// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// TODO(rsc):
// assume CLD?
#include <u.h>
#include <libc.h>
#include "gg.h"
void
mgen(Node *n, Node *n1, Node *rg)
{
Node n2;
n1->op = OEMPTY;
if(n->addable) {
*n1 = *n;
if(n1->op == OREGISTER || n1->op == OINDREG)
reg[n->val.u.reg]++;
return;
}
tempname(n1, n->type);
cgen(n, n1);
if(n->type->width <= widthptr || isfloat[n->type->etype]) {
n2 = *n1;
regalloc(n1, n->type, rg);
gmove(&n2, n1);
}
}
void
mfree(Node *n)
{
if(n->op == OREGISTER)
regfree(n);
}
/*
* generate:
* res = n;
* simplifies and calls gmove.
*
* TODO:
* sudoaddable
*/
void
cgen(Node *n, Node *res)
{
Node *nl, *nr, *r, n1, n2, nt;
Prog *p1, *p2, *p3;
int a;
if(debug['g']) {
dump("\ncgen-n", n);
dump("cgen-res", res);
}
if(n == N || n->type == T)
fatal("cgen: n nil");
if(res == N || res->type == T)
fatal("cgen: res nil");
switch(n->op) {
case OSLICE:
case OSLICEARR:
case OSLICESTR:
case OSLICE3:
case OSLICE3ARR:
if (res->op != ONAME || !res->addable) {
tempname(&n1, n->type);
cgen_slice(n, &n1);
cgen(&n1, res);
} else
cgen_slice(n, res);
return;
case OEFACE:
if (res->op != ONAME || !res->addable) {
tempname(&n1, n->type);
cgen_eface(n, &n1);
cgen(&n1, res);
} else
cgen_eface(n, res);
return;
}
while(n->op == OCONVNOP)
n = n->left;
// function calls on both sides? introduce temporary
if(n->ullman >= UINF && res->ullman >= UINF) {
tempname(&n1, n->type);
cgen(n, &n1);
cgen(&n1, res);
return;
}
// structs etc get handled specially
if(isfat(n->type)) {
if(n->type->width < 0)
fatal("forgot to compute width for %T", n->type);
sgen(n, res, n->type->width);
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 OSPTR:
case OLEN:
if(isslice(n->left->type) || istype(n->left->type, TSTRING))
n->addable = n->left->addable;
break;
case OCAP:
if(isslice(n->left->type))
n->addable = n->left->addable;
break;
case OITAB:
n->addable = n->left->addable;
break;
}
// if both are addressable, move
if(n->addable && res->addable) {
gmove(n, res);
return;
}
// if both are not addressable, use a temporary.
if(!n->addable && !res->addable) {
// could use regalloc here sometimes,
// but have to check for ullman >= UINF.
tempname(&n1, n->type);
cgen(n, &n1);
cgen(&n1, res);
return;
}
// if result is not addressable directly but n is,
// compute its address and then store via the address.
if(!res->addable) {
igen(res, &n1, N);
cgen(n, &n1);
regfree(&n1);
return;
}
// complex types
if(complexop(n, res)) {
complexgen(n, res);
return;
}
// otherwise, the result is addressable but n is not.
// let's do some computation.
// use ullman to pick operand to eval first.
nl = n->left;
nr = n->right;
if(nl != N && nl->ullman >= UINF)
if(nr != N && nr->ullman >= UINF) {
// both are hard
tempname(&n1, nl->type);
cgen(nl, &n1);
n2 = *n;
n2.left = &n1;
cgen(&n2, res);
return;
}
// 64-bit ops are hard on 32-bit machine.
if(is64(n->type) || is64(res->type) || n->left != N && is64(n->left->type)) {
switch(n->op) {
// math goes to cgen64.
