ref: 14d4a8e93c6804eb049eec51a5102c9d8b10c1c5
dir: /6/simp.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 "parse.h"
#include "mi.h"
#include "asm.h"
#include "../config.h"
/* takes a list of nodes, and reduces it (and it's subnodes) to a list
* following these constraints:
* - All nodes are expression nodes
* - Nodes with side effects are root nodes
* - All nodes operate on machine-primitive types and tuples
*/
typedef struct Simp Simp;
struct Simp {
int isglobl;
Node **stmts;
size_t nstmts;
/* return handling */
Node *endlbl;
Node *ret;
int hasenv;
int isbigret;
/* pre/postinc handling */
Node **incqueue;
size_t nqueue;
/* break/continue handling */
Node **loopstep;
size_t nloopstep;
Node **loopexit;
size_t nloopexit;
/* location handling */
Node **blobs;
size_t nblobs;
Htab *globls;
Htab *stkoff;
Htab *envoff;
size_t stksz;
Node **args;
size_t nargs;
};
static int envcmp(const void *pa, const void *pb);
static Node *simp(Simp *s, Node *n);
static Node *rval(Simp *s, Node *n, Node *dst);
static Node *lval(Simp *s, Node *n);
static Node *assign(Simp *s, Node *lhs, Node *rhs);
static Node *assignat(Simp *s, Node *r, size_t off, Node *val);
static Node *getcode(Simp *s, Node *n);
static void simpcond(Simp *s, Node *n, Node *ltrue, Node *lfalse);
static void simpconstinit(Simp *s, Node *dcl);
static Node *simpcast(Simp *s, Node *val, Type *to);
static Node *simpslice(Simp *s, Node *n, Node *dst);
static Node *idxaddr(Simp *s, Node *seq, Node *idx);
static void matchpattern(Simp *s, Node *pat, Node *val, Type *t, Node *iftrue, Node *iffalse);
/* useful constants */
Type *tyintptr;
Type *tyword;
Type *tyvoid;
Node *abortoob;
static void append(Simp *s, Node *n)
{
lappend(&s->stmts, &s->nstmts, n);
}
static int ispure(Node *n)
{
return opispure[exprop(n)];
}
size_t alignto(size_t sz, Type *t)
{
size_t a;
size_t i;
t = tybase(t);
a = 0;
switch (t->type) {
case Tyarray:
a = alignto(1, t->sub[0]);
case Tytuple:
for (i = 0; i < t->nsub; i++)
a = max(alignto(1, t->sub[i]), a);
break;
case Tystruct:
for (i = 0; i < t->nmemb; i++)
a = max(alignto(1, decltype(t->sdecls[i])), a);
break;
default:
a = tysize(t);
break;
}
return align(sz, min(a, Ptrsz));
}
static Type *base(Type *t)
{
assert(t->nsub == 1);
return t->sub[0];
}
static Node *add(Node *a, Node *b)
{
Node *n;
assert(size(a) == size(b));
n = mkexpr(a->loc, Oadd, a, b, NULL);
n->expr.type = a->expr.type;
return n;
}
static Node *addk(Node *n, uvlong v)
{
Node *k;
k = mkintlit(n->loc, v);
k->expr.type = exprtype(n);
return add(n, k);
}
static Node *sub(Node *a, Node *b)
{
Node *n;
n = mkexpr(a->loc, Osub, a, b, NULL);
n->expr.type = a->expr.type;
return n;
}
static Node *subk(Node *n, uvlong v)
{
Node *k;
k = mkintlit(n->loc, v);
k->expr.type = exprtype(n);
return sub(n, k);
}
static Node *mul(Node *a, Node *b)
{
Node *n;
n = mkexpr(a->loc, Omul, a, b, NULL);
n->expr.type = a->expr.type;
return n;
}
static int addressable(Simp *s, Node *a)
{
if (a->type == Ndecl || (a->type == Nexpr && exprop(a) == Ovar))
return hthas(s->envoff, a) || hthas(s->stkoff, a) || hthas(s->globls, a);
else
return stacknode(a);
}
int stacknode(Node *n)
{
if (n->type == Nexpr)
return isstacktype(n->expr.type);
else
return isstacktype(n->decl.type);
}
int floatnode(Node *n)
{
if (n->type == Nexpr)
return istyfloat(n->expr.type);
else
return istyfloat(n->decl.type);
}
static void forcelocal(Simp *s, Node *n)
{
assert(n->type == Ndecl || (n->type == Nexpr && exprop(n) == Ovar));
s->stksz += size(n);
s->stksz = align(s->stksz, min(size(n), Ptrsz));
if (debugopt['i']) {
dump(n, stdout);
printf("declared at %zd, size = %zd\n", s->stksz, size(n));
}
htput(s->stkoff, n, itop(s->stksz));
}
static void declarelocal(Simp *s, Node *n)
{
if (stacknode(n))
forcelocal(s, n);
}
/* takes the address of a node, possibly converting it to
* a pointer to the base type 'bt' */
static Node *addr(Simp *s, Node *a, Type *bt)
{
Node *n;
n = mkexpr(a->loc, Oaddr, a, NULL);
if (!addressable(s, a))
forcelocal(s, a);
if (!bt)
n->expr.type = mktyptr(a->loc, a->expr.type);
else
n->expr.type = mktyptr(a->loc, bt);
return n;
}
static Node *load(Node *a)
{
Node *n;
assert(a->expr.type->type == Typtr);
n = mkexpr(a->loc, Oderef, a, NULL);
n->expr.type = base(a->expr.type);
return n;
}
static Node *deref(Node *a, Type *t)
{
Node *n;
assert(a->expr.type->type == Typtr);
n = mkexpr(a->loc, Oderef, a, NULL);
if (t)
n->expr.type = t;
else
n->expr.type = base(a->expr.type);
return n;
}
static Node *set(Node *a, Node *b)
{
Node *n;
assert(a != NULL && b != NULL);
assert(exprop(a) == Ovar || exprop(a) == Oderef);
n = mkexpr(a->loc, Oset, a, b, NULL);
n->expr.type = exprtype(a);
return n;
}
static void def(Simp *s, Node *var)
{
Node *d;
d = mkexpr(var->loc, Odef, var, NULL);
d->expr.type = mktype(var->loc, Tyvoid);
append(s, d);
}
static Node *disp(Srcloc loc, uint v)
{
Node *n;
n = mkintlit(loc, v);
n->expr.type = tyintptr;
return n;
}
static Node *word(Srcloc loc, uint v)
{
Node *n;
n = mkintlit(loc, v);
n->expr.type = tyword;
return n;
}
static Node *gentemp(Simp *simp, Srcloc loc, Type *ty, Node **dcl)
{
char buf[128];
static int nexttmp;
Node *t, *r, *n;
bprintf(buf, 128, ".t%d", nexttmp++);
n = mkname(loc, buf);
t = mkdecl(loc, n, ty);
r = mkexpr(loc, Ovar, n, NULL);
r->expr.type = t->decl.type;
