64.ASUB { // TODO(aram): also logical after we have bimm.
continue
}
if p1.From.Type != obj.TYPE_REG || p1.From.Reg != p.To.Reg {
continue
}
if p1.To.Type != obj.TYPE_REG {
continue
}
if gc.Debug['P'] != 0 {
fmt.Printf("encoding $%d directly into %v in:\n%v\n%v\n", p.From.Offset, obj.Aconv(p1.As), p, p1)
}
p1.From.Type = obj.TYPE_CONST
p1.From = p.From
excise(r)
}
/* TODO(minux):
* look for OP x,y,R; CMP R, $0 -> OP.S x,y,R
* when OP can set condition codes correctly
*/
ret:
gc.Flowend(g)
}
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// _Read if v only used
// _ReadWriteSame if v is set and used in one address (read-alter-rewrite;
// can't substitute)
// _Write if v is only set
// _ReadWriteDiff if v is set in one address and used in another (so addresses
// can be rewritten independently)
// _None otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) usage {
if p.From3Type() != obj.TYPE_NONE && p.From3Type() != obj.TYPE_CONST {
// Currently we never generate a From3 with anything other than a constant in it.
fmt.Printf("copyu: From3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
}
switch p.As {
default:
fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
return _ReadWriteSame
case // read p.From, write p.To
s390x.AMOVH,
s390x.AMOVHZ,
s390x.AMOVB,
s390x.AMOVBZ,
s390x.AMOVW,
s390x.AMOVWZ,
s390x.AMOVD,
s390x.ANEG,
s390x.AADDME,
s390x.AADDZE,
s390x.ASUBME,
s390x.ASUBZE,
s390x.AFMOVS,
s390x.AFMOVD,
s390x.ALEDBR,
s390x.AFNEG,
s390x.ALDEBR,
s390x.ACLFEBR,
s390x.ACLGEBR,
s390x.ACLFDBR,
s390x.ACLGDBR,
s390x.ACFEBRA,
s390x.ACGEBRA,
s390x.ACFDBRA,
s390x.ACGDBRA,
s390x.ACELFBR,
s390x.ACELGBR,
s390x.ACDLFBR,
s390x.ACDLGBR,
s390x.ACEFBRA,
s390x.ACEGBRA,
s390x.ACDFBRA,
s390x.ACDGBRA,
s390x.AFSQRT:
if s != nil {
copysub(&p.From, v, s)
// Update only indirect uses of v in p.To
if !copyas(&p.To, v) {
copysub(&p.To, v, s)
}
return _None
}
if copyas(&p.To, v) {
// Fix up implicit from
if p.From.Type == obj.TYPE_NONE {
p.From = p.To
}
if copyau(&p.From, v) {
return _ReadWriteDiff
}
return _Write
}
if copyau(&p.From, v) {
return _Read
}
if copyau(&p.To, v) {
// p.To only indirectly uses v
return _Read
}
return _None
// read p.From, read p.Reg, write p.To
case s390x.AADD,
s390x.AADDC,
s390x.AADDE,
s390x.ASUB,
s390x.ASLW,
s390x.ASRW,
s390x.ASRAW,
s390x.ASLD,
s390x.ASRD,
s390x.ASRAD,
s390x.ARLL,
s390x.ARLLG,
s390x.AOR,
s390x.AORN,
s390x.AAND,
s390x.AANDN,
s390x.ANAND,
s390x.ANOR,
s390x.AXOR,
s390x.AMULLW,
s390x.AMULLD,
s390x.AMULHD,
s390x.AMULHDU,
s390x.ADIVW,
s390x.ADIVD,
s390x.ADIVWU,
s390x.ADIVDU,
s390x.AFADDS,
s390x.AFADD,
s390x.AFSUBS,
s390x.AFSUB,
s390x.AFMULS,
s390x.AFMUL,
s390x.AFDIVS,
s390x.AFDIV:
if s != nil {
copysub(&p.From, v, s)
copysub1(p, v, s)
// Update only indirect uses of v in p.To
if !copyas(&p.To, v) {
copysub(&p.To, v, s)
}
}
if copyas(&p.To, v) {
if p.Reg == 0 {
p.Reg = p.To.Reg
}
if copyau(&p.From, v) || copyau1(p, v) {
return _ReadWriteDiff
}
return _Write
}
if copyau(&p.From, v) {
return _Read