case OMINUS:
case OCOM:
case OADD:
case OSUB:
case OMUL:
case OLROT:
case OLSH:
case ORSH:
case OAND:
case OOR:
case OXOR:
cgen64(n, res);
return;
}
}
if(nl != N && isfloat[n->type->etype] && isfloat[nl->type->etype]) {
cgen_float(n, res);
return;
}
switch(n->op) {
default:
dump("cgen", n);
fatal("cgen %O", n->op);
break;
case OREAL:
case OIMAG:
case OCOMPLEX:
fatal("unexpected complex");
return;
// these call bgen to get a bool value
case OOROR:
case OANDAND:
case OEQ:
case ONE:
case OLT:
case OLE:
case OGE:
case OGT:
case ONOT:
p1 = gbranch(AJMP, T, 0);
p2 = pc;
gmove(nodbool(1), res);
p3 = gbranch(AJMP, T, 0);
patch(p1, pc);
bgen(n, 1, 0, p2);
gmove(nodbool(0), res);
patch(p3, pc);
return;
case OPLUS:
cgen(nl, res);
return;
case OMINUS:
case OCOM:
a = optoas(n->op, nl->type);
goto uop;
// symmetric binary
case OAND:
case OOR:
case OXOR:
case OADD:
case OADDPTR:
case OMUL:
a = optoas(n->op, nl->type);
if(a == AIMULB) {
cgen_bmul(n->op, nl, nr, res);
break;
}
goto sbop;
// asymmetric binary
case OSUB:
a = optoas(n->op, nl->type);
goto abop;
case OHMUL:
cgen_hmul(nl, nr, res);
break;
case OCONV:
if(eqtype(n->type, nl->type) || noconv(n->type, nl->type)) {
cgen(nl, res);
break;
}
tempname(&n2, n->type);
mgen(nl, &n1, res);
gmove(&n1, &n2);
gmove(&n2, res);
mfree(&n1);
break;
case ODOT:
case ODOTPTR:
case OINDEX:
case OIND:
case ONAME: // PHEAP or PPARAMREF var
igen(n, &n1, res);
gmove(&n1, res);
regfree(&n1);
break;
case OITAB:
igen(nl, &n1, res);
n1.type = ptrto(types[TUINTPTR]);
gmove(&n1, res);
regfree(&n1);
break;
case OSPTR:
// pointer is the first word of string or slice.
if(isconst(nl, CTSTR)) {
regalloc(&n1, types[tptr], res);
p1 = gins(ALEAL, N, &n1);
datastring(nl->val.u.sval->s, nl->val.u.sval->len, &p1->from);
gmove(&n1, res);
regfree(&n1);
break;
}
igen(nl, &n1, res);
n1.type = n->type;
gmove(&n1, res);
regfree(&n1);
break;
case OLEN:
if(istype(nl->type, TMAP) || istype(nl->type, TCHAN)) {
// map has len in the first 32-bit word.
// a zero pointer means zero length
tempname(&n1, types[tptr]);
cgen(nl, &n1);
regalloc(&n2, types[tptr], N);
gmove(&n1, &n2);
n1 = n2;
nodconst(&n2, types[tptr], 0);
gins(optoas(OCMP, types[tptr]), &n1, &n2);
p1 = gbranch(optoas(OEQ, types[tptr]), T, -1);
n2 = n1;
n2.op = OINDREG;
n2.type = types[TINT32];
gmove(&n2, &n1);
patch(p1, pc);
gmove(&n1, res);
regfree(&n1);
break;
}
if(istype(nl->type, TSTRING) || isslice(nl->type)) {
// both slice and string have len one pointer into the struct.
igen(nl, &n1, res);
n1.type = types[TUINT32];
n1.xoffset += Array_nel;
gmove(&n1, res);
regfree(&n1);
break;
}
fatal("cgen: OLEN: unknown type %lT", nl->type);
break;
case OCAP:
if(istype(nl->type, TCHAN)) {
// chan has cap in the second 32-bit word.