r->expr.did = t->decl.did;
if (dcl)
*dcl = t;
return r;
}
static Node *temp(Simp *simp, Node *e)
{
Node *t, *dcl;
assert(e->type == Nexpr);
t = gentemp(simp, e->loc, e->expr.type, &dcl);
if (stacknode(e))
declarelocal(simp, dcl);
return t;
}
static void jmp(Simp *s, Node *lbl)
{
append(s, mkexpr(lbl->loc, Ojmp, lbl, NULL));
}
static void cjmp(Simp *s, Node *cond, Node *iftrue, Node *iffalse)
{
Node *jmp;
jmp = mkexpr(cond->loc, Ocjmp, cond, iftrue, iffalse, NULL);
append(s, jmp);
}
static Node *slicelen(Simp *s, Node *sl)
{
/* *(&sl + sizeof(size_t)) */
return load(addk(addr(s, sl, tyintptr), Ptrsz));
}
Node *loadvar(Simp *s, Node *n, Node *dst)
{
Node *p, *f, *r;
if (isconstfn(n)) {
if (dst)
r = dst;
else
r = temp(s, n);
f = getcode(s, n);
p = addr(s, r, exprtype(n));
assignat(s, p, Ptrsz, f);
} else {
r = n;
}
return r;
}
static Node *seqlen(Simp *s, Node *n, Type *ty)
{
Node *t, *r;
if (exprtype(n)->type == Tyslice) {
t = slicelen(s, n);
r = simpcast(s, t, ty);
} else if (exprtype(n)->type == Tyarray) {
t = exprtype(n)->asize;
r = simpcast(s, t, ty);
} else {
r = NULL;
}
return r;
}
/* if foo; bar; else baz;;
* => cjmp (foo) :bar :baz */
static void simpif(Simp *s, Node *n, Node *exit)
{
Node *l1, *l2, *l3;
Node *iftrue, *iffalse;
l1 = genlbl(n->loc);
l2 = genlbl(n->loc);
if (exit)
l3 = exit;
else
l3 = genlbl(n->loc);
iftrue = n->ifstmt.iftrue;
iffalse = n->ifstmt.iffalse;
simpcond(s, n->ifstmt.cond, l1, l2);
simp(s, l1);
simp(s, iftrue);
jmp(s, l3);
simp(s, l2);
/* because lots of bunched up end labels are ugly,
* coalesce them by handling 'elif'-like constructs
* separately */
if (iffalse && iffalse->type == Nifstmt) {
simpif(s, iffalse, exit);
} else {
simp(s, iffalse);
jmp(s, l3);
}
if (!exit)
simp(s, l3);
}
/* init; while cond; body;;
* => init
* jmp :cond
* :body
* ...body...
* ...step...
* :cond
* ...cond...
* cjmp (cond) :body :end
* :end
*/
static void simploop(Simp *s, Node *n)
{
Node *lbody;
Node *lend;
Node *lcond;
Node *lstep;
lbody = genlbl(n->loc);
lcond = genlbl(n->loc);
lstep = genlbl(n->loc);
lend = genlbl(n->loc);
lappend(&s->loopstep, &s->nloopstep, lstep);
lappend(&s->loopexit, &s->nloopexit, lend);
simp(s, n->loopstmt.init); /* init */
jmp(s, lcond); /* goto test */
simp(s, lbody); /* body lbl */
simp(s, n->loopstmt.body); /* body */
simp(s, lstep); /* test lbl */
simp(s, n->loopstmt.step); /* step */
simp(s, lcond); /* test lbl */
simpcond(s, n->loopstmt.cond, lbody, lend); /* repeat? */
simp(s, lend); /* exit */
s->nloopstep--;
s->nloopexit--;
}
/* pat; seq;
* body;;
*
* =>
* .pseudo = seqinit
* jmp :cond
* :body
* ...body...
* :step
* ...step...
* :cond
* ...cond...
* cjmp (cond) :match :end
* :match
* ...match...
* cjmp (match) :body :step
* :end
*/
static void simpiter(Simp *s, Node *n)
{
Node *lbody, *lstep, *lcond, *lmatch, *lend;
Node *idx, *len, *dcl, *seq, *val, *done;
Node *zero;
lbody = genlbl(n->loc);
lstep = genlbl(n->loc);
lcond = genlbl(n->loc);
lmatch = genlbl(n->loc);
lend = genlbl(n->loc);
lappend(&s->loopstep, &s->nloopstep, lstep);
lappend(&s->loopexit, &s->nloopexit, lend);
zero = mkintlit(n->loc, 0);
zero->expr.type = tyintptr;
seq = rval(s, n->iterstmt.seq, NULL);
idx = gentemp(s, n->loc, tyintptr, &dcl);
declarelocal(s, dcl);
/* setup */
append(s, assign(s, idx, zero));
jmp(s, lcond);
simp(s, lbody);
/* body */
simp(s, n->iterstmt.body);
/* step */
simp(s, lstep);
simp(s, assign(s, idx, addk(idx, 1)));
/* condition */
simp(s, lcond);
len = seqlen(s, seq, tyintptr);
done = mkexpr(n->loc, Olt, idx, len, NULL);
cjmp(s, done, lmatch, lend);
simp(s, lmatch);
val = load(idxaddr(s, seq, idx));
matchpattern(s, n->iterstmt.elt, val, val->expr.type, lbody, lstep);
simp(s, lend);
s->nloopstep--;
s->nloopexit--;
}
static Node *uconid(Simp *s, Node *n)
{
Ucon *uc;
if (exprop(n) != Oucon)
return load(addr(s, n, mktype(n->loc, Tyuint)));
uc = finducon(exprtype(n), n->expr.args[0]);
return word(uc->loc, uc->id);
}
static Node *patval(Simp *s, Node *n, Type *t)
{
if (exprop(n) == Oucon)
return n->expr.args[1];
else if (exprop(n) == Olit)
return n;
else
return load(addk(addr(s, n, t), Wordsz));
}
static void matchpattern(Simp *s, Node *pat, Node *val, Type *t, Node *iftrue, Node *iffalse)
{
Node *n, *v, *x, *y;
Node *deeper, *next;
Node **patarg, *lit, *idx;
char *str;
size_t len;
Ucon *uc;
size_t i;
size_t off;
assert(pat->type == Nexpr);
t = tybase(t);
if (exprop(pat) == Ovar) {
n = decls[pat->expr.did];
if (n->decl.isconst) {
pat = n->decl.init;
if (!pat)
die("decl has no init in this file: this is currently unsupported.");
} else {
v = assign(s, pat, val);
append(s, v);
jmp(s, iftrue);
return;
}
} else if (exprop(pat) == Ogap) {
jmp(s, iftrue);
return;
}
switch (t->type) {
/* Never supported */
case Tyvoid: case Tybad: case Tyvalist: case Tyvar:
case Typaram: case Tyunres: case Tyname: case Ntypes:
case Tyfunc: case Tycode:
die("Unsupported type for pattern");
break;
/* only valid for string literals */
case Tybool: case Tychar: case Tybyte:
case Tyint8: case Tyint16: case Tyint32: case Tyint:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint:
case Tyint64: case Tyuint64:
case Tyflt32: case Tyflt64:
case Typtr:
v = mkexpr(pat->loc, Oeq, pat, val, NULL);
v->expr.type = mktype(pat->loc, Tybool);
cjmp(s, v, iftrue, iffalse);
