/*
* generate:
* res = &n;
* The generated code checks that the result is not nil.
*/
func agen(n *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("\nagen-res", res)
gc.Dump("agen-r", n)
}
if n == nil || n.Type == nil {
return
}
for n.Op == gc.OCONVNOP {
n = n.Left
}
if gc.Isconst(n, gc.CTNIL) && n.Type.Width > int64(gc.Widthptr) {
// Use of a nil interface or nil slice.
// Create a temporary we can take the address of and read.
// The generated code is just going to panic, so it need not
// be terribly efficient. See issue 3670.
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Gvardef(&n1)
clearfat(&n1)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], res)
var n3 gc.Node
n3.Op = gc.OADDR
n3.Left = &n1
gins(ppc64.AMOVD, &n3, &n2)
gmove(&n2, res)
regfree(&n2)
return
}
if n.Addable != 0 {
var n1 gc.Node
n1.Op = gc.OADDR
n1.Left = n
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], res)
gins(ppc64.AMOVD, &n1, &n2)
gmove(&n2, res)
regfree(&n2)
return
}
nl := n.Left
switch n.Op {
default:
gc.Fatal("agen: unknown op %v", gc.Nconv(n, obj.FmtShort|obj.FmtSign))
// TODO(minux): 5g has this: Release res so that it is available for cgen_call.
// Pick it up again after the call for OCALLMETH and OCALLFUNC.
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
cgen_aret(n, res)
case gc.OCALLINTER:
cgen_callinter(n, res, 0)
cgen_aret(n, res)
case gc.OCALLFUNC:
cgen_call(n, 0)
cgen_aret(n, res)
case gc.OSLICE,
gc.OSLICEARR,
gc.OSLICESTR,
gc.OSLICE3,
gc.OSLICE3ARR:
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_slice(n, &n1)
agen(&n1, res)
case gc.OEFACE:
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_eface(n, &n1)
agen(&n1, res)
case gc.OINDEX:
var n1 gc.Node
agenr(n, &n1, res)
gmove(&n1, res)
regfree(&n1)
// should only get here with names in this func.
case gc.ONAME:
if n.Funcdepth > 0 && n.Funcdepth != gc.Funcdepth {
gc.Dump("bad agen", n)
gc.Fatal("agen: bad ONAME funcdepth %d != %d", n.Funcdepth, gc.Funcdepth)
}
// should only get here for heap vars or paramref
if n.Class&gc.PHEAP == 0 && n.Class != gc.PPARAMREF {
gc.Dump("bad agen", n)
gc.Fatal("agen: bad ONAME class %#x", n.Class)
}
cgen(n.Heapaddr, res)
if n.Xoffset != 0 {
ginsadd(optoas(gc.OADD, gc.Types[gc.Tptr]), n.Xoffset, res)
}
case gc.OIND:
cgen(nl, res)
gc.Cgen_checknil(res)
case gc.ODOT:
agen(nl, res)
if n.Xoffset != 0 {
ginsadd(optoas(gc.OADD, gc.Types[gc.Tptr]), n.Xoffset, res)
}
case gc.ODOTPTR:
cgen(nl, res)
gc.Cgen_checknil(res)
if n.Xoffset != 0 {
ginsadd(optoas(gc.OADD, gc.Types[gc.Tptr]), n.Xoffset, res)
}
}
}
func stackcopy(n, ns *gc.Node, osrc, odst, w int64) {
var noddi gc.Node
gc.Nodreg(&noddi, gc.Types[gc.Tptr], x86.REG_DI)
var nodsi gc.Node
gc.Nodreg(&nodsi, gc.Types[gc.Tptr], x86.REG_SI)
var nodl gc.Node
var nodr gc.Node
if n.Ullman >= ns.Ullman {
gc.Agenr(n, &nodr, &nodsi)
if ns.Op == gc.ONAME {
gc.Gvardef(ns)
}
gc.Agenr(ns, &nodl, &noddi)
} else {
if ns.Op == gc.ONAME {
gc.Gvardef(ns)
}
gc.Agenr(ns, &nodl, &noddi)
gc.Agenr(n, &nodr, &nodsi)
}
if nodl.Val.U.Reg != x86.REG_DI {
gmove(&nodl, &noddi)
}
if nodr.Val.U.Reg != x86.REG_SI {
gmove(&nodr, &nodsi)
}
gc.Regfree(&nodl)
gc.Regfree(&nodr)
c := w % 8 // bytes
q := w / 8 // quads
var oldcx gc.Node
var cx gc.Node
savex(x86.REG_CX, &cx, &oldcx, nil, gc.Types[gc.TINT64])
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
if osrc < odst && odst < osrc+w {
// reverse direction
gins(x86.ASTD, nil, nil) // set direction flag
if c > 0 {
gconreg(addptr, w-1, x86.REG_SI)
gconreg(addptr, w-1, x86.REG_DI)
gconreg(movptr, c, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)-,*(DI)-
}
if q > 0 {
if c > 0 {
gconreg(addptr, -7, x86.REG_SI)
gconreg(addptr, -7, x86.REG_DI)
} else {
gconreg(addptr, w-8, x86.REG_SI)
gconreg(addptr, w-8, x86.REG_DI)
}
gconreg(movptr, q, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSQ, nil, nil) // MOVQ *(SI)-,*(DI)-
}
// we leave with the flag clear
gins(x86.ACLD, nil, nil)
} else {
// normal direction
if q > 128 || (gc.Nacl && q >= 4) {
gconreg(movptr, q, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSQ, nil, nil) // MOVQ *(SI)+,*(DI)+
} else if q >= 4 {
p := gins(obj.ADUFFCOPY, nil, nil)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffcopy", gc.Runtimepkg))
// 14 and 128 = magic constants: see ../../runtime/asm_amd64.s
p.To.Offset = 14 * (128 - q)
} else if !gc.Nacl && c == 0 {
// We don't need the MOVSQ side-effect of updating SI and DI,
// and issuing a sequence of MOVQs directly is faster.