// a zero pointer means zero length
regalloc(&n1, types[tptr], res);
cgen(nl, &n1);
nodconst(&n2, types[tptr], 0);
gins(optoas(OCMP, types[tptr]), &n1, &n2);
p1 = gbranch(optoas(OEQ, types[tptr]), T, -1);
n2 = n1;
n2.op = OINDREG;
n2.xoffset = 4;
n2.type = types[TINT32];
gmove(&n2, &n1);
patch(p1, pc);
gmove(&n1, res);
regfree(&n1);
break;
}
if(isslice(nl->type)) {
igen(nl, &n1, res);
n1.type = types[TUINT32];
n1.xoffset += Array_cap;
gmove(&n1, res);
regfree(&n1);
break;
}
fatal("cgen: OCAP: unknown type %lT", nl->type);
break;
case OADDR:
agen(nl, res);
break;
case OCALLMETH:
cgen_callmeth(n, 0);
cgen_callret(n, res);
break;
case OCALLINTER:
cgen_callinter(n, res, 0);
cgen_callret(n, res);
break;
case OCALLFUNC:
cgen_call(n, 0);
cgen_callret(n, res);
break;
case OMOD:
case ODIV:
cgen_div(n->op, nl, nr, res);
break;
case OLSH:
case ORSH:
case OLROT:
cgen_shift(n->op, n->bounded, nl, nr, res);
break;
}
return;
sbop: // symmetric binary
if(nl->ullman < nr->ullman || nl->op == OLITERAL) {
r = nl;
nl = nr;
nr = r;
}
abop: // asymmetric binary
if(smallintconst(nr)) {
mgen(nl, &n1, res);
regalloc(&n2, nl->type, &n1);
gmove(&n1, &n2);
gins(a, nr, &n2);
gmove(&n2, res);
regfree(&n2);
mfree(&n1);
} else if(nl->ullman >= nr->ullman) {
tempname(&nt, nl->type);
cgen(nl, &nt);
mgen(nr, &n2, N);
regalloc(&n1, nl->type, res);
gmove(&nt, &n1);
gins(a, &n2, &n1);
gmove(&n1, res);
regfree(&n1);
mfree(&n2);
} else {
regalloc(&n2, nr->type, res);
cgen(nr, &n2);
regalloc(&n1, nl->type, N);
cgen(nl, &n1);
gins(a, &n2, &n1);
regfree(&n2);
gmove(&n1, res);
regfree(&n1);
}
return;
uop: // unary
tempname(&n1, nl->type);
cgen(nl, &n1);
gins(a, N, &n1);
gmove(&n1, res);
return;
}
/*
* generate an addressable node in res, containing the value of n.
* n is an array index, and might be any size; res width is <= 32-bit.
* returns Prog* to patch to panic call.
*/
static Prog*
igenindex(Node *n, Node *res, int bounded)
{
Node tmp, lo, hi, zero;
if(!is64(n->type)) {
if(n->addable) {
// nothing to do.
*res = *n;
} else {
tempname(res, types[TUINT32]);
cgen(n, res);
}
return nil;
}
tempname(&tmp, types[TINT64]);
cgen(n, &tmp);
split64(&tmp, &lo, &hi);
tempname(res, types[TUINT32]);
gmove(&lo, res);
if(bounded) {
splitclean();
return nil;
}
nodconst(&zero, types[TINT32], 0);
gins(ACMPL, &hi, &zero);
splitclean();
return gbranch(AJNE, T, +1);
}
/*
* address gen
* res = &n;
* The generated code checks that the result is not nil.
*/
void
agen(Node *n, Node *res)
{
Node *nl, *nr;
Node n1, n2, n3, tmp, nlen;
Type *t;
uint32 w;
uint64 v;
Prog *p1, *p2;
int bounded;
if(debug['g']) {
dump("\nagen-res", res);
dump("agen-r", n);
}
if(n == N || n->type == T || res == N || res->type == T)
fatal("agen");
while(n->op == OCONVNOP)
n = n->left;
if(isconst(n, CTNIL) && n->type->width > 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.
tempname(&n1, n->type);
gvardef(&n1);
clearfat(&n1);
regalloc(&n2, types[tptr], res);
gins(ALEAL, &n1, &n2);
gmove(&n2, res);
regfree(&n2);
return;
}
// addressable var is easy
if(n->addable) {
if(n->op == OREGISTER)
fatal("agen OREGISTER");
regalloc(&n1, types[tptr], res);
gins(ALEAL, n, &n1);
gmove(&n1, res);
regfree(&n1);
return;
}
// let's compute
nl = n->left;
nr = n->right;
switch(n->op) {
default:
fatal("agen %O", n->op);
case OCALLMETH:
cgen_callmeth(n, 0);
cgen_aret(n, res);
break;
case OCALLINTER:
cgen_callinter(n, res, 0);
cgen_aret(n, res);
break;
case OCALLFUNC:
cgen_call(n, 0);
cgen_aret(n, res);
break;
case OSLICE:
case OSLICEARR:
case OSLICESTR:
case OSLICE3:
case OSLICE3ARR:
tempname(&n1, n->type);
cgen_slice(n, &n1);
agen(&n1, res);
break;
case OEFACE:
tempname(&n1, n->type);
cgen_eface(n, &n1);
agen(&n1, res);
break;
case OINDEX:
p2 = nil; // to be patched to panicindex.