break;
case Tyslice:
lit = pat->expr.args[0];
if (exprop(pat) != Olit || lit->lit.littype != Lstr)
die("Unsupported pattern");
str = lit->lit.strval.buf;
len = lit->lit.strval.len;
/* load slice length */
next = genlbl(pat->loc);
x = slicelen(s, val);
y = mkintlit(lit->loc, len);
y->expr.type = tyintptr;
v = mkexpr(pat->loc, Oeq, x, y, NULL);
cjmp(s, v, next, iffalse);
append(s, next);
for (i = 0; i < len; i++) {
next = genlbl(pat->loc);
x = mkintlit(pat->loc, str[i]);
x->expr.type = mktype(pat->loc, Tybyte);
idx = mkintlit(pat->loc, i);
idx->expr.type = tyintptr;
y = load(idxaddr(s, val, idx));
v = mkexpr(pat->loc, Oeq, x, y, NULL);
v->expr.type = mktype(pat->loc, Tybool);
cjmp(s, v, next, iffalse);
append(s, next);
}
jmp(s, iftrue);
break;
/* We got lucky. The structure of tuple, array, and struct literals
* is the same, so long as we don't inspect the type, so we can
* share the code*/
case Tytuple: case Tyarray:
patarg = pat->expr.args;
off = 0;
for (i = 0; i < pat->expr.nargs; i++) {
off = alignto(off, exprtype(patarg[i]));
next = genlbl(pat->loc);
v = load(addk(addr(s, val, exprtype(patarg[i])), off));
matchpattern(s, patarg[i], v, exprtype(patarg[i]), next, iffalse);
append(s, next);
off += size(patarg[i]);
}
jmp(s, iftrue);
break;
case Tystruct:
patarg = pat->expr.args;
for (i = 0; i < pat->expr.nargs; i++) {
off = offset(pat, patarg[i]->expr.idx);
next = genlbl(pat->loc);
v = load(addk(addr(s, val, exprtype(patarg[i])), off));
matchpattern(s, patarg[i], v, exprtype(patarg[i]), next, iffalse);
append(s, next);
}
break;
case Tyunion:
if (exprop(pat) == Oucon)
uc = finducon(exprtype(pat), pat->expr.args[0]);
else
uc = finducon(exprtype(val), val->expr.args[0]);
deeper = genlbl(pat->loc);
x = uconid(s, pat);
y = uconid(s, val);
v = mkexpr(pat->loc, Oeq, x, y, NULL);
v->expr.type = tyintptr;
cjmp(s, v, deeper, iffalse);
append(s, deeper);
if (uc->etype) {
pat = patval(s, pat, uc->etype);
val = patval(s, val, uc->etype);
matchpattern(s, pat, val, uc->etype, iftrue, iffalse);
}
break;
case Tygeneric:
break;
}
}
static void simpmatch(Simp *s, Node *n)
{
Node *end, *cur, *next; /* labels */
Node *val, *tmp;
Node *m;
size_t i;
gensimpmatch(n);
end = genlbl(n->loc);
val = temp(s, n->matchstmt.val);
tmp = rval(s, n->matchstmt.val, val);
if (val != tmp)
append(s, assign(s, val, tmp));
for (i = 0; i < n->matchstmt.nmatches; i++) {
m = n->matchstmt.matches[i];
/* check pattern */
cur = genlbl(n->loc);
next = genlbl(n->loc);
matchpattern(s, m->match.pat, val, val->expr.type, cur, next);
/* do the action if it matches */
append(s, cur);
simp(s, m->match.block);
jmp(s, end);
append(s, next);
}
append(s, mkexpr(n->loc, Odead, NULL));
append(s, end);
}
static void simpblk(Simp *s, Node *n)
{
size_t i;
for (i = 0; i < n->block.nstmts; i++) {
n->block.stmts[i] = fold(n->block.stmts[i], 0);
simp(s, n->block.stmts[i]);
}
}
static Node *geninitdecl(Node *init, Type *ty, Node **dcl)
{
Node *n, *d, *r;
char lbl[128];
n = mkname(init->loc, genlblstr(lbl, 128));
d = mkdecl(init->loc, n, ty);
r = mkexpr(init->loc, Ovar, n, NULL);
d->decl.init = init;
d->decl.type = ty;
d->decl.isconst = 1;
d->decl.isglobl = 1;
r->expr.did = d->decl.did;
r->expr.type = ty;
r->expr.isconst = 1;
if (dcl)
*dcl = d;
return r;
}
static Node *simpcode(Simp *s, Node *fn)
{
Node *r, *d;
r = geninitdecl(fn, codetype(exprtype(fn)), &d);
htput(s->globls, d, asmname(d));
lappend(&file->file.stmts, &file->file.nstmts, d);
return r;
}
static Node *simpblob(Simp *s, Node *blob)
{
Node *r, *d;
r = geninitdecl(blob, exprtype(blob), &d);
htput(s->globls, d, asmname(d));
lappend(&s->blobs, &s->nblobs, d);
return r;
}
static Node *ptrsized(Simp *s, Node *v)
{
if (size(v) == Ptrsz)
return v;
else if (size(v) < Ptrsz)
v = mkexpr(v->loc, Ozwiden, v, NULL);
else if (size(v) > Ptrsz)
v = mkexpr(v->loc, Otrunc, v, NULL);
v->expr.type = tyintptr;
return v;
}
static Node *membaddr(Simp *s, Node *n)
{
Node *t, *u, *r;
Node **args;
Type *ty;
args = n->expr.args;
ty = tybase(exprtype(args[0]));
if (ty->type == Typtr) {
t = lval(s, args[0]);
} else {
t = addr(s, lval(s, args[0]), exprtype(n));
}
u = disp(n->loc, offset(args[0], args[1]));
r = add(t, u);
r->expr.type = mktyptr(n->loc, n->expr.type);
return r;
}
static void checkidx(Simp *s, Node *len, Node *idx)
{
Node *cmp, *die;
Node *ok, *fail;
if (!len)
return;
/* create expressions */
cmp = mkexpr(idx->loc, Olt, ptrsized(s, idx), ptrsized(s, len), NULL);
cmp->expr.type = mktype(len->loc, Tybool);
ok = genlbl(len->loc);
fail = genlbl(len->loc);
die = mkexpr(idx->loc, Ocall, abortoob, NULL);
die->expr.type = mktype(len->loc, Tyvoid);
/* insert them */
cjmp(s, cmp, ok, fail);
append(s, fail);
append(s, die);
append(s, ok);
}
static Node *idxaddr(Simp *s, Node *seq, Node *idx)
{
Node *a, *t, *u, *v, *w; /* temps */
Node *r; /* result */
Type *ty;
size_t sz;
a = rval(s, seq, NULL);
ty = exprtype(seq)->sub[0];
if (exprtype(seq)->type == Tyarray) {
t = addr(s, a, ty);
w = exprtype(a)->asize;
} else if (seq->expr.type->type == Tyslice) {
t = load(addr(s, a, mktyptr(seq->loc, ty)));
w = slicelen(s, a);
} else {
die("Can't index type %s\n", tystr(seq->expr.type));
}
assert(t->expr.type->type == Typtr);
u = rval(s, idx, NULL);
u = ptrsized(s, u);
checkidx(s, w, u);
sz = tysize(ty);
v = mul(u, disp(seq->loc, sz));
