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go/src/cmd/5l/span.c

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// Inferno utils/5l/span.c
// http://code.google.com/p/inferno-os/source/browse/utils/5l/span.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.
// Instruction layout.
#include "l.h"
#include "../ld/lib.h"
static struct {
uint32 start;
uint32 size;
uint32 extra;
} pool;
int checkpool(Prog*, int);
int flushpool(Prog*, int, int);
int
isbranch(Prog *p)
{
int as = p->as;
return (as >= ABEQ && as <= ABLE) || as == AB || as == ABL || as == ABX;
}
static int
scan(Prog *op, Prog *p, int c)
{
Prog *q;
for(q = op->link; q != p && q != P; q = q->link){
q->pc = c;
c += oplook(q)->size;
nocache(q);
}
return c;
}
/* size of a case statement including jump table */
static int32
casesz(Prog *p)
{
int jt = 0;
int32 n = 0;
Optab *o;
for( ; p != P; p = p->link){
if(p->as == ABCASE)
jt = 1;
else if(jt)
break;
o = oplook(p);
n += o->size;
}
return n;
}
void
span(void)
{
Prog *p, *op;
Optab *o;
int m, bflag, i, v;
int32 c, otxt, out[6];
Section *sect;
uchar *bp;
Sym *sub, *gmsym;
if(debug['v'])
Bprint(&bso, "%5.2f span\n", cputime());
Bflush(&bso);
sect = addsection(&segtext, ".text", 05);
lookup("text", 0)->sect = sect;
lookup("etext", 0)->sect = sect;
bflag = 0;
c = INITTEXT;
otxt = c;
for(cursym = textp; cursym != nil; cursym = cursym->next) {
cursym->sect = sect;
p = cursym->text;
if(p == P || p->link == P) { // handle external functions and ELF section symbols
if(cursym->type & SSUB)
continue;
if(cursym->align != 0)
c = rnd(c, cursym->align);
cursym->value = 0;
for(sub = cursym; sub != S; sub = sub->sub) {
sub->value += c;
for(p = sub->text; p != P; p = p->link)
p->pc += sub->value;
}
c += cursym->size;
continue;
}
p->pc = c;
cursym->value = c;
autosize = p->to.offset + 4;
if(p->from.sym != S)
p->from.sym->value = c;
/* need passes to resolve branches */
if(c-otxt >= 1L<<17)
bflag = 1;
otxt = c;
for(op = p, p = p->link; p != P; op = p, p = p->link) {
curp = p;
p->pc = c;
o = oplook(p);
m = o->size;
// must check literal pool here in case p generates many instructions
if(blitrl){
if(checkpool(op, p->as == ACASE ? casesz(p) : m))
c = p->pc = scan(op, p, c);
}
if(m == 0 && (p->as != AFUNCDATA && p->as != APCDATA)) {
diag("zero-width instruction\n%P", p);
continue;
}
switch(o->flag & (LFROM|LTO|LPOOL)) {
case LFROM:
addpool(p, &p->from);
break;
case LTO:
addpool(p, &p->to);
break;
case LPOOL:
if ((p->scond&C_SCOND) == 14)
flushpool(p, 0, 0);
break;
}
if(p->as==AMOVW && p->to.type==D_REG && p->to.reg==REGPC && (p->scond&C_SCOND) == 14)
flushpool(p, 0, 0);
c += m;
}
if(blitrl){
if(checkpool(op, 0))
c = scan(op, P, c);
}
cursym->size = c - cursym->value;
}
/*
* if any procedure is large enough to
* generate a large SBRA branch, then
* generate extra passes putting branches
* around jmps to fix. this is rare.