w = n->type->width;
bounded = debug['B'] || n->bounded;
if(nr->addable) {
// Generate &nl first, and move nr into register.
if(!isconst(nl, CTSTR))
igen(nl, &n3, res);
if(!isconst(nr, CTINT)) {
p2 = igenindex(nr, &tmp, bounded);
regalloc(&n1, tmp.type, N);
gmove(&tmp, &n1);
}
} else if(nl->addable) {
// Generate nr first, and move &nl into register.
if(!isconst(nr, CTINT)) {
p2 = igenindex(nr, &tmp, bounded);
regalloc(&n1, tmp.type, N);
gmove(&tmp, &n1);
}
if(!isconst(nl, CTSTR))
igen(nl, &n3, res);
} else {
p2 = igenindex(nr, &tmp, bounded);
nr = &tmp;
if(!isconst(nl, CTSTR))
igen(nl, &n3, res);
regalloc(&n1, tmp.type, N);
gins(optoas(OAS, tmp.type), &tmp, &n1);
}
// For fixed array we really want the pointer in n3.
if(isfixedarray(nl->type)) {
regalloc(&n2, types[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(isconst(nr, CTINT)) {
if(isconst(nl, CTSTR))
fatal("constant string constant index"); // front end should handle
v = mpgetfix(nr->val.u.xval);
if(isslice(nl->type) || nl->type->etype == TSTRING) {
if(!debug['B'] && !n->bounded) {
nlen = n3;
nlen.type = types[TUINT32];
nlen.xoffset += Array_nel;
nodconst(&n2, types[TUINT32], v);
gins(optoas(OCMP, types[TUINT32]), &nlen, &n2);
p1 = gbranch(optoas(OGT, types[TUINT32]), T, +1);
ginscall(panicindex, -1);
patch(p1, pc);
}
}
// Load base pointer in n2 = n3.
regalloc(&n2, types[tptr], &n3);
n3.type = types[tptr];
n3.xoffset += Array_array;
gmove(&n3, &n2);
regfree(&n3);
if (v*w != 0) {
nodconst(&n1, types[tptr], v*w);
gins(optoas(OADD, types[tptr]), &n1, &n2);
}
gmove(&n2, res);
regfree(&n2);
break;
}
// i is in register n1, extend to 32 bits.
t = types[TUINT32];
if(issigned[n1.type->etype])
t = types[TINT32];
regalloc(&n2, t, &n1); // i
gmove(&n1, &n2);
regfree(&n1);
if(!debug['B'] && !n->bounded) {
// check bounds
t = types[TUINT32];
if(isconst(nl, CTSTR)) {
nodconst(&nlen, t, nl->val.u.sval->len);
} else if(isslice(nl->type) || nl->type->etype == TSTRING) {
nlen = n3;
nlen.type = t;
nlen.xoffset += Array_nel;
} else {
nodconst(&nlen, t, nl->type->bound);
}
gins(optoas(OCMP, t), &n2, &nlen);
p1 = gbranch(optoas(OLT, t), T, +1);
if(p2)
patch(p2, pc);
ginscall(panicindex, -1);
patch(p1, pc);
}
if(isconst(nl, CTSTR)) {
regalloc(&n3, types[tptr], res);
p1 = gins(ALEAL, N, &n3);
datastring(nl->val.u.sval->s, nl->val.u.sval->len, &p1->from);
p1->from.scale = 1;
p1->from.index = n2.val.u.reg;
goto indexdone;
}
// Load base pointer in n3.
regalloc(&tmp, types[tptr], &n3);
if(isslice(nl->type) || nl->type->etype == TSTRING) {
n3.type = types[tptr];
n3.xoffset += Array_array;
gmove(&n3, &tmp);
}
regfree(&n3);
n3 = tmp;
if(w == 0) {
// nothing to do
} else if(w == 1 || w == 2 || w == 4 || w == 8) {
// LEAL (n3)(n2*w), n3
p1 = gins(ALEAL, &n2, &n3);
p1->from.scale = w;
p1->from.index = p1->from.type;
p1->from.type = p1->to.type + D_INDIR;
} else {
nodconst(&tmp, types[TUINT32], w);
gins(optoas(OMUL, types[TUINT32]), &tmp, &n2);
gins(optoas(OADD, types[tptr]), &n2, &n3);
}
indexdone:
gmove(&n3, res);
regfree(&n2);
regfree(&n3);
break;
case ONAME:
// should only get here with names in this func.
