blob: f66c87b5a456db8f3c318483d78b100bc8b10f3e [file] [log] [blame]
// Derived from Inferno utils/5c/txt.c
// http://code.google.com/p/inferno-os/source/browse/utils/5c/txt.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#include <u.h>
#include <libc.h>
#include "gg.h"
#include "../../pkg/runtime/funcdata.h"
// TODO(rsc): Can make this bigger if we move
// the text segment up higher in 5l for all GOOS.
// At the same time, can raise StackBig in ../../pkg/runtime/stack.h.
long unmappedzero = 4096;
void
clearp(Prog *p)
{
p->as = AEND;
p->reg = NREG;
p->scond = C_SCOND_NONE;
p->from.type = D_NONE;
p->from.name = D_NONE;
p->from.reg = NREG;
p->to.type = D_NONE;
p->to.name = D_NONE;
p->to.reg = NREG;
p->pc = pcloc;
pcloc++;
}
static int ddumped;
static Prog *dfirst;
static Prog *dpc;
/*
* generate and return proc with p->as = as,
* linked into program. pc is next instruction.
*/
Prog*
prog(int as)
{
Prog *p;
if(as == ADATA || as == AGLOBL) {
if(ddumped)
fatal("already dumped data");
if(dpc == nil) {
dpc = mal(sizeof(*dpc));
dfirst = dpc;
}
p = dpc;
dpc = mal(sizeof(*dpc));
p->link = dpc;
p->reg = 0; // used for flags
} else {
p = pc;
pc = mal(sizeof(*pc));
clearp(pc);
p->link = pc;
}
if(lineno == 0) {
if(debug['K'])
warn("prog: line 0");
}
p->as = as;
p->lineno = lineno;
return p;
}
void
dumpdata(void)
{
ddumped = 1;
if(dfirst == nil)
return;
newplist();
*pc = *dfirst;
pc = dpc;
clearp(pc);
}
/*
* generate a branch.
* t is ignored.
* likely values are for branch prediction:
* -1 unlikely
* 0 no opinion
* +1 likely
*/
Prog*
gbranch(int as, Type *t, int likely)
{
Prog *p;
USED(t);
USED(likely); // TODO: record this for linker
p = prog(as);
p->to.type = D_BRANCH;
p->to.u.branch = P;
return p;
}
/*
* patch previous branch to jump to to.
*/
void
patch(Prog *p, Prog *to)
{
if(p->to.type != D_BRANCH)
fatal("patch: not a branch");
p->to.u.branch = to;
p->to.offset = to->pc;
}
Prog*
unpatch(Prog *p)
{
Prog *q;
if(p->to.type != D_BRANCH)
fatal("unpatch: not a branch");
q = p->to.u.branch;
p->to.u.branch = P;
p->to.offset = 0;
return q;
}
/*
* start a new Prog list.
*/
Plist*
newplist(void)
{
Plist *pl;
pl = linknewplist(ctxt);
pc = mal(sizeof(*pc));
clearp(pc);
pl->firstpc = pc;
return pl;
}
void
gused(Node *n)
{
gins(ANOP, n, N); // used
}
Prog*
gjmp(Prog *to)
{
Prog *p;
p = gbranch(AB, T, 0);
if(to != P)
patch(p, to);
return p;
}
void
ggloblnod(Node *nam)
{
Prog *p;
p = gins(AGLOBL, nam, N);
p->lineno = nam->lineno;
p->from.sym->gotype = linksym(ngotype(nam));
p->to.sym = nil;
p->to.type = D_CONST;
p->to.offset = nam->type->width;
if(nam->readonly)
p->reg = RODATA;
if(nam->type != T && !haspointers(nam->type))
p->reg |= NOPTR;
}
void
gargsize(int32 size)
{
Node n1, n2;
nodconst(&n1, types[TINT32], PCDATA_ArgSize);
nodconst(&n2, types[TINT32], size);
gins(APCDATA, &n1, &n2);
}
void
ggloblsym(Sym *s, int32 width, int dupok, int rodata)
{
Prog *p;
p = gins(AGLOBL, N, N);
p->from.type = D_OREG;
p->from.name = D_EXTERN;
p->from.sym = linksym(s);
p->to.type = D_CONST;
p->to.name = D_NONE;
p->to.offset = width;
if(dupok)
p->reg |= DUPOK;
if(rodata)
p->reg |= RODATA;
}
void
gtrack(Sym *s)
{
Prog *p;
p = gins(AUSEFIELD, N, N);
p->from.type = D_OREG;
p->from.name = D_EXTERN;
p->from.sym = linksym(s);
}
int
isfat(Type *t)
{
if(t != T)
switch(t->etype) {
case TSTRUCT:
case TARRAY:
case TSTRING:
case TINTER: // maybe remove later
return 1;
}
return 0;
}
/*
* naddr of func generates code for address of func.
* if using opcode that can take address implicitly,
* call afunclit to fix up the argument.
* also fix up direct register references to be D_OREG.
*/
void
afunclit(Addr *a, Node *n)
{
if(a->type == D_CONST && a->name == D_EXTERN || a->type == D_REG) {
a->type = D_OREG;
if(n->op == ONAME)
a->sym = linksym(n->sym);
}
}
static int resvd[] =
{
9, // reserved for m
10, // reserved for g
REGSP, // reserved for SP
};
void
ginit(void)
{
int i;
for(i=0; i<nelem(reg); i++)
reg[i] = 0;
for(i=0; i<nelem(resvd); i++)
reg[resvd[i]]++;
}
void
gclean(void)
{
int i;
for(i=0; i<nelem(resvd); i++)
reg[resvd[i]]--;
for(i=0; i<nelem(reg); i++)
if(reg[i])
yyerror("reg %R left allocated\n", i);
}
int32
anyregalloc(void)
{
int i, j;
for(i=0; i<nelem(reg); i++) {
if(reg[i] == 0)
goto ok;
for(j=0; j<nelem(resvd); j++)
if(resvd[j] == i)
goto ok;
return 1;
ok:;
}
return 0;
}
uintptr regpc[REGALLOC_FMAX+1];
/*
* allocate register of type t, leave in n.
* if o != N, o is desired fixed register.
* caller must regfree(n).