}
if copyau1(p, v) {
return _Read
}
if copyau(&p.To, v) {
return _Read
}
return _None
case s390x.ABEQ,
s390x.ABGT,
s390x.ABGE,
s390x.ABLT,
s390x.ABLE,
s390x.ABNE,
s390x.ABVC,
s390x.ABVS:
return _None
case obj.ACHECKNIL, // read p.From
s390x.ACMP, // read p.From, read p.To
s390x.ACMPU,
s390x.ACMPW,
s390x.ACMPWU,
s390x.AFCMPO,
s390x.AFCMPU,
s390x.ACEBR,
s390x.AMVC,
s390x.ACLC,
s390x.AXC,
s390x.AOC,
s390x.ANC:
if s != nil {
copysub(&p.From, v, s)
copysub(&p.To, v, s)
return _None
}
if copyau(&p.From, v) {
return _Read
}
if copyau(&p.To, v) {
return _Read
}
return _None
case s390x.ACMPBNE, s390x.ACMPBEQ,
s390x.ACMPBLT, s390x.ACMPBLE,
s390x.ACMPBGT, s390x.ACMPBGE,
s390x.ACMPUBNE, s390x.ACMPUBEQ,
s390x.ACMPUBLT, s390x.ACMPUBLE,
s390x.ACMPUBGT, s390x.ACMPUBGE:
if s != nil {
copysub(&p.From, v, s)
copysub1(p, v, s)
return _None
}
if copyau(&p.From, v) {
return _Read
}
if copyau1(p, v) {
return _Read
}
return _None
case s390x.ACLEAR:
if s != nil {
copysub(&p.To, v, s)
return _None
}
if copyau(&p.To, v) {
return _Read
}
return _None
// go never generates a branch to a GPR
// read p.To
case s390x.ABR:
if s != nil {
copysub(&p.To, v, s)
return _None
}
if copyau(&p.To, v) {
return _Read
}
return _None
case obj.ARET, obj.AUNDEF:
if s != nil {
return _None
}
// All registers die at this point, so claim
// everything is set (and not used).
return _Write
case s390x.ABL:
if v.Type == obj.TYPE_REG {
if s390x.REGARG != -1 && v.Reg == s390x.REGARG {
return _ReadWriteSame
}
if p.From.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
return _ReadWriteSame
}
if v.Reg == s390x.REGZERO {
// Deliberately inserted nops set R0.
return _ReadWriteSame
}
if v.Reg == s390x.REGCTXT {
// Context register for closures.
// TODO(mundaym): not sure if we need to exclude this.
return _ReadWriteSame
}
}
if s != nil {
copysub(&p.To, v, s)
return _None
}
if copyau(&p.To, v) {
return _ReadWriteDiff
}
return _Write
case obj.ATEXT:
if v.Type == obj.TYPE_REG {
if v.Reg == s390x.REGARG {
return _Write
}
}
return _None
case obj.APCDATA,
obj.AFUNCDATA,
obj.AVARDEF,
obj.AVARKILL,
obj.AVARLIVE,
obj.AUSEFIELD,
obj.ANOP:
return _None
}
}
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
if ctxt.Headtype == obj.Hplan9 && ctxt.Plan9privates == nil {
ctxt.Plan9privates = obj.Linklookup(ctxt, "_privates", 0)
}
ctxt.Cursym = cursym
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
p := cursym.Text
autoffset := int32(p.To.Offset)
if autoffset < 0 {
autoffset = 0
}
var bpsize int
if p.Mode == 64 && ctxt.Framepointer_enabled && autoffset > 0 && p.From3.Offset&obj.NOFRAME == 0 {
// Make room for to save a base pointer. If autoffset == 0,
// this might do something special like a tail jump to
// another function, so in that case we omit this.
bpsize = ctxt.Arch.PtrSize
autoffset += int32(bpsize)
p.To.Offset += int64(bpsize)
} else {
bpsize = 0
}
textarg := int64(p.To.Val.(int32))
cursym.Args = int32(textarg)
cursym.Locals = int32(p.To.Offset)
// TODO(rsc): Remove.