r = add(t, v);
return r;
}
static Node *slicebase(Simp *s, Node *n, Node *off)
{
Node *t, *u, *v;
Type *ty;
int sz;
t = rval(s, n, NULL);
u = NULL;
ty = tybase(exprtype(n));
switch (ty->type) {
case Typtr: u = t; break;
case Tyarray: u = addr(s, t, base(exprtype(n))); break;
case Tyslice: u = load(addr(s, t, mktyptr(n->loc, base(exprtype(n))))); break;
default: die("Unslicable type %s", tystr(n->expr.type));
}
/* safe: all types we allow here have a sub[0] that we want to grab */
if (off) {
off = ptrsized(s, rval(s, off, NULL));
sz = tysize(n->expr.type->sub[0]);
v = mul(off, disp(n->loc, sz));
return add(u, v);
} else {
return u;
}
}
static Node *lval(Simp *s, Node *n)
{
Node *r;
Node **args;
args = n->expr.args;
switch (exprop(n)) {
case Ovar: r = loadvar(s, n, NULL); break;
case Oidx: r = deref(idxaddr(s, args[0], args[1]), NULL); break;
case Oderef: r = deref(rval(s, args[0], NULL), NULL); break;
case Omemb: r = rval(s, n, NULL); break;
case Ostruct: r = rval(s, n, NULL); break;
case Oucon: r = rval(s, n, NULL); break;
case Oarr: r = rval(s, n, NULL); break;
case Ogap: r = temp(s, n); break;
default:
fatal(n, "%s cannot be an lvalue", opstr[exprop(n)]);
break;
}
return r;
}
static void simpcond(Simp *s, Node *n, Node *ltrue, Node *lfalse)
{
Node **args;
Node *v, *lnext;
args = n->expr.args;
switch (exprop(n)) {
case Oland:
lnext = genlbl(n->loc);
simpcond(s, args[0], lnext, lfalse);
append(s, lnext);
simpcond(s, args[1], ltrue, lfalse);
break;
case Olor:
lnext = genlbl(n->loc);
simpcond(s, args[0], ltrue, lnext);
append(s, lnext);
simpcond(s, args[1], ltrue, lfalse);
break;
case Olnot:
simpcond(s, args[0], lfalse, ltrue);
break;
default:
v = rval(s, n, NULL);
cjmp(s, v, ltrue, lfalse);
break;
}
}
static Node *intconvert(Simp *s, Node *from, Type *to, int issigned)
{
Node *r;
size_t fromsz, tosz;
fromsz = size(from);
tosz = tysize(to);
r = rval(s, from, NULL);
if (fromsz > tosz) {
r = mkexpr(from->loc, Otrunc, r, NULL);
} else if (tosz > fromsz) {
if (issigned)
r = mkexpr(from->loc, Oswiden, r, NULL);
else
r = mkexpr(from->loc, Ozwiden, r, NULL);
}
r->expr.type = to;
return r;
}
static Node *simpcast(Simp *s, Node *val, Type *to)
{
Node *r;
Type *t;
r = NULL;
/* do the type conversion */
switch (tybase(to)->type) {
case Tybool:
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyint: case Tyuint: case Tychar: case Tybyte:
case Typtr:
t = tybase(exprtype(val));
switch (t->type) {
/* ptr -> slice conversion is disallowed */
case Tyslice:
/* FIXME: we should only allow casting to pointers. */
if (tysize(to) != Ptrsz)
fatal(val, "bad cast from %s to %s", tystr(exprtype(val)), tystr(to));
r = slicebase(s, val, NULL);
break;
case Tyfunc:
if (to->type != Typtr)
fatal(val, "bad cast from %s to %s", tystr(exprtype(val)), tystr(to));
r = getcode(s, val);
break;
/* signed conversions */
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyint:
r = intconvert(s, val, to, 1);
break;
/* unsigned conversions */
case Tybool:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyuint: case Tychar: case Tybyte:
case Typtr:
r = intconvert(s, val, to, 0);
break;
case Tyflt32: case Tyflt64:
if (tybase(to)->type == Typtr)
fatal(val, "bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
r = mkexpr(val->loc, Oflt2int, rval(s, val, NULL), NULL);
r->expr.type = to;
break;
default:
fatal(val, "bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
}
break;
case Tyflt32: case Tyflt64:
t = tybase(exprtype(val));
switch (t->type) {
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyint: case Tyuint: case Tychar: case Tybyte:
r = mkexpr(val->loc, Oint2flt, rval(s, val, NULL), NULL);
r->expr.type = to;
break;
case Tyflt32: case Tyflt64:
r = mkexpr(val->loc, Oflt2flt, rval(s, val, NULL), NULL);
r->expr.type = to;
break;
default:
fatal(val, "bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
break;
}
break;
/* no other destination types are handled as things stand */
default:
fatal(val, "bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
}
return r;
}
/* Simplifies taking a slice of an array, pointer,
* or other slice down to primitive pointer operations */
static Node *simpslice(Simp *s, Node *n, Node *dst)
{
Node *t;
Node *start, *end;
Node *base, *sz, *len;
Node *stbase, *stlen;
if (dst)
t = dst;
else
t = temp(s, n);
/* *(&slice) = (void*)base + off*sz */
base = slicebase(s, n->expr.args[0], n->expr.args[1]);
start = ptrsized(s, rval(s, n->expr.args[1], NULL));
end = ptrsized(s, rval(s, n->expr.args[2], NULL));
len = sub(end, start);
/* we can be storing through a pointer, in the case
* of '*foo = bar'. */
if (tybase(exprtype(t))->type == Typtr) {
stbase = set(simpcast(s, t, mktyptr(t->loc, tyintptr)), base);
sz = addk(simpcast(s, t, mktyptr(t->loc, tyintptr)), Ptrsz);
} else {
stbase = set(deref(addr(s, t, tyintptr), NULL), base);
sz = addk(addr(s, t, tyintptr), Ptrsz);
}
/* *(&slice + ptrsz) = len */
stlen = set(deref(sz, NULL), len);
append(s, stbase);
append(s, stlen);
return t;
}
static Node *visit(Simp *s, Node *n)
{
size_t i;
Node *r;
for (i = 0; i < n->expr.nargs; i++)
n->expr.args[i] = rval(s, n->expr.args[i], NULL);
if (ispure(n)) {
r = n;
} else {
if (exprtype(n)->type == Tyvoid) {
r = NULL;
append(s, n);
} else {
r = temp(s, n);
append(s, set(r, n));
}
}
return r;