if(n->funcdepth > 0 && n->funcdepth != funcdepth) {
dump("bad agen", n);
fatal("agen: bad ONAME funcdepth %d != %d",
n->funcdepth, funcdepth);
}
// should only get here for heap vars or paramref
if(!(n->class & PHEAP) && n->class != PPARAMREF) {
dump("bad agen", n);
fatal("agen: bad ONAME class %#x", n->class);
}
cgen(n->heapaddr, res);
if(n->xoffset != 0) {
nodconst(&n1, types[tptr], n->xoffset);
gins(optoas(OADD, types[tptr]), &n1, res);
}
break;
case OIND:
cgen(nl, res);
cgen_checknil(res);
break;
case ODOT:
agen(nl, res);
if(n->xoffset != 0) {
nodconst(&n1, types[tptr], n->xoffset);
gins(optoas(OADD, types[tptr]), &n1, res);
}
break;
case ODOTPTR:
t = nl->type;
if(!isptr[t->etype])
fatal("agen: not ptr %N", n);
cgen(nl, res);
cgen_checknil(res);
if(n->xoffset != 0) {
nodconst(&n1, types[tptr], n->xoffset);
gins(optoas(OADD, types[tptr]), &n1, res);
}
break;
}
}
/*
* 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.
*/
void
igen(Node *n, Node *a, Node *res)
{
Type *fp;
Iter flist;
Node n1;
if(debug['g']) {
dump("\nigen-n", n);
}
switch(n->op) {
case ONAME:
if((n->class&PHEAP) || n->class == PPARAMREF)
break;
*a = *n;
return;
case OINDREG:
// Increase the refcount of the register so that igen's caller
// has to call regfree.
if(n->val.u.reg != D_SP)
reg[n->val.u.reg]++;
*a = *n;
return;
case ODOT:
igen(n->left, a, res);
a->xoffset += n->xoffset;
a->type = n->type;
return;
case ODOTPTR:
switch(n->left->op) {
case ODOT:
case ODOTPTR:
case OCALLFUNC:
case OCALLMETH:
case OCALLINTER:
// igen-able nodes.
igen(n->left, &n1, res);
regalloc(a, types[tptr], &n1);
gmove(&n1, a);
regfree(&n1);
break;
default:
regalloc(a, types[tptr], res);
cgen(n->left, a);
}
cgen_checknil(a);
a->op = OINDREG;
a->xoffset += n->xoffset;
a->type = n->type;
return;
case OCALLFUNC:
case OCALLMETH:
case OCALLINTER:
switch(n->op) {
case OCALLFUNC:
cgen_call(n, 0);
break;
case OCALLMETH:
cgen_callmeth(n, 0);
break;
case OCALLINTER:
cgen_callinter(n, N, 0);
break;
}
fp = structfirst(&flist, getoutarg(n->left->type));
memset(a, 0, sizeof *a);
a->op = OINDREG;
a->val.u.reg = D_SP;
a->addable = 1;
a->xoffset = fp->width;
a->type = n->type;
return;
case OINDEX:
// 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.
if(isfixedarray(n->left->type) ||
(isptr[n->left->type->etype] && isfixedarray(n->left->left->type)))
if(isconst(n->right, CTINT)) {
// Compute &a.
if(!isptr[n->left->type->etype])
igen(n->left, a, res);
else {
igen(n->left, &n1, res);
cgen_checknil(&n1);
regalloc(a, types[tptr], res);
gmove(&n1, a);
regfree(&n1);
a->op = OINDREG;
}
// Compute &a[i] as &a + i*width.
a->type = n->type;
a->xoffset += mpgetfix(n->right->val.u.xval)*n->type->width;
return;
}
break;
}
// release register for now, to avoid
// confusing tempname.
