4.3BSD-Tahoe/usr/src/usr.bin/yacc/y4.c
#ifndef lint
static char sccsid[] = "@(#)y4.c 4.1 (Berkeley) 2/11/83";
#endif not lint
# include "dextern"
# define a amem
# define mem mem0
# define pa indgo
# define yypact temp1
# define greed tystate
int * ggreed = lkst[0].lset;
int * pgo = wsets[0].ws.lset;
int *yypgo = &nontrst[0].tvalue;
int maxspr = 0; /* maximum spread of any entry */
int maxoff = 0; /* maximum offset into a array */
int *pmem = mem;
int *maxa;
# define NOMORE -1000
int nxdb = 0;
int adb = 0;
callopt(){
register i, *p, j, k, *q;
/* read the arrays from tempfile and set parameters */
if( (finput=fopen(TEMPNAME,"r")) == NULL ) error( "optimizer cannot open tempfile" );
pgo[0] = 0;
yypact[0] = 0;
nstate = 0;
nnonter = 0;
for(;;){
switch( gtnm() ){
case '\n':
yypact[++nstate] = (--pmem) - mem;
case ',':
continue;
case '$':
break;
default:
error( "bad tempfile" );
}
break;
}
yypact[nstate] = yypgo[0] = (--pmem) - mem;
for(;;){
switch( gtnm() ){
case '\n':
yypgo[++nnonter]= pmem-mem;
case ',':
continue;
case EOF:
break;
default:
error( "bad tempfile" );
}
break;
}
yypgo[nnonter--] = (--pmem) - mem;
for( i=0; i<nstate; ++i ){
k = 32000;
j = 0;
q = mem + yypact[i+1];
for( p = mem + yypact[i]; p<q ; p += 2 ){
if( *p > j ) j = *p;
if( *p < k ) k = *p;
}
if( k <= j ){ /* nontrivial situation */
/* temporarily, kill this for compatibility
j -= k; /* j is now the range */
if( k > maxoff ) maxoff = k;
}
greed[i] = (yypact[i+1]-yypact[i]) + 2*j;
if( j > maxspr ) maxspr = j;
}
/* initialize ggreed table */
for( i=1; i<=nnonter; ++i ){
ggreed[i] = 1;
j = 0;
/* minimum entry index is always 0 */
q = mem + yypgo[i+1] -1;
for( p = mem+yypgo[i]; p<q ; p += 2 ) {
ggreed[i] += 2;
if( *p > j ) j = *p;
}
ggreed[i] = ggreed[i] + 2*j;
if( j > maxoff ) maxoff = j;
}
/* now, prepare to put the shift actions into the a array */
for( i=0; i<ACTSIZE; ++i ) a[i] = 0;
maxa = a;
for( i=0; i<nstate; ++i ) {
if( greed[i]==0 && adb>1 ) fprintf( ftable, "State %d: null\n", i );
pa[i] = YYFLAG1;
}
while( (i = nxti()) != NOMORE ) {
if( i >= 0 ) stin(i);
else gin(-i);
}
if( adb>2 ){ /* print a array */
for( p=a; p <= maxa; p += 10){
fprintf( ftable, "%4d ", p-a );
for( i=0; i<10; ++i ) fprintf( ftable, "%4d ", p[i] );
fprintf( ftable, "\n" );
}
}
/* write out the output appropriate to the language */
aoutput();
osummary();
ZAPFILE(TEMPNAME);
}
gin(i){
register *p, *r, *s, *q1, *q2;
/* enter gotos on nonterminal i into array a */
ggreed[i] = 0;
q2 = mem+ yypgo[i+1] - 1;
q1 = mem + yypgo[i];
/* now, find a place for it */
for( p=a; p < &a[ACTSIZE]; ++p ){
if( *p ) continue;
for( r=q1; r<q2; r+=2 ){
s = p + *r +1;
if( *s ) goto nextgp;
if( s > maxa ){
if( (maxa=s) > &a[ACTSIZE] ) error( "a array overflow" );
}
}
/* we have found a spot */
*p = *q2;
if( p > maxa ){
if( (maxa=p) > &a[ACTSIZE] ) error( "a array overflow" );
}
for( r=q1; r<q2; r+=2 ){
s = p + *r + 1;
*s = r[1];
}
pgo[i] = p-a;
