func ginscmp(op int, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
if gc.Isint[t.Etype] && n1.Op == gc.OLITERAL && n2.Op != gc.OLITERAL {
// Reverse comparison to place constant last.
op = gc.Brrev(op)
n1, n2 = n2, n1
}
var r1, r2, g1, g2 gc.Node
gc.Regalloc(&r1, t, n1)
gc.Regalloc(&g1, n1.Type, &r1)
gc.Cgen(n1, &g1)
gmove(&g1, &r1)
if gc.Isint[t.Etype] && gc.Isconst(n2, gc.CTINT) {
ginscon2(optoas(gc.OCMP, t), &r1, n2.Int())
} else {
gc.Regalloc(&r2, t, n2)
gc.Regalloc(&g2, n1.Type, &r2)
gc.Cgen(n2, &g2)
gmove(&g2, &r2)
rawgins(optoas(gc.OCMP, t), &r1, &r2)
gc.Regfree(&g2)
gc.Regfree(&r2)
}
gc.Regfree(&g1)
gc.Regfree(&r1)
return gc.Gbranch(optoas(op, t), nil, likely)
}
/*
* call to n has already been generated.
* generate:
* res = &return value from call.
*/
func cgen_aret(n *gc.Node, res *gc.Node) {
t := n.Left.Type
if gc.Isptr[t.Etype] {
t = t.Type
}
var flist gc.Iter
fp := gc.Structfirst(&flist, gc.Getoutarg(t))
if fp == nil {
gc.Fatal("cgen_aret: nil")
}
var nod1 gc.Node
nod1.Op = gc.OINDREG
nod1.Val.U.Reg = x86.REG_SP
nod1.Addable = 1
nod1.Xoffset = fp.Width
nod1.Type = fp.Type
if res.Op != gc.OREGISTER {
var nod2 gc.Node
regalloc(&nod2, gc.Types[gc.Tptr], res)
gins(x86.ALEAL, &nod1, &nod2)
gins(x86.AMOVL, &nod2, res)
regfree(&nod2)
} else {
gins(x86.ALEAL, &nod1, res)
}
}
func ginscmp(op int, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
if gc.Isint[t.Etype] && n1.Op == gc.OLITERAL && n1.Int() == 0 && n2.Op != gc.OLITERAL {
op = gc.Brrev(op)
n1, n2 = n2, n1
}
var r1, r2, g1, g2 gc.Node
gc.Regalloc(&r1, t, n1)
gc.Regalloc(&g1, n1.Type, &r1)
gc.Cgen(n1, &g1)
gmove(&g1, &r1)
if gc.Isint[t.Etype] && n2.Op == gc.OLITERAL && n2.Int() == 0 {
gins(arm.ACMP, &r1, n2)
} else {
gc.Regalloc(&r2, t, n2)
gc.Regalloc(&g2, n1.Type, &r2)
gc.Cgen(n2, &g2)
gmove(&g2, &r2)
gins(optoas(gc.OCMP, t), &r1, &r2)
gc.Regfree(&g2)
gc.Regfree(&r2)
}
gc.Regfree(&g1)
gc.Regfree(&r1)
return gc.Gbranch(optoas(op, t), nil, likely)
}
/*
* call to n has already been generated.
* generate:
* res = &return value from call.
*/
func cgen_aret(n *gc.Node, res *gc.Node) {
t := n.Left.Type
if gc.Isptr[t.Etype] {
t = t.Type
}
var flist gc.Iter
fp := gc.Structfirst(&flist, gc.Getoutarg(t))
if fp == nil {
gc.Fatal("cgen_aret: nil")
}
var nod1 gc.Node
nod1.Op = gc.OINDREG
nod1.Val.U.Reg = ppc64.REGSP
nod1.Addable = 1
nod1.Xoffset = fp.Width + int64(gc.Widthptr) // +widthptr: saved lr at 0(SP)
nod1.Type = fp.Type
if res.Op != gc.OREGISTER {
var nod2 gc.Node
regalloc(&nod2, gc.Types[gc.Tptr], res)
agen(&nod1, &nod2)
gins(ppc64.AMOVD, &nod2, res)
regfree(&nod2)
} else {
agen(&nod1, res)
}
}
/*
* n is a 64-bit value. fill in lo and hi to refer to its 32-bit halves.
*/
func split64(n *gc.Node, lo *gc.Node, hi *gc.Node) {
if !gc.Is64(n.Type) {
gc.Fatal("split64 %v", gc.Tconv(n.Type, 0))
}
if nsclean >= len(sclean) {
gc.Fatal("split64 clean")
}
sclean[nsclean].Op = gc.OEMPTY
nsclean++
switch n.Op {
default:
switch n.Op {
default:
var n1 gc.Node
if !dotaddable(n, &n1) {
gc.Igen(n, &n1, nil)
sclean[nsclean-1] = n1
}
n = &n1
case gc.ONAME:
if n.Class == gc.PPARAMREF {
var n1 gc.Node
gc.Cgen(n.Heapaddr, &n1)
sclean[nsclean-1] = n1
n = &n1
}
// nothing
case gc.OINDREG:
break
}
*lo = *n
*hi = *n
lo.Type = gc.Types[gc.TUINT32]
if n.Type.Etype == gc.TINT64 {
hi.Type = gc.Types[gc.TINT32]
} else {
hi.Type = gc.Types[gc.TUINT32]
}
hi.Xoffset += 4
case gc.OLITERAL:
var n1 gc.Node
gc.Convconst(&n1, n.Type, &n.Val)
i := gc.Mpgetfix(n1.Val.U.Xval)
gc.Nodconst(lo, gc.Types[gc.TUINT32], int64(uint32(i)))
i >>= 32
if n.Type.Etype == gc.TINT64 {
gc.Nodconst(hi, gc.Types[gc.TINT32], int64(int32(i)))
} else {
gc.Nodconst(hi, gc.Types[gc.TUINT32], int64(uint32(i)))
}
}
}
func intLiteral(n *gc.Node) (x int64, ok bool) {
switch {
case n == nil:
return
case gc.Isconst(n, gc.CTINT):
return n.Int(), true
case gc.Isconst(n, gc.CTBOOL):
return int64(obj.Bool2int(n.Bool())), true
}
return
}
func dotaddable(n *gc.Node, n1 *gc.Node) bool {
if n.Op != gc.ODOT {
return false
}
var oary [10]int64
var nn *gc.Node
o := gc.Dotoffset(n, oary[:], &nn)
if nn != nil && nn.Addable && o == 1 && oary[0] >= 0 {
*n1 = *nn
n1.Type = n.Type
n1.Xoffset += oary[0]
return true
}
return false
}
/*
* register dr is one of the special ones (AX, CX, DI, SI, etc.).
* we need to use it. if it is already allocated as a temporary
* (r > 1; can only happen if a routine like sgen passed a
* special as cgen's res and then cgen used regalloc to reuse
* it as its own temporary), then move it for now to another
* register. caller must call restx to move it back.
* the move is not necessary if dr == res, because res is
* known to be dead.