if(res != N && res->op == OREGISTER)
reg[res->val.u.reg]--;
tempname(&n1, types[tptr]);
agen(n, &n1);
if(res != N && res->op == OREGISTER)
reg[res->val.u.reg]++;
regalloc(a, types[tptr], res);
gmove(&n1, a);
a->op = OINDREG;
a->type = n->type;
}
/*
* branch gen
* if(n == true) goto to;
*/
void
bgen(Node *n, int true, int likely, Prog *to)
{
int et, a;
Node *nl, *nr, *r;
Node n1, n2, tmp;
Prog *p1, *p2;
if(debug['g']) {
dump("\nbgen", n);
}
if(n == N)
n = nodbool(1);
if(n->ninit != nil)
genlist(n->ninit);
if(n->type == T) {
convlit(&n, types[TBOOL]);
if(n->type == T)
return;
}
et = n->type->etype;
if(et != TBOOL) {
yyerror("cgen: bad type %T for %O", n->type, n->op);
patch(gins(AEND, N, N), to);
return;
}
while(n->op == OCONVNOP) {
n = n->left;
if(n->ninit != nil)
genlist(n->ninit);
}
nl = n->left;
nr = N;
if(nl != N && isfloat[nl->type->etype]) {
bgen_float(n, true, likely, to);
return;
}
switch(n->op) {
default:
def:
regalloc(&n1, n->type, N);
cgen(n, &n1);
nodconst(&n2, n->type, 0);
gins(optoas(OCMP, n->type), &n1, &n2);
a = AJNE;
if(!true)
a = AJEQ;
patch(gbranch(a, n->type, likely), to);
regfree(&n1);
return;
case OLITERAL:
// need to ask if it is bool?
if(!true == !n->val.u.bval)
patch(gbranch(AJMP, T, 0), to);
return;
case ONAME:
if(!n->addable)
goto def;
nodconst(&n1, n->type, 0);
gins(optoas(OCMP, n->type), n, &n1);
a = AJNE;
if(!true)
a = AJEQ;
patch(gbranch(a, n->type, likely), to);
return;
case OANDAND:
if(!true)
goto caseor;
caseand:
p1 = gbranch(AJMP, T, 0);
p2 = gbranch(AJMP, T, 0);
patch(p1, pc);
bgen(n->left, !true, -likely, p2);
bgen(n->right, !true, -likely, p2);
p1 = gbranch(AJMP, T, 0);
patch(p1, to);
patch(p2, pc);
return;
case OOROR:
if(!true)
goto caseand;
caseor:
bgen(n->left, true, likely, to);
bgen(n->right, true, likely, to);
return;
case OEQ:
case ONE:
case OLT:
case OGT:
case OLE:
case OGE:
nr = n->right;
if(nr == N || nr->type == T)
return;
case ONOT: // unary
nl = n->left;
if(nl == N || nl->type == T)
return;
}
switch(n->op) {
case ONOT:
bgen(nl, !true, likely, to);
break;
case OEQ:
case ONE:
case OLT:
case OGT:
case OLE:
case OGE:
a = n->op;
if(!true) {
a = brcom(a);
true = !true;
}
// make simplest on right
if(nl->op == OLITERAL || (nl->ullman < nr->ullman && nl->ullman < UINF)) {
a = brrev(a);
r = nl;
nl = nr;
nr = r;
}
if(isslice(nl->type)) {
// front end should only leave cmp to literal nil
if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
yyerror("illegal slice comparison");
break;
}
a = optoas(a, types[tptr]);
igen(nl, &n1, N);
n1.xoffset += Array_array;
n1.type = types[tptr];
nodconst(&tmp, types[tptr], 0);
gins(optoas(OCMP, types[tptr]), &n1, &tmp);
patch(gbranch(a, types[tptr], likely), to);
regfree(&n1);
break;
}
if(isinter(nl->type)) {
// front end should only leave cmp to literal nil
if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
yyerror("illegal interface comparison");
break;
}
a = optoas(a, types[tptr]);
igen(nl, &n1, N);
n1.type = types[tptr];
nodconst(&tmp, types[tptr], 0);
gins(optoas(OCMP, types[tptr]), &n1, &tmp);
patch(gbranch(a, types[tptr], likely), to);
regfree(&n1);
break;
}
if(iscomplex[nl->type->etype]) {
complexbool(a, nl, nr, true, likely, to);
break;
}
if(is64(nr->type)) {
if(!nl->addable || isconst(nl, CTINT)) {
tempname(&n1, nl->type);
cgen(nl, &n1);
nl = &n1;
}
if(!nr->addable) {
tempname(&n2, nr->type);
cgen(nr, &n2);
nr = &n2;
