[unix-history] / usr / src / old / pcc / ccom.tahoe / code.c

#ifndef lint
static char sccsid[] = "@(#)code.c      1.2 (Berkeley) %G%";
#endif

# include "pass1.h"
# include <sys/types.h>
# include <a.out.h>
# include <stab.h>

int proflg = 0; /* are we generating profiling code? */
int strftn = 0;  /* is the current function one which returns a value */
int gdebug;
int fdefflag;  /* are we within a function definition ? */
#ifndef STABDOT
char NULLNAME[8];
#endif
int labelno;

branch( n ){
       /* output a branch to label n */
       /* exception is an ordinary function branching to retlab: then, return */
       if( n == retlab && !strftn ){
               register TWORD t;
               register r;
                       /* set number of regs in assem comment field */
                       /* so optimizers can do a better job */
               r = 0;
               if( retstat & RETVAL ){ /* the function rets a val somewhere */
                       t = (&stab[curftn])->stype;
                       t = DECREF(t);
                       r++;    /* it is at least one */
                       if(t == DOUBLE)
                               r++;    /* it takes two */
               } else          /* the fn does not ret a val    */
                       r = 2;
               printf( "       ret#%d\n", r );
               }
       else printf( "  jbr     L%d\n", n );
       }

int lastloc = { -1 };

short log2tab[] = {0, 0, 1, 2, 2, 3, 3, 3, 3};
#define LOG2SZ 9

defalign(n) {
       /* cause the alignment to become a multiple of n */
       n /= SZCHAR;
       if( lastloc != PROG && n > 1 ) printf( "        .align  %d\n", n >= 0 && n < LOG2SZ ? log2tab[n] : 0 );
       }

locctr( l ){
       register temp;
       /* l is PROG, ADATA, DATA, STRNG, ISTRNG, or STAB */

       if( l == lastloc ) return(l);
       temp = lastloc;
       lastloc = l;
       switch( l ){

       case PROG:
               printf( "       .text\n" );
               psline();
               break;

       case DATA:
       case ADATA:
               printf( "       .data\n" );
               break;

       case STRNG:
               printf( "       .data   1\n" );
               break;

       case ISTRNG:
               printf( "       .data   2\n" );
               break;

       case STAB:
               printf( "       .stab\n" );
               break;

       default:
               cerror( "illegal location counter" );
               }

       return( temp );
       }

deflab( n ){
       /* output something to define the current position as label n */
       printf( "L%d:\n", n );
       }

int crslab = 10;

getlab(){
       /* return a number usable for a label */
       return( ++crslab );
       }


efcode(){
       /* code for the end of a function */

       if( strftn ){  /* copy output (in R2) to caller */
               register NODE *l, *r;
               register struct symtab *p;
               register TWORD t;
               register int i;

               p = &stab[curftn];
               t = p->stype;
               t = DECREF(t);

               deflab( retlab );

               i = getlab();   /* label for return area */
#ifndef LCOMM
               printf("        .data\n" );
               printf("        .align  2\n" );
               printf("L%d:    .space  %d\n", i, tsize(t, p->dimoff, p->sizoff)/SZCHAR );
               printf("        .text\n" );
#else
               { int sz = tsize(t, p->dimoff, p->sizoff) / SZCHAR;
               if (sz % (SZINT/SZCHAR))
                       sz += (SZINT/SZCHAR) - (sz % (SZINT/SZCHAR));
               printf("        .lcomm  L%d,%d\n", i, sz);
               }
#endif
               psline();
               printf("        movab   L%d,r1\n", i);

               reached = 1;
               l = block( REG, NIL, NIL, PTR|t, p->dimoff, p->sizoff );
               l->tn.rval = 1;  /* R1 */
               l->tn.lval = 0;  /* no offset */
               r = block( REG, NIL, NIL, PTR|t, p->dimoff, p->sizoff );
               r->tn.rval = 0;  /* R0 */
               r->tn.lval = 0;
               l = buildtree( UNARY MUL, l, NIL );
               r = buildtree( UNARY MUL, r, NIL );
               l = buildtree( ASSIGN, l, r );
               l->in.op = FREE;
               ecomp( l->in.left );
               printf( "       movab   L%d,r0\n", i );
               /* turn off strftn flag, so return sequence will be generated */
               strftn = 0;
               }
       branch( retlab );
       p2bend();
       fdefflag = 0;
       }

int ftlab1, ftlab2;

bfcode( a, n ) int a[]; {
       /* code for the beginning of a function; a is an array of
               indices in stab for the arguments; n is the number */
       register i;
       register temp;
       register struct symtab *p;
       int off;
#ifdef REG_CHAR
       char *toreg();
#endif
       char *rname();

       locctr( PROG );
       p = &stab[curftn];
       printf( "       .align  1\n");
       defnam( p );
       temp = p->stype;
       temp = DECREF(temp);
       strftn = (temp==STRTY) || (temp==UNIONTY);

       retlab = getlab();

