/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Hans van Staveren
*/
#include "assert.h"
#include "param.h"
#include "tables.h"
#include "types.h"
#include <cg_pattern.h>
#include "data.h"
#include "result.h"
#include "state.h"
#include "equiv.h"
#include "extern.h"
#include "subr.h"
#include "gencode.h"
#include "reg.h"
#include "salloc.h"
#include "fillem.h"
#define SHORTCUT /* Stop searching at distance 0 */
#if NREGS >= MAXRULE
#define MAXPOS NREGS
#else
#define MAXPOS MAXRULE
#endif
#define MAXPATTERN 5
#define MAXREPLLEN 5 /* Max length of EM-replacement, should come from boot */
byte startupcode[] =
{ DO_NEXTEM };
extern byte *nextem(int);
string tostring();
extern int move(token_p,token_p,int,int,unsigned int);
extern struct perm* tuples(rl_p*, int);
#ifdef NDEBUG
#define DEBUG(xxxxx)
#else
#include <stdio.h>
#define DEBUG(string) {if(Debug) fprintf(stderr,"%-*d%s\n",4*level,level,string);}
#endif
#define BROKE() {assert(origcp!=startupcode);DEBUG("BROKE");goto doreturn;}
#define CHKCOST() {if (totalcost>=costlimit) BROKE();}
unsigned int codegen(byte *codep, int ply, int toplevel, unsigned int costlimit, int forced)
{
#ifndef NDEBUG
byte *origcp = codep;
static int level = 0;
#endif
unsigned totalcost = 0;
byte *bp;
int n;
unsigned mindistance, dist;
register int i;
int cindex;
int npos, npos2, pos[MAXPOS], pos2[MAXPOS];
#ifdef STONSTACK
state_t state;
#define SAVEST savestatus(&state)
#define RESTST restorestatus(&state)
#define FREEST /* nothing */
#else
state_p state;
#define SAVEST state=savestatus()
#define RESTST restorestatus(state)
#define FREEST freestatus(state)
#endif
unsigned mincost, t;
int texpno, nodeno;
token_p tp;
tkdef_p tdp;
int tinstno;
register struct reginfo *rp;
struct reginfo **rpp;
token_t token, mtoken, token2;
int propno;
int exactmatch;
int j;
int decision;
int stringno;
result_t result;
cost_t cost;
int size, lsize, repllen;
int tokexp[MAXPATTERN];
int nregneeded;
token_p regtp[MAXCREG];
c3_p regcp[MAXCREG];
rl_p regls[MAXCREG];
#ifdef MAXSPLIT
int sret;
#endif /* MAXSPLIT */
token_t reptoken[MAXREPLLEN];
int emrepllen, eminstr;
int inscoerc = 0;
int stackpad;
struct perm *tup, *ntup, *besttup;
#ifndef NDEBUG
level++;
DEBUG("Entering codegen");
#endif
for (;;)
{
switch ((*codep++) & 037)
{
default:
assert(FALSE);
/* NOTREACHED */
case DO_NEXTEM:
DEBUG("NEXTEM")
;
tokpatlen = 0;
nallreg = 0;
if (toplevel)
{
garbage_collect();
totalcost = 0;
}
else
{
if (--ply <= 0)
goto doreturn;
}
if (stackheight > MAXFSTACK - 7)
totalcost += stackupto(&fakestack[6], ply, toplevel);
bp = nextem(toplevel);
if (bp == 0)
{
/*
* No pattern found, can be pseudo or error
* in table.
*/
if (toplevel)
{
codep--;
DEBUG("pseudo");
dopseudo();
}
else
goto doreturn;
}
else
{
#ifndef NDEBUG
chkregs();
#endif
if (!toplevel)
{
ply -= emp - saveemp + 1;
if (ply <= 0)
ply = 1;
}
n = *bp++;
assert(n>0 && n<=MAXRULE);
if (n > 1)
{
mindistance = MAXINT;
npos = 0;
for (i = 0; i < n; i++)
{
getint(cindex, bp);
dist = distance(cindex);
#ifndef NDEBUG
if (Debug)
fprintf(stderr, "distance of pos %d is %u\n", i,
dist);
#endif
if (dist <= mindistance)
{
if (dist < mindistance)
{
#ifdef SHORTCUT
if (dist == 0)
goto gotit;
#endif
npos = 0;
mindistance = dist;
}
pos[npos++] = cindex;
}
}
assert(mindistance<MAXINT);
if (npos > 1)
{
/*
* More than 1 tokenpattern is a candidate.