*/
func savex(dr int, x *gc.Node, oldx *gc.Node, res *gc.Node, t *gc.Type) {
r := int(reg[dr])
// save current ax and dx if they are live
// and not the destination
*oldx = gc.Node{}
gc.Nodreg(x, t, dr)
if r > 1 && !gc.Samereg(x, res) {
gc.Regalloc(oldx, gc.Types[gc.TINT64], nil)
x.Type = gc.Types[gc.TINT64]
gmove(x, oldx)
x.Type = t
oldx.Ostk = int32(r) // squirrel away old r value
reg[dr] = 1
}
}
func restx(x *gc.Node, oldx *gc.Node) {
if oldx.Op != 0 {
x.Type = gc.Types[gc.TINT64]
reg[x.Reg] = uint8(oldx.Ostk)
gmove(oldx, x)
gc.Regfree(oldx)
}
}
func restx(x *gc.Node, oldx *gc.Node) {
gc.Regfree(x)
if oldx.Op != 0 {
x.Type = gc.Types[gc.TINT32]
gmove(oldx, x)
}
}
/*
* generate function call;
* proc=0 normal call
* proc=1 goroutine run in new proc
* proc=2 defer call save away stack
*/
func cgen_call(n *gc.Node, proc int) {
if n == nil {
return
}
var afun gc.Node
if n.Left.Ullman >= gc.UINF {
// if name involves a fn call
// precompute the address of the fn
gc.Tempname(&afun, gc.Types[gc.Tptr])
cgen(n.Left, &afun)
}
gc.Genlist(n.List) // assign the args
t := n.Left.Type
// call tempname pointer
if n.Left.Ullman >= gc.UINF {
var nod gc.Node
regalloc(&nod, gc.Types[gc.Tptr], nil)
gc.Cgen_as(&nod, &afun)
nod.Type = t
ginscall(&nod, proc)
regfree(&nod)
return
}
// call pointer
if n.Left.Op != gc.ONAME || n.Left.Class != gc.PFUNC {
var nod gc.Node
regalloc(&nod, gc.Types[gc.Tptr], nil)
gc.Cgen_as(&nod, n.Left)
nod.Type = t
ginscall(&nod, proc)
regfree(&nod)
return
}
// call direct
n.Left.Method = 1
ginscall(n.Left, proc)
}
/*
* call to n has already been generated.
* generate:
* res = return value from call.
*/
func cgen_callret(n *gc.Node, res *gc.Node) {
t := n.Left.Type
if t.Etype == gc.TPTR32 || t.Etype == gc.TPTR64 {
t = t.Type
}
var flist gc.Iter
fp := gc.Structfirst(&flist, gc.Getoutarg(t))
if fp == nil {
gc.Fatal("cgen_callret: nil")
}
var nod gc.Node
nod.Op = gc.OINDREG
nod.Val.U.Reg = x86.REG_SP
nod.Addable = 1
nod.Xoffset = fp.Width
nod.Type = fp.Type
gc.Cgen_as(res, &nod)
}
func fixlargeoffset(n *gc.Node) {
if n == nil {
return
}
if n.Op != gc.OINDREG {
return
}
if -4096 <= n.Xoffset && n.Xoffset < 4096 {
return
}
a := gc.Node(*n)
a.Op = gc.OREGISTER
a.Type = gc.Types[gc.Tptr]
a.Xoffset = 0
gc.Cgen_checknil(&a)
ginscon(optoas(gc.OADD, gc.Types[gc.Tptr]), n.Xoffset, &a)
n.Xoffset = 0
}
/*
* peep.c
*/
func mgen(n *gc.Node, n1 *gc.Node, rg *gc.Node) {
n1.Op = gc.OEMPTY
if n.Addable != 0 {
*n1 = *n
if n1.Op == gc.OREGISTER || n1.Op == gc.OINDREG {
reg[n.Val.U.Reg]++
}
return
}
gc.Tempname(n1, n.Type)
cgen(n, n1)
if n.Type.Width <= int64(gc.Widthptr) || gc.Isfloat[n.Type.Etype] {
n2 := *n1
regalloc(n1, n.Type, rg)
gmove(&n2, n1)
}
}
func fixlargeoffset(n *gc.Node) {
if n == nil {
return
}
if n.Op != gc.OINDREG {
return
}
if n.Val.U.Reg == ppc64.REGSP { // stack offset cannot be large
return
}
if n.Xoffset != int64(int32(n.Xoffset)) {
// TODO(minux): offset too large, move into R31 and add to R31 instead.
// this is used only in test/fixedbugs/issue6036.go.
gc.Fatal("offset too large: %v", gc.Nconv(n, 0))
a := gc.Node(*n)
a.Op = gc.OREGISTER
a.Type = gc.Types[gc.Tptr]
a.Xoffset = 0
gc.Cgen_checknil(&a)
ginscon(optoas(gc.OADD, gc.Types[gc.Tptr]), n.Xoffset, &a)
n.Xoffset = 0
}
}
/*
* generate:
* res = n;
* simplifies and calls gmove.
*/
func cgen(n *gc.Node, res *gc.Node) {
//print("cgen %N(%d) -> %N(%d)\n", n, n->addable, res, res->addable);
if gc.Debug['g'] != 0 {
gc.Dump("\ncgen-n", n)
gc.Dump("cgen-res", res)
}
if n == nil || n.Type == nil {
return
}
if res == nil || res.Type == nil {
gc.Fatal("cgen: res nil")
}
for n.Op == gc.OCONVNOP {
n = n.Left
}
switch n.Op {
case gc.OSLICE,
gc.OSLICEARR,
gc.OSLICESTR,
gc.OSLICE3,
gc.OSLICE3ARR:
if res.Op != gc.ONAME || res.Addable == 0 {
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_slice(n, &n1)
cgen(&n1, res)
} else {
gc.Cgen_slice(n, res)
}
return
case gc.OEFACE:
if res.Op != gc.ONAME || res.Addable == 0 {
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_eface(n, &n1)
cgen(&n1, res)
} else {
gc.Cgen_eface(n, res)
}
return
}
if n.Ullman >= gc.UINF {
if n.Op == gc.OINDREG {
gc.Fatal("cgen: this is going to misscompile")
}
if res.Ullman >= gc.UINF {
var n1 gc.Node
gc.Tempname(&n1, n.Type)
cgen(n, &n1)
cgen(&n1, res)
return
}
}
if gc.Isfat(n.Type) {
if n.Type.Width < 0 {
gc.Fatal("forgot to compute width for %v", gc.Tconv(n.Type, 0))
}
sgen(n, res, n.Type.Width)
return
}
if res.Addable == 0 {
if n.Ullman > res.Ullman {
var n1 gc.Node
regalloc(&n1, n.Type, res)
cgen(n, &n1)
if n1.Ullman > res.Ullman {
gc.Dump("n1", &n1)
gc.Dump("res", res)
gc.Fatal("loop in cgen")
}
cgen(&n1, res)
regfree(&n1)
return
}
var f int
if res.Ullman >= gc.UINF {
goto gen
}
if gc.Complexop(n, res) {
gc.Complexgen(n, res)
return
}
f = 1 // gen thru register
switch n.Op {
case gc.OLITERAL:
if gc.Smallintconst(n) {
f = 0
}
case gc.OREGISTER:
f = 0
}
if !gc.Iscomplex[n.Type.Etype] {
a := optoas(gc.OAS, res.Type)
var addr obj.Addr
if sudoaddable(a, res, &addr) {
var p1 *obj.Prog
if f != 0 {
var n2 gc.Node
regalloc(&n2, res.Type, nil)
cgen(n, &n2)
p1 = gins(a, &n2, nil)
regfree(&n2)
} else {
p1 = gins(a, n, nil)
}
p1.To = addr
if gc.Debug['g'] != 0 {
fmt.Printf("%v [ignore previous line]\n", p1)
}
sudoclean()
return
}
}
gen:
var n1 gc.Node
igen(res, &n1, nil)
cgen(n, &n1)
regfree(&n1)
return
}
// update addressability for string, slice
// can't do in walk because n->left->addable
// changes if n->left is an escaping local variable.