*/
void
regalloc(Node *n, Type *t, Node *o)
{
int i, et, fixfree, floatfree;
if(0 && debug['r']) {
fixfree = 0;
for(i=REGALLOC_R0; i<=REGALLOC_RMAX; i++)
if(reg[i] == 0)
fixfree++;
floatfree = 0;
for(i=REGALLOC_F0; i<=REGALLOC_FMAX; i++)
if(reg[i] == 0)
floatfree++;
print("regalloc fix %d float %d\n", fixfree, floatfree);
}
if(t == T)
fatal("regalloc: t nil");
et = simtype[t->etype];
if(is64(t))
fatal("regalloc: 64 bit type %T");
switch(et) {
case TINT8:
case TUINT8:
case TINT16:
case TUINT16:
case TINT32:
case TUINT32:
case TPTR32:
case TBOOL:
if(o != N && o->op == OREGISTER) {
i = o->val.u.reg;
if(i >= REGALLOC_R0 && i <= REGALLOC_RMAX)
goto out;
}
for(i=REGALLOC_R0; i<=REGALLOC_RMAX; i++)
if(reg[i] == 0) {
regpc[i] = (uintptr)getcallerpc(&n);
goto out;
}
print("registers allocated at\n");
for(i=REGALLOC_R0; i<=REGALLOC_RMAX; i++)
print("%d %p\n", i, regpc[i]);
yyerror("out of fixed registers");
goto err;
case TFLOAT32:
case TFLOAT64:
if(o != N && o->op == OREGISTER) {
i = o->val.u.reg;
if(i >= REGALLOC_F0 && i <= REGALLOC_FMAX)
goto out;
}
for(i=REGALLOC_F0; i<=REGALLOC_FMAX; i++)
if(reg[i] == 0)
goto out;
yyerror("out of floating point registers");
goto err;
case TCOMPLEX64:
case TCOMPLEX128:
tempname(n, t);
return;
}
yyerror("regalloc: unknown type %T", t);
err:
nodreg(n, t, 0);
return;
out:
reg[i]++;
nodreg(n, t, i);
}
void
regfree(Node *n)
{
int i, fixfree, floatfree;
if(0 && debug['r']) {
fixfree = 0;
for(i=REGALLOC_R0; i<=REGALLOC_RMAX; i++)
if(reg[i] == 0)
fixfree++;
floatfree = 0;
for(i=REGALLOC_F0; i<=REGALLOC_FMAX; i++)
if(reg[i] == 0)
floatfree++;
print("regalloc fix %d float %d\n", fixfree, floatfree);
}
if(n->op == ONAME)
return;
if(n->op != OREGISTER && n->op != OINDREG)
fatal("regfree: not a register");
i = n->val.u.reg;
if(i == REGSP)
return;
if(i < 0 || i >= nelem(reg) || i >= nelem(regpc))
fatal("regfree: reg out of range");
if(reg[i] <= 0)
fatal("regfree: reg %R not allocated", i);
reg[i]--;
if(reg[i] == 0)
regpc[i] = 0;
}
/*
* initialize n to be register r of type t.
*/
void
nodreg(Node *n, Type *t, int r)
{
if(t == T)
fatal("nodreg: t nil");
memset(n, 0, sizeof(*n));
n->op = OREGISTER;
n->addable = 1;
ullmancalc(n);
n->val.u.reg = r;
n->type = t;
}
/*
* initialize n to be indirect of register r; n is type t.
*/
void
nodindreg(Node *n, Type *t, int r)
{
nodreg(n, t, r);
n->op = OINDREG;
}
Node*
nodarg(Type *t, int fp)
{
Node *n;
NodeList *l;
Type *first;
Iter savet;
// entire argument struct, not just one arg
if(t->etype == TSTRUCT && t->funarg) {
n = nod(ONAME, N, N);
n->sym = lookup(".args");
n->type = t;
first = structfirst(&savet, &t);
if(first == nil)
fatal("nodarg: bad struct");
if(first->width == BADWIDTH)
fatal("nodarg: offset not computed for %T", t);
n->xoffset = first->width;
n->addable = 1;
goto fp;
}
if(t->etype != TFIELD)
fatal("nodarg: not field %T", t);
if(fp == 1) {
for(l=curfn->dcl; l; l=l->next) {
n = l->n;
if((n->class == PPARAM || n->class == PPARAMOUT) && !isblanksym(t->sym) && n->sym == t->sym)
return n;
}
}
n = nod(ONAME, N, N);
n->type = t->type;
n->sym = t->sym;
if(t->width == BADWIDTH)
fatal("nodarg: offset not computed for %T", t);
n->xoffset = t->width;
n->addable = 1;
n->orig = t->nname;
fp:
// Rewrite argument named _ to __,
// or else the assignment to _ will be
// discarded during code generation.
if(isblank(n))
n->sym = lookup("__");
switch(fp) {
default:
fatal("nodarg %T %d", t, fp);
case 0: // output arg for calling another function
n->op = OINDREG;
n->val.u.reg = REGSP;
n->xoffset += 4;
break;
case 1: // input arg to current function
n->class = PPARAM;
break;
}
n->typecheck = 1;
return n;
}
/*
* return constant i node.
* overwritten by next call, but useful in calls to gins.
*/
Node*
ncon(uint32 i)
{
static Node n;
if(n.type == T)
nodconst(&n, types[TUINT32], 0);
mpmovecfix(n.val.u.xval, i);
return &n;
}
/*
* Is this node a memory operand?
*/
int
ismem(Node *n)
{
switch(n->op) {
case OINDREG:
case ONAME:
case OPARAM:
case OCLOSUREVAR:
return 1;
}
return 0;
}
Node sclean[10];
int nsclean;
/*
* n is a 64-bit value. fill in lo and hi to refer to its 32-bit halves.