nodsi.Op = gc.OINDREG
noddi.Op = gc.OINDREG
for q > 0 {
gmove(&nodsi, &cx) // MOVQ x+(SI),CX
gmove(&cx, &noddi) // MOVQ CX,x+(DI)
nodsi.Xoffset += 8
noddi.Xoffset += 8
q--
}
} else {
for q > 0 {
gins(x86.AMOVSQ, nil, nil) // MOVQ *(SI)+,*(DI)+
q--
}
}
// copy the remaining c bytes
if w < 4 || c <= 1 || (odst < osrc && osrc < odst+w) {
for c > 0 {
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)+,*(DI)+
c--
}
} else if w < 8 || c <= 4 {
nodsi.Op = gc.OINDREG
noddi.Op = gc.OINDREG
cx.Type = gc.Types[gc.TINT32]
nodsi.Type = gc.Types[gc.TINT32]
noddi.Type = gc.Types[gc.TINT32]
if c > 4 {
nodsi.Xoffset = 0
noddi.Xoffset = 0
gmove(&nodsi, &cx)
gmove(&cx, &noddi)
}
nodsi.Xoffset = c - 4
noddi.Xoffset = c - 4
gmove(&nodsi, &cx)
gmove(&cx, &noddi)
} else {
nodsi.Op = gc.OINDREG
noddi.Op = gc.OINDREG
cx.Type = gc.Types[gc.TINT64]
nodsi.Type = gc.Types[gc.TINT64]
noddi.Type = gc.Types[gc.TINT64]
nodsi.Xoffset = c - 8
noddi.Xoffset = c - 8
gmove(&nodsi, &cx)
gmove(&cx, &noddi)
}
}
restx(&cx, &oldcx)
}
/*
* block copy:
* memmove(&ns, &n, w);
*/
func sgen(n *gc.Node, ns *gc.Node, w int64) {
var res *gc.Node = ns
if gc.Debug['g'] != 0 {
fmt.Printf("\nsgen w=%d\n", w)
gc.Dump("r", n)
gc.Dump("res", ns)
}
if n.Ullman >= gc.UINF && ns.Ullman >= gc.UINF {
gc.Fatal("sgen UINF")
}
if w < 0 {
gc.Fatal("sgen copy %d", w)
}
// If copying .args, that's all the results, so record definition sites
// for them for the liveness analysis.
if ns.Op == gc.ONAME && ns.Sym.Name == ".args" {
for l := gc.Curfn.Dcl; l != nil; l = l.Next {
if l.N.Class == gc.PPARAMOUT {
gc.Gvardef(l.N)
}
}
}
// Avoid taking the address for simple enough types.
//if(componentgen(n, ns))
// return;
if w == 0 {
// evaluate side effects only.
var dst gc.Node
regalloc(&dst, gc.Types[gc.Tptr], nil)
agen(res, &dst)
agen(n, &dst)
regfree(&dst)
return
}
// determine alignment.
// want to avoid unaligned access, so have to use
// smaller operations for less aligned types.
// for example moving [4]byte must use 4 MOVB not 1 MOVW.
align := int(n.Type.Align)
var op int
switch align {
default:
gc.Fatal("sgen: invalid alignment %d for %v", align, gc.Tconv(n.Type, 0))
case 1:
op = ppc64.AMOVBU
case 2:
op = ppc64.AMOVHU
case 4:
op = ppc64.AMOVWZU // there is no lwau, only lwaux
case 8:
op = ppc64.AMOVDU
}
if w%int64(align) != 0 {
gc.Fatal("sgen: unaligned size %d (align=%d) for %v", w, align, gc.Tconv(n.Type, 0))
}
c := int32(w / int64(align))
// offset on the stack
osrc := int32(stkof(n))
odst := int32(stkof(res))
if osrc != -1000 && odst != -1000 && (osrc == 1000 || odst == 1000) {
// osrc and odst both on stack, and at least one is in
// an unknown position. Could generate code to test
// for forward/backward copy, but instead just copy
// to a temporary location first.
var tmp gc.Node
gc.Tempname(&tmp, n.Type)
sgen(n, &tmp, w)
sgen(&tmp, res, w)
return
}
if osrc%int32(align) != 0 || odst%int32(align) != 0 {
gc.Fatal("sgen: unaligned offset src %d or dst %d (align %d)", osrc, odst, align)
}
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
dir := align
if osrc < odst && int64(odst) < int64(osrc)+w {
dir = -dir
}
var dst gc.Node
var src gc.Node
if n.Ullman >= res.Ullman {
agenr(n, &dst, res) // temporarily use dst
regalloc(&src, gc.Types[gc.Tptr], nil)
gins(ppc64.AMOVD, &dst, &src)
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
agen(res, &dst)
} else {
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
agenr(res, &dst, res)
agenr(n, &src, nil)
}
var tmp gc.Node
regalloc(&tmp, gc.Types[gc.Tptr], nil)
// set up end marker
var nend gc.Node
// move src and dest to the end of block if necessary
if dir < 0 {
if c >= 4 {
regalloc(&nend, gc.Types[gc.Tptr], nil)
gins(ppc64.AMOVD, &src, &nend)
}
p := gins(ppc64.AADD, nil, &src)
p.From.Type = obj.TYPE_CONST
p.From.Offset = w
p = gins(ppc64.AADD, nil, &dst)
p.From.Type = obj.TYPE_CONST
p.From.Offset = w
} else {
p := gins(ppc64.AADD, nil, &src)
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(-dir)
p = gins(ppc64.AADD, nil, &dst)
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(-dir)
if c >= 4 {
regalloc(&nend, gc.Types[gc.Tptr], nil)
p := gins(ppc64.AMOVD, &src, &nend)
p.From.Type = obj.TYPE_ADDR
p.From.Offset = w
}
}
// move
// TODO: enable duffcopy for larger copies.
if c >= 4 {
p := gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
ploop := p
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
p = gins(ppc64.ACMP, &src, &nend)
gc.Patch(gc.Gbranch(ppc64.ABNE, nil, 0), ploop)
regfree(&nend)
} else {
// TODO(austin): Instead of generating ADD $-8,R8; ADD
// $-8,R7; n*(MOVDU 8(R8),R9; MOVDU R9,8(R7);) just
// generate the offsets directly and eliminate the
// ADDs. That will produce shorter, more
// pipeline-able code.
var p *obj.Prog
for {
tmp14 := c
c--
if tmp14 <= 0 {
break
}
p = gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
}
}
regfree(&dst)
regfree(&src)
regfree(&tmp)
}
/*
* copy a composite value by moving its individual components.
* Slices, strings and interfaces are supported.
* Small structs or arrays with elements of basic type are
* also supported.
* nr is N when assigning a zero value.
* return 1 if can do, 0 if can't.
*/
func componentgen(nr *gc.Node, nl *gc.Node) bool {
var nodl gc.Node
var nodr gc.Node
freel := 0
freer := 0
switch nl.Type.Etype {
default:
goto no
case gc.TARRAY:
t := nl.Type
// Slices are ok.
if gc.Isslice(t) {
break
}
// Small arrays are ok.
if t.Bound > 0 && t.Bound <= 3 && !gc.Isfat(t.Type) {
break
}
goto no
// Small structs with non-fat types are ok.
