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2025-10-24 08:54:17 +00:00 · 2020-11-06 18:50:37 +01:00
parent 621ed8ccaf
commit 31738079c4
8481 changed files with 1888323 additions and 0 deletions
--- a/SOURCES/v102a/as68/pass1a.c
+++ b/SOURCES/v102a/as68/pass1a.c
@@ -0,0 +1,107 @@
+/*
+    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*/
+        }
+    }
+}