*/
void
split64(Node *n, Node *lo, Node *hi)
{
Node n1;
int64 i;
if(!is64(n->type))
fatal("split64 %T", n->type);
if(nsclean >= nelem(sclean))
fatal("split64 clean");
sclean[nsclean].op = OEMPTY;
nsclean++;
switch(n->op) {
default:
if(!dotaddable(n, &n1)) {
igen(n, &n1, N);
sclean[nsclean-1] = n1;
}
n = &n1;
goto common;
case ONAME:
if(n->class == PPARAMREF) {
cgen(n->heapaddr, &n1);
sclean[nsclean-1] = n1;
// fall through.
n = &n1;
}
goto common;
case OINDREG:
common:
*lo = *n;
*hi = *n;
lo->type = types[TUINT32];
if(n->type->etype == TINT64)
hi->type = types[TINT32];
else
hi->type = types[TUINT32];
hi->xoffset += 4;
break;
case OLITERAL:
convconst(&n1, n->type, &n->val);
i = mpgetfix(n1.val.u.xval);
nodconst(lo, types[TUINT32], (uint32)i);
i >>= 32;
if(n->type->etype == TINT64)
nodconst(hi, types[TINT32], (int32)i);
else
nodconst(hi, types[TUINT32], (uint32)i);
break;
}
}
void
splitclean(void)
{
if(nsclean <= 0)
fatal("splitclean");
nsclean--;
if(sclean[nsclean].op != OEMPTY)
regfree(&sclean[nsclean]);
}
#define CASE(a,b) (((a)<<16)|((b)<<0))
void
gmove(Node *f, Node *t)
{
int a, ft, tt, fa, ta;
Type *cvt;
Node r1, r2, flo, fhi, tlo, thi, con;
Prog *p1;
if(debug['M'])
print("gmove %N -> %N\n", f, t);
ft = simsimtype(f->type);
tt = simsimtype(t->type);
cvt = t->type;
if(iscomplex[ft] || iscomplex[tt]) {
complexmove(f, t);
return;
}
// cannot have two memory operands;
// except 64-bit, which always copies via registers anyway.
if(!is64(f->type) && !is64(t->type) && ismem(f) && ismem(t))
goto hard;
// convert constant to desired type
if(f->op == OLITERAL) {
switch(tt) {
default:
convconst(&con, t->type, &f->val);
break;
case TINT16:
case TINT8:
convconst(&con, types[TINT32], &f->val);
regalloc(&r1, con.type, t);
gins(AMOVW, &con, &r1);
gmove(&r1, t);
regfree(&r1);
return;
case TUINT16:
case TUINT8:
convconst(&con, types[TUINT32], &f->val);
regalloc(&r1, con.type, t);
gins(AMOVW, &con, &r1);
gmove(&r1, t);
regfree(&r1);
return;
}
f = &con;
ft = simsimtype(con.type);
// constants can't move directly to memory
if(ismem(t) && !is64(t->type)) goto hard;
}
// value -> value copy, only one memory operand.
// figure out the instruction to use.
// break out of switch for one-instruction gins.
// goto rdst for "destination must be register".
// goto hard for "convert to cvt type first".
// otherwise handle and return.
switch(CASE(ft, tt)) {
default:
goto fatal;
/*
* integer copy and truncate
*/
case CASE(TINT8, TINT8): // same size
if(!ismem(f)) {
a = AMOVB;
break;
}
case CASE(TUINT8, TINT8):
case CASE(TINT16, TINT8): // truncate
case CASE(TUINT16, TINT8):
case CASE(TINT32, TINT8):
case CASE(TUINT32, TINT8):
a = AMOVBS;
break;
case CASE(TUINT8, TUINT8):
if(!ismem(f)) {
a = AMOVB;
break;
}
case CASE(TINT8, TUINT8):
case CASE(TINT16, TUINT8):
case CASE(TUINT16, TUINT8):
case CASE(TINT32, TUINT8):
case CASE(TUINT32, TUINT8):
a = AMOVBU;
break;
case CASE(TINT64, TINT8): // truncate low word
case CASE(TUINT64, TINT8):
a = AMOVBS;
goto trunc64;
case CASE(TINT64, TUINT8):
case CASE(TUINT64, TUINT8):
a = AMOVBU;
goto trunc64;
case CASE(TINT16, TINT16): // same size
if(!ismem(f)) {
a = AMOVH;
break;
}
case CASE(TUINT16, TINT16):
case CASE(TINT32, TINT16): // truncate
case CASE(TUINT32, TINT16):
a = AMOVHS;
break;
case CASE(TUINT16, TUINT16):
if(!ismem(f)) {
a = AMOVH;
break;
}
case CASE(TINT16, TUINT16):
case CASE(TINT32, TUINT16):
case CASE(TUINT32, TUINT16):
a = AMOVHU;
break;
case CASE(TINT64, TINT16): // truncate low word
case CASE(TUINT64, TINT16):
a = AMOVHS;
goto trunc64;
case CASE(TINT64, TUINT16):
case CASE(TUINT64, TUINT16):
a = AMOVHU;
goto trunc64;
case CASE(TINT32, TINT32): // same size
case CASE(TINT32, TUINT32):
case CASE(TUINT32, TINT32):
case CASE(TUINT32, TUINT32):
a = AMOVW;
break;
case CASE(TINT64, TINT32): // truncate
case CASE(TUINT64, TINT32):
case CASE(TINT64, TUINT32):
case CASE(TUINT64, TUINT32):
split64(f, &flo, &fhi);
regalloc(&r1, t->type, N);
gins(AMOVW, &flo, &r1);
gins(AMOVW, &r1, t);
regfree(&r1);
splitclean();
return;
case CASE(TINT64, TINT64): // same size
case CASE(TINT64, TUINT64):
case CASE(TUINT64, TINT64):
case CASE(TUINT64, TUINT64):
split64(f, &flo, &fhi);
split64(t, &tlo, &thi);
regalloc(&r1, flo.type, N);
regalloc(&r2, fhi.type, N);
gins(AMOVW, &flo, &r1);
gins(AMOVW, &fhi, &r2);
gins(AMOVW, &r1, &tlo);