// Zero-sized structs are treated separately elsewhere.
case gc.TSTRUCT:
fldcount := int64(0)
for t := nl.Type.Type; t != nil; t = t.Down {
if gc.Isfat(t.Type) {
goto no
}
if t.Etype != gc.TFIELD {
gc.Fatal("componentgen: not a TFIELD: %v", gc.Tconv(t, obj.FmtLong))
}
fldcount++
}
if fldcount == 0 || fldcount > 4 {
goto no
}
case gc.TSTRING,
gc.TINTER:
break
}
nodl = *nl
if !cadable(nl) {
if nr != nil && !cadable(nr) {
goto no
}
igen(nl, &nodl, nil)
freel = 1
}
if nr != nil {
nodr = *nr
if !cadable(nr) {
igen(nr, &nodr, nil)
freer = 1
}
} else {
// When zeroing, prepare a register containing zero.
var tmp gc.Node
gc.Nodconst(&tmp, nl.Type, 0)
regalloc(&nodr, gc.Types[gc.TUINT], nil)
gmove(&tmp, &nodr)
freer = 1
}
// nl and nr are 'cadable' which basically means they are names (variables) now.
// If they are the same variable, don't generate any code, because the
// VARDEF we generate will mark the old value as dead incorrectly.
// (And also the assignments are useless.)
if nr != nil && nl.Op == gc.ONAME && nr.Op == gc.ONAME && nl == nr {
goto yes
}
switch nl.Type.Etype {
// componentgen for arrays.
case gc.TARRAY:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
t := nl.Type
if !gc.Isslice(t) {
nodl.Type = t.Type
nodr.Type = nodl.Type
for fldcount := int64(0); fldcount < t.Bound; fldcount++ {
if nr == nil {
gc.Clearslim(&nodl)
} else {
gmove(&nodr, &nodl)
}
nodl.Xoffset += t.Type.Width
nodr.Xoffset += t.Type.Width
}
goto yes
}
// componentgen for slices.
nodl.Xoffset += int64(gc.Array_array)
nodl.Type = gc.Ptrto(nl.Type.Type)
if nr != nil {
nodr.Xoffset += int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodl.Type = gc.Types[gc.Simtype[gc.TUINT]]
if nr != nil {
nodr.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_cap) - int64(gc.Array_nel)
nodl.Type = gc.Types[gc.Simtype[gc.TUINT]]
if nr != nil {
nodr.Xoffset += int64(gc.Array_cap) - int64(gc.Array_nel)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
goto yes
case gc.TSTRING:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
nodl.Xoffset += int64(gc.Array_array)
nodl.Type = gc.Ptrto(gc.Types[gc.TUINT8])
if nr != nil {
nodr.Xoffset += int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodl.Type = gc.Types[gc.Simtype[gc.TUINT]]
if nr != nil {
nodr.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
goto yes
case gc.TINTER:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
nodl.Xoffset += int64(gc.Array_array)
nodl.Type = gc.Ptrto(gc.Types[gc.TUINT8])
if nr != nil {
nodr.Xoffset += int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodl.Type = gc.Ptrto(gc.Types[gc.TUINT8])
if nr != nil {
nodr.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
goto yes
case gc.TSTRUCT:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
loffset := nodl.Xoffset
roffset := nodr.Xoffset
// funarg structs may not begin at offset zero.
if nl.Type.Etype == gc.TSTRUCT && nl.Type.Funarg != 0 && nl.Type.Type != nil {
loffset -= nl.Type.Type.Width
}
if nr != nil && nr.Type.Etype == gc.TSTRUCT && nr.Type.Funarg != 0 && nr.Type.Type != nil {
roffset -= nr.Type.Type.Width
}
for t := nl.Type.Type; t != nil; t = t.Down {
nodl.Xoffset = loffset + t.Width
nodl.Type = t.Type
if nr == nil {
gc.Clearslim(&nodl)
} else {
nodr.Xoffset = roffset + t.Width
nodr.Type = nodl.Type
gmove(&nodr, &nodl)
}
}
goto yes
}
no:
if freer != 0 {
regfree(&nodr)
}
if freel != 0 {
regfree(&nodl)
}
return false
yes:
if freer != 0 {
regfree(&nodr)
}
if freel != 0 {
regfree(&nodl)
}
return true
}
func blockcopy(n, res *gc.Node, osrc, odst, w int64) {
// determine alignment.
// want to avoid unaligned access, so have to use
// smaller operations for less aligned types.
// for example moving [4]byte must use 4 MOVB not 1 MOVW.
align := int(n.Type.Align)
var op int
switch align {
default:
gc.Fatal("sgen: invalid alignment %d for %v", align, n.Type)
case 1:
op = ppc64.AMOVBU
case 2:
op = ppc64.AMOVHU
case 4:
op = ppc64.AMOVWZU // there is no lwau, only lwaux
case 8:
op = ppc64.AMOVDU
}
if w%int64(align) != 0 {
gc.Fatal("sgen: unaligned size %d (align=%d) for %v", w, align, n.Type)
}
c := int32(w / int64(align))
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
dir := align
if osrc < odst && int64(odst) < int64(osrc)+w {
dir = -dir
}
var dst gc.Node
var src gc.Node
if n.Ullman >= res.Ullman {
gc.Agenr(n, &dst, res) // temporarily use dst
gc.Regalloc(&src, gc.Types[gc.Tptr], nil)
gins(ppc64.AMOVD, &dst, &src)
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
gc.Agen(res, &dst)
} else {
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
gc.Agenr(res, &dst, res)
gc.Agenr(n, &src, nil)
}
var tmp gc.Node
gc.Regalloc(&tmp, gc.Types[gc.Tptr], nil)
// set up end marker
var nend gc.Node
// move src and dest to the end of block if necessary
if dir < 0 {
if c >= 4 {
gc.Regalloc(&nend, gc.Types[gc.Tptr], nil)
gins(ppc64.AMOVD, &src, &nend)
}
p := gins(ppc64.AADD, nil, &src)
p.From.Type = obj.TYPE_CONST
p.From.Offset = w
p = gins(ppc64.AADD, nil, &dst)
p.From.Type = obj.TYPE_CONST
p.From.Offset = w
} else {
p := gins(ppc64.AADD, nil, &src)
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(-dir)
p = gins(ppc64.AADD, nil, &dst)
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(-dir)
if c >= 4 {
gc.Regalloc(&nend, gc.Types[gc.Tptr], nil)
p := gins(ppc64.AMOVD, &src, &nend)
p.From.Type = obj.TYPE_ADDR
p.From.Offset = w
}
}
// move
// TODO: enable duffcopy for larger copies.