if( adb>1 ) fprintf( ftable, "Nonterminal %d, entry at %d\n" , i, pgo[i] );
goto nextgi;
nextgp: ;
}
error( "cannot place goto %d\n", i );
nextgi: ;
}
stin(i){
register *r, *s, n, flag, j, *q1, *q2;
greed[i] = 0;
/* enter state i into the a array */
q2 = mem+yypact[i+1];
q1 = mem+yypact[i];
/* find an acceptable place */
for( n= -maxoff; n<ACTSIZE; ++n ){
flag = 0;
for( r = q1; r < q2; r += 2 ){
if( (s = *r + n + a ) < a ) goto nextn;
if( *s == 0 ) ++flag;
else if( *s != r[1] ) goto nextn;
}
/* check that the position equals another only if the states are identical */
for( j=0; j<nstate; ++j ){
if( pa[j] == n ) {
if( flag ) goto nextn; /* we have some disagreement */
if( yypact[j+1] + yypact[i] == yypact[j] + yypact[i+1] ){
/* states are equal */
pa[i] = n;
if( adb>1 ) fprintf( ftable, "State %d: entry at %d equals state %d\n",
i, n, j );
return;
}
goto nextn; /* we have some disagreement */
}
}
for( r = q1; r < q2; r += 2 ){
if( (s = *r + n + a ) >= &a[ACTSIZE] ) error( "out of space in optimizer a array" );
if( s > maxa ) maxa = s;
if( *s != 0 && *s != r[1] ) error( "clobber of a array, pos'n %d, by %d", s-a, r[1] );
*s = r[1];
}
pa[i] = n;
if( adb>1 ) fprintf( ftable, "State %d: entry at %d\n", i, pa[i] );
return;
nextn: ;
}
error( "Error; failure to place state %d\n", i );
}
nxti(){ /* finds the next i */
register i, max, maxi;
max = 0;
for( i=1; i<= nnonter; ++i ) if( ggreed[i] >= max ){
max = ggreed[i];
maxi = -i;
}
for( i=0; i<nstate; ++i ) if( greed[i] >= max ){
max = greed[i];
maxi = i;
}
if( nxdb ) fprintf( ftable, "nxti = %d, max = %d\n", maxi, max );
if( max==0 ) return( NOMORE );
else return( maxi );
}
osummary(){
/* write summary */
register i, *p;
if( foutput == NULL ) return;
i=0;
for( p=maxa; p>=a; --p ) {
if( *p == 0 ) ++i;
}
fprintf( foutput, "Optimizer space used: input %d/%d, output %d/%d\n",
pmem-mem+1, MEMSIZE, maxa-a+1, ACTSIZE );
fprintf( foutput, "%d table entries, %d zero\n", (maxa-a)+1, i );
fprintf( foutput, "maximum spread: %d, maximum offset: %d\n", maxspr, maxoff );
}
aoutput(){ /* this version is for C */
/* write out the optimized parser */
fprintf( ftable, "# define YYLAST %d\n", maxa-a+1 );
arout( "yyact", a, (maxa-a)+1 );
arout( "yypact", pa, nstate );
arout( "yypgo", pgo, nnonter+1 );
}
arout( s, v, n ) char *s; int *v, n; {
register i;
fprintf( ftable, "short %s[]={\n", s );
for( i=0; i<n; ){
if( i%10 == 0 ) fprintf( ftable, "\n" );
fprintf( ftable, "%4d", v[i] );
if( ++i == n ) fprintf( ftable, " };\n" );
else fprintf( ftable, "," );
}
}
gtnm(){
register s, val, c;
/* read and convert an integer from the standard input */
/* return the terminating character */
/* blanks, tabs, and newlines are ignored */
s = 1;
val = 0;
while( (c=getc(finput)) != EOF ){
if( isdigit(c) ){
val = val * 10 + c - '0';
}
else if ( c == '-' ) s = -1;
else break;
}
*pmem++ = s*val;
if( pmem > &mem[MEMSIZE] ) error( "out of space" );
return( c );
}