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ack/mach/proto/cg/codegen.c

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#ifndef NORCSID
static char rcsid[] = "$Header$";
#endif
#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"
/*
* (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
*/
#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 };
byte *nextem();
unsigned costcalc();
unsigned docoerc();
unsigned stackupto();
string tostring();
#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 codegen(codep,ply,toplevel,costlimit,forced) byte *codep; unsigned costlimit; {
#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];
c3_p findcoerc();
int sret;
token_t reptoken[MAXREPLLEN];
int emrepllen,eminstr;
int inscoerc=0;
int stackpad;
struct perm *tup,*ntup,*besttup,*tuples();
#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
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);
}
}
}
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