if c >= 4 {
p := gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
ploop := p
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
p = gins(ppc64.ACMP, &src, &nend)
gc.Patch(gc.Gbranch(ppc64.ABNE, nil, 0), ploop)
gc.Regfree(&nend)
} else {
// TODO(austin): Instead of generating ADD $-8,R8; ADD
// $-8,R7; n*(MOVDU 8(R8),R9; MOVDU R9,8(R7);) just
// generate the offsets directly and eliminate the
// ADDs. That will produce shorter, more
// pipeline-able code.
var p *obj.Prog
for {
tmp14 := c
c--
if tmp14 <= 0 {
break
}
p = gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
}
}
gc.Regfree(&dst)
gc.Regfree(&src)
gc.Regfree(&tmp)
}
func stackcopy(n, res *gc.Node, osrc, odst, w int64) {
var dst gc.Node
gc.Nodreg(&dst, gc.Types[gc.Tptr], x86.REG_DI)
var src gc.Node
gc.Nodreg(&src, gc.Types[gc.Tptr], x86.REG_SI)
var tsrc gc.Node
gc.Tempname(&tsrc, gc.Types[gc.Tptr])
var tdst gc.Node
gc.Tempname(&tdst, gc.Types[gc.Tptr])
if n.Addable == 0 {
gc.Agen(n, &tsrc)
}
if res.Addable == 0 {
gc.Agen(res, &tdst)
}
if n.Addable != 0 {
gc.Agen(n, &src)
} else {
gmove(&tsrc, &src)
}
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
if res.Addable != 0 {
gc.Agen(res, &dst)
} else {
gmove(&tdst, &dst)
}
c := int32(w % 4) // bytes
q := int32(w / 4) // doublewords
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
if osrc < odst && int64(odst) < int64(osrc)+w {
// reverse direction
gins(x86.ASTD, nil, nil) // set direction flag
if c > 0 {
gconreg(x86.AADDL, w-1, x86.REG_SI)
gconreg(x86.AADDL, w-1, x86.REG_DI)
gconreg(x86.AMOVL, int64(c), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)-,*(DI)-
}
if q > 0 {
if c > 0 {
gconreg(x86.AADDL, -3, x86.REG_SI)
gconreg(x86.AADDL, -3, x86.REG_DI)
} else {
gconreg(x86.AADDL, w-4, x86.REG_SI)
gconreg(x86.AADDL, w-4, x86.REG_DI)
}
gconreg(x86.AMOVL, int64(q), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSL, nil, nil) // MOVL *(SI)-,*(DI)-
}
// we leave with the flag clear
gins(x86.ACLD, nil, nil)
} else {
gins(x86.ACLD, nil, nil) // paranoia. TODO(rsc): remove?
// normal direction
if q > 128 || (q >= 4 && gc.Nacl) {
gconreg(x86.AMOVL, int64(q), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSL, nil, nil) // MOVL *(SI)+,*(DI)+
} else if q >= 4 {
p := gins(obj.ADUFFCOPY, nil, nil)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffcopy", gc.Runtimepkg))
// 10 and 128 = magic constants: see ../../runtime/asm_386.s
p.To.Offset = 10 * (128 - int64(q))
} else if !gc.Nacl && c == 0 {
var cx gc.Node
gc.Nodreg(&cx, gc.Types[gc.TINT32], x86.REG_CX)
// We don't need the MOVSL side-effect of updating SI and DI,
// and issuing a sequence of MOVLs directly is faster.
src.Op = gc.OINDREG
dst.Op = gc.OINDREG
for q > 0 {
gmove(&src, &cx) // MOVL x+(SI),CX
gmove(&cx, &dst) // MOVL CX,x+(DI)
src.Xoffset += 4
dst.Xoffset += 4
q--
}
} else {
for q > 0 {
gins(x86.AMOVSL, nil, nil) // MOVL *(SI)+,*(DI)+
q--
}
}
for c > 0 {
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)+,*(DI)+
c--
}
}
}
func blockcopy(n, res *gc.Node, osrc, odst, w int64) {
// determine alignment.
// want to avoid unaligned access, so have to use
// smaller operations for less aligned types.
// for example moving [4]byte must use 4 MOVB not 1 MOVW.
align := int(n.Type.Align)
var op int
switch align {
default:
gc.Fatal("sgen: invalid alignment %d for %v", align, n.Type)
case 1:
op = arm.AMOVB
case 2:
op = arm.AMOVH
case 4:
op = arm.AMOVW
}
if w%int64(align) != 0 {
gc.Fatal("sgen: unaligned size %d (align=%d) for %v", w, align, n.Type)
}
c := int32(w / int64(align))
if osrc%int64(align) != 0 || odst%int64(align) != 0 {
gc.Fatal("sgen: unaligned offset src %d or dst %d (align %d)", osrc, odst, align)
}
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
dir := align
if osrc < odst && int64(odst) < int64(osrc)+w {
dir = -dir
}
if op == arm.AMOVW && !gc.Nacl && dir > 0 && c >= 4 && c <= 128 {
var r0 gc.Node
r0.Op = gc.OREGISTER
r0.Reg = arm.REG_R0
var r1 gc.Node
r1.Op = gc.OREGISTER
r1.Reg = arm.REG_R0 + 1
var r2 gc.Node
r2.Op = gc.OREGISTER
r2.Reg = arm.REG_R0 + 2
var src gc.Node
gc.Regalloc(&src, gc.Types[gc.Tptr], &r1)
var dst gc.Node
gc.Regalloc(&dst, gc.Types[gc.Tptr], &r2)
if n.Ullman >= res.Ullman {
// eval n first
gc.Agen(n, &src)
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
gc.Agen(res, &dst)
} else {
// eval res first
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
gc.Agen(res, &dst)
gc.Agen(n, &src)
}
var tmp gc.Node
gc.Regalloc(&tmp, gc.Types[gc.Tptr], &r0)
f := gc.Sysfunc("duffcopy")
p := gins(obj.ADUFFCOPY, nil, f)
gc.Afunclit(&p.To, f)
// 8 and 128 = magic constants: see ../../runtime/asm_arm.s
p.To.Offset = 8 * (128 - int64(c))
gc.Regfree(&tmp)
gc.Regfree(&src)
gc.Regfree(&dst)
return
}
var dst gc.Node
var src gc.Node
if n.Ullman >= res.Ullman {
gc.Agenr(n, &dst, res) // temporarily use dst
gc.Regalloc(&src, gc.Types[gc.Tptr], nil)
gins(arm.AMOVW, &dst, &src)
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
gc.Agen(res, &dst)
} else {
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
gc.Agenr(res, &dst, res)
gc.Agenr(n, &src, nil)
}
var tmp gc.Node
gc.Regalloc(&tmp, gc.Types[gc.TUINT32], nil)
// set up end marker
var nend gc.Node
if c >= 4 {
gc.Regalloc(&nend, gc.Types[gc.TUINT32], nil)
p := gins(arm.AMOVW, &src, &nend)
p.From.Type = obj.TYPE_ADDR
if dir < 0 {
p.From.Offset = int64(dir)
} else {
p.From.Offset = w
}
}
// move src and dest to the end of block if necessary
if dir < 0 {
p := gins(arm.AMOVW, &src, &src)
p.From.Type = obj.TYPE_ADDR
p.From.Offset = w + int64(dir)
p = gins(arm.AMOVW, &dst, &dst)
p.From.Type = obj.TYPE_ADDR
p.From.Offset = w + int64(dir)
}
// move
if c >= 4 {
p := gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
p.Scond |= arm.C_PBIT
ploop := p
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
p.Scond |= arm.C_PBIT
p = gins(arm.ACMP, &src, nil)
raddr(&nend, p)
gc.Patch(gc.Gbranch(arm.ABNE, nil, 0), ploop)
gc.Regfree(&nend)
} else {
var p *obj.Prog
for {
tmp14 := c
c--
if tmp14 <= 0 {
break
}
p = gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
p.Scond |= arm.C_PBIT
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
p.Scond |= arm.C_PBIT
}
}
gc.Regfree(&dst)
gc.Regfree(&src)
gc.Regfree(&tmp)
}
/*
* block copy:
* memmove(&ns, &n, w);
*/
func sgen(n *gc.Node, ns *gc.Node, w int64) {
if gc.Debug['g'] != 0 {
fmt.Printf("\nsgen w=%d\n", w)
gc.Dump("r", n)
gc.Dump("res", ns)
}
if n.Ullman >= gc.UINF && ns.Ullman >= gc.UINF {
gc.Fatal("sgen UINF")
}
if w < 0 {
gc.Fatal("sgen copy %d", w)
}
// If copying .args, that's all the results, so record definition sites
// for them for the liveness analysis.
