ref: 334ffbc2750c2be18dbbf8dc3ebbe8b22e8a9db3
dir: /6/gengas.c/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <inttypes.h>
#include <ctype.h>
#include <string.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "util.h"
#include "parse.h"
#include "mi.h"
#include "asm.h"
#include "../config.h"
#define Tdindirect 0x80
static char * insnfmt[] = {
#define Insn(val, gasfmt, p9fmt, use, def) gasfmt,
#include "insns.def"
#undef Insn
};
static char * regnames[] = {
#define Reg(r, gasname, p9name, mode) gasname,
#include "regs.def"
#undef Reg
};
static char *modenames[] = {
[ModeB] = "b",
[ModeW] = "w",
[ModeL] = "l",
[ModeQ] = "q",
[ModeF] = "s",
[ModeD] = "d"
};
static void locprint(FILE *fd, Loc *l, char spec);
void
printmem(FILE *fd, Loc *l, char spec)
{
if (l->type == Locmem) {
if (l->mem.constdisp)
fprintf(fd, "%ld", l->mem.constdisp);
} else {
if (l->mem.lbldisp)
fprintf(fd, "%s", l->mem.lbldisp);
}
if (l->mem.base) {
fprintf(fd, "(");
locprint(fd, l->mem.base, 'r');
if (l->mem.idx) {
fprintf(fd, ",");
locprint(fd, l->mem.idx, 'r');
}
if (l->mem.scale > 1)
fprintf(fd, ",%d", l->mem.scale);
if (l->mem.base)
fprintf(fd, ")");
} else if (l->type != Locmeml) {
die("Only locmeml can have unspecified base reg");
}
}
static void
locprint(FILE *fd, Loc *l, char spec)
{
assert(l->mode);
switch (l->type) {
case Loclitl:
assert(spec == 'i' || spec == 'x' || spec == 'u');
fprintf(fd, "$%s", l->lbl);
break;
case Loclbl:
assert(spec == 'm' || spec == 'v' || spec == 'x');
fprintf(fd, "%s", l->lbl);
break;
case Locreg:
assert((spec == 'r' && isintmode(l->mode)) ||
(spec == 'f' && isfloatmode(l->mode)) ||
spec == 'v' ||
spec == 'x' ||
spec == 'u');
if (l->reg.colour == Rnone)
fprintf(fd, "%%P.%zd%s", l->reg.id, modenames[l->mode]);
else
fprintf(fd, "%s", regnames[l->reg.colour]);
break;
case Locmem:
case Locmeml:
assert(spec == 'm' || spec == 'v' || spec == 'x');
printmem(fd, l, spec);
break;
case Loclit:
assert(spec == 'i' || spec == 'x' || spec == 'u');
fprintf(fd, "$%ld", l->lit);
break;
case Locnone:
die("Bad location in locprint()");
break;
}
}
static int
issubreg(Loc *a, Loc *b)
{
return rclass(a) == rclass(b) && a->mode != b->mode;
}
void
iprintf(FILE *fd, Insn *insn)
{
char *p;
int i;
int idx;
/* x64 has a quirk; it has no movzlq because mov zero extends. Thi
* means that we need to do a movl when we really want a movzlq. Since
* we don't know the name of the reg to use, we need to sub it in when
* writing... */
switch (insn->op) {
case Imovzx:
if (insn->args[0]->mode == ModeL && insn->args[1]->mode == ModeQ) {
if (insn->args[1]->reg.colour) {
insn->op = Imov;
insn->args[1] = coreg(insn->args[1]->reg.colour, ModeL);
}
}
/* moving a reg to itself is dumb. */
if (insn->args[0]->reg.colour == insn->args[1]->reg.colour)
return;
break;
case Imovs:
if (insn->args[0]->reg.colour == Rnone || insn->args[1]->reg.colour == Rnone)
break;
/* moving a reg to itself is dumb. */
if (insn->args[0]->reg.colour == insn->args[1]->reg.colour)
return;
break;
case Imov:
assert(!isfloatmode(insn->args[0]->mode));
if (insn->args[0]->type != Locreg || insn->args[1]->type != Locreg)
break;
if (insn->args[0]->reg.colour == Rnone || insn->args[1]->reg.colour == Rnone)
break;
/* if one reg is a subreg of another, we can just use the right
* mode to move between them. */
if (issubreg(insn->args[0], insn->args[1]))
insn->args[0] = coreg(insn->args[0]->reg.colour, insn->args[1]->mode);
/* moving a reg to itself is dumb. */