gins(AMOVW, &r2, &thi);
regfree(&r1);
regfree(&r2);
splitclean();
splitclean();
return;
/*
* integer up-conversions
*/
case CASE(TINT8, TINT16): // sign extend int8
case CASE(TINT8, TUINT16):
case CASE(TINT8, TINT32):
case CASE(TINT8, TUINT32):
a = AMOVBS;
goto rdst;
case CASE(TINT8, TINT64): // convert via int32
case CASE(TINT8, TUINT64):
cvt = types[TINT32];
goto hard;
case CASE(TUINT8, TINT16): // zero extend uint8
case CASE(TUINT8, TUINT16):
case CASE(TUINT8, TINT32):
case CASE(TUINT8, TUINT32):
a = AMOVBU;
goto rdst;
case CASE(TUINT8, TINT64): // convert via uint32
case CASE(TUINT8, TUINT64):
cvt = types[TUINT32];
goto hard;
case CASE(TINT16, TINT32): // sign extend int16
case CASE(TINT16, TUINT32):
a = AMOVHS;
goto rdst;
case CASE(TINT16, TINT64): // convert via int32
case CASE(TINT16, TUINT64):
cvt = types[TINT32];
goto hard;
case CASE(TUINT16, TINT32): // zero extend uint16
case CASE(TUINT16, TUINT32):
a = AMOVHU;
goto rdst;
case CASE(TUINT16, TINT64): // convert via uint32
case CASE(TUINT16, TUINT64):
cvt = types[TUINT32];
goto hard;
case CASE(TINT32, TINT64): // sign extend int32
case CASE(TINT32, TUINT64):
split64(t, &tlo, &thi);
regalloc(&r1, tlo.type, N);
regalloc(&r2, thi.type, N);
gmove(f, &r1);
p1 = gins(AMOVW, &r1, &r2);
p1->from.type = D_SHIFT;
p1->from.offset = 2 << 5 | 31 << 7 | r1.val.u.reg; // r1->31
p1->from.reg = NREG;
//print("gmove: %P\n", p1);
gins(AMOVW, &r1, &tlo);
gins(AMOVW, &r2, &thi);
regfree(&r1);
regfree(&r2);
splitclean();
return;
case CASE(TUINT32, TINT64): // zero extend uint32
case CASE(TUINT32, TUINT64):
split64(t, &tlo, &thi);
gmove(f, &tlo);
regalloc(&r1, thi.type, N);
gins(AMOVW, ncon(0), &r1);
gins(AMOVW, &r1, &thi);
regfree(&r1);
splitclean();
return;
/*
* float to integer
*/
case CASE(TFLOAT32, TINT8):
case CASE(TFLOAT32, TUINT8):
case CASE(TFLOAT32, TINT16):
case CASE(TFLOAT32, TUINT16):
case CASE(TFLOAT32, TINT32):
case CASE(TFLOAT32, TUINT32):
// case CASE(TFLOAT32, TUINT64):
case CASE(TFLOAT64, TINT8):
case CASE(TFLOAT64, TUINT8):
case CASE(TFLOAT64, TINT16):
case CASE(TFLOAT64, TUINT16):
case CASE(TFLOAT64, TINT32):
case CASE(TFLOAT64, TUINT32):
// case CASE(TFLOAT64, TUINT64):
fa = AMOVF;
a = AMOVFW;
if(ft == TFLOAT64) {
fa = AMOVD;
a = AMOVDW;
}
ta = AMOVW;
switch(tt) {
case TINT8:
ta = AMOVBS;
break;
case TUINT8:
ta = AMOVBU;
break;
case TINT16:
ta = AMOVHS;
break;
case TUINT16:
ta = AMOVHU;
break;
}
regalloc(&r1, types[ft], f);
regalloc(&r2, types[tt], t);
gins(fa, f, &r1); // load to fpu
p1 = gins(a, &r1, &r1); // convert to w
switch(tt) {
case TUINT8:
case TUINT16:
case TUINT32:
p1->scond |= C_UBIT;
}
gins(AMOVW, &r1, &r2); // copy to cpu
gins(ta, &r2, t); // store
regfree(&r1);
regfree(&r2);
return;
/*
* integer to float
*/
case CASE(TINT8, TFLOAT32):
case CASE(TUINT8, TFLOAT32):
case CASE(TINT16, TFLOAT32):
case CASE(TUINT16, TFLOAT32):
case CASE(TINT32, TFLOAT32):
case CASE(TUINT32, TFLOAT32):
case CASE(TINT8, TFLOAT64):
case CASE(TUINT8, TFLOAT64):
case CASE(TINT16, TFLOAT64):
case CASE(TUINT16, TFLOAT64):
case CASE(TINT32, TFLOAT64):
case CASE(TUINT32, TFLOAT64):
fa = AMOVW;
switch(ft) {
case TINT8:
fa = AMOVBS;
break;
case TUINT8:
fa = AMOVBU;
break;
case TINT16:
fa = AMOVHS;
break;
case TUINT16:
fa = AMOVHU;
break;
}
a = AMOVWF;
ta = AMOVF;
if(tt == TFLOAT64) {
a = AMOVWD;
ta = AMOVD;
}
regalloc(&r1, types[ft], f);
regalloc(&r2, types[tt], t);
gins(fa, f, &r1); // load to cpu
gins(AMOVW, &r1, &r2); // copy to fpu
p1 = gins(a, &r2, &r2); // convert
switch(ft) {
case TUINT8:
case TUINT16:
case TUINT32:
p1->scond |= C_UBIT;
}
gins(ta, &r2, t); // store
regfree(&r1);
regfree(&r2);
return;
case CASE(TUINT64, TFLOAT32):
case CASE(TUINT64, TFLOAT64):
fatal("gmove UINT64, TFLOAT not implemented");
return;
/*
* float to float
*/
case CASE(TFLOAT32, TFLOAT32):
a = AMOVF;
break;
case CASE(TFLOAT64, TFLOAT64):
a = AMOVD;
break;
case CASE(TFLOAT32, TFLOAT64):
regalloc(&r1, types[TFLOAT64], t);
gins(AMOVF, f, &r1);
gins(AMOVFD, &r1, &r1);
gins(AMOVD, &r1, t);
regfree(&r1);
return;
case CASE(TFLOAT64, TFLOAT32):
regalloc(&r1, types[TFLOAT64], t);
gins(AMOVD, f, &r1);
gins(AMOVDF, &r1, &r1);
gins(AMOVF, &r1, t);
regfree(&r1);
return;
}
gins(a, f, t);
return;
rdst:
// TODO(kaib): we almost always require a register dest anyway, this can probably be
// removed.