switch n.Op {
case gc.OSPTR,
gc.OLEN:
if gc.Isslice(n.Left.Type) || gc.Istype(n.Left.Type, gc.TSTRING) {
n.Addable = n.Left.Addable
}
case gc.OCAP:
if gc.Isslice(n.Left.Type) {
n.Addable = n.Left.Addable
}
case gc.OITAB:
n.Addable = n.Left.Addable
}
if gc.Complexop(n, res) {
gc.Complexgen(n, res)
return
}
// if both are addressable, move
if n.Addable != 0 {
if n.Op == gc.OREGISTER || res.Op == gc.OREGISTER {
gmove(n, res)
} else {
var n1 gc.Node
regalloc(&n1, n.Type, nil)
gmove(n, &n1)
cgen(&n1, res)
regfree(&n1)
}
return
}
nl := n.Left
nr := n.Right
if nl != nil && nl.Ullman >= gc.UINF {
if nr != nil && nr.Ullman >= gc.UINF {
var n1 gc.Node
gc.Tempname(&n1, nl.Type)
cgen(nl, &n1)
n2 := *n
n2.Left = &n1
cgen(&n2, res)
return
}
}
if !gc.Iscomplex[n.Type.Etype] {
a := optoas(gc.OAS, n.Type)
var addr obj.Addr
if sudoaddable(a, n, &addr) {
if res.Op == gc.OREGISTER {
p1 := gins(a, nil, res)
p1.From = addr
} else {
var n2 gc.Node
regalloc(&n2, n.Type, nil)
p1 := gins(a, nil, &n2)
p1.From = addr
gins(a, &n2, res)
regfree(&n2)
}
sudoclean()
return
}
}
// TODO(minux): we shouldn't reverse FP comparisons, but then we need to synthesize
// OGE, OLE, and ONE ourselves.
// if(nl != N && isfloat[n->type->etype] && isfloat[nl->type->etype]) goto flt;
var a int
switch n.Op {
default:
gc.Dump("cgen", n)
gc.Fatal("cgen: unknown op %v", gc.Nconv(n, obj.FmtShort|obj.FmtSign))
// these call bgen to get a bool value
case gc.OOROR,
gc.OANDAND,
gc.OEQ,
gc.ONE,
gc.OLT,
gc.OLE,
gc.OGE,
gc.OGT,
gc.ONOT:
p1 := gc.Gbranch(ppc64.ABR, nil, 0)
p2 := gc.Pc
gmove(gc.Nodbool(true), res)
p3 := gc.Gbranch(ppc64.ABR, nil, 0)
gc.Patch(p1, gc.Pc)
bgen(n, true, 0, p2)
gmove(gc.Nodbool(false), res)
gc.Patch(p3, gc.Pc)
return
case gc.OPLUS:
cgen(nl, res)
return
// unary
case gc.OCOM:
a := optoas(gc.OXOR, nl.Type)
var n1 gc.Node
regalloc(&n1, nl.Type, nil)
cgen(nl, &n1)
var n2 gc.Node
gc.Nodconst(&n2, nl.Type, -1)
gins(a, &n2, &n1)
gmove(&n1, res)
regfree(&n1)
return
case gc.OMINUS:
if gc.Isfloat[nl.Type.Etype] {
nr = gc.Nodintconst(-1)
gc.Convlit(&nr, n.Type)
a = optoas(gc.OMUL, nl.Type)
goto sbop
}
a := optoas(int(n.Op), nl.Type)
// unary
var n1 gc.Node
regalloc(&n1, nl.Type, res)
cgen(nl, &n1)
gins(a, nil, &n1)
gmove(&n1, res)
regfree(&n1)
return
// symmetric binary
case gc.OAND,
gc.OOR,
gc.OXOR,
gc.OADD,
gc.OMUL:
a = optoas(int(n.Op), nl.Type)
goto sbop
// asymmetric binary
case gc.OSUB:
a = optoas(int(n.Op), nl.Type)
goto abop
case gc.OHMUL:
cgen_hmul(nl, nr, res)
case gc.OCONV:
if n.Type.Width > nl.Type.Width {
// If loading from memory, do conversion during load,
// so as to avoid use of 8-bit register in, say, int(*byteptr).
switch nl.Op {
case gc.ODOT,
gc.ODOTPTR,
gc.OINDEX,
gc.OIND,
gc.ONAME:
var n1 gc.Node
igen(nl, &n1, res)
var n2 gc.Node
regalloc(&n2, n.Type, res)
gmove(&n1, &n2)
gmove(&n2, res)
regfree(&n2)
regfree(&n1)
return
}
}
var n1 gc.Node
regalloc(&n1, nl.Type, res)
var n2 gc.Node
regalloc(&n2, n.Type, &n1)
cgen(nl, &n1)
// if we do the conversion n1 -> n2 here
// reusing the register, then gmove won't
// have to allocate its own register.
gmove(&n1, &n2)
gmove(&n2, res)
regfree(&n2)
regfree(&n1)
case gc.ODOT,
gc.ODOTPTR,
gc.OINDEX,
gc.OIND,
gc.ONAME: // PHEAP or PPARAMREF var
var n1 gc.Node
igen(n, &n1, res)
gmove(&n1, res)
regfree(&n1)
// interface table is first word of interface value
case gc.OITAB:
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = n.Type
gmove(&n1, res)
regfree(&n1)
// pointer is the first word of string or slice.
case gc.OSPTR:
if gc.Isconst(nl, gc.CTSTR) {
var n1 gc.Node
regalloc(&n1, gc.Types[gc.Tptr], res)
p1 := gins(ppc64.AMOVD, nil, &n1)
gc.Datastring(nl.Val.U.Sval, &p1.From)
gmove(&n1, res)
regfree(&n1)
break
}
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = n.Type
gmove(&n1, res)
regfree(&n1)
case gc.OLEN:
if gc.Istype(nl.Type, gc.TMAP) || gc.Istype(nl.Type, gc.TCHAN) {
// map and chan have len in the first int-sized word.
// a zero pointer means zero length
var n1 gc.Node
regalloc(&n1, gc.Types[gc.Tptr], res)
cgen(nl, &n1)
var n2 gc.Node
gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, 0)
n2 = n1
n2.Op = gc.OINDREG
n2.Type = gc.Types[gc.Simtype[gc.TINT]]
gmove(&n2, &n1)
gc.Patch(p1, gc.Pc)
gmove(&n1, res)
regfree(&n1)
break
}
if gc.Istype(nl.Type, gc.TSTRING) || gc.Isslice(nl.Type) {
// both slice and string have len one pointer into the struct.
// a zero pointer means zero length
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = gc.Types[gc.Simtype[gc.TUINT]]
n1.Xoffset += int64(gc.Array_nel)
gmove(&n1, res)
regfree(&n1)
break
}
gc.Fatal("cgen: OLEN: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))
case gc.OCAP:
if gc.Istype(nl.Type, gc.TCHAN) {
// chan has cap in the second int-sized word.