if p.Mode == 32 && cursym.Locals < 0 {
cursym.Locals = 0
}
// TODO(rsc): Remove 'p.Mode == 64 &&'.
if p.Mode == 64 && autoffset < obj.StackSmall && p.From3Offset()&obj.NOSPLIT == 0 {
for q := p; q != nil; q = q.Link {
if q.As == obj.ACALL {
goto noleaf
}
if (q.As == obj.ADUFFCOPY || q.As == obj.ADUFFZERO) && autoffset >= obj.StackSmall-8 {
goto noleaf
}
}
p.From3.Offset |= obj.NOSPLIT
noleaf:
}
if p.From3Offset()&obj.NOSPLIT == 0 || p.From3Offset()&obj.WRAPPER != 0 {
p = obj.Appendp(ctxt, p)
p = load_g_cx(ctxt, p) // load g into CX
}
if cursym.Text.From3Offset()&obj.NOSPLIT == 0 {
p = stacksplit(ctxt, p, autoffset, int32(textarg)) // emit split check
}
if autoffset != 0 {
if autoffset%int32(ctxt.Arch.RegSize) != 0 {
ctxt.Diag("unaligned stack size %d", autoffset)
}
p = obj.Appendp(ctxt, p)
p.As = AADJSP
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(autoffset)
p.Spadj = autoffset
} else {
// zero-byte stack adjustment.
// Insert a fake non-zero adjustment so that stkcheck can
// recognize the end of the stack-splitting prolog.
p = obj.Appendp(ctxt, p)
p.As = obj.ANOP
p.Spadj = int32(-ctxt.Arch.PtrSize)
p = obj.Appendp(ctxt, p)
p.As = obj.ANOP
p.Spadj = int32(ctxt.Arch.PtrSize)
}
deltasp := autoffset
if bpsize > 0 {
// Save caller's BP
p = obj.Appendp(ctxt, p)
p.As = AMOVQ
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_BP
p.To.Type = obj.TYPE_MEM
p.To.Reg = REG_SP
p.To.Scale = 1
p.To.Offset = int64(autoffset) - int64(bpsize)
// Move current frame to BP
p = obj.Appendp(ctxt, p)
p.As = ALEAQ
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_SP
p.From.Scale = 1
p.From.Offset = int64(autoffset) - int64(bpsize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_BP
}
if cursym.Text.From3Offset()&obj.WRAPPER != 0 {
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
//
// MOVQ g_panic(CX), BX
// TESTQ BX, BX
// JEQ end
// LEAQ (autoffset+8)(SP), DI
// CMPQ panic_argp(BX), DI
// JNE end
// MOVQ SP, panic_argp(BX)
// end:
// NOP
//
// The NOP is needed to give the jumps somewhere to land.
// It is a liblink NOP, not an x86 NOP: it encodes to 0 instruction bytes.
p = obj.Appendp(ctxt, p)
p.As = AMOVQ
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_CX
p.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_BX
if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
p.As = AMOVL
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_R15
p.From.Scale = 1
p.From.Index = REG_CX
}
if p.Mode == 32 {
p.As = AMOVL
}
p = obj.Appendp(ctxt, p)
p.As = ATESTQ
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_BX
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_BX
if ctxt.Headtype == obj.Hnacl || p.Mode == 32 {
p.As = ATESTL
}
p = obj.Appendp(ctxt, p)
p.As = AJEQ
p.To.Type = obj.TYPE_BRANCH
p1 := p
p = obj.Appendp(ctxt, p)
p.As = ALEAQ
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_SP
p.From.Offset = int64(autoffset) + int64(ctxt.Arch.RegSize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_DI
if ctxt.Headtype == obj.Hnacl || p.Mode == 32 {
p.As = ALEAL
}
p = obj.Appendp(ctxt, p)
p.As = ACMPQ
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_BX
p.From.Offset = 0 // Panic.argp
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_DI
if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