*/
while(bflag) {
if(debug['v'])
Bprint(&bso, "%5.2f span1\n", cputime());
bflag = 0;
c = INITTEXT;
for(cursym = textp; cursym != nil; cursym = cursym->next) {
if(!cursym->text || !cursym->text->link)
continue;
cursym->value = c;
for(p = cursym->text; p != P; p = p->link) {
curp = p;
p->pc = c;
o = oplook(p);
/* very large branches
if(o->type == 6 && p->cond) {
otxt = p->cond->pc - c;
if(otxt < 0)
otxt = -otxt;
if(otxt >= (1L<<17) - 10) {
q = prg();
q->link = p->link;
p->link = q;
q->as = AB;
q->to.type = D_BRANCH;
q->cond = p->cond;
p->cond = q;
q = prg();
q->link = p->link;
p->link = q;
q->as = AB;
q->to.type = D_BRANCH;
q->cond = q->link->link;
bflag = 1;
}
}
*/
m = o->size;
if(m == 0 && (p->as != AFUNCDATA && p->as != APCDATA)) {
if(p->as == ATEXT) {
autosize = p->to.offset + 4;
if(p->from.sym != S)
p->from.sym->value = c;
continue;
}
diag("zero-width instruction\n%P", p);
continue;
}
c += m;
}
cursym->size = c - cursym->value;
}
}
c = rnd(c, 8);
/*
* lay out the code. all the pc-relative code references,
* even cross-function, are resolved now;
* only data references need to be relocated.
* with more work we could leave cross-function
* code references to be relocated too, and then
* perhaps we'd be able to parallelize the span loop above.
*/
gmsym = S;
if(linkmode == LinkExternal)
gmsym = lookup("runtime.tlsgm", 0);
for(cursym = textp; cursym != nil; cursym = cursym->next) {
p = cursym->text;
if(p == P || p->link == P)
continue;
autosize = p->to.offset + 4;
symgrow(cursym, cursym->size);
bp = cursym->p;
for(p = p->link; p != P; p = p->link) {
pc = p->pc;
curp = p;
o = oplook(p);
asmout(p, o, out, gmsym);
for(i=0; i<o->size/4; i++) {
v = out[i];
*bp++ = v;
*bp++ = v>>8;
*bp++ = v>>16;
*bp++ = v>>24;
}
}
}
sect->vaddr = INITTEXT;
sect->len = c - INITTEXT;
}
/*
* when the first reference to the literal pool threatens
* to go out of range of a 12-bit PC-relative offset,
* drop the pool now, and branch round it.
* this happens only in extended basic blocks that exceed 4k.
*/
int
checkpool(Prog *p, int sz)
{
if(pool.size >= 0xffc || immaddr((p->pc+sz+4)+4+pool.size - pool.start+8) == 0)
return flushpool(p, 1, 0);
else if(p->link == P)
return flushpool(p, 2, 0);
return 0;
}
int
flushpool(Prog *p, int skip, int force)
{
Prog *q;
if(blitrl) {
if(skip){
if(0 && skip==1)print("note: flush literal pool at %ux: len=%ud ref=%ux\n", p->pc+4, pool.size, pool.start);
q = prg();
q->as = AB;
q->to.type = D_BRANCH;
q->cond = p->link;
q->link = blitrl;
q->line = p->line;
blitrl = q;
}
else if(!force && (p->pc+pool.size-pool.start < 2048))
return 0;
elitrl->link = p->link;
p->link = blitrl;
// BUG(minux): how to correctly handle line number for constant pool entries?
// for now, we set line number to the last instruction preceding them at least
// this won't bloat the .debug_line tables
while(blitrl) {
blitrl->line = p->line;
blitrl = blitrl->link;
}
blitrl = 0; /* BUG: should refer back to values until out-of-range */
elitrl = 0;
pool.size = 0;
pool.start = 0;
pool.extra = 0;
return 1;
}
return 0;
}
void
addpool(Prog *p, Adr *a)
{
Prog *q, t;
int c;