}
static Node *tupget(Simp *s, Node *tup, size_t idx, Node *dst)
{
Node *plv, *prv, *sz, *stor, *dcl;
size_t off, i;
Type *ty;
off = 0;
ty = exprtype(tup);
for (i = 0; i < ty->nsub; i++) {
off = alignto(off, ty->sub[i]);
if (i == idx)
break;
off += tysize(ty->sub[i]);
}
if (!dst) {
dst = gentemp(s, tup->loc, ty->sub[idx], &dcl);
if (isstacktype(ty->sub[idx]))
declarelocal(s, dcl);
}
prv = add(addr(s, tup, ty->sub[i]), disp(tup->loc, off));
if (stacknode(dst)) {
sz = disp(dst->loc, size(dst));
plv = addr(s, dst, exprtype(dst));
stor = mkexpr(dst->loc, Oblit, plv, prv, sz, NULL);
} else {
stor = set(dst, load(prv));
}
append(s, stor);
return dst;
}
/* Takes a tuple and binds the i'th element of it to the
* i'th name on the rhs of the assignment. */
static Node *destructure(Simp *s, Node *lhs, Node *rhs)
{
Node *lv, *rv, **args;
size_t i;
args = lhs->expr.args;
rhs = rval(s, rhs, NULL);
for (i = 0; i < lhs->expr.nargs; i++) {
lv = lval(s, args[i]);
rv = tupget(s, rhs, i, lv);
assert(rv == lv);
}
return NULL;
}
static Node *assign(Simp *s, Node *lhs, Node *rhs)
{
Node *t, *u, *v, *r;
if (exprop(lhs) == Otup) {
r = destructure(s, lhs, rhs);
} else {
t = lval(s, lhs);
u = rval(s, rhs, t);
/* if we stored the result into t, rval() should return that,
* so we know our work is done. */
if (u == t) {
r = t;
} else if (stacknode(lhs)) {
t = addr(s, t, exprtype(lhs));
u = addr(s, u, exprtype(lhs));
v = disp(lhs->loc, size(lhs));
r = mkexpr(lhs->loc, Oblit, t, u, v, NULL);
} else {
r = set(t, u);
}
}
return r;
}
static Node *assignat(Simp *s, Node *r, size_t off, Node *val)
{
Node *pval, *pdst;
Node *sz;
Node *st;
pdst = add(r, disp(val->loc, off));
if (stacknode(val)) {
sz = disp(val->loc, size(val));
pval = addr(s, val, exprtype(val));
st = mkexpr(val->loc, Oblit, pdst, pval, sz, NULL);
} else {
st = set(deref(pdst, val->expr.type), val);
}
append(s, st);
return r;
}
/* Simplify tuple construction to a stack allocated
* value by evaluating the rvalue of each node on the
* rhs and assigning it to the correct offset from the
* head of the tuple. */
static Node *simptup(Simp *s, Node *n, Node *dst)
{
Node **args;
Node *r;
size_t i, off;
args = n->expr.args;
if (!dst)
dst = temp(s, n);
r = addr(s, dst, exprtype(dst));
off = 0;
for (i = 0; i < n->expr.nargs; i++) {
off = alignto(off, exprtype(args[i]));
assignat(s, r, off, rval(s, args[i], NULL));
off += size(args[i]);
}
return dst;
}
static Node *simpucon(Simp *s, Node *n, Node *dst)
{
Node *tmp, *u, *tag, *elt, *sz;
Node *r;
Type *ty;
Ucon *uc;
size_t i;
/* find the ucon we're constructing here */
ty = tybase(n->expr.type);
uc = NULL;
for (i = 0; i < ty->nmemb; i++) {
if (!strcmp(namestr(n->expr.args[0]), namestr(ty->udecls[i]->name))) {
uc = ty->udecls[i];
break;
}
}
if (!uc)
die("Couldn't find union constructor");
if (dst)
tmp = dst;
else
tmp = temp(s, n);
/* Set the tag on the ucon */
u = addr(s, tmp, mktype(n->loc, Tyuint));
tag = mkintlit(n->loc, uc->id);
tag->expr.type = mktype(n->loc, Tyuint);
append(s, set(deref(u, tyword), tag));
/* fill the value, if needed */
if (!uc->etype)
return tmp;
elt = rval(s, n->expr.args[1], NULL);
u = addk(u, Wordsz);
if (isstacktype(uc->etype)) {
elt = addr(s, elt, uc->etype);
sz = disp(n->loc, tysize(uc->etype));
r = mkexpr(n->loc, Oblit, u, elt, sz, NULL);
} else {
r = set(deref(u, uc->etype), elt);
}
append(s, r);
return tmp;
}
static Node *simpuget(Simp *s, Node *n, Node *dst)
{
die("No uget simplification yet");
return NULL;
}
/* simplifies
* a || b
* to
* if a || b
* t = true
* else
* t = false
* ;;
*/
static Node *simplazy(Simp *s, Node *n)
{
Node *r, *t, *u;
Node *ltrue, *lfalse, *ldone;
/* set up temps and labels */
r = temp(s, n);
ltrue = genlbl(n->loc);
lfalse = genlbl(n->loc);
ldone = genlbl(n->loc);
/* simp the conditional */
simpcond(s, n, ltrue, lfalse);
/* if true */
append(s, ltrue);
u = mkexpr(n->loc, Olit, mkbool(n->loc, 1), NULL);
u->expr.type = mktype(n->loc, Tybool);
t = set(r, u);
append(s, t);
jmp(s, ldone);
/* if false */
append(s, lfalse);
u = mkexpr(n->loc, Olit, mkbool(n->loc, 0), NULL);
u->expr.type = mktype(n->loc, Tybool);
t = set(r, u);
append(s, t);
jmp(s, ldone);
/* finish */
append(s, ldone);
return r;
}
static Node *comparecomplex(Simp *s, Node *n, Op op)
{
fatal(n, "Complex comparisons not yet supported\n");
return NULL;
}
static Node *compare(Simp *s, Node *n, int fields)
{
const Op cmpmap[Numops][3] = {
[Oeq] = {Oeq, Oueq, Ofeq},
[One] = {One, Oune, Ofne},
[Ogt] = {Ogt, Ougt, Ofgt},
[Oge] = {Oge, Ouge, Ofge},
[Olt] = {Olt, Oult, Oflt},
[Ole] = {Ole, Oule, Ofle}
};
Node *r;
Op newop;
newop = Obad;
if (istysigned(tybase(exprtype(n->expr.args[0]))))
newop = cmpmap[n->expr.op][0];
else if (istyunsigned(tybase(exprtype(n->expr.args[0]))))
newop = cmpmap[n->expr.op][1];
else if (istyfloat(tybase(exprtype(n->expr.args[0]))))
newop = cmpmap[n->expr.op][2];
if (newop != Obad) {
n->expr.op = newop;
r = visit(s, n);
} else if (fields) {
r = comparecomplex(s, n, exprop(n));
} else {
fatal(n, "unsupported comparison on values");
}
return r;
}
static Node *vatypeinfo(Simp *s, Node *n)
{
Node *ti, *tp, *td, *tn;
Type *ft, *vt, **st;
size_t nst, i;
char buf[1024];
st = NULL;
nst = 0;
ft = exprtype(n->expr.args[0]);
/* The structure of ft->sub:
* [return, normal, args, ...]