}
cmp64(nl, nr, a, likely, to);
break;
}
if(nr->ullman >= UINF) {
if(!nl->addable) {
tempname(&n1, nl->type);
cgen(nl, &n1);
nl = &n1;
}
if(!nr->addable) {
tempname(&tmp, nr->type);
cgen(nr, &tmp);
nr = &tmp;
}
regalloc(&n2, nr->type, N);
cgen(nr, &n2);
nr = &n2;
goto cmp;
}
if(!nl->addable) {
tempname(&n1, nl->type);
cgen(nl, &n1);
nl = &n1;
}
if(smallintconst(nr)) {
gins(optoas(OCMP, nr->type), nl, nr);
patch(gbranch(optoas(a, nr->type), nr->type, likely), to);
break;
}
if(!nr->addable) {
tempname(&tmp, nr->type);
cgen(nr, &tmp);
nr = &tmp;
}
regalloc(&n2, nr->type, N);
gmove(nr, &n2);
nr = &n2;
cmp:
gins(optoas(OCMP, nr->type), nl, nr);
patch(gbranch(optoas(a, nr->type), nr->type, likely), to);
if(nl->op == OREGISTER)
regfree(nl);
regfree(nr);
break;
}
}
/*
* n is on stack, either local variable
* or return value from function call.
* return n's offset from SP.
*/
int32
stkof(Node *n)
{
Type *t;
Iter flist;
int32 off;
switch(n->op) {
case OINDREG:
return n->xoffset;
case ODOT:
t = n->left->type;
if(isptr[t->etype])
break;
off = stkof(n->left);
if(off == -1000 || off == 1000)
return off;
return off + n->xoffset;
case OINDEX:
t = n->left->type;
if(!isfixedarray(t))
break;
off = stkof(n->left);
if(off == -1000 || off == 1000)
return off;
if(isconst(n->right, CTINT))
return off + t->type->width * mpgetfix(n->right->val.u.xval);
return 1000;
case OCALLMETH:
case OCALLINTER:
case OCALLFUNC:
t = n->left->type;
if(isptr[t->etype])
t = t->type;
t = structfirst(&flist, getoutarg(t));
if(t != T)
return t->width;
break;
}
// botch - probably failing to recognize address
// arithmetic on the above. eg INDEX and DOT
return -1000;
}
/*
* struct gen
* memmove(&res, &n, w);
*/
void
sgen(Node *n, Node *res, int64 w)
{
Node dst, src, tdst, tsrc;
int32 c, q, odst, osrc;
NodeList *l;
Prog *p;
if(debug['g']) {
print("\nsgen w=%lld\n", w);
dump("r", n);
dump("res", res);
}
if(n->ullman >= UINF && res->ullman >= UINF)
fatal("sgen UINF");
if(w < 0 || (int32)w != w)
fatal("sgen copy %lld", w);
if(w == 0) {
// evaluate side effects only.
tempname(&tdst, types[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 == ONAME && strcmp(res->sym->name, ".args") == 0)
for(l = curfn->dcl; l != nil; l = l->next)
if(l->n->class == PPARAMOUT)
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.
tempname(&tsrc, n->type);
sgen(n, &tsrc, w);
sgen(&tsrc, res, w);
return;
}
nodreg(&dst, types[tptr], D_DI);
nodreg(&src, types[tptr], D_SI);
tempname(&tsrc, types[tptr]);
tempname(&tdst, types[tptr]);
if(!n->addable)
agen(n, &tsrc);
if(!res->addable)
agen(res, &tdst);
if(n->addable)
agen(n, &src);
else
gmove(&tsrc, &src);
if(res->op == ONAME)
gvardef(res);
if(res->addable)
agen(res, &dst);
else
gmove(&tdst, &dst);
c = w % 4; // bytes
q = w / 4; // doublewords
// 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(ASTD, N, N); // set direction flag
if(c > 0) {
gconreg(AADDL, w-1, D_SI);
gconreg(AADDL, w-1, D_DI);
gconreg(AMOVL, c, D_CX);
gins(AREP, N, N); // repeat
gins(AMOVSB, N, N); // MOVB *(SI)-,*(DI)-
}
if(q > 0) {
if(c > 0) {
gconreg(AADDL, -3, D_SI);
gconreg(AADDL, -3, D_DI);
} else {
gconreg(AADDL, w-4, D_SI);
gconreg(AADDL, w-4, D_DI);
}
gconreg(AMOVL, q, D_CX);
gins(AREP, N, N); // repeat
gins(AMOVSL, N, N); // MOVL *(SI)-,*(DI)-
}
// we leave with the flag clear
gins(ACLD, N, N);
} else {
gins(ACLD, N, N); // paranoia. TODO(rsc): remove?