       /* routine prolog */

       printf( "       .word   L%d\n", ftnno);
       if (gdebug) {
#ifdef STABDOT
               pstabdot(N_SLINE, lineno);
#else
               pstab(NULLNAME, N_SLINE);
               printf("0,%d,LL%d\n", lineno, labelno);
               printf("LL%d:\n", labelno++);
#endif
       }
       ftlab1 = getlab();
       ftlab2 = getlab();
       printf( "       jbr     L%d\n", ftlab1);
       printf( "L%d:\n", ftlab2);
       if( proflg ) {  /* profile code */
               i = getlab();
               printf("        pushl   $L%d\n", i);
               printf("        callf   $8,mcount\n");
               printf("        .data\n");
               printf("        .align  2\n");
               printf("L%d:    .long   0\n", i);
               printf("        .text\n");
               psline();
               }

       off = ARGINIT;

       for( i=0; i<n; ++i ){
               p = &stab[a[i]];
               if( p->sclass == REGISTER ){
                       temp = p->offset;  /* save register number */
                       p->sclass = PARAM;  /* forget that it is a register */
                       p->offset = NOOFFSET;
                       oalloc( p, &off );
#ifdef REG_CHAR
                       printf( "       %s", toreg(p->stype)) );
#else
                       printf("        movl");
#endif
                       printf( "       %d(fp),%s\n", p->offset/SZCHAR, rname(temp) );
                       p->offset = temp;  /* remember register number */
                       p->sclass = REGISTER;   /* remember that it is a register */
#ifdef REG_CHAR
                       temp = p->stype;
                       if( temp==CHAR || temp==SHORT )
                               p->stype = INT;
                       else if( temp==UCHAR || temp==USHORT )
                               p->stype = UNSIGNED;
#endif
                       }
               else if( p->stype == STRTY || p->stype == UNIONTY ) {
                       p->offset = NOOFFSET;
                       if( oalloc( p, &off ) ) cerror( "bad argument" );
                       SETOFF( off, ALSTACK );
                       }
               else {
                       if( oalloc( p, &off ) ) cerror( "bad argument" );
                       }

               }
       fdefflag = 1;
       }

bccode(){ /* called just before the first executable statment */
               /* by now, the automatics and register variables are allocated */
       SETOFF( autooff, SZINT );
       /* set aside store area offset */
       p2bbeg( autooff, regvar );
       }

ejobcode( flag ){
       /* called just before final exit */
       /* flag is 1 if errors, 0 if none */
       }

aobeg(){
       /* called before removing automatics from stab */
       }

aocode(p) struct symtab *p; {
       /* called when automatic p removed from stab */
       }

aoend(){
       /* called after removing all automatics from stab */
       }

defnam( p ) register struct symtab *p; {
       /* define the current location as the name p->sname */

       if( p->sclass == EXTDEF ){
               printf( "       .globl  %s\n", exname( p->sname ) );
               }
       if( p->sclass == STATIC && p->slevel>1 ) deflab( p->offset );
       else printf( "%s:\n", exname( p->sname ) );

       }

bycode( t, i ){
#ifdef ASSTRINGS
static  int     lastoctal = 0;
#endif

       /* put byte i+1 in a string */

#ifdef ASSTRINGS

       i &= 077;
       if ( t < 0 ){
               if ( i != 0 )   printf( "\"\n" );
       } else {
               if ( i == 0 ) printf("\t.ascii\t\"");
               if ( t == '\\' || t == '"'){
                       lastoctal = 0;
                       printf("\\%c", t);
               }
               else if ( t < 040 || t >= 0177 ){
                       lastoctal++;
                       printf("\\%o",t);
               }
               else if ( lastoctal && '0' <= t && t <= '9' ){
                       lastoctal = 0;
                       printf("\"\n\t.ascii\t\"%c", t );
               }
               else
               {       
                       lastoctal = 0;
                       putchar(t);
               }
               if ( i == 077 ) printf("\"\n");
       }
#else

       i &= 07;
       if( t < 0 ){ /* end of the string */
               if( i != 0 ) printf( "\n" );
               }

       else { /* stash byte t into string */
               if( i == 0 ) printf( "  .byte   " );
               else printf( "," );
               printf( "0x%x", t );
               if( i == 07 ) printf( "\n" );
               }
#endif
       }

zecode( n ){
       /* n integer words of zeros */
       OFFSZ temp;
       if( n <= 0 ) return;
       printf( "       .space  %d\n", (SZINT/SZCHAR)*n );
       temp = n;
       inoff += temp*SZINT;
       }

fldal( t ) unsigned t; { /* return the alignment of field of type t */
       uerror( "illegal field type" );
       return( ALINT );
       }

fldty( p ) struct symtab *p; { /* fix up type of field p */
       ;
       }

where(c){ /* print location of error  */
       /* c is either 'u', 'c', or 'w' */
       /* GCOS version */
       fprintf( stderr, "%s, line %d: ", ftitle, lineno );
       }