if ns.Op == gc.ONAME && ns.Sym.Name == ".args" {
for l := gc.Curfn.Dcl; l != nil; l = l.Next {
if l.N.Class == gc.PPARAMOUT {
gc.Gvardef(l.N)
}
}
}
// Avoid taking the address for simple enough types.
if componentgen(n, ns) {
return
}
if w == 0 {
// evaluate side effects only
var nodr gc.Node
regalloc(&nodr, gc.Types[gc.Tptr], nil)
agen(ns, &nodr)
agen(n, &nodr)
regfree(&nodr)
return
}
// offset on the stack
osrc := stkof(n)
odst := stkof(ns)
if osrc != -1000 && odst != -1000 && (osrc == 1000 || odst == 1000) {
// osrc and odst both on stack, and at least one is in
// an unknown position. Could generate code to test
// for forward/backward copy, but instead just copy
// to a temporary location first.
var tmp gc.Node
gc.Tempname(&tmp, n.Type)
sgen(n, &tmp, w)
sgen(&tmp, ns, w)
return
}
var noddi gc.Node
gc.Nodreg(&noddi, gc.Types[gc.Tptr], x86.REG_DI)
var nodsi gc.Node
gc.Nodreg(&nodsi, gc.Types[gc.Tptr], x86.REG_SI)
var nodl gc.Node
var nodr gc.Node
if n.Ullman >= ns.Ullman {
agenr(n, &nodr, &nodsi)
if ns.Op == gc.ONAME {
gc.Gvardef(ns)
}
agenr(ns, &nodl, &noddi)
} else {
if ns.Op == gc.ONAME {
gc.Gvardef(ns)
}
agenr(ns, &nodl, &noddi)
agenr(n, &nodr, &nodsi)
}
if nodl.Val.U.Reg != x86.REG_DI {
gmove(&nodl, &noddi)
}
if nodr.Val.U.Reg != x86.REG_SI {
gmove(&nodr, &nodsi)
}
regfree(&nodl)
regfree(&nodr)
c := w % 8 // bytes
q := w / 8 // quads
var oldcx gc.Node
var cx gc.Node
savex(x86.REG_CX, &cx, &oldcx, nil, gc.Types[gc.TINT64])
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
if osrc < odst && odst < osrc+w {
// reverse direction
gins(x86.ASTD, nil, nil) // set direction flag
if c > 0 {
gconreg(addptr, w-1, x86.REG_SI)
gconreg(addptr, w-1, x86.REG_DI)
gconreg(movptr, c, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)-,*(DI)-
}
if q > 0 {
if c > 0 {
gconreg(addptr, -7, x86.REG_SI)
gconreg(addptr, -7, x86.REG_DI)
} else {
gconreg(addptr, w-8, x86.REG_SI)
gconreg(addptr, w-8, x86.REG_DI)
}
gconreg(movptr, q, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSQ, nil, nil) // MOVQ *(SI)-,*(DI)-
}
// we leave with the flag clear
gins(x86.ACLD, nil, nil)
} else {
// normal direction
if q > 128 || (gc.Nacl && q >= 4) {
gconreg(movptr, q, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSQ, nil, nil) // MOVQ *(SI)+,*(DI)+
} else if q >= 4 {
p := gins(obj.ADUFFCOPY, nil, nil)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffcopy", gc.Runtimepkg))
// 14 and 128 = magic constants: see ../../runtime/asm_amd64.s
p.To.Offset = 14 * (128 - q)
} else if !gc.Nacl && c == 0 {
// We don't need the MOVSQ side-effect of updating SI and DI,
// and issuing a sequence of MOVQs directly is faster.
nodsi.Op = gc.OINDREG
noddi.Op = gc.OINDREG
for q > 0 {
gmove(&nodsi, &cx) // MOVQ x+(SI),CX
gmove(&cx, &noddi) // MOVQ CX,x+(DI)
nodsi.Xoffset += 8
noddi.Xoffset += 8
q--
}
} else {
for q > 0 {
gins(x86.AMOVSQ, nil, nil) // MOVQ *(SI)+,*(DI)+
q--
}
}
// copy the remaining c bytes
if w < 4 || c <= 1 || (odst < osrc && osrc < odst+w) {
for c > 0 {
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)+,*(DI)+
c--
}
} else if w < 8 || c <= 4 {
nodsi.Op = gc.OINDREG
noddi.Op = gc.OINDREG
cx.Type = gc.Types[gc.TINT32]
nodsi.Type = gc.Types[gc.TINT32]
noddi.Type = gc.Types[gc.TINT32]
if c > 4 {
nodsi.Xoffset = 0
noddi.Xoffset = 0
gmove(&nodsi, &cx)
gmove(&cx, &noddi)
}
nodsi.Xoffset = c - 4
noddi.Xoffset = c - 4
gmove(&nodsi, &cx)
gmove(&cx, &noddi)
} else {
nodsi.Op = gc.OINDREG
noddi.Op = gc.OINDREG
cx.Type = gc.Types[gc.TINT64]
nodsi.Type = gc.Types[gc.TINT64]
noddi.Type = gc.Types[gc.TINT64]
nodsi.Xoffset = c - 8
noddi.Xoffset = c - 8
gmove(&nodsi, &cx)
gmove(&cx, &noddi)
}
}
restx(&cx, &oldcx)
}
/*
* block copy:
* memmove(&res, &n, w);
* NB: character copy assumed little endian architecture
*/
func sgen(n *gc.Node, res *gc.Node, w int64) {
if gc.Debug['g'] != 0 {
fmt.Printf("\nsgen w=%d\n", w)
gc.Dump("r", n)
gc.Dump("res", res)
}
if n.Ullman >= gc.UINF && res.Ullman >= gc.UINF {
gc.Fatal("sgen UINF")
}
if w < 0 || int64(int32(w)) != w {
gc.Fatal("sgen copy %d", w)
}
if n.Type == nil {
gc.Fatal("sgen: missing type")
}
if w == 0 {
// evaluate side effects only.