*
* The structure of n->expr.sub:
* [fn, normal, args, , variadic, args]
*
* We want to start at variadic, so we want
* to count from ft->nsub - 1, up to n->expr.nsub.
*/
for (i = ft->nsub - 1; i < n->expr.nargs; i++)
lappend(&st, &nst, exprtype(n->expr.args[i]));
vt = mktytuple(n->loc, st, nst);
vt->isreflect = 1;
/* make the decl */
tn = mkname(Zloc, tydescid(buf, sizeof buf, vt));
td = mkdecl(Zloc, tn, mktype(n->loc, Tybyte));
td->decl.isglobl = 1;
td->decl.isconst = 1;
td->decl.ishidden = 1;
/* and the var */
ti = mkexpr(Zloc, Ovar, tn, NULL);
ti->expr.type = td->decl.type;
ti->expr.did = td->decl.did;
/* and the pointer */
tp = mkexpr(Zloc, Oaddr, ti, NULL);
tp->expr.type = mktyptr(n->loc, td->decl.type);
htput(s->globls, td, asmname(td));
return tp;
}
static Node *capture(Simp *s, Node *n, Node *dst)
{
Node *fn, *t, *f, *e, *val, *dcl, *fp, *envsz;
size_t nenv, nenvt, off, i;
Type **envt;
Node **env;
f = simpcode(s, n);
fn = n->expr.args[0];
fn = fn->lit.fnval;
if (!dst) {
dst = gentemp(s, n->loc, closuretype(exprtype(f)), &dcl);
forcelocal(s, dcl);
}
fp = addr(s, dst, exprtype(dst));
env = getclosure(fn->func.scope, &nenv);
if (env) {
/* we need these in a deterministic order so that we can
put them in the right place both when we use them and
when we capture them. */
qsort(env, nenv, sizeof(Node*), envcmp);
/* make the tuple that will hold the environment */
envt = NULL;
nenvt = 0;
/* reserve space for size */
lappend(&envt, &nenvt, tyintptr);
for (i = 0; i < nenv; i++)
lappend(&envt, &nenvt, decltype(env[i]));
t = gentemp(s, n->loc, mktytuple(n->loc, envt, nenvt), &dcl);
forcelocal(s, dcl);
e = addr(s, t, exprtype(t));
off = Ptrsz; /* we start with the size of the env */
for (i = 0; i < nenv; i++) {
off = alignto(off, decltype(env[i]));
val = mkexpr(n->loc, Ovar, env[i]->decl.name, NULL);
val->expr.type = env[i]->decl.type;
val->expr.did = env[i]->decl.did;
assignat(s, e, off, rval(s, val, NULL));
off += size(env[i]);
}
free(env);
envsz = mkintlit(n->loc, off);
envsz->expr.type = tyintptr;
assignat(s, e, 0, envsz);
assignat(s, fp, 0, e);
}
assignat(s, fp, Ptrsz, f);
return dst;
}
static Node *getenvptr(Simp *s, Node *n)
{
assert(tybase(exprtype(n))->type == Tyfunc);
return load(addr(s, n, tyintptr));
}
static Node *getcode(Simp *s, Node *n)
{
Node *r, *p, *d;
Type *ty;
if (isconstfn(n)) {
d = decls[n->expr.did];
r = mkexpr(n->loc, Ovar, n->expr.args[0], NULL);
r->expr.did = d->decl.did;
r->expr.type = codetype(exprtype(n));
} else {
ty = tybase(exprtype(n));
assert(ty->type == Tyfunc);
p = addr(s, rval(s, n, NULL), codetype(ty));
r = load(addk(p, Ptrsz));
}
return r;
}
static Node *simpcall(Simp *s, Node *n, Node *dst)
{
Node *r, *call, *fn;
size_t i, nargs;
Node **args;
Type *ft;
Op op;
/* NB: If we called rval() on a const function, , we would end up with
a stack allocated closure. We don't want to do this. */
fn = n->expr.args[0];
if (!isconstfn(fn))
fn = rval(s, fn, NULL);
ft = tybase(exprtype(fn));
if (exprtype(n)->type == Tyvoid)
r = NULL;
else if (isstacktype(exprtype(n)) && dst)
r = dst;
else
r = temp(s, n);
args = NULL;
nargs = 0;
op = Ocall;
lappend(&args, &nargs, getcode(s, fn));
if (!isconstfn(fn)) {
op = Ocallind;
lappend(&args, &nargs, getenvptr(s, fn));
}
if (exprtype(n)->type != Tyvoid && isstacktype(exprtype(n)))
lappend(&args, &nargs, addr(s, r, exprtype(n)));
for (i = 1; i < n->expr.nargs; i++) {
if (i < ft->nsub && tybase(ft->sub[i])->type == Tyvalist)
lappend(&args, &nargs, vatypeinfo(s, n));
lappend(&args, &nargs, rval(s, n->expr.args[i], NULL));
if (exprop(n->expr.args[i]) == Oaddr)
if (exprop(n->expr.args[i]->expr.args[0]) == Ovar)
def(s, n->expr.args[i]->expr.args[0]);
}
if (i < ft->nsub && tybase(ft->sub[i])->type == Tyvalist)
lappend(&args, &nargs, vatypeinfo(s, n));
if (r)
def(s, r);
call = mkexprl(n->loc, op, args, nargs);
call->expr.type = exprtype(n);
if (r && !isstacktype(exprtype(n))) {
append(s, set(r, call));
} else {
append(s, call);
}
return r;
}
static Node *rval(Simp *s, Node *n, Node *dst)
{
Node *t, *u, *v; /* temporary nodes */
Node *r; /* expression result */
Node **args;
size_t i;
Type *ty;
const Op fusedmap[Numops] = {
[Oaddeq] = Oadd,
[Osubeq] = Osub,
[Omuleq] = Omul,
[Odiveq] = Odiv,
[Omodeq] = Omod,
[Oboreq] = Obor,
[Obandeq] = Oband,
[Obxoreq] = Obxor,
[Obsleq] = Obsl,
[Obsreq] = Obsr,
};
r = NULL;
args = n->expr.args;
switch (exprop(n)) {
case Olor: case Oland:
r = simplazy(s, n);
break;
case Osize:
r = mkintlit(n->loc, size(args[0]));
r->expr.type = exprtype(n);
break;
case Oslice:
r = simpslice(s, n, dst);
break;
case Oidx:
t = idxaddr(s, n->expr.args[0], n->expr.args[1]);
r = load(t);
break;
/* array.len slice.len are magic 'virtual' members.