p.As = ACMPL
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_R15
p.From.Scale = 1
p.From.Index = REG_BX
}
if p.Mode == 32 {
p.As = ACMPL
}
p = obj.Appendp(ctxt, p)
p.As = AJNE
p.To.Type = obj.TYPE_BRANCH
p2 := p
p = obj.Appendp(ctxt, p)
p.As = AMOVQ
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_SP
p.To.Type = obj.TYPE_MEM
p.To.Reg = REG_BX
p.To.Offset = 0 // Panic.argp
if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
p.As = AMOVL
p.To.Type = obj.TYPE_MEM
p.To.Reg = REG_R15
p.To.Scale = 1
p.To.Index = REG_BX
}
if p.Mode == 32 {
p.As = AMOVL
}
p = obj.Appendp(ctxt, p)
p.As = obj.ANOP
p1.Pcond = p
p2.Pcond = p
}
var a int
var pcsize int
for ; p != nil; p = p.Link {
pcsize = int(p.Mode) / 8
a = int(p.From.Name)
if a == obj.NAME_AUTO {
p.From.Offset += int64(deltasp) - int64(bpsize)
}
if a == obj.NAME_PARAM {
p.From.Offset += int64(deltasp) + int64(pcsize)
}
if p.From3 != nil {
a = int(p.From3.Name)
if a == obj.NAME_AUTO {
p.From3.Offset += int64(deltasp) - int64(bpsize)
}
if a == obj.NAME_PARAM {
p.From3.Offset += int64(deltasp) + int64(pcsize)
}
}
a = int(p.To.Name)
if a == obj.NAME_AUTO {
p.To.Offset += int64(deltasp) - int64(bpsize)
}
if a == obj.NAME_PARAM {
p.To.Offset += int64(deltasp) + int64(pcsize)
}
switch p.As {
default:
continue
case APUSHL, APUSHFL:
deltasp += 4
p.Spadj = 4
continue
case APUSHQ, APUSHFQ:
deltasp += 8
p.Spadj = 8
continue
case APUSHW, APUSHFW:
deltasp += 2
p.Spadj = 2
continue
case APOPL, APOPFL:
deltasp -= 4
p.Spadj = -4
continue
case APOPQ, APOPFQ:
deltasp -= 8
p.Spadj = -8
continue
case APOPW, APOPFW:
deltasp -= 2
p.Spadj = -2
continue
case obj.ARET:
break
}
if autoffset != deltasp {
ctxt.Diag("unbalanced PUSH/POP")
}
if autoffset != 0 {
if bpsize > 0 {
// Restore caller's BP
p.As = AMOVQ
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_SP
p.From.Scale = 1
p.From.Offset = int64(autoffset) - int64(bpsize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_BP
p = obj.Appendp(ctxt, p)
}
p.As = AADJSP
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(-autoffset)
p.Spadj = -autoffset
p = obj.Appendp(ctxt, p)
p.As = obj.ARET
// If there are instructions following
// this ARET, they come from a branch
// with the same stackframe, so undo
// the cleanup.
p.Spadj = +autoffset
}
if p.To.Sym != nil { // retjmp
p.As = obj.AJMP
}
}
}
func indir_cx(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
a.Type = obj.TYPE_MEM
a.Reg = REG_R15
a.Index = REG_CX
a.Scale = 1
return
}
a.Type = obj.TYPE_MEM
a.Reg = REG_CX
}
// Append code to p to load g into cx.
// Overwrites p with the first instruction (no first appendp).
// Overwriting p is unusual but it lets use this in both the
// prologue (caller must call appendp first) and in the epilogue.
// Returns last new instruction.
func load_g_cx(ctxt *obj.Link, p *obj.Prog) *obj.Prog {
p.As = AMOVQ
if ctxt.Arch.PtrSize == 4 {
p.As = AMOVL
}
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_TLS
p.From.Offset = 0
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_CX
next := p.Link
progedit(ctxt, p)
for p.Link != next {
p = p.Link
}
if p.From.Index == REG_TLS {
p.From.Scale = 2
}
return p
}
// Append code to p to check for stack split.
// Appends to (does not overwrite) p.
// Assumes g is in CX.