// requires register destination
regalloc(&r1, t->type, t);
gins(a, f, &r1);
gmove(&r1, t);
regfree(&r1);
return;
hard:
// requires register intermediate
regalloc(&r1, cvt, t);
gmove(f, &r1);
gmove(&r1, t);
regfree(&r1);
return;
trunc64:
// truncate 64 bit integer
split64(f, &flo, &fhi);
regalloc(&r1, t->type, N);
gins(a, &flo, &r1);
gins(a, &r1, t);
regfree(&r1);
splitclean();
return;
fatal:
// should not happen
fatal("gmove %N -> %N", f, t);
}
int
samaddr(Node *f, Node *t)
{
if(f->op != t->op)
return 0;
switch(f->op) {
case OREGISTER:
if(f->val.u.reg != t->val.u.reg)
break;
return 1;
}
return 0;
}
/*
* generate one instruction:
* as f, t
*/
Prog*
gins(int as, Node *f, Node *t)
{
// Node nod;
// int32 v;
Prog *p;
Addr af, at;
if(f != N && f->op == OINDEX) {
fatal("gins OINDEX not implemented");
// regalloc(&nod, &regnode, Z);
// v = constnode.vconst;
// cgen(f->right, &nod);
// constnode.vconst = v;
// idx.reg = nod.reg;
// regfree(&nod);
}
if(t != N && t->op == OINDEX) {
fatal("gins OINDEX not implemented");
// regalloc(&nod, &regnode, Z);
// v = constnode.vconst;
// cgen(t->right, &nod);
// constnode.vconst = v;
// idx.reg = nod.reg;
// regfree(&nod);
}
memset(&af, 0, sizeof af);
memset(&at, 0, sizeof at);
if(f != N)
naddr(f, &af, 1);
if(t != N)
naddr(t, &at, 1);
p = prog(as);
if(f != N)
p->from = af;
if(t != N)
p->to = at;
if(debug['g'])
print("%P\n", p);
return p;
}
/*
* insert n into reg slot of p
*/
void
raddr(Node *n, Prog *p)
{
Addr a;
naddr(n, &a, 1);
if(a.type != D_REG && a.type != D_FREG) {
if(n)
fatal("bad in raddr: %O", n->op);
else
fatal("bad in raddr: <null>");
p->reg = NREG;
} else
p->reg = a.reg;
}
/* generate a comparison
TODO(kaib): one of the args can actually be a small constant. relax the constraint and fix call sites.
*/
Prog*
gcmp(int as, Node *lhs, Node *rhs)
{
Prog *p;
if(lhs->op != OREGISTER)
fatal("bad operands to gcmp: %O %O", lhs->op, rhs->op);
p = gins(as, rhs, N);
raddr(lhs, p);
return p;
}
/* generate a constant shift
* arm encodes a shift by 32 as 0, thus asking for 0 shift is illegal.
*/
Prog*
gshift(int as, Node *lhs, int32 stype, int32 sval, Node *rhs)
{
Prog *p;
if(sval <= 0 || sval > 32)
fatal("bad shift value: %d", sval);
sval = sval&0x1f;
p = gins(as, N, rhs);
p->from.type = D_SHIFT;
p->from.offset = stype | sval<<7 | lhs->val.u.reg;
return p;
}
/* generate a register shift
*/
Prog *
gregshift(int as, Node *lhs, int32 stype, Node *reg, Node *rhs)
{
Prog *p;
p = gins(as, N, rhs);
p->from.type = D_SHIFT;
p->from.offset = stype | reg->val.u.reg << 8 | 1<<4 | lhs->val.u.reg;
return p;
}
/*
* generate code to compute n;
* make a refer to result.
*/
void
naddr(Node *n, Addr *a, int canemitcode)
{
Sym *s;
a->type = D_NONE;
a->name = D_NONE;
a->reg = NREG;
a->gotype = nil;
a->node = N;
a->etype = 0;
if(n == N)
return;
if(n->type != T && n->type->etype != TIDEAL) {
dowidth(n->type);
a->width = n->type->width;
}
switch(n->op) {
default:
fatal("naddr: bad %O %D", n->op, a);
break;
case OREGISTER:
if(n->val.u.reg <= REGALLOC_RMAX) {
a->type = D_REG;
a->reg = n->val.u.reg;
} else {
a->type = D_FREG;
a->reg = n->val.u.reg - REGALLOC_F0;
}
a->sym = nil;
break;
case OINDEX:
case OIND:
fatal("naddr: OINDEX");
// naddr(n->left, a);
// if(a->type >= D_AX && a->type <= D_DI)
// a->type += D_INDIR;
// else
// if(a->type == D_CONST)
// a->type = D_NONE+D_INDIR;
// else
// if(a->type == D_ADDR) {
// a->type = a->index;
// a->index = D_NONE;
// } else
// goto bad;
// if(n->op == OINDEX) {
// a->index = idx.reg;
// a->scale = n->scale;
// }
// break;
case OINDREG:
a->type = D_OREG;
a->reg = n->val.u.reg;
a->sym = linksym(n->sym);
a->offset = n->xoffset;
break;
case OPARAM:
// n->left is PHEAP ONAME for stack parameter.
// compute address of actual parameter on stack.