var dst gc.Node
regalloc(&dst, gc.Types[gc.Tptr], nil)
agen(res, &dst)
agen(n, &dst)
regfree(&dst)
return
}
// If copying .args, that's all the results, so record definition sites
// for them for the liveness analysis.
if res.Op == gc.ONAME && res.Sym.Name == ".args" {
for l := gc.Curfn.Dcl; l != nil; l = l.Next {
if l.N.Class == gc.PPARAMOUT {
gc.Gvardef(l.N)
}
}
}
// Avoid taking the address for simple enough types.
if componentgen(n, res) {
return
}
// determine alignment.
// want to avoid unaligned access, so have to use
// smaller operations for less aligned types.
// for example moving [4]byte must use 4 MOVB not 1 MOVW.
align := int(n.Type.Align)
var op int
switch align {
default:
gc.Fatal("sgen: invalid alignment %d for %v", align, gc.Tconv(n.Type, 0))
case 1:
op = arm.AMOVB
case 2:
op = arm.AMOVH
case 4:
op = arm.AMOVW
}
if w%int64(align) != 0 {
gc.Fatal("sgen: unaligned size %d (align=%d) for %v", w, align, gc.Tconv(n.Type, 0))
}
c := int32(w / int64(align))
// offset on the stack
osrc := stkof(n)
odst := stkof(res)
if osrc != -1000 && odst != -1000 && (osrc == 1000 || odst == 1000) {
// osrc and odst both on stack, and at least one is in
// an unknown position. Could generate code to test
// for forward/backward copy, but instead just copy
// to a temporary location first.
var tmp gc.Node
gc.Tempname(&tmp, n.Type)
sgen(n, &tmp, w)
sgen(&tmp, res, w)
return
}
if osrc%int32(align) != 0 || odst%int32(align) != 0 {
gc.Fatal("sgen: unaligned offset src %d or dst %d (align %d)", osrc, odst, align)
}
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
dir := align
if osrc < odst && int64(odst) < int64(osrc)+w {
dir = -dir
}
if op == arm.AMOVW && !gc.Nacl && dir > 0 && c >= 4 && c <= 128 {
var r0 gc.Node
r0.Op = gc.OREGISTER
r0.Val.U.Reg = REGALLOC_R0
var r1 gc.Node
r1.Op = gc.OREGISTER
r1.Val.U.Reg = REGALLOC_R0 + 1
var r2 gc.Node
r2.Op = gc.OREGISTER
r2.Val.U.Reg = REGALLOC_R0 + 2
var src gc.Node
regalloc(&src, gc.Types[gc.Tptr], &r1)
var dst gc.Node
regalloc(&dst, gc.Types[gc.Tptr], &r2)
if n.Ullman >= res.Ullman {
// eval n first
agen(n, &src)
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
agen(res, &dst)
} else {
// eval res first
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
agen(res, &dst)
agen(n, &src)
}
var tmp gc.Node
regalloc(&tmp, gc.Types[gc.Tptr], &r0)
f := gc.Sysfunc("duffcopy")
p := gins(obj.ADUFFCOPY, nil, f)
gc.Afunclit(&p.To, f)
// 8 and 128 = magic constants: see ../../runtime/asm_arm.s
p.To.Offset = 8 * (128 - int64(c))
regfree(&tmp)
regfree(&src)
regfree(&dst)
return
}
var dst gc.Node
var src gc.Node
if n.Ullman >= res.Ullman {
agenr(n, &dst, res) // temporarily use dst
regalloc(&src, gc.Types[gc.Tptr], nil)
gins(arm.AMOVW, &dst, &src)
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
agen(res, &dst)
} else {
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
agenr(res, &dst, res)
agenr(n, &src, nil)
}
var tmp gc.Node
regalloc(&tmp, gc.Types[gc.TUINT32], nil)
// set up end marker
var nend gc.Node
if c >= 4 {
regalloc(&nend, gc.Types[gc.TUINT32], nil)
p := gins(arm.AMOVW, &src, &nend)
p.From.Type = obj.TYPE_ADDR
if dir < 0 {
p.From.Offset = int64(dir)
} else {
p.From.Offset = w
}
}
// move src and dest to the end of block if necessary
if dir < 0 {
p := gins(arm.AMOVW, &src, &src)
p.From.Type = obj.TYPE_ADDR
p.From.Offset = w + int64(dir)
p = gins(arm.AMOVW, &dst, &dst)
p.From.Type = obj.TYPE_ADDR
p.From.Offset = w + int64(dir)
}
// move
if c >= 4 {
p := gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
p.Scond |= arm.C_PBIT
ploop := p
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
p.Scond |= arm.C_PBIT
p = gins(arm.ACMP, &src, nil)
raddr(&nend, p)
gc.Patch(gc.Gbranch(arm.ABNE, nil, 0), ploop)
regfree(&nend)
} else {
var p *obj.Prog
for {
tmp14 := c
c--
if tmp14 <= 0 {
break
}
p = gins(op, &src, &tmp)
p.From.Type = obj.TYPE_MEM
p.From.Offset = int64(dir)
p.Scond |= arm.C_PBIT
p = gins(op, &tmp, &dst)
p.To.Type = obj.TYPE_MEM
p.To.Offset = int64(dir)
p.Scond |= arm.C_PBIT
}
}
regfree(&dst)
regfree(&src)
regfree(&tmp)
}
/*
* address gen
* res = &n;
* The generated code checks that the result is not nil.