c = aclass(a);
t = zprg;
t.as = AWORD;
switch(c) {
default:
t.to = *a;
if(flag_shared && t.to.sym != S)
t.pcrel = p;
break;
case C_SROREG:
case C_LOREG:
case C_ROREG:
case C_FOREG:
case C_SOREG:
case C_HOREG:
case C_FAUTO:
case C_SAUTO:
case C_LAUTO:
case C_LACON:
t.to.type = D_CONST;
t.to.offset = instoffset;
break;
}
if(t.pcrel == P) {
for(q = blitrl; q != P; q = q->link) /* could hash on t.t0.offset */
if(q->pcrel == P && memcmp(&q->to, &t.to, sizeof(t.to)) == 0) {
p->cond = q;
return;
}
}
q = prg();
*q = t;
q->pc = pool.size;
if(blitrl == P) {
blitrl = q;
pool.start = p->pc;
q->align = 4;
} else
elitrl->link = q;
elitrl = q;
pool.size += 4;
p->cond = q;
}
void
xdefine(char *p, int t, int32 v)
{
Sym *s;
s = lookup(p, 0);
s->type = t;
s->value = v;
s->reachable = 1;
s->special = 1;
}
int32
regoff(Adr *a)
{
instoffset = 0;
aclass(a);
return instoffset;
}
int32
immrot(uint32 v)
{
int i;
for(i=0; i<16; i++) {
if((v & ~0xff) == 0)
return (i<<8) | v | (1<<25);
v = (v<<2) | (v>>30);
}
return 0;
}
int32
immaddr(int32 v)
{
if(v >= 0 && v <= 0xfff)
return (v & 0xfff) |
(1<<24) | /* pre indexing */
(1<<23); /* pre indexing, up */
if(v >= -0xfff && v < 0)
return (-v & 0xfff) |
(1<<24); /* pre indexing */
return 0;
}
int
immfloat(int32 v)
{
return (v & 0xC03) == 0; /* offset will fit in floating-point load/store */
}
int
immhalf(int32 v)
{
if(v >= 0 && v <= 0xff)
return v|
(1<<24)| /* pre indexing */
(1<<23); /* pre indexing, up */
if(v >= -0xff && v < 0)
return (-v & 0xff)|
(1<<24); /* pre indexing */
return 0;
}
int32
symaddr(Sym *s)
{
if(!s->reachable)
diag("unreachable symbol in symaddr - %s", s->name);
return s->value;
}
int
aclass(Adr *a)
{
Sym *s;
int t;
switch(a->type) {
case D_NONE:
return C_NONE;
case D_REG:
return C_REG;
case D_REGREG:
return C_REGREG;
case D_REGREG2:
return C_REGREG2;
case D_SHIFT:
return C_SHIFT;
case D_FREG:
return C_FREG;
case D_FPCR:
return C_FCR;
case D_OREG:
switch(a->name) {
case D_EXTERN:
case D_STATIC:
if(a->sym == 0 || a->sym->name == 0) {
print("null sym external\n");
print("%D\n", a);
return C_GOK;
}
instoffset = 0; // s.b. unused but just in case
return C_ADDR;
case D_AUTO:
instoffset = autosize + a->offset;
t = immaddr(instoffset);
if(t){
if(immhalf(instoffset))
return immfloat(t) ? C_HFAUTO : C_HAUTO;
if(immfloat(t))
return C_FAUTO;
return C_SAUTO;
}
return C_LAUTO;
case D_PARAM:
instoffset = autosize + a->offset + 4L;
t = immaddr(instoffset);
if(t){
if(immhalf(instoffset))
return immfloat(t) ? C_HFAUTO : C_HAUTO;
if(immfloat(t))
return C_FAUTO;
return C_SAUTO;
}
return C_LAUTO;
case D_NONE:
instoffset = a->offset;
t = immaddr(instoffset);
if(t) {
if(immhalf(instoffset)) /* n.b. that it will also satisfy immrot */
return immfloat(t) ? C_HFOREG : C_HOREG;
if(immfloat(t))
return C_FOREG; /* n.b. that it will also satisfy immrot */
t = immrot(instoffset);
if(t)
return C_SROREG;
if(immhalf(instoffset))
return C_HOREG;
return C_SOREG;
}
t = immrot(instoffset);
if(t)
return C_ROREG;
return C_LOREG;
}
return C_GOK;
case D_PSR:
return C_PSR;
case D_OCONST:
switch(a->name) {
case D_EXTERN:
case D_STATIC:
instoffset = 0; // s.b. unused but just in case
return C_ADDR;
}
return C_GOK;
case D_FCONST:
if(chipzero(&a->ieee) >= 0)
return C_ZFCON;
if(chipfloat(&a->ieee) >= 0)
return C_SFCON;
return C_LFCON;
case D_CONST:
case D_CONST2:
switch(a->name) {
case D_NONE:
instoffset = a->offset;
if(a->reg != NREG)
goto aconsize;
t = immrot(instoffset);
if(t)
return C_RCON;
t = immrot(~instoffset);
if(t)
return C_NCON;
return C_LCON;
case D_EXTERN:
case D_STATIC:
s = a->sym;
if(s == S)
break;
instoffset = 0; // s.b. unused but just in case
return C_LCONADDR;
case D_AUTO:
instoffset = autosize + a->offset;
goto aconsize;
case D_PARAM:
instoffset = autosize + a->offset + 4L;
aconsize:
t = immrot(instoffset);
if(t)
return C_RACON;
return C_LACON;
}
return C_GOK;
case D_BRANCH:
return C_SBRA;
}
return C_GOK;
}
Optab*
oplook(Prog *p)
{
int a1, a2, a3, r;
char *c1, *c3;
Optab *o, *e;
a1 = p->optab;
if(a1)
return optab+(a1-1);
a1 = p->from.class;
if(a1 == 0) {
a1 = aclass(&p->from) + 1;
p->from.class = a1;
}
a1--;
a3 = p->to.class;
if(a3 == 0) {
a3 = aclass(&p->to) + 1;
p->to.class = a3;
}
a3--;
a2 = C_NONE;
if(p->reg != NREG)
a2 = C_REG;
r = p->as;
o = oprange[r].start;
if(o == 0) {
a1 = opcross[repop[r]][a1][a2][a3];
if(a1) {
p->optab = a1+1;
return optab+a1;
}
o = oprange[r].stop; /* just generate an error */
}
if(debug['O']) {
print("oplook %A %O %O %O\n",
(int)p->as, a1, a2, a3);
print(" %d %d\n", p->from.type, p->to.type);
}
e = oprange[r].stop;
c1 = xcmp[a1];
c3 = xcmp[a3];
for(; o<e; o++)
if(o->a2 == a2)
if(c1[o->a1])
if(c3[o->a3]) {
p->optab = (o-optab)+1;
return o;
}
diag("illegal combination %A %O %O %O, %d %d",
p->as, a1, a2, a3, p->from.type, p->to.type);
prasm(p);
if(o == 0)
o = optab;
return o;
}
int
cmp(int a, int b)
{
if(a == b)
return 1;
switch(a) {
case C_LCON:
if(b == C_RCON || b == C_NCON)
return 1;
break;
case C_LACON:
if(b == C_RACON)
return 1;
break;
case C_LFCON:
if(b == C_ZFCON || b == C_SFCON)
return 1;
break;
case C_HFAUTO:
return b == C_HAUTO || b == C_FAUTO;
case C_FAUTO:
case C_HAUTO:
return b == C_HFAUTO;
case C_SAUTO:
return cmp(C_HFAUTO, b);
case C_LAUTO:
return cmp(C_SAUTO, b);
case C_HFOREG:
return b == C_HOREG || b == C_FOREG;
case C_FOREG:
case C_HOREG:
return b == C_HFOREG;
case C_SROREG:
return cmp(C_SOREG, b) || cmp(C_ROREG, b);
case C_SOREG:
case C_ROREG:
return b == C_SROREG || cmp(C_HFOREG, b);
case C_LOREG:
return cmp(C_SROREG, b);
case C_LBRA:
if(b == C_SBRA)
return 1;
break;
case C_HREG:
return cmp(C_SP, b) || cmp(C_PC, b);
}
return 0;
}
int
ocmp(const void *a1, const void *a2)
{
Optab *p1, *p2;
int n;
p1 = (Optab*)a1;
p2 = (Optab*)a2;
n = p1->as - p2->as;
if(n)
return n;
n = p1->a1 - p2->a1;
if(n)
return n;
n = p1->a2 - p2->a2;
if(n)
return n;
n = p1->a3 - p2->a3;
if(n)
return n;
return 0;
}
void
buildop(void)
{
int i, n, r;
for(i=0; i<C_GOK; i++)
for(n=0; n<C_GOK; n++)
xcmp[i][n] = cmp(n, i);
for(n=0; optab[n].as != AXXX; n++) {
if((optab[n].flag & LPCREL) != 0) {
if(flag_shared)
optab[n].size += optab[n].pcrelsiz;
else
optab[n].flag &= ~LPCREL;
}
}
qsort(optab, n, sizeof(optab[0]), ocmp);
for(i=0; i<n; i++) {