a->etype = simtype[n->left->type->etype];
a->width = n->left->type->width;
a->offset = n->xoffset;
a->sym = linksym(n->left->sym);
a->type = D_OREG;
a->name = D_PARAM;
a->node = n->left->orig;
break;
case OCLOSUREVAR:
if(!curfn->needctxt)
fatal("closurevar without needctxt");
a->type = D_OREG;
a->reg = 7;
a->offset = n->xoffset;
a->sym = nil;
break;
case OCFUNC:
naddr(n->left, a, canemitcode);
a->sym = linksym(n->left->sym);
break;
case ONAME:
a->etype = 0;
a->width = 0;
a->reg = NREG;
if(n->type != T) {
a->etype = simtype[n->type->etype];
a->width = n->type->width;
}
a->offset = n->xoffset;
s = n->sym;
a->node = n->orig;
//if(a->node >= (Node*)&n)
// fatal("stack node");
if(s == S)
s = lookup(".noname");
if(n->method) {
if(n->type != T)
if(n->type->sym != S)
if(n->type->sym->pkg != nil)
s = pkglookup(s->name, n->type->sym->pkg);
}
a->type = D_OREG;
switch(n->class) {
default:
fatal("naddr: ONAME class %S %d\n", n->sym, n->class);
case PEXTERN:
a->name = D_EXTERN;
break;
case PAUTO:
a->name = D_AUTO;
break;
case PPARAM:
case PPARAMOUT:
a->name = D_PARAM;
break;
case PFUNC:
a->name = D_EXTERN;
a->type = D_CONST;
s = funcsym(s);
break;
}
a->sym = linksym(s);
break;
case OLITERAL:
switch(n->val.ctype) {
default:
fatal("naddr: const %lT", n->type);
break;
case CTFLT:
a->type = D_FCONST;
a->u.dval = mpgetflt(n->val.u.fval);
break;
case CTINT:
case CTRUNE:
a->sym = nil;
a->type = D_CONST;
a->offset = mpgetfix(n->val.u.xval);
break;
case CTSTR:
datagostring(n->val.u.sval, a);
break;
case CTBOOL:
a->sym = nil;
a->type = D_CONST;
a->offset = n->val.u.bval;
break;
case CTNIL:
a->sym = nil;
a->type = D_CONST;
a->offset = 0;
break;
}
break;
case OITAB:
// itable of interface value
naddr(n->left, a, canemitcode);
a->etype = TINT32;
if(a->type == D_CONST && a->offset == 0)
break; // len(nil)
break;
case OSPTR:
// pointer in a string or slice
naddr(n->left, a, canemitcode);
if(a->type == D_CONST && a->offset == 0)
break; // ptr(nil)
a->etype = simtype[tptr];
a->offset += Array_array;
a->width = widthptr;
break;
case OLEN:
// len of string or slice
naddr(n->left, a, canemitcode);
a->etype = TINT32;
if(a->type == D_CONST && a->offset == 0)
break; // len(nil)
a->offset += Array_nel;
break;
case OCAP:
// cap of string or slice
naddr(n->left, a, canemitcode);
a->etype = TINT32;
if(a->type == D_CONST && a->offset == 0)
break; // cap(nil)
a->offset += Array_cap;
break;
case OADDR:
naddr(n->left, a, canemitcode);
a->etype = tptr;
switch(a->type) {
case D_OREG:
a->type = D_CONST;
break;
case D_REG:
case D_CONST:
break;
default:
fatal("naddr: OADDR %d\n", a->type);
}
}
if(a->width < 0)
fatal("naddr: bad width for %N -> %D", n, a);
}
/*
* return Axxx for Oxxx on type t.
*/
int
optoas(int op, Type *t)
{
int a;
if(t == T)
fatal("optoas: t is nil");
a = AGOK;
switch(CASE(op, simtype[t->etype])) {
default:
fatal("optoas: no entry %O-%T etype %T simtype %T", op, t, types[t->etype], types[simtype[t->etype]]);
break;
/* case CASE(OADDR, TPTR32):
a = ALEAL;
break;
case CASE(OADDR, TPTR64):
a = ALEAQ;
break;
*/
// TODO(kaib): make sure the conditional branches work on all edge cases
case CASE(OEQ, TBOOL):
case CASE(OEQ, TINT8):
case CASE(OEQ, TUINT8):
case CASE(OEQ, TINT16):
case CASE(OEQ, TUINT16):
case CASE(OEQ, TINT32):
case CASE(OEQ, TUINT32):
case CASE(OEQ, TINT64):
case CASE(OEQ, TUINT64):
case CASE(OEQ, TPTR32):
case CASE(OEQ, TPTR64):
case CASE(OEQ, TFLOAT32):
case CASE(OEQ, TFLOAT64):
a = ABEQ;
break;
case CASE(ONE, TBOOL):
case CASE(ONE, TINT8):
case CASE(ONE, TUINT8):
case CASE(ONE, TINT16):
case CASE(ONE, TUINT16):
case CASE(ONE, TINT32):
case CASE(ONE, TUINT32):
case CASE(ONE, TINT64):
case CASE(ONE, TUINT64):
case CASE(ONE, TPTR32):
case CASE(ONE, TPTR64):
case CASE(ONE, TFLOAT32):
case CASE(ONE, TFLOAT64):
a = ABNE;
break;
case CASE(OLT, TINT8):
case CASE(OLT, TINT16):
case CASE(OLT, TINT32):
case CASE(OLT, TINT64):
case CASE(OLT, TFLOAT32):
case CASE(OLT, TFLOAT64):
a = ABLT;
break;
case CASE(OLT, TUINT8):
case CASE(OLT, TUINT16):
case CASE(OLT, TUINT32):
case CASE(OLT, TUINT64):
a = ABLO;
break;
case CASE(OLE, TINT8):
case CASE(OLE, TINT16):
case CASE(OLE, TINT32):
case CASE(OLE, TINT64):
case CASE(OLE, TFLOAT32):
case CASE(OLE, TFLOAT64):
a = ABLE;
break;
case CASE(OLE, TUINT8):
case CASE(OLE, TUINT16):
case CASE(OLE, TUINT32):
case CASE(OLE, TUINT64):
a = ABLS;
break;
case CASE(OGT, TINT8):
case CASE(OGT, TINT16):
case CASE(OGT, TINT32):
case CASE(OGT, TINT64):
case CASE(OGT, TFLOAT32):
case CASE(OGT, TFLOAT64):
a = ABGT;
break;
case CASE(OGT, TUINT8):
case CASE(OGT, TUINT16):
case CASE(OGT, TUINT32):
case CASE(OGT, TUINT64):