*/
func agen(n *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("\nagen-res", res)
gc.Dump("agen-r", n)
}
if n == nil || n.Type == nil || res == nil || res.Type == nil {
gc.Fatal("agen")
}
for n.Op == gc.OCONVNOP {
n = n.Left
}
if gc.Isconst(n, gc.CTNIL) && n.Type.Width > int64(gc.Widthptr) {
// Use of a nil interface or nil slice.
// Create a temporary we can take the address of and read.
// The generated code is just going to panic, so it need not
// be terribly efficient. See issue 3670.
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Gvardef(&n1)
clearfat(&n1)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], res)
gins(x86.ALEAL, &n1, &n2)
gmove(&n2, res)
regfree(&n2)
return
}
// addressable var is easy
if n.Addable != 0 {
if n.Op == gc.OREGISTER {
gc.Fatal("agen OREGISTER")
}
var n1 gc.Node
regalloc(&n1, gc.Types[gc.Tptr], res)
gins(x86.ALEAL, n, &n1)
gmove(&n1, res)
regfree(&n1)
return
}
// let's compute
nl := n.Left
nr := n.Right
switch n.Op {
default:
gc.Fatal("agen %v", gc.Oconv(int(n.Op), 0))
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
cgen_aret(n, res)
case gc.OCALLINTER:
cgen_callinter(n, res, 0)
cgen_aret(n, res)
case gc.OCALLFUNC:
cgen_call(n, 0)
cgen_aret(n, res)
case gc.OSLICE,
gc.OSLICEARR,
gc.OSLICESTR,
gc.OSLICE3,
gc.OSLICE3ARR:
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_slice(n, &n1)
agen(&n1, res)
case gc.OEFACE:
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_eface(n, &n1)
agen(&n1, res)
case gc.OINDEX:
var p2 *obj.Prog // to be patched to panicindex.
w := uint32(n.Type.Width)
bounded := gc.Debug['B'] != 0 || n.Bounded
var n3 gc.Node
var tmp gc.Node
var n1 gc.Node
if nr.Addable != 0 {
// Generate &nl first, and move nr into register.
if !gc.Isconst(nl, gc.CTSTR) {
igen(nl, &n3, res)
}
if !gc.Isconst(nr, gc.CTINT) {
p2 = igenindex(nr, &tmp, bool2int(bounded))
regalloc(&n1, tmp.Type, nil)
gmove(&tmp, &n1)
}
} else if nl.Addable != 0 {
// Generate nr first, and move &nl into register.
if !gc.Isconst(nr, gc.CTINT) {
p2 = igenindex(nr, &tmp, bool2int(bounded))
regalloc(&n1, tmp.Type, nil)
gmove(&tmp, &n1)
}
if !gc.Isconst(nl, gc.CTSTR) {
igen(nl, &n3, res)
}
} else {
p2 = igenindex(nr, &tmp, bool2int(bounded))
nr = &tmp
if !gc.Isconst(nl, gc.CTSTR) {
igen(nl, &n3, res)
}
regalloc(&n1, tmp.Type, nil)
gins(optoas(gc.OAS, tmp.Type), &tmp, &n1)
}
// For fixed array we really want the pointer in n3.
var n2 gc.Node
if gc.Isfixedarray(nl.Type) {
regalloc(&n2, gc.Types[gc.Tptr], &n3)
agen(&n3, &n2)
regfree(&n3)
n3 = n2
}
// &a[0] is in n3 (allocated in res)
// i is in n1 (if not constant)
// len(a) is in nlen (if needed)
// w is width
// constant index
if gc.Isconst(nr, gc.CTINT) {
if gc.Isconst(nl, gc.CTSTR) {
gc.Fatal("constant string constant index") // front end should handle
}
v := uint64(gc.Mpgetfix(nr.Val.U.Xval))
if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
if gc.Debug['B'] == 0 && !n.Bounded {
nlen := n3
nlen.Type = gc.Types[gc.TUINT32]
nlen.Xoffset += int64(gc.Array_nel)
gc.Nodconst(&n2, gc.Types[gc.TUINT32], int64(v))
gins(optoas(gc.OCMP, gc.Types[gc.TUINT32]), &nlen, &n2)
p1 := gc.Gbranch(optoas(gc.OGT, gc.Types[gc.TUINT32]), nil, +1)
ginscall(gc.Panicindex, -1)
gc.Patch(p1, gc.Pc)
}
}
// Load base pointer in n2 = n3.
regalloc(&n2, gc.Types[gc.Tptr], &n3)
n3.Type = gc.Types[gc.Tptr]
n3.Xoffset += int64(gc.Array_array)
gmove(&n3, &n2)
regfree(&n3)
if v*uint64(w) != 0 {
gc.Nodconst(&n1, gc.Types[gc.Tptr], int64(v*uint64(w)))
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n1, &n2)
}
gmove(&n2, res)
regfree(&n2)
break
}
// i is in register n1, extend to 32 bits.
t := gc.Types[gc.TUINT32]
if gc.Issigned[n1.Type.Etype] {
t = gc.Types[gc.TINT32]
}
regalloc(&n2, t, &n1) // i
gmove(&n1, &n2)
regfree(&n1)
if gc.Debug['B'] == 0 && !n.Bounded {
// check bounds
t := gc.Types[gc.TUINT32]
var nlen gc.Node
if gc.Isconst(nl, gc.CTSTR) {
gc.Nodconst(&nlen, t, int64(len(nl.Val.U.Sval)))
} else if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
nlen = n3
nlen.Type = t
nlen.Xoffset += int64(gc.Array_nel)
} else {
gc.Nodconst(&nlen, t, nl.Type.Bound)
}
gins(optoas(gc.OCMP, t), &n2, &nlen)
p1 := gc.Gbranch(optoas(gc.OLT, t), nil, +1)
if p2 != nil {
gc.Patch(p2, gc.Pc)
}
ginscall(gc.Panicindex, -1)
gc.Patch(p1, gc.Pc)
}
if gc.Isconst(nl, gc.CTSTR) {
regalloc(&n3, gc.Types[gc.Tptr], res)
p1 := gins(x86.ALEAL, nil, &n3)
gc.Datastring(nl.Val.U.Sval, &p1.From)
p1.From.Scale = 1
p1.From.Index = n2.Val.U.Reg
goto indexdone
}
// Load base pointer in n3.
regalloc(&tmp, gc.Types[gc.Tptr], &n3)
if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
n3.Type = gc.Types[gc.Tptr]
n3.Xoffset += int64(gc.Array_array)
gmove(&n3, &tmp)
}
regfree(&n3)
n3 = tmp
if w == 0 {
} else // nothing to do
if w == 1 || w == 2 || w == 4 || w == 8 {
// LEAL (n3)(n2*w), n3
p1 := gins(x86.ALEAL, &n2, &n3)
p1.From.Scale = int16(w)
p1.From.Type = obj.TYPE_MEM
p1.From.Index = p1.From.Reg
p1.From.Reg = p1.To.Reg
} else {
gc.Nodconst(&tmp, gc.Types[gc.TUINT32], int64(w))
gins(optoas(gc.OMUL, gc.Types[gc.TUINT32]), &tmp, &n2)
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n2, &n3)
}
indexdone:
gmove(&n3, res)
regfree(&n2)
regfree(&n3)
// should only get here with names in this func.