if (insn->args[0]->reg.colour == insn->args[1]->reg.colour)
return;
break;
default:
break;
}
p = insnfmt[insn->op];
i = 0;
for (; *p; p++) {
if (*p != '%') {
fputc(*p, fd);
continue;
}
/* %-formating */
p++;
idx = i;
again:
switch (*p) {
case '\0':
goto done; /* skip the final p++ */
case 'r': /* int register */
case 'f': /* float register */
case 'm': /* memory */
case 'i': /* imm */
case 'v': /* reg/mem */
case 'u': /* reg/imm */
case 'x': /* reg/mem/imm */
locprint(fd, insn->args[idx], *p);
i++;
break;
case 't':
fputs(modenames[insn->args[idx]->mode], fd);
break;
default:
/* the asm description uses 1-based indexing, so that 0
* can be used as a sentinel. */
if (!isdigit(*p))
die("Invalid %%-specifier '%c'", *p);
idx = strtol(p, &p, 10) - 1;
goto again;
break;
}
}
done
:
return;
}
static void
writebytes(FILE *fd, char *p, size_t sz)
{
size_t i;
for (i = 0; i < sz; i++) {
if (i % 60 == 0)
fprintf(fd, "\t.ascii \"");
if (p[i] == '"' || p[i] == '\\')
fprintf(fd, "\\");
if (isprint(p[i]))
fprintf(fd, "%c", p[i]);
else
fprintf(fd, "\\%03o", (uint8_t)p[i] & 0xff);
/* line wrapping for readability */
if (i % 60 == 59 || i == sz - 1)
fprintf(fd, "\"\n");
}
}
void
genstrings(FILE *fd, Htab *strtab)
{
void **k;
Str *s;
size_t i, nk;
k = htkeys(strtab, &nk);
for (i = 0; i < nk; i++) {
s = k[i];
fprintf(fd, "%s:\n", (char*)htget(strtab, k[i]));
writebytes(fd, s->buf, s->len);
}
}
static void
writeasm(FILE *fd, Isel *s, Func *fn)
{
size_t i, j;
switch (asmsyntax) {
case Gnugaself:
//fprintf(fd, ".section .text.%s,\"ax\",@progbits\n", fn->name);
fprintf(fd, ".type %s, @function\n", fn->name);
break;
case Gnugasmacho:
fprintf(fd, ".section __TEXT,__text,regular\n");
break;
default:
die("unknown target"); break;
}
if (fn->isexport)
fprintf(fd, ".globl %s\n", fn->name);
fprintf(fd, "%s:\n", fn->name);
for (j = 0; j < s->cfg->nbb; j++) {
if (!s->bb[j])
continue;
for (i = 0; i < s->bb[j]->nlbls; i++)
fprintf(fd, "%s:\n", s->bb[j]->lbls[i]);
for (i = 0; i < s->bb[j]->ni; i++)
iprintf(fd, s->bb[j]->il[i]);
}
}
static void
encodemin(FILE *fd, uvlong val)
{
size_t i, shift;
uint8_t b;
if (val < 128) {
fprintf(fd, "\t.byte %llu\n", val);
return;
}
for (i = 1; i < 8; i++)
if (val < 1ULL << (7*i))
break;
shift = 8 - i;
b = ~0ull << (shift + 1);
b |= val & ~(~0ull << shift);
fprintf(fd, "\t.byte %u\n", b);
val >>= shift;
while (val != 0) {
fprintf(fd, "\t.byte %u\n", (uint)val & 0xff);
val >>= 8;
}
}
static void
emitonce(FILE *fd, Blob *b)
{
if (asmsyntax == Gnugaself) {
fprintf(fd, ".section .text.%s%s,\"aG\",%s%s,comdat\n",
Symprefix, b->lbl, Symprefix, b->lbl);
} else if (asmsyntax == Gnugasmacho) {
if (b->isglobl)
fprintf(fd, ".weak_def_can_be_hidden %s%s\n", Symprefix, b->lbl);
} else {
die("Unknown asm flavor");
}
}
static void
writeblob(FILE *fd, Blob *b)
{
size_t i;
if (!b)
return;
if (b->lbl) {
if (b->iscomdat)
emitonce(fd, b);
if (b->isglobl)
fprintf(fd, ".globl %s%s\n", Symprefix, b->lbl);
fprintf(fd, "%s%s:\n", Symprefix, b->lbl);
}
switch (b->type) {
case Btimin: encodemin(fd, b->ival); break;
case Bti8: fprintf(fd, "\t.byte %llu\n", b->ival); break;
case Bti16: fprintf(fd, "\t.short %llu\n", b->ival); break;
case Bti32: fprintf(fd, "\t.long %llu\n", b->ival); break;
case Bti64: fprintf(fd, "\t.quad %llu\n", b->ival); break;
case Btbytes: writebytes(fd, b->bytes.buf, b->bytes.len); break;
case Btpad: fprintf(fd, "\t.fill %llu,1,0\n", b->npad); break;
case Btref: fprintf(fd, "\t.quad %s + %zd\n", b->ref.str, b->ref.off); break;
