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Sepp J Morris 31738079c4 Upload
Digital Research
2020-11-06 18:50:37 +01:00

108 lines
3.6 KiB
C

/*
Copyright 1983
Alcyon Corporation
8716 Production Ave.
San Diego, Ca. 92121
*/
/* reduce long relative branches to short if possible*/
#include "as68.h"
pass1a()
{
register long reduced;
register short writfn, i, wsize;
pitix = &itbuf[ITBSZ];
reduced = itoffset = 0L; stbuf[0].itrl = 0;
wsize = 3*STBFSIZE; /* [vlh] don't calculate many times */
close(itfn);
LASTCHTFN = itfnc;
itfn = openfi(tfilname,0,1); /*open it for reading*/
writfn = open(tfilname,1,1); /*may need to rewrite some of it*/
if(writfn<0)
abort();
while(1) {
ristb(); /*read it for one statement*/
opcpt = stbuf[2].itop.ptrw2; /*ptr to opcode entry in main tab*/
if(!(opcpt->flags&OPDR)) { /*not a directive*/
format = (opcpt->flags)&OPFF;
p1inlen = stbuf[1].itrl; /*pass 1 instr length guess*/
if(((format==6 && p1inlen==4) || opcpt==jsrptr) &&
(rlflg=stbuf[3].itrl)==TEXT) {
nite = stbuf[0].itrl & 0377;/* # of it entries */
pnite = &stbuf[nite].itty; /*ptr to end of stmt*/
modelen = stbuf[2].itrl; /*instr mode length*/
opdix = ITOP1; /*first operand*/
pitw = &stbuf[ITOP1].itty; /*ptr to first operand*/
loctr = stbuf[3].itop - reduced;
expr(&p2gi);
ival -= loctr+2L;
if(itype==ITCN && !extflg && reloc!=ABS) {
if(format==9) { /*jsr*/
i = (ival>= -128 && ival<=127) ? p1inlen-2 :
(ival>= -32768 && ival<=32767) ? p1inlen-4 : 0;
if (!i)
continue;
stbuf[2].itop.ptrw2 = bsrptr; /*chng to bsr*/
}
else if(ival>= -128 && ival<=127) {
if (ival==2) /* branch to next instr - delete */
i = 4;
else /* reduce long branch to short */
i = 2;
}
else
continue;
fixsyadr(i);
reduced += i;
stbuf[1].itrl -= i; /*reduced instr lenght somewhat*/
if(!stbuf[1].itrl)
stbuf[1].itrl = -1; /*ignore flag*/
if(lseek(writfn,itoffset,0) == -1L) {
rpterr("seek error on intermediate file\n");
abort();
}
if(write(writfn,&stbuf[0],wsize) != wsize) {
rpterr("write error on it file\n");
abort();
}
}
}
}
else if(opcpt == endptr) {
savelc[TEXT] -= reduced;
close(writfn);
return;
}
}
}
/* fix all symbol addresses that are text based and greater than loctr*/
/* fix means subtract al from them*/
fixsyadr(al)
{
register char **sx1, **sx2;
register short l;
l = al;
/* loop thru symbol initial reference table*/
for(sx1 = sirt; sx1 < &sirt[SZIRT-1]; sx1 += 2) {
if(*(sx2 = sx1+1)==0) /* this chain is empty*/
continue;
/* symbols on one chain*/
sx2 = *sx2; /*first entry on this chain*/
while(1) {
if((sx2->flags&SYDF || sx2->flags&SYPC) && sx2->flags&SYRO &&
sx2->vl1 > loctr) /* [vlh] */
sx2->vl1 -= l;
if(sx2 == *sx1) /*end of chain*/
break;
sx2 = sx2->tlnk; /*next entry in chain*/
}
}
}