* Decision has to be made by lookahead.
*/
SAVEST;
mincost = costlimit - totalcost + 1;
for (i = 0; i < npos; i++)
{
t = codegen(&coderules[pos[i]], ply, FALSE,
costlimit < MAXINT ? mincost : MAXINT,
0);
#ifndef NDEBUG
if (Debug)
fprintf(stderr,
"mincost %u,cost %u,pos %d\n",
mincost, t, i);
#endif
if (t < mincost)
{
mincost = t;
cindex = pos[i];
}
RESTST;
} FREEST;
if (totalcost + mincost > costlimit)
{
totalcost += mincost;
BROKE();
}
}
else
{
cindex = pos[0];
}
}
else
{
getint(cindex, bp);
}
gotit:
/*
* Now cindex contains the code-index of the best candidate
* so proceed to use it.
*/
codep = &coderules[cindex];
}
break;
case DO_COERC:
DEBUG("COERC")
;
tokpatlen = 1;
inscoerc = 1;
break;
case DO_XXMATCH:
DEBUG("XXMATCH")
;
case DO_XMATCH:
DEBUG("XMATCH")
;
tokpatlen = (codep[-1] >> 5) & 07;
for (i = 0; i < tokpatlen; i++)
getint(tokexp[i], codep)
;
tokexp[i] = 0;
break; /* match already checked by distance() */
case DO_MATCH:
DEBUG("MATCH")
;
tokpatlen = (codep[-1] >> 5) & 07;
for (i = 0; i < tokpatlen; i++)
getint(tokexp[i], codep)
;
tokexp[i] = 0;
tp = &fakestack[stackheight - 1];
i = 0;
while (i < tokpatlen && tp >= fakestack)
{
size = tsize(tp);
while (i < tokpatlen && (lsize = ssize(tokexp[i])) <= size)
{
size -= lsize;
i++;
}
if (i < tokpatlen && size != 0)
{
totalcost += stackupto(tp, ply, toplevel);
CHKCOST();
break;
}
tp--;
}
tp = &fakestack[stackheight - 1];
i = 0;
while (i < tokpatlen && tp >= fakestack)
{
size = tsize(tp);
lsize = ssize(tokexp[i]);
if (size != lsize)
{ /* find coercion */
#ifdef MAXSPLIT
sret = split(tp,&tokexp[i],ply,toplevel);
if (sret==0)
{
#endif /* MAXSPLIT */
totalcost += stackupto(tp, ply, toplevel);
CHKCOST();
break;
#ifdef MAXSPLIT
}
i += sret;
#endif /* MAXSPLIT */
}
else
i += 1;
tp--;
}
nextmatch: tp = &fakestack[stackheight - 1];
i = 0;
nregneeded = 0;
while (i < tokpatlen && tp >= fakestack)
{
if (!match(tp, &machsets[tokexp[i]], 0))
{
register c3_p cp = findcoerc(tp, &machsets[tokexp[i]]);
if (cp == 0)
{
for (j = 0; j < nregneeded; j++)
regtp[j] -= (tp - fakestack + 1);
totalcost += stackupto(tp, ply, toplevel);
CHKCOST();
break;
}
else
{
if (cp->c3_prop == 0)
{
totalcost += docoerc(tp, cp, ply, toplevel, 0);
CHKCOST();
}
else
{
assert(nregneeded<MAXCREG);
regtp[nregneeded] = tp;
regcp[nregneeded] = cp;
regls[nregneeded] = curreglist;
nregneeded++;
}
}
}
i++;
tp--;
}
if (tokpatlen > stackheight)
{
int k;
stackpad = tokpatlen - stackheight;
for (j = stackheight - 1, k = j + stackpad; j >= 0;
j--, k--)
{
fakestack[k] = fakestack[j];