// a zero pointer means zero length
var n1 gc.Node
regalloc(&n1, gc.Types[gc.Tptr], res)
cgen(nl, &n1)
var n2 gc.Node
gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, 0)
n2 = n1
n2.Op = gc.OINDREG
n2.Xoffset = int64(gc.Widthint)
n2.Type = gc.Types[gc.Simtype[gc.TINT]]
gmove(&n2, &n1)
gc.Patch(p1, gc.Pc)
gmove(&n1, res)
regfree(&n1)
break
}
if gc.Isslice(nl.Type) {
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = gc.Types[gc.Simtype[gc.TUINT]]
n1.Xoffset += int64(gc.Array_cap)
gmove(&n1, res)
regfree(&n1)
break
}
gc.Fatal("cgen: OCAP: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))
case gc.OADDR:
if n.Bounded { // let race detector avoid nil checks
gc.Disable_checknil++
}
agen(nl, res)
if n.Bounded {
gc.Disable_checknil--
}
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
cgen_callret(n, res)
case gc.OCALLINTER:
cgen_callinter(n, res, 0)
cgen_callret(n, res)
case gc.OCALLFUNC:
cgen_call(n, 0)
cgen_callret(n, res)
case gc.OMOD,
gc.ODIV:
if gc.Isfloat[n.Type.Etype] {
a = optoas(int(n.Op), nl.Type)
goto abop
}
if nl.Ullman >= nr.Ullman {
var n1 gc.Node
regalloc(&n1, nl.Type, res)
cgen(nl, &n1)
cgen_div(int(n.Op), &n1, nr, res)
regfree(&n1)
} else {
var n2 gc.Node
if !gc.Smallintconst(nr) {
regalloc(&n2, nr.Type, res)
cgen(nr, &n2)
} else {
n2 = *nr
}
cgen_div(int(n.Op), nl, &n2, res)
if n2.Op != gc.OLITERAL {
regfree(&n2)
}
}
case gc.OLSH,
gc.ORSH,
gc.OLROT:
cgen_shift(int(n.Op), n.Bounded, nl, nr, res)
}
return
/*
* put simplest on right - we'll generate into left
* and then adjust it using the computation of right.
* constants and variables have the same ullman
* count, so look for constants specially.
*
* an integer constant we can use as an immediate
* is simpler than a variable - we can use the immediate
* in the adjustment instruction directly - so it goes
* on the right.
*
* other constants, like big integers or floating point
* constants, require a mov into a register, so those
* might as well go on the left, so we can reuse that
* register for the computation.
*/
sbop: // symmetric binary
if nl.Ullman < nr.Ullman || (nl.Ullman == nr.Ullman && (gc.Smallintconst(nl) || (nr.Op == gc.OLITERAL && !gc.Smallintconst(nr)))) {
r := nl
nl = nr
nr = r
}
abop: // asymmetric binary
var n1 gc.Node
var n2 gc.Node
if nl.Ullman >= nr.Ullman {
regalloc(&n1, nl.Type, res)
cgen(nl, &n1)
/*
* This generates smaller code - it avoids a MOV - but it's
* easily 10% slower due to not being able to
* optimize/manipulate the move.
* To see, run: go test -bench . crypto/md5
* with and without.
*
if(sudoaddable(a, nr, &addr)) {
p1 = gins(a, N, &n1);
p1->from = addr;
gmove(&n1, res);
sudoclean();
regfree(&n1);
goto ret;
}
*
*/
// TODO(minux): enable using constants directly in certain instructions.
//if(smallintconst(nr))
// n2 = *nr;
//else {
regalloc(&n2, nr.Type, nil)
cgen(nr, &n2)
} else //}
{
//if(smallintconst(nr))
// n2 = *nr;
//else {
regalloc(&n2, nr.Type, res)
cgen(nr, &n2)
//}
regalloc(&n1, nl.Type, nil)
cgen(nl, &n1)
}
gins(a, &n2, &n1)
// Normalize result for types smaller than word.
if n.Type.Width < int64(gc.Widthreg) {
switch n.Op {
case gc.OADD,
gc.OSUB,
gc.OMUL,
gc.OLSH:
gins(optoas(gc.OAS, n.Type), &n1, &n1)
}
}
gmove(&n1, res)
regfree(&n1)
if n2.Op != gc.OLITERAL {
regfree(&n2)
}
return
}
func clearfat(nl *gc.Node) {
/* clear a fat object */
if gc.Debug['g'] != 0 {
gc.Dump("\nclearfat", nl)
}
w := uint32(nl.Type.Width)
// Avoid taking the address for simple enough types.
if gc.Componentgen(nil, nl) {
return
}
c := w % 4 // bytes
q := w / 4 // quads
if q < 4 {
// Write sequence of MOV 0, off(base) instead of using STOSL.
// The hope is that although the code will be slightly longer,
// the MOVs will have no dependencies and pipeline better
// than the unrolled STOSL loop.
// NOTE: Must use agen, not igen, so that optimizer sees address
// being taken. We are not writing on field boundaries.
var n1 gc.Node
gc.Regalloc(&n1, gc.Types[gc.Tptr], nil)
gc.Agen(nl, &n1)
n1.Op = gc.OINDREG
var z gc.Node
gc.Nodconst(&z, gc.Types[gc.TUINT64], 0)
for {
tmp14 := q
q--
if tmp14 <= 0 {
break
}
n1.Type = z.Type
gins(x86.AMOVL, &z, &n1)
n1.Xoffset += 4
}
gc.Nodconst(&z, gc.Types[gc.TUINT8], 0)
for {
tmp15 := c
c--
if tmp15 <= 0 {
break
}
n1.Type = z.Type
gins(x86.AMOVB, &z, &n1)
n1.Xoffset++
}
gc.Regfree(&n1)
return
}
var n1 gc.Node
gc.Nodreg(&n1, gc.Types[gc.Tptr], x86.REG_DI)
gc.Agen(nl, &n1)
gconreg(x86.AMOVL, 0, x86.REG_AX)
if q > 128 || (q >= 4 && gc.Nacl) {
gconreg(x86.AMOVL, int64(q), x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.ASTOSL, nil, nil) // STOL AL,*(DI)+
} else if q >= 4 {
p := gins(obj.ADUFFZERO, nil, nil)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffzero", gc.Runtimepkg))
// 1 and 128 = magic constants: see ../../runtime/asm_386.s
p.To.Offset = 1 * (128 - int64(q))
} else {
for q > 0 {
gins(x86.ASTOSL, nil, nil) // STOL AL,*(DI)+
q--
}
}
for c > 0 {
gins(x86.ASTOSB, nil, nil) // STOB AL,*(DI)+
c--
}
}
func clearfat(nl *gc.Node) {
/* clear a fat object */
if gc.Debug['g'] != 0 {
gc.Dump("\nclearfat", nl)
}
w := nl.Type.Width
// Avoid taking the address for simple enough types.
if gc.Componentgen(nil, nl) {
return
}
c := w % 8 // bytes
q := w / 8 // quads
if q < 4 {
// Write sequence of MOV 0, off(base) instead of using STOSQ.
// The hope is that although the code will be slightly longer,
// the MOVs will have no dependencies and pipeline better
// than the unrolled STOSQ loop.
// NOTE: Must use agen, not igen, so that optimizer sees address
// being taken. We are not writing on field boundaries.