// normal direction
if(q > 128 || (q >= 4 && nacl)) {
gconreg(AMOVL, q, D_CX);
gins(AREP, N, N); // repeat
gins(AMOVSL, N, N); // MOVL *(SI)+,*(DI)+
} else if(q >= 4) {
p = gins(ADUFFCOPY, N, N);
p->to.type = D_ADDR;
p->to.sym = linksym(pkglookup("duffcopy", runtimepkg));
// 10 and 128 = magic constants: see ../../pkg/runtime/asm_386.s
p->to.offset = 10*(128-q);
} else
while(q > 0) {
gins(AMOVSL, N, N); // MOVL *(SI)+,*(DI)+
q--;
}
while(c > 0) {
gins(AMOVSB, N, N); // MOVB *(SI)+,*(DI)+
c--;
}
}
}
static int
cadable(Node *n)
{
if(!n->addable) {
// dont know how it happens,
// but it does
return 0;
}
switch(n->op) {
case ONAME:
return 1;
}
return 0;
}
/*
* copy a composite value by moving its individual components.
* Slices, strings and interfaces are supported.
* nr is N when assigning a zero value.
* return 1 if can do, 0 if can't.
*/
int
componentgen(Node *nr, Node *nl)
{
Node nodl, nodr;
int freel, freer;
freel = 0;
freer = 0;
switch(nl->type->etype) {
default:
goto no;
case TARRAY:
if(!isslice(nl->type))
goto no;
case TSTRING:
case TINTER:
break;
}
nodl = *nl;
if(!cadable(nl)) {
if(nr == N || !cadable(nr))
goto no;
igen(nl, &nodl, N);
freel = 1;
}
if(nr != N) {
nodr = *nr;
if(!cadable(nr)) {
igen(nr, &nodr, N);
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 != N && nl->op == ONAME && nr->op == ONAME && nl == nr)
goto yes;
switch(nl->type->etype) {
case TARRAY:
if(nl->op == ONAME)
gvardef(nl);
nodl.xoffset += Array_array;
nodl.type = ptrto(nl->type->type);
if(nr != N) {
nodr.xoffset += Array_array;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
nodl.xoffset += Array_nel-Array_array;
nodl.type = types[TUINT32];
if(nr != N) {
nodr.xoffset += Array_nel-Array_array;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
nodl.xoffset += Array_cap-Array_nel;
nodl.type = types[TUINT32];
if(nr != N) {
nodr.xoffset += Array_cap-Array_nel;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
goto yes;
case TSTRING:
if(nl->op == ONAME)
gvardef(nl);
nodl.xoffset += Array_array;
nodl.type = ptrto(types[TUINT8]);
if(nr != N) {
nodr.xoffset += Array_array;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
nodl.xoffset += Array_nel-Array_array;
nodl.type = types[TUINT32];
if(nr != N) {
nodr.xoffset += Array_nel-Array_array;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
goto yes;
case TINTER:
if(nl->op == ONAME)
gvardef(nl);
nodl.xoffset += Array_array;
nodl.type = ptrto(types[TUINT8]);
if(nr != N) {
nodr.xoffset += Array_array;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
nodl.xoffset += Array_nel-Array_array;
nodl.type = ptrto(types[TUINT8]);
if(nr != N) {
nodr.xoffset += Array_nel-Array_array;
nodr.type = nodl.type;
} else
nodconst(&nodr, nodl.type, 0);
gmove(&nodr, &nodl);
goto yes;
}
no:
if(freer)
regfree(&nodr);
if(freel)
regfree(&nodl);
return 0;
yes:
if(freer)
regfree(&nodr);
if(freel)
regfree(&nodl);
return 1;
}