// Returns last new instruction.
func stacksplit(ctxt *obj.Link, p *obj.Prog, framesize int32, textarg int32) *obj.Prog {
cmp := ACMPQ
lea := ALEAQ
mov := AMOVQ
sub := ASUBQ
if ctxt.Headtype == obj.Hnacl || p.Mode == 32 {
cmp = ACMPL
lea = ALEAL
mov = AMOVL
sub = ASUBL
}
var q1 *obj.Prog
if framesize <= obj.StackSmall {
// small stack: SP <= stackguard
// CMPQ SP, stackguard
p = obj.Appendp(ctxt, p)
p.As = cmp
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_SP
indir_cx(ctxt, p, &p.To)
p.To.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
if ctxt.Cursym.Cfunc {
p.To.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
}
} else if framesize <= obj.StackBig {
// large stack: SP-framesize <= stackguard-StackSmall
// LEAQ -xxx(SP), AX
// CMPQ AX, stackguard
p = obj.Appendp(ctxt, p)
p.As = lea
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_SP
p.From.Offset = -(int64(framesize) - obj.StackSmall)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_AX
p = obj.Appendp(ctxt, p)
p.As = cmp
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_AX
indir_cx(ctxt, p, &p.To)
p.To.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
if ctxt.Cursym.Cfunc {
p.To.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
}
} else {
// Such a large stack we need to protect against wraparound.
// If SP is close to zero:
// SP-stackguard+StackGuard <= framesize + (StackGuard-StackSmall)
// The +StackGuard on both sides is required to keep the left side positive:
// SP is allowed to be slightly below stackguard. See stack.h.
//
// Preemption sets stackguard to StackPreempt, a very large value.
// That breaks the math above, so we have to check for that explicitly.
// MOVQ stackguard, CX
// CMPQ CX, $StackPreempt
// JEQ label-of-call-to-morestack
// LEAQ StackGuard(SP), AX
// SUBQ CX, AX
// CMPQ AX, $(framesize+(StackGuard-StackSmall))
p = obj.Appendp(ctxt, p)
p.As = mov
indir_cx(ctxt, p, &p.From)
p.From.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
if ctxt.Cursym.Cfunc {
p.From.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
}
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_SI
p = obj.Appendp(ctxt, p)
p.As = cmp
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_SI
p.To.Type = obj.TYPE_CONST
p.To.Offset = obj.StackPreempt
if p.Mode == 32 {
p.To.Offset = int64(uint32(obj.StackPreempt & (1<<32 - 1)))
}
p = obj.Appendp(ctxt, p)
p.As = AJEQ
p.To.Type = obj.TYPE_BRANCH
q1 = p
p = obj.Appendp(ctxt, p)
p.As = lea
p.From.Type = obj.TYPE_MEM
p.From.Reg = REG_SP
p.From.Offset = obj.StackGuard
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_AX
p = obj.Appendp(ctxt, p)
p.As = sub
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_SI
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_AX
p = obj.Appendp(ctxt, p)
p.As = cmp
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_AX
p.To.Type = obj.TYPE_CONST
p.To.Offset = int64(framesize) + (obj.StackGuard - obj.StackSmall)
}
// common
jls := obj.Appendp(ctxt, p)
jls.As = AJLS
jls.To.Type = obj.TYPE_BRANCH
var last *obj.Prog
for last = ctxt.Cursym.Text; last.Link != nil; last = last.Link {
}
spfix := obj.Appendp(ctxt, last)
spfix.As = obj.ANOP
spfix.Spadj = -framesize
call := obj.Appendp(ctxt, spfix)
call.Lineno = ctxt.Cursym.Text.Lineno
call.Mode = ctxt.Cursym.Text.Mode
call.As = obj.ACALL
call.To.Type = obj.TYPE_BRANCH
call.To.Name = obj.NAME_EXTERN
morestack := "runtime.morestack"
switch {
case ctxt.Cursym.Cfunc:
morestack = "runtime.morestackc"
case ctxt.Cursym.Text.From3Offset()&obj.NEEDCTXT == 0:
morestack = "runtime.morestack_noctxt"
}
call.To.Sym = obj.Linklookup(ctxt, morestack, 0)
// When compiling 386 code for dynamic linking, the call needs to be adjusted
// to follow PIC rules. This in turn can insert more instructions, so we need
// to keep track of the start of the call (where the jump will be to) and the
// end (which following instructions are appended to).