* they need to be special cased. */
case Omemb:
if (exprtype(args[0])->type == Tyslice || exprtype(args[0])->type == Tyarray) {
r = seqlen(s, args[0], exprtype(n));
} else {
t = membaddr(s, n);
r = load(t);
}
break;
case Oucon:
r = simpucon(s, n, dst);
break;
case Outag:
r = uconid(s, args[0]);
break;
case Oudata:
r = simpuget(s, n, dst);
break;
case Otup:
r = simptup(s, n, dst);
break;
case Oarr:
if (!dst)
dst = temp(s, n);
t = addr(s, dst, exprtype(dst));
for (i = 0; i < n->expr.nargs; i++)
assignat(s, t, size(n->expr.args[i])*i, rval(s, n->expr.args[i], NULL));
r = dst;
break;
case Ostruct:
if (!dst)
dst = temp(s, n);
u = mkexpr(dst->loc, Odef, dst, NULL);
u->expr.type = mktype(u->loc, Tyvoid);
append(s, u);
t = addr(s, dst, exprtype(dst));
ty = exprtype(n);
/* we only need to clear if we don't have things fully initialized */
if (tybase(ty)->nmemb != n->expr.nargs)
append(s, mkexpr(n->loc, Oclear, t, mkintlit(n->loc, size(n)), NULL));
for (i = 0; i < n->expr.nargs; i++)
assignat(s, t, offset(n, n->expr.args[i]->expr.idx), rval(s, n->expr.args[i], NULL));
r = dst;
break;
case Ocast:
r = simpcast(s, args[0], exprtype(n));
break;
/* fused ops:
* foo ?= blah
* =>
* foo = foo ? blah*/
case Oaddeq: case Osubeq: case Omuleq: case Odiveq: case Omodeq:
case Oboreq: case Obandeq: case Obxoreq: case Obsleq: case Obsreq:
assert(fusedmap[exprop(n)] != Obad);
u = lval(s, args[0]);
v = rval(s, args[1], NULL);
v = mkexpr(n->loc, fusedmap[exprop(n)], u, v, NULL);
v->expr.type = u->expr.type;
r = set(u, v);
break;
/* ++expr(x)
* => args[0] = args[0] + 1
* expr(x) */
case Opreinc:
v = assign(s, args[0], addk(args[0], 1));
append(s, v);
r = rval(s, args[0], NULL);
break;
case Opredec:
v = assign(s, args[0], subk(args[0], 1));
append(s, v);
r = rval(s, args[0], NULL);
break;
/* expr(x++)
* => expr
* x = x + 1
*/
case Opostinc:
r = lval(s, args[0]);
t = assign(s, r, addk(r, 1));
lappend(&s->incqueue, &s->nqueue, t);
break;
case Opostdec:
r = lval(s, args[0]);
t = assign(s, r, subk(r, 1));
lappend(&s->incqueue, &s->nqueue, t);
break;
case Olit:
switch (args[0]->lit.littype) {
case Lchr: case Lbool: case Llbl:
r = n;
break;
case Lint:
/* we can only have up to 4 byte immediates, but they
* can be moved into 64 bit regs */
if ((uint64_t)args[0]->lit.intval < 0x7fffffffULL)
r = n;
else
r = simpblob(s, n);
break;
case Lstr: case Lflt:
r = simpblob(s, n);
break;
case Lfunc:
r = capture(s, n, dst);
break;
}
break;
case Ovar:
r = loadvar(s, n, dst);
break;
case Ogap:
fatal(n, "'_' may not be an rvalue");
break;
case Oret:
if (s->isbigret) {
t = rval(s, args[0], NULL);
t = addr(s, t, exprtype(args[0]));
u = disp(n->loc, size(args[0]));
v = mkexpr(n->loc, Oblit, s->ret, t, u, NULL);
append(s, v);
} else if (n->expr.nargs && n->expr.args[0]) {
t = s->ret;
/* void calls return nothing */
if (t) {
t = set(t, rval(s, args[0], NULL));
append(s, t);
}
}
/* drain the increment queue before we return */
for (i = 0; i < s->nqueue; i++)
append(s, s->incqueue[i]);
lfree(&s->incqueue, &s->nqueue);
append(s, mkexpr(n->loc, Oret, NULL));
break;
case Oasn:
r = assign(s, args[0], args[1]);
break;
case Ocall:
r = simpcall(s, n, dst);
break;
case Oaddr:
t = lval(s, args[0]);
if (exprop(t) == Ovar) /* Ovar is the only one that doesn't return Oderef(Oaddr(...)) */
r = addr(s, t, exprtype(t));
else
r = t->expr.args[0];
break;
case Oneg:
if (istyfloat(exprtype(n))) {
t =mkfloat(n->loc, -1.0);
u = mkexpr(n->loc, Olit, t, NULL);
t->lit.type = n->expr.type;
u->expr.type = n->expr.type;
v = simpblob(s, u);
r = mkexpr(n->loc, Ofmul, v, rval(s, args[0], NULL), NULL);
r->expr.type = n->expr.type;
} else {
r = visit(s, n);
}
break;
case Obreak:
if (s->nloopexit == 0)
fatal(n, "trying to break when not in loop");
jmp(s, s->loopexit[s->nloopexit - 1]);
break;
case Ocontinue:
if (s->nloopstep == 0)
fatal(n, "trying to continue when not in loop");
jmp(s, s->loopstep[s->nloopstep - 1]);
break;
case Oeq: case One:
r = compare(s, n, 1);
break;
case Ogt: case Oge: case Olt: case Ole:
r = compare(s, n, 0);
break;
case Otupget:
assert(exprop(args[0]) == Olit);
i = args[0]->expr.args[0]->lit.intval;
r = tupget(s, args[0], i, dst);
case Obad:
die("bad operator");
break;
default:
if (istyfloat(exprtype(n))) {
switch (exprop(n)) {
case Oadd: n->expr.op = Ofadd; break;
case Osub: n->expr.op = Ofsub; break;
case Omul: n->expr.op = Ofmul; break;
case Odiv: n->expr.op = Ofdiv; break;
default: break;
}
}
r = visit(s, n);
break;
}
return r;
}
static void declarearg(Simp *s, Node *n)
{
assert(n->type == Ndecl || (n->type == Nexpr && exprop(n) == Ovar));
lappend(&s->args, &s->nargs, n);
}
static int islbl(Node *n)
{
Node *l;
if (exprop(n) != Olit)
return 0;
l = n->expr.args[0];
return l->type == Nlit && l->lit.littype == Llbl;
}
static Node *simp(Simp *s, Node *n)
{
Node *r, *t, *u;
size_t i;
if (!n)
return NULL;
r = NULL;
switch (n->type) {
case Nblock: simpblk(s, n); break;
case Nifstmt: simpif(s, n, NULL); break;
case Nloopstmt: simploop(s, n); break;
case Niterstmt: simpiter(s, n); break;
case Nmatchstmt: simpmatch(s, n); break;
case Nexpr:
if (islbl(n))
append(s, n);
else
r = rval(s, n, NULL);
if (r)
append(s, r);
/* drain the increment queue for this expr */
for (i = 0; i < s->nqueue; i++)
append(s, s->incqueue[i]);
lfree(&s->incqueue, &s->nqueue);
break;
case Ndecl:
declarelocal(s, n);
t = mkexpr(n->loc, Ovar, n->decl.name, NULL);
if (n->decl.init) {
u = mkexpr(n->loc, Oasn, t, n->decl.init, NULL);
u->expr.type = n->decl.type;
t->expr.type = n->decl.type;
t->expr.did = n->decl.did;
simp(s, u);
}
break;
default:
dump(n, stderr);
die("bad node passsed to simp()");
break;
}
return r;
}
/*
* Turns a deeply nested function body into a flatter
* and simpler representation, which maps easily and
* directly to assembly instructions.