/* fakestack[j+stackpad] = fakestack[j]; does not
compile under Xenix
*/
}
for (j = 0; j < stackpad; j++)
fakestack[j].t_token = 0;
stackheight += stackpad;
for (j = 0; j < nregneeded; j++)
regtp[j] += stackpad;
tp = &fakestack[stackpad - 1];
while (i < tokpatlen && tp >= fakestack)
{
register c3_p cp = findcoerc((token_p) 0,
&machsets[tokexp[i]]);
if (cp == 0)
{
assert(!toplevel);
for (j = 0; j < nregneeded; j++)
myfree(regls[j]);
totalcost = INFINITY;
BROKE();
}
if (cp->c3_prop == 0)
{
totalcost += docoerc(tp, cp, ply, toplevel, 0);
CHKCOST();
}
else
{
assert(nregneeded<MAXCREG);
regtp[nregneeded] = tp;
regcp[nregneeded] = cp;
regls[nregneeded] = curreglist;
nregneeded++;
}
i++;
tp--;
}
}
else
stackpad = 0;
assert(i == tokpatlen);
if (nregneeded == 0)
break;
SAVEST;
mincost = costlimit - totalcost + 1;
tup = tuples(regls, nregneeded);
besttup = 0;
for (; tup != 0; tup = ntup)
{
#ifndef NDEBUG
if (Debug > 1)
{
fprintf(stderr, "Next tuple %d,%d,%d,%d\n",
tup->p_rar[0], tup->p_rar[1], tup->p_rar[2],
tup->p_rar[3]);
fprintf(stderr,
"totalcost = %u, costlimit = %u, mincost = %u\n",
totalcost, costlimit, mincost);
}
#endif
ntup = tup->p_next;
for (i = 0, t = 0; i < nregneeded && t < mincost; i++)
t += docoerc(regtp[i], regcp[i], ply, FALSE,
tup->p_rar[i]);
#ifndef NDEBUG
if (Debug > 1)
fprintf(stderr, "cost after coercions: %u\n", t);
#endif
if (t < mincost)
t += codegen(codep, ply, FALSE,
mincost < MAXINT ? mincost - t : MAXINT, 0);
if (t < mincost)
{
mincost = t;
besttup = tup;
}
else
myfree(tup);
RESTST;
}
FREEST;
for (i = 0; i < nregneeded; i++)
myfree(regls[i]);
if (totalcost + mincost > costlimit)
{
if (besttup)
myfree(besttup);
if (stackpad != tokpatlen)
{
if (stackpad)
{
if (costlimit < MAXINT)
{
totalcost = costlimit + 1;
BROKE();
}
for (i = 0; i < stackheight - stackpad; i++)
fakestack[i] = fakestack[i + stackpad];
stackheight -= stackpad;
totalcost += stackupto(&fakestack[stackheight - 1],
ply, toplevel);
}
else
totalcost += stackupto(fakestack, ply, toplevel);
CHKCOST();
goto nextmatch;
}
totalcost += mincost;
BROKE();
}
for (i = 0; i < nregneeded; i++)
totalcost += docoerc(regtp[i], regcp[i], ply, toplevel,
besttup->p_rar[i]);
myfree(besttup);
break;
case DO_REMOVE:
DEBUG("REMOVE")
;
if (codep[-1] & 32)
{
getint(texpno, codep);
getint(nodeno, codep);
}
else
{
getint(texpno, codep);
nodeno = 0;
}
for (tp = &fakestack[stackheight - tokpatlen - 1];
tp >= &fakestack[0]; tp--)
if (match(tp, &machsets[texpno], nodeno))
{
/* investigate possible coercion to register */
totalcost += stackupto(tp, ply, toplevel);