callend := call
progedit(ctxt, callend)
for ; callend.Link != nil; callend = callend.Link {
progedit(ctxt, callend.Link)
}
jmp := obj.Appendp(ctxt, callend)
jmp.As = obj.AJMP
jmp.To.Type = obj.TYPE_BRANCH
jmp.Pcond = ctxt.Cursym.Text.Link
jmp.Spadj = +framesize
jls.Pcond = call
if q1 != nil {
q1.Pcond = call
}
return jls
}
func follow(ctxt *obj.Link, s *obj.LSym) {
ctxt.Cursym = s
firstp := ctxt.NewProg()
lastp := firstp
xfol(ctxt, s.Text, &lastp)
lastp.Link = nil
s.Text = firstp.Link
}
func nofollow(a obj.As) bool {
switch a {
case obj.AJMP,
obj.ARET,
AIRETL,
AIRETQ,
AIRETW,
ARETFL,
ARETFQ,
ARETFW,
obj.AUNDEF:
return true
}
return false
}
func pushpop(a obj.As) bool {
switch a {
case APUSHL,
APUSHFL,
APUSHQ,
APUSHFQ,
APUSHW,
APUSHFW,
APOPL,
APOPFL,
APOPQ,
APOPFQ,
APOPW,
APOPFW:
return true
}
return false
}
func relinv(a obj.As) obj.As {
switch a {
case AJEQ:
return AJNE
case AJNE:
return AJEQ
case AJLE:
return AJGT
case AJLS:
return AJHI
case AJLT:
return AJGE
case AJMI:
return AJPL
case AJGE:
return AJLT
case AJPL:
return AJMI
case AJGT:
return AJLE
case AJHI:
return AJLS
case AJCS:
return AJCC
case AJCC:
return AJCS
case AJPS:
return AJPC
case AJPC:
return AJPS
case AJOS:
return AJOC
case AJOC:
return AJOS
}
log.Fatalf("unknown relation: %s", obj.Aconv(a))
return 0
}
func xfol(ctxt *obj.Link, p *obj.Prog, last **obj.Prog) {
var q *obj.Prog
var i int
var a obj.As
loop:
if p == nil {
return
}
if p.As == obj.AJMP {
q = p.Pcond
if q != nil && q.As != obj.ATEXT {
/* mark instruction as done and continue layout at target of jump */
p.Mark |= DONE
p = q
if p.Mark&DONE == 0 {
goto loop
}
}
}
if p.Mark&DONE != 0 {
/*
* p goes here, but already used it elsewhere.
* copy up to 4 instructions or else branch to other copy.
*/
i = 0
q = p
for ; i < 4; i, q = i+1, q.Link {
if q == nil {
break
}
if q == *last {
break
}
a = q.As
if a == obj.ANOP {
i--
continue
}
if nofollow(a) || pushpop(a) {
break // NOTE(rsc): arm does goto copy
}
if q.Pcond == nil || q.Pcond.Mark&DONE != 0 {
continue
}
if a == obj.ACALL || a == ALOOP {
continue
}
for {
if p.As == obj.ANOP {
p = p.Link
continue
}
q = obj.Copyp(ctxt, p)
p = p.Link
q.Mark |= DONE
(*last).Link = q
*last = q
if q.As != a || q.Pcond == nil || q.Pcond.Mark&DONE != 0 {
continue
}
q.As = relinv(q.As)
p = q.Pcond
q.Pcond = q.Link
q.Link = p
xfol(ctxt, q.Link, last)
p = q.Link
if p.Mark&DONE != 0 {
return
}
goto loop
/* */
}
}
q = ctxt.NewProg()
q.As = obj.AJMP
q.Lineno = p.Lineno
q.To.Type = obj.TYPE_BRANCH
q.To.Offset = p.Pc
q.Pcond = p
p = q
}
/* emit p */
p.Mark |= DONE
(*last).Link = p
*last = p
a = p.As
/* continue loop with what comes after p */
if nofollow(a) {
return
}
if p.Pcond != nil && a != obj.ACALL {
/*
* some kind of conditional branch.
* recurse to follow one path.
* continue loop on the other.
*/
q = obj.Brchain(ctxt, p.Pcond)
if q != nil {
p.Pcond = q
}
q = obj.Brchain(ctxt, p.Link)
if q != nil {
p.Link = q
}
if p.From.Type == obj.TYPE_CONST {
if p.From.Offset == 1 {
/*
* expect conditional jump to be taken.
* rewrite so that's the fall-through case.