*/
static void flatten(Simp *s, Node *f)
{
Node *dcl;
Type *ty;
size_t i;
assert(f->type == Nfunc);
s->nstmts = 0;
s->stmts = NULL;
s->endlbl = genlbl(f->loc);
s->ret = NULL;
/* make a temp for the return type */
ty = f->func.type->sub[0];
if (isstacktype(ty)) {
s->isbigret = 1;
s->ret = gentemp(s, f->loc, mktyptr(f->loc, ty), &dcl);
declarearg(s, dcl);
} else if (ty->type != Tyvoid) {
s->isbigret = 0;
s->ret = gentemp(s, f->loc, ty, &dcl);
}
for (i = 0; i < f->func.nargs; i++) {
declarearg(s, f->func.args[i]);
}
simp(s, f->func.body);
append(s, s->endlbl);
}
static int isexport(Node *dcl)
{
Node *n;
/* Vishidden should also be exported. */
if (dcl->decl.vis != Visintern)
return 1;
n = dcl->decl.name;
if (!n->name.ns && streq(n->name.name, "main"))
return 1;
if (streq(n->name.name, "__init__"))
return 1;
return 0;
}
static int envcmp(const void *pa, const void *pb)
{
const Node *a, *b;
a = *(const Node**)pa;
b = *(const Node**)pb;
return b->decl.did - a->decl.did;
}
static void collectenv(Simp *s, Node *fn)
{
size_t nenv, i;
Node **env;
size_t off;
env = getclosure(fn->func.scope, &nenv);
if (!env)
return;
/*
we need these in a deterministic order so that we can
put them in the right place both when we use them and
when we capture them.
*/
s->hasenv = 1;
qsort(env, nenv, sizeof(Node*), envcmp);
off = Ptrsz; /* we start with the size of the env */
for (i = 0; i < nenv; i++) {
off = alignto(off, decltype(env[i]));
htput(s->envoff, env[i], itop(off));
off += size(env[i]);
}
free(env);
}
static Func *simpfn(Simp *s, char *name, Node *dcl)
{
Node *n;
size_t i;
Func *fn;
Cfg *cfg;
n = dcl->decl.init;
if(debugopt['i'] || debugopt['F'] || debugopt['f'])
printf("\n\nfunction %s\n", name);
/* set up the simp context */
/* unwrap to the function body */
n = n->expr.args[0];
n = n->lit.fnval;
collectenv(s, n);
flatten(s, n);
if (debugopt['f'] || debugopt['F'])
for (i = 0; i < s->nstmts; i++)
dump(s->stmts[i], stdout);
for (i = 0; i < s->nstmts; i++) {
if (s->stmts[i]->type != Nexpr)
continue;
if (debugopt['f']) {
printf("FOLD FROM ----------\n");
dump(s->stmts[i], stdout);
}
s->stmts[i] = fold(s->stmts[i], 0);
if (debugopt['f']) {
printf("TO ------------\n");
dump(s->stmts[i], stdout);
printf("DONE ----------------\n");
}
}
cfg = mkcfg(dcl, s->stmts, s->nstmts);
check(cfg);
if (debugopt['t'] || debugopt['s'])
dumpcfg(cfg, stdout);
fn = zalloc(sizeof(Func));
fn->name = strdup(name);
fn->type = dcl->decl.type;
fn->isexport = isexport(dcl);
fn->stksz = align(s->stksz, 8);
fn->stkoff = s->stkoff;
fn->envoff = s->envoff;
fn->ret = s->ret;
fn->args = s->args;
fn->nargs = s->nargs;
fn->cfg = cfg;
fn->hasenv = s->hasenv;
return fn;
}
static void extractsub(Simp *s, Node *e)
{
size_t i;
assert(e != NULL);
switch (exprop(e)) {
case Oslice:
if (exprop(e->expr.args[0]) == Oarr)
e->expr.args[0] = simpblob(s, e->expr.args[0]);
break;
case Oarr:
case Ostruct:
for (i = 0; i < e->expr.nargs; i++)
extractsub(s, e->expr.args[i]);
break;
default:
break;
}
}
static void simpconstinit(Simp *s, Node *dcl)
{
Node *e;
dcl->decl.init = fold(dcl->decl.init, 1);;
e = dcl->decl.init;
if (e && exprop(e) == Olit) {
if (e->expr.args[0]->lit.littype == Lfunc)
simpcode(s, e);
else
lappend(&s->blobs, &s->nblobs, dcl);
} else if (dcl->decl.isconst) {
switch (exprop(e)) {
case Oarr:
case Ostruct:
case Oslice:
extractsub(s, e);
lappend(&s->blobs, &s->nblobs, dcl);
break;
default:
fatal(dcl, "unsupported initializer for %s", declname(dcl));
break;
}
} else if (!dcl->decl.isconst && !e) {
lappend(&s->blobs, &s->nblobs, dcl);
} else {
die("Non-constant initializer for %s\n", declname(dcl));
}
}
int ismain(Node *dcl)
{
Node *n;
n = dcl->decl.name;
if (n->name.ns)
return 0;
return strcmp(n->name.name, "main") == 0;
}
void simpglobl(Node *dcl, Htab *globls, Func ***fn, size_t *nfn, Node ***blob, size_t *nblob)
{
Simp s = {0,};
char *name;
Func *f;
if (ismain(dcl))
dcl->decl.vis = Vishidden;
s.stkoff = mkht(varhash, vareq);
s.envoff = mkht(varhash, vareq);
s.globls = globls;
s.blobs = *blob;
s.nblobs = *nblob;
s.hasenv = 0;
name = asmname(dcl);
if (dcl->decl.isextern || dcl->decl.isgeneric)
return;
if (isconstfn(dcl)) {
f = simpfn(&s, name, dcl);
lappend(fn, nfn, f);
} else {
simpconstinit(&s, dcl);
}
*blob = s.blobs;
*nblob = s.nblobs;
free(name);
}