r = optab[i].as;
oprange[r].start = optab+i;
while(optab[i].as == r)
i++;
oprange[r].stop = optab+i;
i--;
switch(r)
{
default:
diag("unknown op in build: %A", r);
errorexit();
case AADD:
oprange[AAND] = oprange[r];
oprange[AEOR] = oprange[r];
oprange[ASUB] = oprange[r];
oprange[ARSB] = oprange[r];
oprange[AADC] = oprange[r];
oprange[ASBC] = oprange[r];
oprange[ARSC] = oprange[r];
oprange[AORR] = oprange[r];
oprange[ABIC] = oprange[r];
break;
case ACMP:
oprange[ATEQ] = oprange[r];
oprange[ACMN] = oprange[r];
break;
case AMVN:
break;
case ABEQ:
oprange[ABNE] = oprange[r];
oprange[ABCS] = oprange[r];
oprange[ABHS] = oprange[r];
oprange[ABCC] = oprange[r];
oprange[ABLO] = oprange[r];
oprange[ABMI] = oprange[r];
oprange[ABPL] = oprange[r];
oprange[ABVS] = oprange[r];
oprange[ABVC] = oprange[r];
oprange[ABHI] = oprange[r];
oprange[ABLS] = oprange[r];
oprange[ABGE] = oprange[r];
oprange[ABLT] = oprange[r];
oprange[ABGT] = oprange[r];
oprange[ABLE] = oprange[r];
break;
case ASLL:
oprange[ASRL] = oprange[r];
oprange[ASRA] = oprange[r];
break;
case AMUL:
oprange[AMULU] = oprange[r];
break;
case ADIV:
oprange[AMOD] = oprange[r];
oprange[AMODU] = oprange[r];
oprange[ADIVU] = oprange[r];
break;
case AMOVW:
case AMOVB:
case AMOVBS:
case AMOVBU:
case AMOVH:
case AMOVHS:
case AMOVHU:
break;
case ASWPW:
oprange[ASWPBU] = oprange[r];
break;
case AB:
case ABL:
case ABX:
case ABXRET:
case ASWI:
case AWORD:
case AMOVM:
case ARFE:
case ATEXT:
case AUSEFIELD:
case ACASE:
case ABCASE:
case ATYPE:
break;
case AADDF:
oprange[AADDD] = oprange[r];
oprange[ASUBF] = oprange[r];
oprange[ASUBD] = oprange[r];
oprange[AMULF] = oprange[r];
oprange[AMULD] = oprange[r];
oprange[ADIVF] = oprange[r];
oprange[ADIVD] = oprange[r];
oprange[ASQRTF] = oprange[r];
oprange[ASQRTD] = oprange[r];
oprange[AMOVFD] = oprange[r];
oprange[AMOVDF] = oprange[r];
oprange[AABSF] = oprange[r];
oprange[AABSD] = oprange[r];
break;
case ACMPF:
oprange[ACMPD] = oprange[r];
break;
case AMOVF:
oprange[AMOVD] = oprange[r];
break;
case AMOVFW:
oprange[AMOVDW] = oprange[r];
break;
case AMOVWF:
oprange[AMOVWD] = oprange[r];
break;
case AMULL:
oprange[AMULAL] = oprange[r];
oprange[AMULLU] = oprange[r];
oprange[AMULALU] = oprange[r];
break;
case AMULWT:
oprange[AMULWB] = oprange[r];
break;
case AMULAWT:
oprange[AMULAWB] = oprange[r];
break;
case AMULA:
case ALDREX:
case ASTREX:
case ALDREXD:
case ASTREXD:
case ATST:
case APLD:
case AUNDEF:
case ACLZ:
case AFUNCDATA:
case APCDATA:
break;
}
}
}
/*
void
buildrep(int x, int as)
{
Opcross *p;
Optab *e, *s, *o;
int a1, a2, a3, n;
if(C_NONE != 0 || C_REG != 1 || C_GOK >= 32 || x >= nelem(opcross)) {
diag("assumptions fail in buildrep");
errorexit();
}
repop[as] = x;
p = (opcross + x);
s = oprange[as].start;
e = oprange[as].stop;
for(o=e-1; o>=s; o--) {
n = o-optab;
for(a2=0; a2<2; a2++) {
if(a2) {
if(o->a2 == C_NONE)
continue;
} else
if(o->a2 != C_NONE)
continue;
for(a1=0; a1<32; a1++) {
if(!xcmp[a1][o->a1])
continue;
for(a3=0; a3<32; a3++)
if(xcmp[a3][o->a3])
(*p)[a1][a2][a3] = n;
}
}
}
oprange[as].start = 0;
}
*/
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