*/
p.As = relinv(a)
q = p.Link
p.Link = p.Pcond
p.Pcond = q
}
} else {
q = p.Link
if q.Mark&DONE != 0 {
if a != ALOOP {
p.As = relinv(a)
p.Link = p.Pcond
p.Pcond = q
}
}
}
xfol(ctxt, p.Link, last)
if p.Pcond.Mark&DONE != 0 {
return
}
p = p.Pcond
goto loop
}
p = p.Link
goto loop
}
var unaryDst = map[obj.As]bool{
ABSWAPL: true,
ABSWAPQ: true,
ACMPXCHG8B: true,
ADECB: true,
ADECL: true,
ADECQ: true,
ADECW: true,
AINCB: true,
AINCL: true,
AINCQ: true,
AINCW: true,
ANEGB: true,
ANEGL: true,
ANEGQ: true,
ANEGW: true,
ANOTB: true,
ANOTL: true,
ANOTQ: true,
ANOTW: true,
APOPL: true,
APOPQ: true,
APOPW: true,
ASETCC: true,
ASETCS: true,
ASETEQ: true,
ASETGE: true,
ASETGT: true,
ASETHI: true,
ASETLE: true,
ASETLS: true,
ASETLT: true,
ASETMI: true,
ASETNE: true,
ASETOC: true,
ASETOS: true,
ASETPC: true,
ASETPL: true,
ASETPS: true,
AFFREE: true,
AFLDENV: true,
AFSAVE: true,
AFSTCW: true,
AFSTENV: true,
AFSTSW: true,
AFXSAVE: true,
AFXSAVE64: true,
ASTMXCSR: true,
}
var Linkamd64 = obj.LinkArch{
Arch: sys.ArchAMD64,
Preprocess: preprocess,
Assemble: span6,
Follow: follow,
Progedit: progedit,
UnaryDst: unaryDst,
}
var Linkamd64p32 = obj.LinkArch{
Arch: sys.ArchAMD64P32,
Preprocess: preprocess,
Assemble: span6,
Follow: follow,
Progedit: progedit,
UnaryDst: unaryDst,
}
var Link386 = obj.LinkArch{
Arch: sys.Arch386,
Preprocess: preprocess,
Assemble: span6,
Follow: follow,
Progedit: progedit,
UnaryDst: unaryDst,
}
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 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
}
/*
* return
* 1 if v only used (and substitute),
* 2 if read-alter-rewrite
* 3 if set
* 4 if set and used
* 0 otherwise (not touched)
*/
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
switch p.As {
default:
fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
return 2
case arm.AMOVM:
if v.Type != obj.TYPE_REG {
return 0
}
if p.From.Type == obj.TYPE_CONST { /* read reglist, read/rar */
if s != nil {
if p.From.Offset&(1<<uint(v.Reg)) != 0 {
return 1
}
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
if p.Scond&arm.C_WBIT != 0 {
return 2
}
return 1
}
if p.From.Offset&(1<<uint(v.Reg)) != 0 {
return 1 /* read/rar, write reglist */
}
} else {
if s != nil {
if p.To.Offset&(1<<uint(v.Reg)) != 0 {
return 1
}
if copysub(&p.From, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
if p.Scond&arm.C_WBIT != 0 {
return 2
}
if p.To.Offset&(1<<uint(v.Reg)) != 0 {
return 4
}
return 1
}
if p.To.Offset&(1<<uint(v.Reg)) != 0 {
return 3
}
}
return 0
case obj.ANOP, /* read,, write */
arm.ASQRTD,
arm.AMOVW,
arm.AMOVF,
arm.AMOVD,
arm.AMOVH,
arm.AMOVHS,
arm.AMOVHU,
arm.AMOVB,
arm.AMOVBS,
arm.AMOVBU,
arm.AMOVFW,
arm.AMOVWF,
arm.AMOVDW,
arm.AMOVWD,
arm.AMOVFD,
arm.AMOVDF:
if p.Scond&(arm.C_WBIT|arm.C_PBIT) != 0 {
if v.Type == obj.TYPE_REG {
if p.From.Type == obj.TYPE_MEM || p.From.Type == obj.TYPE_SHIFT {
if p.From.Reg == v.Reg {
return 2
}
} else {
if p.To.Reg == v.Reg {
return 2
}
}
}
}
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