var n1 gc.Node
gc.Agenr(nl, &n1, nil)
n1.Op = gc.OINDREG
var z gc.Node
gc.Nodconst(&z, gc.Types[gc.TUINT64], 0)
for {
tmp14 := q
q--
if tmp14 <= 0 {
break
}
n1.Type = z.Type
gins(x86.AMOVQ, &z, &n1)
n1.Xoffset += 8
}
if c >= 4 {
gc.Nodconst(&z, gc.Types[gc.TUINT32], 0)
n1.Type = z.Type
gins(x86.AMOVL, &z, &n1)
n1.Xoffset += 4
c -= 4
}
gc.Nodconst(&z, gc.Types[gc.TUINT8], 0)
for {
tmp15 := c
c--
if tmp15 <= 0 {
break
}
n1.Type = z.Type
gins(x86.AMOVB, &z, &n1)
n1.Xoffset++
}
gc.Regfree(&n1)
return
}
var oldn1 gc.Node
var n1 gc.Node
savex(x86.REG_DI, &n1, &oldn1, nil, gc.Types[gc.Tptr])
gc.Agen(nl, &n1)
var ax gc.Node
var oldax gc.Node
savex(x86.REG_AX, &ax, &oldax, nil, gc.Types[gc.Tptr])
gconreg(x86.AMOVL, 0, x86.REG_AX)
if q > 128 || gc.Nacl {
gconreg(movptr, q, x86.REG_CX)
gins(x86.AREP, nil, nil) // repeat
gins(x86.ASTOSQ, nil, nil) // STOQ AL,*(DI)+
} else {
if di := dzDI(q); di != 0 {
gconreg(addptr, di, x86.REG_DI)
}
p := gins(obj.ADUFFZERO, nil, nil)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffzero", gc.Runtimepkg))
p.To.Offset = dzOff(q)
}
z := ax
di := n1
if w >= 8 && c >= 4 {
di.Op = gc.OINDREG
z.Type = gc.Types[gc.TINT64]
di.Type = z.Type
p := gins(x86.AMOVQ, &z, &di)
p.To.Scale = 1
p.To.Offset = c - 8
} else if c >= 4 {
di.Op = gc.OINDREG
z.Type = gc.Types[gc.TINT32]
di.Type = z.Type
gins(x86.AMOVL, &z, &di)
if c > 4 {
p := gins(x86.AMOVL, &z, &di)
p.To.Scale = 1
p.To.Offset = c - 4
}
} else {
for c > 0 {
gins(x86.ASTOSB, nil, nil) // STOB AL,*(DI)+
c--
}
}
restx(&n1, &oldn1)
restx(&ax, &oldax)
}
/*
* generate shift according to op, one of:
* res = nl << nr
* res = nl >> nr
*/
func cgen_shift(op int, bounded bool, nl *gc.Node, nr *gc.Node, res *gc.Node) {
a := optoas(op, nl.Type)
if nr.Op == gc.OLITERAL {
var n1 gc.Node
gc.Regalloc(&n1, nl.Type, res)
gc.Cgen(nl, &n1)
sc := uint64(gc.Mpgetfix(nr.Val.U.Xval))
if sc >= uint64(nl.Type.Width*8) {
// large shift gets 2 shifts by width-1
var n3 gc.Node
gc.Nodconst(&n3, gc.Types[gc.TUINT32], nl.Type.Width*8-1)
gins(a, &n3, &n1)
gins(a, &n3, &n1)
} else {
gins(a, nr, &n1)
}
gmove(&n1, res)
gc.Regfree(&n1)
return
}
if nl.Ullman >= gc.UINF {
var n4 gc.Node
gc.Tempname(&n4, nl.Type)
gc.Cgen(nl, &n4)
nl = &n4
}
if nr.Ullman >= gc.UINF {
var n5 gc.Node
gc.Tempname(&n5, nr.Type)
gc.Cgen(nr, &n5)
nr = &n5
}
rcx := int(reg[x86.REG_CX])
var n1 gc.Node
gc.Nodreg(&n1, gc.Types[gc.TUINT32], x86.REG_CX)
// Allow either uint32 or uint64 as shift type,
// to avoid unnecessary conversion from uint32 to uint64
// just to do the comparison.
tcount := gc.Types[gc.Simtype[nr.Type.Etype]]
if tcount.Etype < gc.TUINT32 {
tcount = gc.Types[gc.TUINT32]
}
gc.Regalloc(&n1, nr.Type, &n1) // to hold the shift type in CX
var n3 gc.Node
gc.Regalloc(&n3, tcount, &n1) // to clear high bits of CX
var cx gc.Node
gc.Nodreg(&cx, gc.Types[gc.TUINT64], x86.REG_CX)
var oldcx gc.Node
if rcx > 0 && !gc.Samereg(&cx, res) {
gc.Regalloc(&oldcx, gc.Types[gc.TUINT64], nil)
gmove(&cx, &oldcx)
}
cx.Type = tcount
var n2 gc.Node
if gc.Samereg(&cx, res) {
gc.Regalloc(&n2, nl.Type, nil)
} else {
gc.Regalloc(&n2, nl.Type, res)
}
if nl.Ullman >= nr.Ullman {
gc.Cgen(nl, &n2)
gc.Cgen(nr, &n1)
gmove(&n1, &n3)
} else {
gc.Cgen(nr, &n1)
gmove(&n1, &n3)
gc.Cgen(nl, &n2)
}
gc.Regfree(&n3)
// test and fix up large shifts
if !bounded {
gc.Nodconst(&n3, tcount, nl.Type.Width*8)
gins(optoas(gc.OCMP, tcount), &n1, &n3)
p1 := gc.Gbranch(optoas(gc.OLT, tcount), nil, +1)
if op == gc.ORSH && gc.Issigned[nl.Type.Etype] {
gc.Nodconst(&n3, gc.Types[gc.TUINT32], nl.Type.Width*8-1)
gins(a, &n3, &n2)
} else {
gc.Nodconst(&n3, nl.Type, 0)
gmove(&n3, &n2)
}
gc.Patch(p1, gc.Pc)
}
gins(a, &n1, &n2)
if oldcx.Op != 0 {
cx.Type = gc.Types[gc.TUINT64]
gmove(&oldcx, &cx)
gc.Regfree(&oldcx)
}
gmove(&n2, res)
gc.Regfree(&n1)
gc.Regfree(&n2)
}
/*
* n is call to interface method.
* generate res = n.
*/
func cgen_callinter(n *gc.Node, res *gc.Node, proc int) {
i := n.Left
if i.Op != gc.ODOTINTER {
gc.Fatal("cgen_callinter: not ODOTINTER %v", gc.Oconv(int(i.Op), 0))
}
f := i.Right // field
if f.Op != gc.ONAME {
gc.Fatal("cgen_callinter: not ONAME %v", gc.Oconv(int(f.Op), 0))
}
i = i.Left // interface
if i.Addable == 0 {
var tmpi gc.Node
gc.Tempname(&tmpi, i.Type)
cgen(i, &tmpi)
i = &tmpi
}
gc.Genlist(n.List) // assign the args
// i is now addable, prepare an indirected
// register to hold its address.
var nodi gc.Node
igen(i, &nodi, res) // REG = &inter
var nodsp gc.Node
gc.Nodindreg(&nodsp, gc.Types[gc.Tptr], x86.REG_SP)
nodsp.Xoffset = 0
if proc != 0 {
nodsp.Xoffset += 2 * int64(gc.Widthptr) // leave room for size & fn
}
nodi.Type = gc.Types[gc.Tptr]
nodi.Xoffset += int64(gc.Widthptr)
cgen(&nodi, &nodsp) // {0 or 8}(SP) = 4(REG) -- i.data
var nodo gc.Node
regalloc(&nodo, gc.Types[gc.Tptr], res)
nodi.Type = gc.Types[gc.Tptr]
nodi.Xoffset -= int64(gc.Widthptr)
cgen(&nodi, &nodo) // REG = 0(REG) -- i.tab
regfree(&nodi)
var nodr gc.Node
regalloc(&nodr, gc.Types[gc.Tptr], &nodo)
if n.Left.Xoffset == gc.BADWIDTH {
gc.Fatal("cgen_callinter: badwidth")
}
gc.Cgen_checknil(&nodo)
nodo.Op = gc.OINDREG
nodo.Xoffset = n.Left.Xoffset + 3*int64(gc.Widthptr) + 8
if proc == 0 {
// plain call: use direct c function pointer - more efficient
cgen(&nodo, &nodr) // REG = 20+offset(REG) -- i.tab->fun[f]
proc = 3
} else {
// go/defer. generate go func value.
gins(x86.ALEAL, &nodo, &nodr) // REG = &(20+offset(REG)) -- i.tab->fun[f]
}
nodr.Type = n.Left.Type
ginscall(&nodr, proc)
regfree(&nodr)
regfree(&nodo)
}
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--
}
}
}
/*
* generate division.