a = ABHI;
break;
case CASE(OGE, TINT8):
case CASE(OGE, TINT16):
case CASE(OGE, TINT32):
case CASE(OGE, TINT64):
case CASE(OGE, TFLOAT32):
case CASE(OGE, TFLOAT64):
a = ABGE;
break;
case CASE(OGE, TUINT8):
case CASE(OGE, TUINT16):
case CASE(OGE, TUINT32):
case CASE(OGE, TUINT64):
a = ABHS;
break;
case CASE(OCMP, TBOOL):
case CASE(OCMP, TINT8):
case CASE(OCMP, TUINT8):
case CASE(OCMP, TINT16):
case CASE(OCMP, TUINT16):
case CASE(OCMP, TINT32):
case CASE(OCMP, TUINT32):
case CASE(OCMP, TPTR32):
a = ACMP;
break;
case CASE(OCMP, TFLOAT32):
a = ACMPF;
break;
case CASE(OCMP, TFLOAT64):
a = ACMPD;
break;
case CASE(OAS, TBOOL):
a = AMOVB;
break;
case CASE(OAS, TINT8):
a = AMOVBS;
break;
case CASE(OAS, TUINT8):
a = AMOVBU;
break;
case CASE(OAS, TINT16):
a = AMOVHS;
break;
case CASE(OAS, TUINT16):
a = AMOVHU;
break;
case CASE(OAS, TINT32):
case CASE(OAS, TUINT32):
case CASE(OAS, TPTR32):
a = AMOVW;
break;
case CASE(OAS, TFLOAT32):
a = AMOVF;
break;
case CASE(OAS, TFLOAT64):
a = AMOVD;
break;
case CASE(OADD, TINT8):
case CASE(OADD, TUINT8):
case CASE(OADD, TINT16):
case CASE(OADD, TUINT16):
case CASE(OADD, TINT32):
case CASE(OADD, TUINT32):
case CASE(OADD, TPTR32):
case CASE(OADDPTR, TPTR32):
a = AADD;
break;
case CASE(OADD, TFLOAT32):
a = AADDF;
break;
case CASE(OADD, TFLOAT64):
a = AADDD;
break;
case CASE(OSUB, TINT8):
case CASE(OSUB, TUINT8):
case CASE(OSUB, TINT16):
case CASE(OSUB, TUINT16):
case CASE(OSUB, TINT32):
case CASE(OSUB, TUINT32):
case CASE(OSUB, TPTR32):
a = ASUB;
break;
case CASE(OSUB, TFLOAT32):
a = ASUBF;
break;
case CASE(OSUB, TFLOAT64):
a = ASUBD;
break;
case CASE(OMINUS, TINT8):
case CASE(OMINUS, TUINT8):
case CASE(OMINUS, TINT16):
case CASE(OMINUS, TUINT16):
case CASE(OMINUS, TINT32):
case CASE(OMINUS, TUINT32):
case CASE(OMINUS, TPTR32):
a = ARSB;
break;
case CASE(OAND, TINT8):
case CASE(OAND, TUINT8):
case CASE(OAND, TINT16):
case CASE(OAND, TUINT16):
case CASE(OAND, TINT32):
case CASE(OAND, TUINT32):
case CASE(OAND, TPTR32):
a = AAND;
break;
case CASE(OOR, TINT8):
case CASE(OOR, TUINT8):
case CASE(OOR, TINT16):
case CASE(OOR, TUINT16):
case CASE(OOR, TINT32):
case CASE(OOR, TUINT32):
case CASE(OOR, TPTR32):
a = AORR;
break;
case CASE(OXOR, TINT8):
case CASE(OXOR, TUINT8):
case CASE(OXOR, TINT16):
case CASE(OXOR, TUINT16):
case CASE(OXOR, TINT32):
case CASE(OXOR, TUINT32):
case CASE(OXOR, TPTR32):
a = AEOR;
break;
case CASE(OLSH, TINT8):
case CASE(OLSH, TUINT8):
case CASE(OLSH, TINT16):
case CASE(OLSH, TUINT16):
case CASE(OLSH, TINT32):
case CASE(OLSH, TUINT32):
case CASE(OLSH, TPTR32):
a = ASLL;
break;
case CASE(ORSH, TUINT8):
case CASE(ORSH, TUINT16):
case CASE(ORSH, TUINT32):
case CASE(ORSH, TPTR32):
a = ASRL;
break;
case CASE(ORSH, TINT8):
case CASE(ORSH, TINT16):
case CASE(ORSH, TINT32):
a = ASRA;
break;
case CASE(OMUL, TUINT8):
case CASE(OMUL, TUINT16):
case CASE(OMUL, TUINT32):
case CASE(OMUL, TPTR32):
a = AMULU;
break;
case CASE(OMUL, TINT8):
case CASE(OMUL, TINT16):
case CASE(OMUL, TINT32):
a = AMUL;
break;
case CASE(OMUL, TFLOAT32):
a = AMULF;
break;
case CASE(OMUL, TFLOAT64):
a = AMULD;
break;
case CASE(ODIV, TUINT8):
case CASE(ODIV, TUINT16):
case CASE(ODIV, TUINT32):
case CASE(ODIV, TPTR32):
a = ADIVU;
break;
case CASE(ODIV, TINT8):
case CASE(ODIV, TINT16):
case CASE(ODIV, TINT32):
a = ADIV;
break;
case CASE(OMOD, TUINT8):
case CASE(OMOD, TUINT16):
case CASE(OMOD, TUINT32):
case CASE(OMOD, TPTR32):
a = AMODU;
break;
case CASE(OMOD, TINT8):
case CASE(OMOD, TINT16):
case CASE(OMOD, TINT32):
a = AMOD;
break;
// case CASE(OEXTEND, TINT16):
// a = ACWD;
// break;
// case CASE(OEXTEND, TINT32):
// a = ACDQ;
// break;
// case CASE(OEXTEND, TINT64):
// a = ACQO;
// break;
case CASE(ODIV, TFLOAT32):
a = ADIVF;
break;
case CASE(ODIV, TFLOAT64):
a = ADIVD;
break;
}
return a;
}
enum
{
ODynam = 1<<0,
OPtrto = 1<<1,
};
static Node clean[20];
static int cleani = 0;
void
sudoclean(void)
{
if(clean[cleani-1].op != OEMPTY)
regfree(&clean[cleani-1]);
if(clean[cleani-2].op != OEMPTY)
regfree(&clean[cleani-2]);
cleani -= 2;
}
int
dotaddable(Node *n, Node *n1)
{
int o;
int64 oary[10];
Node *nn;
if(n->op != ODOT)
return 0;
o = dotoffset(n, oary, &nn);
if(nn != N && nn->addable && o == 1 && oary[0] >= 0) {
*n1 = *nn;
n1->type = n->type;
n1->xoffset += oary[0];
return 1;
}
return 0;
}
/*
* generate code to compute address of n,
* a reference to a (perhaps nested) field inside
* an array or struct.
* return 0 on failure, 1 on success.
* on success, leaves usable address in a.
*
* caller is responsible for calling sudoclean
* after successful sudoaddable,
* to release the register used for a.