case gc.ONAME:
if n.Funcdepth > 0 && n.Funcdepth != gc.Funcdepth {
gc.Dump("bad agen", n)
gc.Fatal("agen: bad ONAME funcdepth %d != %d", n.Funcdepth, gc.Funcdepth)
}
// should only get here for heap vars or paramref
if n.Class&gc.PHEAP == 0 && n.Class != gc.PPARAMREF {
gc.Dump("bad agen", n)
gc.Fatal("agen: bad ONAME class %#x", n.Class)
}
cgen(n.Heapaddr, res)
if n.Xoffset != 0 {
var n1 gc.Node
gc.Nodconst(&n1, gc.Types[gc.Tptr], n.Xoffset)
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n1, res)
}
case gc.OIND:
cgen(nl, res)
gc.Cgen_checknil(res)
case gc.ODOT:
agen(nl, res)
if n.Xoffset != 0 {
var n1 gc.Node
gc.Nodconst(&n1, gc.Types[gc.Tptr], n.Xoffset)
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n1, res)
}
case gc.ODOTPTR:
t := nl.Type
if !gc.Isptr[t.Etype] {
gc.Fatal("agen: not ptr %v", gc.Nconv(n, 0))
}
cgen(nl, res)
gc.Cgen_checknil(res)
if n.Xoffset != 0 {
var n1 gc.Node
gc.Nodconst(&n1, gc.Types[gc.Tptr], n.Xoffset)
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n1, res)
}
}
}
/*
* struct gen
* memmove(&res, &n, w);
*/
func sgen(n *gc.Node, res *gc.Node, w int64) {
if gc.Debug['g'] != 0 {
fmt.Printf("\nsgen w=%d\n", w)
gc.Dump("r", n)
gc.Dump("res", res)
}
if n.Ullman >= gc.UINF && res.Ullman >= gc.UINF {
gc.Fatal("sgen UINF")
}
if w < 0 || int64(int32(w)) != w {
gc.Fatal("sgen copy %d", w)
}
if w == 0 {
// evaluate side effects only.
var tdst gc.Node
gc.Tempname(&tdst, gc.Types[gc.Tptr])
agen(res, &tdst)
agen(n, &tdst)
return
}
// If copying .args, that's all the results, so record definition sites
// for them for the liveness analysis.
if res.Op == gc.ONAME && res.Sym.Name == ".args" {
for l := gc.Curfn.Dcl; l != nil; l = l.Next {
if l.N.Class == gc.PPARAMOUT {
gc.Gvardef(l.N)
}
}
}
// Avoid taking the address for simple enough types.
if componentgen(n, res) {
return
}
// offset on the stack
osrc := stkof(n)
odst := stkof(res)
if osrc != -1000 && odst != -1000 && (osrc == 1000 || odst == 1000) {
// osrc and odst both on stack, and at least one is in
// an unknown position. Could generate code to test
// for forward/backward copy, but instead just copy
// to a temporary location first.
var tsrc gc.Node
gc.Tempname(&tsrc, n.Type)
sgen(n, &tsrc, w)
sgen(&tsrc, res, w)
return
}
var dst gc.Node
gc.Nodreg(&dst, gc.Types[gc.Tptr], x86.REG_DI)
var src gc.Node
gc.Nodreg(&src, gc.Types[gc.Tptr], x86.REG_SI)
var tsrc gc.Node
gc.Tempname(&tsrc, gc.Types[gc.Tptr])
var tdst gc.Node
gc.Tempname(&tdst, gc.Types[gc.Tptr])
if n.Addable == 0 {
agen(n, &tsrc)
}
if res.Addable == 0 {
agen(res, &tdst)
}
if n.Addable != 0 {
agen(n, &src)
} else {
gmove(&tsrc, &src)
}
if res.Op == gc.ONAME {
gc.Gvardef(res)
}
if res.Addable != 0 {
agen(res, &dst)
} else {
gmove(&tdst, &dst)
}
c := int32(w % 4) // bytes
q := int32(w / 4) // doublewords
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
if osrc < odst && int64(odst) < int64(osrc)+w {
// reverse direction
gins(x86.ASTD, nil, nil) // set direction flag
if c > 0 {
gconreg(x86.AADDL, w-1, x86.REG_SI)
gconreg(x86.AADDL, w-1, x86.REG_DI)
gconreg(x86.AMOVL, int64(c), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)-,*(DI)-
}
if q > 0 {
if c > 0 {
gconreg(x86.AADDL, -3, x86.REG_SI)
gconreg(x86.AADDL, -3, x86.REG_DI)
} else {
gconreg(x86.AADDL, w-4, x86.REG_SI)
gconreg(x86.AADDL, w-4, x86.REG_DI)
}
gconreg(x86.AMOVL, int64(q), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSL, nil, nil) // MOVL *(SI)-,*(DI)-
}
// we leave with the flag clear
gins(x86.ACLD, nil, nil)
} else {
gins(x86.ACLD, nil, nil) // paranoia. TODO(rsc): remove?
// normal direction
if q > 128 || (q >= 4 && gc.Nacl) {
gconreg(x86.AMOVL, int64(q), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.AMOVSL, nil, nil) // MOVL *(SI)+,*(DI)+
} else if q >= 4 {
p := gins(obj.ADUFFCOPY, nil, nil)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffcopy", gc.Runtimepkg))
// 10 and 128 = magic constants: see ../../runtime/asm_386.s
p.To.Offset = 10 * (128 - int64(q))
} else if !gc.Nacl && c == 0 {
var cx gc.Node
gc.Nodreg(&cx, gc.Types[gc.TINT32], x86.REG_CX)
// We don't need the MOVSL side-effect of updating SI and DI,
// and issuing a sequence of MOVLs directly is faster.
src.Op = gc.OINDREG
dst.Op = gc.OINDREG
for q > 0 {
gmove(&src, &cx) // MOVL x+(SI),CX
gmove(&cx, &dst) // MOVL CX,x+(DI)
src.Xoffset += 4
dst.Xoffset += 4
q--
}
} else {
for q > 0 {
gins(x86.AMOVSL, nil, nil) // MOVL *(SI)+,*(DI)+
q--
}
}
for c > 0 {
gins(x86.AMOVSB, nil, nil) // MOVB *(SI)+,*(DI)+
c--
}
}
}