CHKCOST();
break;
}
for (rp = machregs + 2; rp < machregs + NREGS; rp++)
if (match(&rp->r_contents, &machsets[texpno], nodeno))
rp->r_contents.t_token = 0;
break;
case DO_RREMOVE: /* register remove */
DEBUG("RREMOVE")
;
getint(nodeno, codep)
;
result = compute(&enodes[nodeno]);
assert(result.e_typ==EV_REG);
for (tp = &fakestack[stackheight - tokpatlen - 1];
tp >= &fakestack[0]; tp--)
if (tp->t_token == -1)
{
if (tp->t_att[0].ar == result.e_v.e_reg)
goto gotone;
}
else
{
tdp = &tokens[tp->t_token];
for (i = 0; i < TOKENSIZE; i++)
if (tdp->t_type[i] == EV_REG
&& tp->t_att[i].ar == result.e_v.e_reg)
goto gotone;
}
break;
gotone:
/* investigate possible coercion to register */
totalcost += stackupto(tp, ply, toplevel);
CHKCOST()
;
break;
case DO_DEALLOCATE:
DEBUG("DEALLOCATE")
;
getint(tinstno, codep)
;
instance(tinstno, &token);
if (token.t_token == -1)
chrefcount(token.t_att[0].ar, -1, TRUE);
else
{
tdp = &tokens[token.t_token];
for (i = 0; i < TOKENSIZE; i++)
if (tdp->t_type[i] == EV_REG)
chrefcount(token.t_att[i].ar, -1, TRUE);
}
break;
case DO_REALLOCATE:
DEBUG("REALLOCATE")
;
for (rp = machregs; rp < machregs + NREGS; rp++)
if (rp->r_tcount)
{
rp->r_refcount -= rp->r_tcount;
rp->r_tcount = 0;
}
break;
case DO_ALLOCATE:
DEBUG("ALLOCATE")
;
if (codep[-1] & 32)
{
getint(propno, codep);
getint(tinstno, codep);
}
else
{
getint(propno, codep);
tinstno = 0;
}
instance(tinstno, &token);
if (!forced)
{
do
{
npos = exactmatch = 0;
for (rpp = reglist[propno]; (rp = *rpp); rpp++)
if (getrefcount((int) (rp - machregs), FALSE) == 0)
{
pos[npos++] = rp - machregs;
if (eqtoken(&rp->r_contents, &token))
exactmatch++;
}
/*
* Now pos[] contains all free registers with desired
* property. If none then some stacking has to take place.
*/
if (npos == 0)
{
if (stackheight <= tokpatlen)
{
if (!toplevel)
{
totalcost = INFINITY;
BROKE();
}
else
{
fatal("No regs available");
}
}
totalcost += stackupto(&fakestack[0], ply,
toplevel);
CHKCOST();
}
} while (npos == 0);
if (!exactmatch)
{
npos2 = npos;
for (i = 0; i < npos; i++)
pos2[i] = pos[i];
}
else
{
/*
* Now we are reducing the number of possible registers.
* We take only one equally likely register out of every
* equivalence class as given by set of properties.
*/
mtoken = token;
npos2 = 0;
for (i = 0; i < npos; i++)
if (eqtoken(&machregs[pos[i]].r_contents, &mtoken))
{
pos2[npos2++] = pos[i];
for (j = 0; j < npos2 - 1; j++)
if (eqregclass(pos2[j], pos[i]))
{
npos2--;
break;
}
}
}
/*
* Now pos2[] contains all possibilities to try, if more than
* one, lookahead is necessary.