* generates one of:
* res = nl / nr
* res = nl % nr
* according to op.
*/
func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
// Have to be careful about handling
// most negative int divided by -1 correctly.
// The hardware will trap.
// Also the byte divide instruction needs AH,
// which we otherwise don't have to deal with.
// Easiest way to avoid for int8, int16: use int32.
// For int32 and int64, use explicit test.
// Could use int64 hw for int32.
t := nl.Type
t0 := t
check := 0
if gc.Issigned[t.Etype] {
check = 1
if gc.Isconst(nl, gc.CTINT) && gc.Mpgetfix(nl.Val.U.Xval) != -(1<<uint64(t.Width*8-1)) {
check = 0
} else if gc.Isconst(nr, gc.CTINT) && gc.Mpgetfix(nr.Val.U.Xval) != -1 {
check = 0
}
}
if t.Width < 4 {
if gc.Issigned[t.Etype] {
t = gc.Types[gc.TINT32]
} else {
t = gc.Types[gc.TUINT32]
}
check = 0
}
a := optoas(op, t)
var n3 gc.Node
gc.Regalloc(&n3, t0, nil)
var ax gc.Node
var oldax gc.Node
if nl.Ullman >= nr.Ullman {
savex(x86.REG_AX, &ax, &oldax, res, t0)
gc.Cgen(nl, &ax)
gc.Regalloc(&ax, t0, &ax) // mark ax live during cgen
gc.Cgen(nr, &n3)
gc.Regfree(&ax)
} else {
gc.Cgen(nr, &n3)
savex(x86.REG_AX, &ax, &oldax, res, t0)
gc.Cgen(nl, &ax)
}
if t != t0 {
// Convert
ax1 := ax
n31 := n3
ax.Type = t
n3.Type = t
gmove(&ax1, &ax)
gmove(&n31, &n3)
}
var n4 gc.Node
if gc.Nacl {
// Native Client does not relay the divide-by-zero trap
// to the executing program, so we must insert a check
// for ourselves.
gc.Nodconst(&n4, t, 0)
gins(optoas(gc.OCMP, t), &n3, &n4)
p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if panicdiv == nil {
panicdiv = gc.Sysfunc("panicdivide")
}
gc.Ginscall(panicdiv, -1)
gc.Patch(p1, gc.Pc)
}
var p2 *obj.Prog
if check != 0 {
gc.Nodconst(&n4, t, -1)
gins(optoas(gc.OCMP, t), &n3, &n4)
p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if op == gc.ODIV {
// a / (-1) is -a.
gins(optoas(gc.OMINUS, t), nil, &ax)
gmove(&ax, res)
} else {
// a % (-1) is 0.
gc.Nodconst(&n4, t, 0)
gmove(&n4, res)
}
p2 = gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, gc.Pc)
}
var olddx gc.Node
var dx gc.Node
savex(x86.REG_DX, &dx, &olddx, res, t)
if !gc.Issigned[t.Etype] {
gc.Nodconst(&n4, t, 0)
gmove(&n4, &dx)
} else {
gins(optoas(gc.OEXTEND, t), nil, nil)
}
gins(a, &n3, nil)
gc.Regfree(&n3)
if op == gc.ODIV {
gmove(&ax, res)
} else {
gmove(&dx, res)
}
restx(&dx, &olddx)
if check != 0 {
gc.Patch(p2, gc.Pc)
}
restx(&ax, &oldax)
}
func memname(n *gc.Node, t *gc.Type) {
gc.Tempname(n, t)
n.Sym = gc.Lookup("." + n.Sym.Name[1:]) // keep optimizer from registerizing
n.Orig.Sym = n.Sym
}
/*
* generate:
* newreg = &n;
* res = newreg
*
* on exit, a has been changed to be *newreg.
* caller must regfree(a).
* The generated code checks that the result is not *nil.
*/
func igen(n *gc.Node, a *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("\nigen-n", n)
}
switch n.Op {
case gc.ONAME:
if (n.Class&gc.PHEAP != 0) || n.Class == gc.PPARAMREF {
break
}
*a = *n
return
// Increase the refcount of the register so that igen's caller
// has to call regfree.
case gc.OINDREG:
if n.Val.U.Reg != ppc64.REGSP {
reg[n.Val.U.Reg]++
}
*a = *n
return
case gc.ODOT:
igen(n.Left, a, res)
a.Xoffset += n.Xoffset
a.Type = n.Type
fixlargeoffset(a)
return
case gc.ODOTPTR:
cgenr(n.Left, a, res)
gc.Cgen_checknil(a)
a.Op = gc.OINDREG
a.Xoffset += n.Xoffset
a.Type = n.Type
fixlargeoffset(a)
return
case gc.OCALLFUNC,
gc.OCALLMETH,
gc.OCALLINTER:
switch n.Op {
case gc.OCALLFUNC:
cgen_call(n, 0)
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
case gc.OCALLINTER:
cgen_callinter(n, nil, 0)
}
var flist gc.Iter
fp := gc.Structfirst(&flist, gc.Getoutarg(n.Left.Type))
*a = gc.Node{}
a.Op = gc.OINDREG
a.Val.U.Reg = ppc64.REGSP
a.Addable = 1
a.Xoffset = fp.Width + int64(gc.Widthptr) // +widthptr: saved lr at 0(SP)
a.Type = n.Type
return
// Index of fixed-size array by constant can
// put the offset in the addressing.
// Could do the same for slice except that we need
// to use the real index for the bounds checking.
case gc.OINDEX:
if gc.Isfixedarray(n.Left.Type) || (gc.Isptr[n.Left.Type.Etype] && gc.Isfixedarray(n.Left.Left.Type)) {
if gc.Isconst(n.Right, gc.CTINT) {
// Compute &a.
if !gc.Isptr[n.Left.Type.Etype] {
igen(n.Left, a, res)
} else {
var n1 gc.Node
igen(n.Left, &n1, res)
gc.Cgen_checknil(&n1)
regalloc(a, gc.Types[gc.Tptr], res)
gmove(&n1, a)
regfree(&n1)
a.Op = gc.OINDREG
}
// Compute &a[i] as &a + i*width.
a.Type = n.Type
a.Xoffset += gc.Mpgetfix(n.Right.Val.U.Xval) * n.Type.Width
fixlargeoffset(a)
return
}
}
}
agenr(n, a, res)
a.Op = gc.OINDREG
a.Type = n.Type
}
/*
* generate division.
* generates one of:
* res = nl / nr
* res = nl % nr
* according to op.
*/
func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
// Have to be careful about handling
// most negative int divided by -1 correctly.
// The hardware will generate undefined result.
// Also need to explicitly trap on division on zero,
// the hardware will silently generate undefined result.