*/
int
sudoaddable(int as, Node *n, Addr *a, int *w)
{
int o, i;
int64 oary[10];
int64 v;
Node n1, n2, n3, n4, *nn, *l, *r;
Node *reg, *reg1;
Prog *p1, *p2;
Type *t;
if(n->type == T)
return 0;
switch(n->op) {
case OLITERAL:
if(!isconst(n, CTINT))
break;
v = mpgetfix(n->val.u.xval);
if(v >= 32000 || v <= -32000)
break;
goto lit;
case ODOT:
case ODOTPTR:
cleani += 2;
reg = &clean[cleani-1];
reg1 = &clean[cleani-2];
reg->op = OEMPTY;
reg1->op = OEMPTY;
goto odot;
case OINDEX:
return 0;
// disabled: OINDEX case is now covered by agenr
// for a more suitable register allocation pattern.
if(n->left->type->etype == TSTRING)
return 0;
cleani += 2;
reg = &clean[cleani-1];
reg1 = &clean[cleani-2];
reg->op = OEMPTY;
reg1->op = OEMPTY;
goto oindex;
}
return 0;
lit:
switch(as) {
default:
return 0;
case AADD: case ASUB: case AAND: case AORR: case AEOR:
case AMOVB: case AMOVBS: case AMOVBU:
case AMOVH: case AMOVHS: case AMOVHU:
case AMOVW:
break;
}
cleani += 2;
reg = &clean[cleani-1];
reg1 = &clean[cleani-2];
reg->op = OEMPTY;
reg1->op = OEMPTY;
naddr(n, a, 1);
goto yes;
odot:
o = dotoffset(n, oary, &nn);
if(nn == N)
goto no;
if(nn->addable && o == 1 && oary[0] >= 0) {
// directly addressable set of DOTs
n1 = *nn;
n1.type = n->type;
n1.xoffset += oary[0];
naddr(&n1, a, 1);
goto yes;
}
regalloc(reg, types[tptr], N);
n1 = *reg;
n1.op = OINDREG;
if(oary[0] >= 0) {
agen(nn, reg);
n1.xoffset = oary[0];
} else {
cgen(nn, reg);
cgen_checknil(reg);
n1.xoffset = -(oary[0]+1);
}
for(i=1; i<o; i++) {
if(oary[i] >= 0)
fatal("can't happen");
gins(AMOVW, &n1, reg);
cgen_checknil(reg);
n1.xoffset = -(oary[i]+1);
}
a->type = D_NONE;
a->name = D_NONE;
n1.type = n->type;
naddr(&n1, a, 1);
goto yes;
oindex:
l = n->left;
r = n->right;
if(l->ullman >= UINF && r->ullman >= UINF)
goto no;
// set o to type of array
o = 0;
if(isptr[l->type->etype]) {
o += OPtrto;
if(l->type->type->etype != TARRAY)
fatal("not ptr ary");
if(l->type->type->bound < 0)
o += ODynam;
} else {
if(l->type->etype != TARRAY)
fatal("not ary");
if(l->type->bound < 0)
o += ODynam;
}
*w = n->type->width;
if(isconst(r, CTINT))
goto oindex_const;
switch(*w) {
default:
goto no;
case 1:
case 2:
case 4:
case 8:
break;
}
// load the array (reg)
if(l->ullman > r->ullman) {
regalloc(reg, types[tptr], N);
if(o & OPtrto) {
cgen(l, reg);
cgen_checknil(reg);
} else
agen(l, reg);
}
// load the index (reg1)
t = types[TUINT32];
if(issigned[r->type->etype])
t = types[TINT32];
regalloc(reg1, t, N);
regalloc(&n3, types[TINT32], reg1);
p2 = cgenindex(r, &n3, debug['B'] || n->bounded);
gmove(&n3, reg1);
regfree(&n3);
// load the array (reg)
if(l->ullman <= r->ullman) {
regalloc(reg, types[tptr], N);
if(o & OPtrto) {
cgen(l, reg);
cgen_checknil(reg);
} else
agen(l, reg);
}
// check bounds
if(!debug['B']) {
if(o & ODynam) {
n2 = *reg;
n2.op = OINDREG;
n2.type = types[tptr];
n2.xoffset = Array_nel;
} else {
if(o & OPtrto)
nodconst(&n2, types[TUINT32], l->type->type->bound);
else
nodconst(&n2, types[TUINT32], l->type->bound);
}
regalloc(&n3, n2.type, N);
cgen(&n2, &n3);
gcmp(optoas(OCMP, types[TUINT32]), reg1, &n3);
regfree(&n3);
p1 = gbranch(optoas(OLT, types[TUINT32]), T, +1);
if(p2)
patch(p2, pc);
ginscall(panicindex, 0);
patch(p1, pc);
}
if(o & ODynam) {
n2 = *reg;
n2.op = OINDREG;
n2.type = types[tptr];
n2.xoffset = Array_array;
gmove(&n2, reg);
}
switch(*w) {
case 1:
gins(AADD, reg1, reg);
break;
case 2:
gshift(AADD, reg1, SHIFT_LL, 1, reg);
break;
case 4:
gshift(AADD, reg1, SHIFT_LL, 2, reg);
break;
case 8:
gshift(AADD, reg1, SHIFT_LL, 3, reg);
break;
}
naddr(reg1, a, 1);
a->type = D_OREG;
a->reg = reg->val.u.reg;
a->offset = 0;
goto yes;
oindex_const:
// index is constant
// can check statically and
// can multiply by width statically
regalloc(reg, types[tptr], N);
if(o & OPtrto) {
cgen(l, reg);
cgen_checknil(reg);
} else
agen(l, reg);
v = mpgetfix(r->val.u.xval);
if(o & ODynam) {
if(!debug['B'] && !n->bounded) {
n1 = *reg;
n1.op = OINDREG;
n1.type = types[tptr];
n1.xoffset = Array_nel;
nodconst(&n2, types[TUINT32], v);
regalloc(&n3, types[TUINT32], N);
cgen(&n2, &n3);
regalloc(&n4, n1.type, N);
cgen(&n1, &n4);
gcmp(optoas(OCMP, types[TUINT32]), &n4, &n3);
regfree(&n4);
regfree(&n3);
p1 = gbranch(optoas(OGT, types[TUINT32]), T, +1);
ginscall(panicindex, 0);
patch(p1, pc);
}
n1 = *reg;
n1.op = OINDREG;
n1.type = types[tptr];
n1.xoffset = Array_array;
gmove(&n1, reg);
}
n2 = *reg;
n2.op = OINDREG;
n2.xoffset = v * (*w);
a->type = D_NONE;
a->name = D_NONE;
naddr(&n2, a, 1);
goto yes;
yes:
return 1;
no:
sudoclean();
return 0;
}