*/
token2.t_token = -1;
for (i = 1; i < TOKENSIZE; i++)
token2.t_att[i].aw = 0;
if (npos2 == 1)
decision = pos2[0];
else
{
SAVEST;
mincost = costlimit - totalcost + 1;
for (j = 0; j < npos2; j++)
{
chrefcount(pos2[j], 1, FALSE);
token2.t_att[0].ar = pos2[j];
allreg[nallreg++] = pos2[j];
if (token.t_token != 0)
t = move(&token, &token2, ply, FALSE, mincost);
else
{
t = 0;
erasereg(pos2[j]);
}
if (t < mincost)
t += codegen(codep, ply, FALSE,
mincost < MAXINT ? mincost - t : MAXINT,
0);
if (t < mincost)
{
mincost = t;
decision = pos2[j];
}
RESTST;
} FREEST;
if (totalcost + mincost > costlimit)
{
totalcost = INFINITY;
BROKE();
}
}
}
else
{
decision = forced;
if (getrefcount(decision, FALSE) != 0)
{
totalcost = INFINITY;
BROKE();
}
token2.t_token = -1;
}
chrefcount(decision, 1, FALSE);
token2.t_att[0].ar = decision;
if (token.t_token != 0)
{
totalcost += move(&token, &token2, ply, toplevel, MAXINT);
CHKCOST();
}
else
erasereg(decision);
allreg[nallreg++] = decision;
break;
case DO_LOUTPUT:
DEBUG("LOUTPUT")
;
getint(stringno, codep)
;
getint(nodeno, codep)
;
if (toplevel)
{
gencode(codestrings[stringno]);
genexpr(nodeno);
}
break;
case DO_ROUTPUT:
DEBUG("ROUTPUT")
;
i = ((codep[-1] >> 5) & 07);
do
{
getint(stringno, codep);
if (toplevel)
{
gencode(codestrings[stringno]);
gennl();
}
} while (i--);
break;
case DO_MOVE:
DEBUG("MOVE")
;
getint(tinstno, codep)
;
instance(tinstno, &token);
getint(tinstno, codep)
;
instance(tinstno, &token2);
totalcost += move(&token, &token2, ply, toplevel,
costlimit - totalcost + 1);
CHKCOST()
;
break;
case DO_ERASE:
DEBUG("ERASE")
;
getint(nodeno, codep)
;
result = compute(&enodes[nodeno]);
assert(result.e_typ==EV_REG);
erasereg(result.e_v.e_reg);
break;
case DO_TOKREPLACE:
DEBUG("TOKREPLACE")
;
assert(stackheight >= tokpatlen);
repllen = (codep[-1] >> 5) & 07;
for (i = 0; i < repllen; i++)
{
getint(tinstno, codep);
instance(tinstno, &reptoken[i]);
tref(&reptoken[i], 1);
}
for (i = 0; i < tokpatlen; i++)
{
if (!inscoerc)
tref(&fakestack[stackheight - 1], -1);
stackheight--;
}
for (i = 0; i < repllen; i++)
{
assert(stackheight<MAXFSTACK);
fakestack[stackheight] = reptoken[i];
stackheight++;
/* do not combine previous two statements; that does not
compile under Xenix V3.2
*/
}
for (i = 0; i < nallreg; i++)
chrefcount(allreg[i], -1, FALSE);
break;
case DO_EMREPLACE:
DEBUG("EMREPLACE")
;
emrepllen = (codep[-1] >> 5) & 07;
j = emp - emlines;
if (emrepllen > j)
{
int k = nemlines + emrepllen - j;
assert(k<MAXEMLINES);
for (i = nemlines; i >= 0; i--, k--)
emlines[k] = emlines[i];
nemlines += emrepllen - j;
emp += emrepllen - j;
}
emp -= emrepllen;
for (i = 0; i < emrepllen; i++)
{
getint(eminstr, codep);
getint(nodeno, codep);
emp[i].em_instr = eminstr;
result = compute(&enodes[nodeno]);
switch (result.e_typ)
{
default:
assert(FALSE);
case 0:
emp[i].em_optyp = OPNO;
emp[i].em_soper = 0;
break;
case EV_INT:
emp[i].em_optyp = OPINT;
emp[i].em_soper = tostring(result.e_v.e_con);
emp[i].em_u.em_ioper = result.e_v.e_con;
break;
case EV_STR:
emp[i].em_optyp = OPSYMBOL;
emp[i].em_soper = result.e_v.e_str;
break;
}
}
if (!toplevel)
{
ply += emrepllen;
}
break;
case DO_COST:
DEBUG("COST")
;
getint(cost.c_size, codep)
;
getint(cost.c_time, codep)
;
totalcost += costcalc(cost);
CHKCOST()
;
break;
#ifdef REGVARS
case DO_PRETURN:
if (toplevel)
{
swtxt();
regreturn(); /* in mach.c */
}
break;
#endif
case DO_RETURN:
DEBUG("RETURN")
;
assert(origcp != startupcode);
doreturn:
#ifndef NDEBUG
level--;
#endif
return (totalcost);
}
}
}