// DIVW will leave unpredicable result in higher 32-bit,
// so always use DIVD/DIVDU.
t := nl.Type
t0 := t
check := 0
if gc.Issigned[t.Etype] {
check = 1
if gc.Isconst(nl, gc.CTINT) && gc.Mpgetfix(nl.Val.U.Xval) != -(1<<uint64(t.Width*8-1)) {
check = 0
} else if gc.Isconst(nr, gc.CTINT) && gc.Mpgetfix(nr.Val.U.Xval) != -1 {
check = 0
}
}
if t.Width < 8 {
if gc.Issigned[t.Etype] {
t = gc.Types[gc.TINT64]
} else {
t = gc.Types[gc.TUINT64]
}
check = 0
}
a := optoas(gc.ODIV, t)
var tl gc.Node
gc.Regalloc(&tl, t0, nil)
var tr gc.Node
gc.Regalloc(&tr, t0, nil)
if nl.Ullman >= nr.Ullman {
gc.Cgen(nl, &tl)
gc.Cgen(nr, &tr)
} else {
gc.Cgen(nr, &tr)
gc.Cgen(nl, &tl)
}
if t != t0 {
// Convert
tl2 := tl
tr2 := tr
tl.Type = t
tr.Type = t
gmove(&tl2, &tl)
gmove(&tr2, &tr)
}
// Handle divide-by-zero panic.
p1 := gins(optoas(gc.OCMP, t), &tr, nil)
p1.To.Type = obj.TYPE_REG
p1.To.Reg = ppc64.REGZERO
p1 = gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if panicdiv == nil {
panicdiv = gc.Sysfunc("panicdivide")
}
gc.Ginscall(panicdiv, -1)
gc.Patch(p1, gc.Pc)
var p2 *obj.Prog
if check != 0 {
var nm1 gc.Node
gc.Nodconst(&nm1, t, -1)
gins(optoas(gc.OCMP, t), &tr, &nm1)
p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if op == gc.ODIV {
// a / (-1) is -a.
gins(optoas(gc.OMINUS, t), nil, &tl)
gmove(&tl, res)
} else {
// a % (-1) is 0.
var nz gc.Node
gc.Nodconst(&nz, t, 0)
gmove(&nz, res)
}
p2 = gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, gc.Pc)
}
p1 = gins(a, &tr, &tl)
if op == gc.ODIV {
gc.Regfree(&tr)
gmove(&tl, res)
} else {
// A%B = A-(A/B*B)
var tm gc.Node
gc.Regalloc(&tm, t, nil)
// patch div to use the 3 register form
// TODO(minux): add gins3?
p1.Reg = p1.To.Reg
p1.To.Reg = tm.Val.U.Reg
gins(optoas(gc.OMUL, t), &tr, &tm)
gc.Regfree(&tr)
gins(optoas(gc.OSUB, t), &tm, &tl)
gc.Regfree(&tm)
gmove(&tl, res)
}
gc.Regfree(&tl)
if check != 0 {
gc.Patch(p2, gc.Pc)
}
}
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)
}
/*
* 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)
}
}
}
/*
* allocate a register (reusing res if possible) and generate
* a = &n
* The caller must call regfree(a).
* The generated code checks that the result is not nil.
*/
func agenr(n *gc.Node, a *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("agenr-n", n)
}
nl := n.Left
nr := n.Right
switch n.Op {
case gc.ODOT,
gc.ODOTPTR,
gc.OCALLFUNC,
gc.OCALLMETH,
gc.OCALLINTER:
var n1 gc.Node
igen(n, &n1, res)
regalloc(a, gc.Types[gc.Tptr], &n1)
agen(&n1, a)
regfree(&n1)
case gc.OIND:
cgenr(n.Left, a, res)
gc.Cgen_checknil(a)
case gc.OINDEX:
var p2 *obj.Prog // to be patched to panicindex.
w := uint32(n.Type.Width)
//bounded = debug['B'] || n->bounded;
var n3 gc.Node
var n1 gc.Node
if nr.Addable != 0 {
var tmp gc.Node
if !gc.Isconst(nr, gc.CTINT) {
gc.Tempname(&tmp, gc.Types[gc.TINT64])
}
if !gc.Isconst(nl, gc.CTSTR) {
agenr(nl, &n3, res)
}
if !gc.Isconst(nr, gc.CTINT) {
cgen(nr, &tmp)
regalloc(&n1, tmp.Type, nil)
gmove(&tmp, &n1)
}
} else if nl.Addable != 0 {
if !gc.Isconst(nr, gc.CTINT) {
var tmp gc.Node
gc.Tempname(&tmp, gc.Types[gc.TINT64])
cgen(nr, &tmp)
regalloc(&n1, tmp.Type, nil)
gmove(&tmp, &n1)
}
if !gc.Isconst(nl, gc.CTSTR) {
agenr(nl, &n3, res)
}
} else {
var tmp gc.Node
gc.Tempname(&tmp, gc.Types[gc.TINT64])
cgen(nr, &tmp)
nr = &tmp
if !gc.Isconst(nl, gc.CTSTR) {
agenr(nl, &n3, res)
}
regalloc(&n1, tmp.Type, nil)
gins(optoas(gc.OAS, tmp.Type), &tmp, &n1)
}
// &a is in &n3 (allocated in res)
// i is in &n1 (if not constant)
// w is width
// constant index
if gc.Isconst(nr, gc.CTINT) {
if gc.Isconst(nl, gc.CTSTR) {
gc.Fatal("constant string constant index")
}
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 {
n1 = n3
n1.Op = gc.OINDREG
n1.Type = gc.Types[gc.Tptr]
n1.Xoffset = int64(gc.Array_nel)
var n4 gc.Node
regalloc(&n4, n1.Type, nil)
gmove(&n1, &n4)
ginscon2(optoas(gc.OCMP, gc.Types[gc.TUINT64]), &n4, int64(v))
regfree(&n4)
p1 := gc.Gbranch(optoas(gc.OGT, gc.Types[gc.TUINT64]), nil, +1)
ginscall(gc.Panicindex, 0)
gc.Patch(p1, gc.Pc)
}
n1 = n3
n1.Op = gc.OINDREG
n1.Type = gc.Types[gc.Tptr]
n1.Xoffset = int64(gc.Array_array)
gmove(&n1, &n3)
}
if v*uint64(w) != 0 {
ginscon(optoas(gc.OADD, gc.Types[gc.Tptr]), int64(v*uint64(w)), &n3)
}
*a = n3
break
}
var n2 gc.Node
regalloc(&n2, gc.Types[gc.TINT64], &n1) // i
gmove(&n1, &n2)
regfree(&n1)
var n4 gc.Node
if gc.Debug['B'] == 0 && !n.Bounded {
// check bounds
if gc.Isconst(nl, gc.CTSTR) {
gc.Nodconst(&n4, gc.Types[gc.TUINT64], int64(len(nl.Val.U.Sval)))
} else if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
n1 = n3
n1.Op = gc.OINDREG
n1.Type = gc.Types[gc.Tptr]
n1.Xoffset = int64(gc.Array_nel)
regalloc(&n4, gc.Types[gc.TUINT64], nil)
gmove(&n1, &n4)
} else {
if nl.Type.Bound < (1<<15)-1 {
gc.Nodconst(&n4, gc.Types[gc.TUINT64], nl.Type.Bound)
} else {
regalloc(&n4, gc.Types[gc.TUINT64], nil)
p1 := gins(ppc64.AMOVD, nil, &n4)
p1.From.Type = obj.TYPE_CONST
p1.From.Offset = nl.Type.Bound
}
}
gins(optoas(gc.OCMP, gc.Types[gc.TUINT64]), &n2, &n4)
if n4.Op == gc.OREGISTER {
regfree(&n4)
}
p1 := gc.Gbranch(optoas(gc.OLT, gc.Types[gc.TUINT64]), nil, +1)
if p2 != nil {
gc.Patch(p2, gc.Pc)
}
ginscall(gc.Panicindex, 0)
gc.Patch(p1, gc.Pc)
}
if gc.Isconst(nl, gc.CTSTR) {
regalloc(&n3, gc.Types[gc.Tptr], res)
p1 := gins(ppc64.AMOVD, nil, &n3)
gc.Datastring(nl.Val.U.Sval, &p1.From)
p1.From.Type = obj.TYPE_ADDR
} else if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
n1 = n3
n1.Op = gc.OINDREG
n1.Type = gc.Types[gc.Tptr]
n1.Xoffset = int64(gc.Array_array)
gmove(&n1, &n3)
}
if w == 0 {
} else // nothing to do
if w == 1 {
/* w already scaled */
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n2, &n3)
/* else if(w == 2 || w == 4 || w == 8) {
// TODO(minux): scale using shift
} */
} else {
regalloc(&n4, gc.Types[gc.TUINT64], nil)
gc.Nodconst(&n1, gc.Types[gc.TUINT64], int64(w))
gmove(&n1, &n4)
gins(optoas(gc.OMUL, gc.Types[gc.TUINT64]), &n4, &n2)
gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n2, &n3)
regfree(&n4)
}
*a = n3
regfree(&n2)
default:
regalloc(a, gc.Types[gc.Tptr], res)
agen(n, a)
}
}
/*
* generate:
* if(n == true) goto to;
*/
func bgen(n *gc.Node, true_ bool, likely int, to *obj.Prog) {
if gc.Debug['g'] != 0 {
gc.Dump("\nbgen", n)
}
if n == nil {
n = gc.Nodbool(true)
}
if n.Ninit != nil {
gc.Genlist(n.Ninit)
}
if n.Type == nil {
gc.Convlit(&n, gc.Types[gc.TBOOL])
if n.Type == nil {
return
}
}
et := int(n.Type.Etype)
if et != gc.TBOOL {
gc.Yyerror("cgen: bad type %v for %v", gc.Tconv(n.Type, 0), gc.Oconv(int(n.Op), 0))
gc.Patch(gins(obj.AEND, nil, nil), to)
return
}
var nr *gc.Node
for n.Op == gc.OCONVNOP {
n = n.Left
if n.Ninit != nil {
gc.Genlist(n.Ninit)
}
}
var nl *gc.Node
switch n.Op {
default:
var n1 gc.Node
regalloc(&n1, n.Type, nil)
cgen(n, &n1)
var n2 gc.Node
gc.Nodconst(&n2, n.Type, 0)
gins(optoas(gc.OCMP, n.Type), &n1, &n2)
a := ppc64.ABNE
if !true_ {
a = ppc64.ABEQ
}
gc.Patch(gc.Gbranch(a, n.Type, likely), to)
regfree(&n1)
return
// need to ask if it is bool?