if p.Scond != arm.C_SCOND_NONE {
return 2
}
if copyau(&p.From, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau(&p.To, v) {
return 1
}
return 0
case arm.AMULLU, /* read, read, write, write */
arm.AMULL,
arm.AMULA,
arm.AMVN:
return 2
case arm.AADD, /* read, read, write */
arm.AADC,
arm.ASUB,
arm.ASBC,
arm.ARSB,
arm.ASLL,
arm.ASRL,
arm.ASRA,
arm.AORR,
arm.AAND,
arm.AEOR,
arm.AMUL,
arm.AMULU,
arm.ADIV,
arm.ADIVU,
arm.AMOD,
arm.AMODU,
arm.AADDF,
arm.AADDD,
arm.ASUBF,
arm.ASUBD,
arm.AMULF,
arm.AMULD,
arm.ADIVF,
arm.ADIVD,
obj.ACHECKNIL,
/* read */
arm.ACMPF, /* read, read, */
arm.ACMPD,
arm.ACMP,
arm.ACMN,
arm.ATST:
/* read,, */
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
if !copyas(&p.To, v) {
if copysub(&p.To, v, s, true) {
return 1
}
}
return 0
}
if copyas(&p.To, v) {
if p.Scond != arm.C_SCOND_NONE {
return 2
}
if p.Reg == 0 {
p.Reg = p.To.Reg
}
if copyau(&p.From, v) {
return 4
}
if copyau1(p, v) {
return 4
}
return 3
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
if copyau(&p.To, v) {
return 1
}
return 0
case arm.ABEQ, /* read, read */
arm.ABNE,
arm.ABCS,
arm.ABHS,
arm.ABCC,
arm.ABLO,
arm.ABMI,
arm.ABPL,
arm.ABVS,
arm.ABVC,
arm.ABHI,
arm.ABLS,
arm.ABGE,
arm.ABLT,
arm.ABGT,
arm.ABLE:
if s != nil {
if copysub(&p.From, v, s, true) {
return 1
}
if copysub1(p, v, s, true) {
return 1
}
return 0
}
if copyau(&p.From, v) {
return 1
}
if copyau1(p, v) {
return 1
}
return 0
case arm.AB: /* funny */
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 1
}
return 0
case obj.ARET: /* funny */
if s != nil {
return 1
}
return 3
case arm.ABL: /* funny */
if v.Type == obj.TYPE_REG {
// TODO(rsc): REG_R0 and REG_F0 used to be
// (when register numbers started at 0) exregoffset and exfregoffset,
// which are unset entirely.
// It's strange that this handles R0 and F0 differently from the other
// registers. Possible failure to optimize?
if arm.REG_R0 < v.Reg && v.Reg <= arm.REGEXT {
return 2
}
if v.Reg == arm.REGARG {
return 2
}
if arm.REG_F0 < v.Reg && v.Reg <= arm.FREGEXT {
return 2
}
}
if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
return 2
}
if s != nil {
if copysub(&p.To, v, s, true) {
return 1
}
return 0
}
if copyau(&p.To, v) {
return 4
}
return 3
// R0 is zero, used by DUFFZERO, cannot be substituted.
// R1 is ptr to memory, used and set, cannot be substituted.
case obj.ADUFFZERO:
if v.Type == obj.TYPE_REG {
if v.Reg == arm.REG_R0 {
return 1
}
if v.Reg == arm.REG_R0+1 {
return 2
}
}
return 0
// R0 is scratch, set by DUFFCOPY, cannot be substituted.
// R1, R2 areptr to src, dst, used and set, cannot be substituted.
case obj.ADUFFCOPY:
if v.Type == obj.TYPE_REG {
if v.Reg == arm.REG_R0 {
return 3
}
if v.Reg == arm.REG_R0+1 || v.Reg == arm.REG_R0+2 {
return 2
}
}
return 0
case obj.ATEXT: /* funny */
if v.Type == obj.TYPE_REG {
if v.Reg == arm.REGARG {
return 3
}
}
return 0
case obj.APCDATA,
obj.AFUNCDATA,
obj.AVARDEF,
obj.AVARKILL,
obj.AVARLIVE,
obj.AUSEFIELD:
return 0
}
}