case Btseq:
for (i = 0; i < b->seq.nsub; i++)
writeblob(fd, b->seq.sub[i]);
break;
}
if (b->lbl && b->iscomdat)
fprintf(fd, ".text\n");
}
/* genfunc requires all nodes in 'nl' to map cleanly to operations that are
* natively supported, as promised in the output of reduce(). No 64-bit
* operations on x32, no structures, and so on. */
static void
genfunc(FILE *fd, Func *fn, Htab *globls, Htab *strtab)
{
Isel is = {0,};
char cwd[1024];
resetregs();
if (!getcwd(cwd, sizeof cwd))
die("getcwd failed: %s\n", cwd);
is.reglocs = mkht(varhash, vareq);
is.name = fn->name;
is.stkoff = fn->stkoff;
is.envoff = fn->envoff;
is.globls = globls;
is.ret = fn->ret;
is.cfg = fn->cfg;
is.cwd = strdup(cwd);
if (fn->hasenv)
is.envp = locreg(ModeQ);
selfunc(&is, fn, globls, strtab);
if (debugopt['i'])
writeasm(stdout, &is, fn);
writeasm(fd, &is, fn);
}
static void
gentype(FILE *fd, Type *ty)
{
Blob *b;
ty = tydedup(ty);
if (ty->type == Tyvar || ty->isemitted)
return;
ty->isemitted = 1;
b = tydescblob(ty);
if (b->isglobl)
b->iscomdat = 1;
if (asmsyntax == Gnugaself)
fprintf(fd, ".section .data.%s,\"aw\",@progbits\n", b->lbl);
writeblob(fd, b);
blobfree(b);
}
static void
gentypes(FILE *fd)
{
Type *ty;
size_t i;
for (i = Ntypes; i < ntypes; i++) {
if (!types[i]->isreflect)
continue;
ty = tydedup(types[i]);
if (ty->isemitted || ty->isimport)
continue;
gentype(fd, ty);
}
fprintf(fd, "\n");
}
void
genblob(FILE *fd, Node *blob, Htab *globls, Htab *strtab)
{
char *lbl;
Blob *b;
/* lits and such also get wrapped in decls */
assert(blob->type == Ndecl);
lbl = htget(globls, blob);
if (blob->decl.vis != Visintern)
fprintf(fd, ".globl %s\n", lbl);
if (asmsyntax == Gnugaself)
fprintf(fd, ".section .data.%s,\"aw\",@progbits\n", lbl);
if (blob->decl.init) {
fprintf(fd, ".align %zd\n", tyalign(decltype(blob)));
fprintf(fd, "%s:\n", lbl);
b = litblob(globls, strtab, blob->decl.init);
writeblob(fd, b);
blobfree(b);
} else {
fprintf(fd, ".comm %s,%zd\n", lbl, size(blob));
}
}
void
gengas(FILE *fd)
{
Htab *globls, *strtab;
Node *n, **blob;
Func **fn;
char dir[1024], *path;
size_t nfn, nblob;
size_t i;
/* ensure that all physical registers have a loc created before any
* other locs, so that locmap[Physreg] maps to the Loc for the physreg
* in question */
for (i = 0; i < Nreg; i++)
locphysreg(i);
fn = NULL;
nfn = 0;
blob = NULL;
nblob = 0;
globls = mkht(varhash, vareq);
initconsts(globls);
/* We need to define all global variables before use */
fillglobls(file.globls, globls);
pushstab(file.globls);
for (i = 0; i < file.nstmts; i++) {
n = file.stmts[i];
switch (n->type) {
case Nuse: /* nothing to do */
case Nimpl:
break;
case Ndecl:
n = flattenfn(n);
simpglobl(n, globls, &fn, &nfn, &blob, &nblob);
break;
default:
die("Bad node %s in toplevel", nodestr[n->type]);
break;
}
}
popstab();
if (!getcwd(dir, sizeof dir))
die("could not get cwd: %s\n", strerror(errno));
for (i = 0; i < file.nfiles; i++) {
path = file.files[i];
fprintf(fd, ".file %zd \"%s/%s\"\n", i + 1, dir, path);
}
strtab = mkht(strlithash, strliteq);
fprintf(fd, ".data\n");
for (i = 0; i < nblob; i++)
genblob(fd, blob[i], globls, strtab);
fprintf(fd, "\n");
fprintf(fd, ".text\n");
for (i = 0; i < nfn; i++)
genfunc(fd, fn[i], globls, strtab);
gentypes(fd);
fprintf(fd, "\n");
genstrings(fd, strtab);
fprintf(fd, "\n");
fclose(fd);
}
void
dbglocprint(FILE *fd, Loc *l, char spec)
{
locprint(fd, l, spec);
}
void
dbgiprintf(FILE *fd, Insn *i)
{
iprintf(fd, i);
}