case gc.OLITERAL:
if !true_ == (n.Val.U.Bval == 0) {
gc.Patch(gc.Gbranch(ppc64.ABR, nil, likely), to)
}
return
case gc.OANDAND,
gc.OOROR:
if (n.Op == gc.OANDAND) == true_ {
p1 := gc.Gbranch(obj.AJMP, nil, 0)
p2 := gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, gc.Pc)
bgen(n.Left, !true_, -likely, p2)
bgen(n.Right, !true_, -likely, p2)
p1 = gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, to)
gc.Patch(p2, gc.Pc)
} else {
bgen(n.Left, true_, likely, to)
bgen(n.Right, true_, likely, to)
}
return
case gc.OEQ,
gc.ONE,
gc.OLT,
gc.OGT,
gc.OLE,
gc.OGE:
nr = n.Right
if nr == nil || nr.Type == nil {
return
}
fallthrough
case gc.ONOT: // unary
nl = n.Left
if nl == nil || nl.Type == nil {
return
}
}
switch n.Op {
case gc.ONOT:
bgen(nl, !true_, likely, to)
return
case gc.OEQ,
gc.ONE,
gc.OLT,
gc.OGT,
gc.OLE,
gc.OGE:
a := int(n.Op)
if !true_ {
if gc.Isfloat[nr.Type.Etype] {
// brcom is not valid on floats when NaN is involved.
p1 := gc.Gbranch(ppc64.ABR, nil, 0)
p2 := gc.Gbranch(ppc64.ABR, nil, 0)
gc.Patch(p1, gc.Pc)
ll := n.Ninit // avoid re-genning ninit
n.Ninit = nil
bgen(n, true, -likely, p2)
n.Ninit = ll
gc.Patch(gc.Gbranch(ppc64.ABR, nil, 0), to)
gc.Patch(p2, gc.Pc)
return
}
a = gc.Brcom(a)
true_ = !true_
}
// make simplest on right
if nl.Op == gc.OLITERAL || (nl.Ullman < nr.Ullman && nl.Ullman < gc.UINF) {
a = gc.Brrev(a)
r := nl
nl = nr
nr = r
}
if gc.Isslice(nl.Type) {
// front end should only leave cmp to literal nil
if (a != gc.OEQ && a != gc.ONE) || nr.Op != gc.OLITERAL {
gc.Yyerror("illegal slice comparison")
break
}
a = optoas(a, gc.Types[gc.Tptr])
var n1 gc.Node
igen(nl, &n1, nil)
n1.Xoffset += int64(gc.Array_array)
n1.Type = gc.Types[gc.Tptr]
var tmp gc.Node
gc.Nodconst(&tmp, gc.Types[gc.Tptr], 0)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], &n1)
gmove(&n1, &n2)
gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n2, &tmp)
regfree(&n2)
gc.Patch(gc.Gbranch(a, gc.Types[gc.Tptr], likely), to)
regfree(&n1)
break
}
if gc.Isinter(nl.Type) {
// front end should only leave cmp to literal nil
if (a != gc.OEQ && a != gc.ONE) || nr.Op != gc.OLITERAL {
gc.Yyerror("illegal interface comparison")
break
}
a = optoas(a, gc.Types[gc.Tptr])
var n1 gc.Node
igen(nl, &n1, nil)
n1.Type = gc.Types[gc.Tptr]
var tmp gc.Node
gc.Nodconst(&tmp, gc.Types[gc.Tptr], 0)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], &n1)
gmove(&n1, &n2)
gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n2, &tmp)
regfree(&n2)
gc.Patch(gc.Gbranch(a, gc.Types[gc.Tptr], likely), to)
regfree(&n1)
break
}
if gc.Iscomplex[nl.Type.Etype] {
gc.Complexbool(a, nl, nr, true_, likely, to)
break
}
var n1 gc.Node
var n2 gc.Node
if nr.Ullman >= gc.UINF {
regalloc(&n1, nl.Type, nil)
cgen(nl, &n1)
var tmp gc.Node
gc.Tempname(&tmp, nl.Type)
gmove(&n1, &tmp)
regfree(&n1)
regalloc(&n2, nr.Type, nil)
cgen(nr, &n2)
regalloc(&n1, nl.Type, nil)
cgen(&tmp, &n1)
goto cmp
}
regalloc(&n1, nl.Type, nil)
cgen(nl, &n1)
// TODO(minux): cmpi does accept 16-bit signed immediate as p->to.
// and cmpli accepts 16-bit unsigned immediate.
//if(smallintconst(nr)) {
// gins(optoas(OCMP, nr->type), &n1, nr);
// patch(gbranch(optoas(a, nr->type), nr->type, likely), to);
// regfree(&n1);
// break;
//}
regalloc(&n2, nr.Type, nil)
cgen(nr, &n2)
cmp:
l := &n1
r := &n2
gins(optoas(gc.OCMP, nr.Type), l, r)
if gc.Isfloat[nr.Type.Etype] && (a == gc.OLE || a == gc.OGE) {
// To get NaN right, must rewrite x <= y into separate x < y or x = y.
switch a {
case gc.OLE:
a = gc.OLT
case gc.OGE:
a = gc.OGT
}
gc.Patch(gc.Gbranch(optoas(a, nr.Type), nr.Type, likely), to)
gc.Patch(gc.Gbranch(optoas(gc.OEQ, nr.Type), nr.Type, likely), to)
} else {
gc.Patch(gc.Gbranch(optoas(a, nr.Type), nr.Type, likely), to)
}
regfree(&n1)
regfree(&n2)
}
return
}
/*
* 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
}