#ifdef REG_CHAR
/* tbl - toreg() returns a pointer to a char string
                 which is the correct  "register move" for the passed type 
*/
struct type_move {TWORD fromtype; char tostrng[8];} toreg_strs[] =
       {
       CHAR, "cvtbl",
       SHORT, "cvtwl",
       UCHAR,  "movzbl",
       USHORT, "movzwl",
       0, "movl"
       };

char
*toreg(type)
       TWORD type;
{
       struct type_move *p;

       for ( p=toreg_strs; p->fromtype != 0; p++)
               if (p->fromtype == type) return(p->tostrng);

       /* type not found, must be a word type */
       return(p->tostrng);
}
/* tbl */
#endif


main( argc, argv ) char *argv[]; {
#ifdef BUFSTDERR
       char errbuf[BUFSIZ];
       setbuf(stderr, errbuf);
#endif
       return(mainp1( argc, argv ));
       }

struct sw heapsw[SWITSZ];       /* heap for switches */

genswitch(p,n) register struct sw *p;{
       /*      p points to an array of structures, each consisting
               of a constant value and a label.
               The first is >=0 if there is a default label;
               its value is the label number
               The entries p[1] to p[n] are the nontrivial cases
               */
       register i;
       register CONSZ j;
       register CONSZ unsigned range;
       register dlab, swlab;

       range = p[n].sval-p[1].sval;

       if( range <= 3*n && n>=4 ){ /* implement a direct switch */

               swlab = getlab();
               dlab = p->slab >= 0 ? p->slab : getlab();

               /* already in r0 */
               printf( "       casel   r0,$" );
               printf( CONFMT, p[1].sval );
               printf(",$");
               printf( CONFMT, range);
               printf("\n      .align 1\nL%d:\n", swlab);
               for( i=1,j=p[1].sval; i<=n; j++) {
                       printf("        .word   L%d-L%d\n", (j == p[i].sval ? ((j=p[i++].sval), p[i-1].slab) : dlab),
                               swlab);
                       }

               if( p->slab >= 0 ) branch( dlab );
               else printf("L%d:\n", dlab);
               return;

               }

       if( n>8 ) {     /* heap switch */

               heapsw[0].slab = dlab = p->slab >= 0 ? p->slab : getlab();
               makeheap(p, n, 1);      /* build heap */

               walkheap(1, n); /* produce code */

               if( p->slab >= 0 )
                       branch( dlab );
               else
                       printf("L%d:\n", dlab);
               return;
       }

       /* debugging code */

       /* out for the moment
       if( n >= 4 ) werror( "inefficient switch: %d, %d", n, (int) (range/n) );
       */

       /* simple switch code */

       for( i=1; i<=n; ++i ){
               /* already in r0 */

               printf( "       cmpl    r0,$" );
               printf( CONFMT, p[i].sval );
               printf( "\n     jeql    L%d\n", p[i].slab );
               }

       if( p->slab>=0 ) branch( p->slab );
       }

makeheap(p, m, n)
register struct sw *p;
{
       register int q;

       q = select(m);
       heapsw[n] = p[q];
       if( q>1 ) makeheap(p, q-1, 2*n);
       if( q<m ) makeheap(p+q, m-q, 2*n+1);
}

select(m) {
       register int l,i,k;

       for(i=1; ; i*=2)
               if( (i-1) > m ) break;
       l = ((k = i/2 - 1) + 1)/2;
       return( l + (m-k < l ? m-k : l));
}

walkheap(start, limit)
{
       int label;


       if( start > limit ) return;
       printf( "       cmpl    r0,$" );
       printf( CONFMT, heapsw[start].sval);
       printf("\n      jeql    L%d\n", heapsw[start].slab);
       if( (2*start) > limit ) {
               printf("        jbr     L%d\n", heapsw[0].slab);
               return;
       }
       if( (2*start+1) <= limit ) {
               label = getlab();
               printf("        jgtr    L%d\n", label);
       } else
               printf("        jgtr    L%d\n", heapsw[0].slab);
       walkheap( 2*start, limit);
       if( (2*start+1) <= limit ) {
               printf("L%d:\n", label);
               walkheap( 2*start+1, limit);
       }
}