VAX: Add optional simulator time and logging to disk for instruction history.

simulator time allows instruction history to be precisely correlated with
debug output.  It also provides a way to reproduce and review simulation
activities by stopping at predetermined time values (via STEP) to
examine details of simulator state.

disk logging can be useful to compare activities performed in separate
simulator runs.

VAX/vax_cpu.c

@@ -230,9 +230,10 @@
 
 
 #define HIST_MIN        64
-#define HIST_MAX        65536
+#define HIST_MAX        250000
 
 typedef struct {
+    double              time;
     int32               iPC;
     int32               PSL;
     int32               opc;
@@ -266,8 +267,6 @@ int32 crd_err = 0;
 int32 p1 = 0, p2 = 0;                                   /* fault parameters */
 int32 fault_PC;                                         /* fault PC */
 int32 pcq_p = 0;                                        /* PC queue ptr */
-int32 hst_p = 0;                                        /* history pointer */
-int32 hst_lnt = 0;                                      /* history length */
 int32 badabo = 0;
 int32 cpu_astop = 0;
 int32 mchk_va, mchk_ref;                                /* mem ref param */
@@ -279,6 +278,11 @@ jmp_buf save_env;
 REG *pcq_r = NULL;                                      /* PC queue reg ptr */
 int32 pcq[PCQ_SIZE] = { 0 };                            /* PC queue */
 InstHistory *hst = NULL;                                /* instruction history */
+int32 hst_p = 0;                                        /* history pointer */
+int32 hst_lnt = 0;                                      /* history length */
+int32 hst_switches;                                     /* history option switches */
+FILE *hst_log;                                          /* history log file */
+int32 hst_log_p;                                        /* history last log written pointer */
 
 const uint32 byte_mask[33] = { 0x00000000,
  0x00000001, 0x00000003, 0x00000007, 0x0000000F,
@@ -395,6 +399,7 @@ int32 cpu_get_vsw (int32 sw);
 static SIM_INLINE int32 get_istr (int32 lnt, int32 acc);
 int32 ReadOcta (int32 va, int32 *opnd, int32 j, int32 acc);
 t_bool cpu_show_opnd (FILE *st, InstHistory *h, int32 line);
+t_stat cpu_show_hist_records (FILE *st, t_bool do_header, int32 start, int32 count);
 t_stat cpu_idle_svc (UNIT *uptr);
 void cpu_idle (void);
 
@@ -574,6 +579,10 @@ abortval = setjmp (save_env);                           /* set abort hdlr */
 if (abortval > 0) {                                     /* sim stop? */
     PSL = PSL | cc;                                     /* put PSL together */
     pcq_r->qptr = pcq_p;                                /* update pc q ptr */
+    if (hst_log) {                                      /* auto logging history? */
+        cpu_show_hist_records (hst_log, FALSE, hst_log_p, (hst_p < hst_log_p) ? hst_lnt - (hst_log_p - hst_p) : hst_p - hst_log_p);
+        hst_log_p = hst_p;                              /* record everything logged */
+        }
     return abortval;                                    /* return to SCP */
     }
 else if (abortval < 0) {                                /* mm or rsrv or int */
@@ -1556,26 +1565,31 @@ for ( ;; ) {
     if (hst_lnt) {
         int32 lim;
         t_value wd;
+        InstHistory *h = &hst[hst_p];
 
-        hst[hst_p].iPC = fault_PC;
+        h->iPC = fault_PC;
-        hst[hst_p].PSL = PSL | cc;
+        h->PSL = PSL | cc;
-        hst[hst_p].opc = opc;
+        h->opc = opc;
         for (i = 0; i < j; i++)
-            hst[hst_p].opnd[i] = opnd[i];
+            h->opnd[i] = opnd[i];
         lim = PC - fault_PC;
         if ((uint32) lim > INST_SIZE)
             lim = INST_SIZE;
         for (i = 0; i < lim; i++) {
             if ((cpu_ex (&wd, fault_PC + i, &cpu_unit, SWMASK ('V'))) == SCPE_OK)
-                hst[hst_p].inst[i] = (uint8) wd;
+                h->inst[i] = (uint8) wd;
             else {
-                hst[hst_p].inst[0] = hst[hst_p].inst[1] = 0xFF;
+                h->inst[0] = h->inst[1] = 0xFF;
                 break;
                 }
             }
+        if (hst_switches & SWMASK('T'))
+            h->time = sim_gtime();
         hst_p = hst_p + 1;
         if (hst_p >= hst_lnt)
             hst_p = 0;
+        if (hst_log && (hst_p == hst_log_p))
+            cpu_show_hist_records (hst_log, FALSE, hst_log_p, hst_lnt);
         }
 
 /* Dispatch to instructions */
@@ -3390,28 +3404,53 @@ return ACC_MASK (md);
 t_stat cpu_set_hist (UNIT *uptr, int32 val, char *cptr, void *desc)
 {
 int32 i, lnt;
+char gbuf[CBUFSIZE];
 t_stat r;
 
 if (cptr == NULL) {
     for (i = 0; i < hst_lnt; i++)
         hst[i].iPC = 0;
     hst_p = 0;
+    if (hst_log) {
+        sim_set_fsize (hst_log, (t_addr)0);
+        hst_log_p = 0;
+        cpu_show_hist_records (hst_log, TRUE, 0, 0);
+        }
     return SCPE_OK;
     }
-lnt = (int32) get_uint (cptr, 10, HIST_MAX, &r);
+cptr = get_glyph (cptr, gbuf, ':');
-if ((r != SCPE_OK) || (lnt && (lnt < HIST_MIN)))
+lnt = (int32) get_uint (gbuf, 10, HIST_MAX, &r);
-    return SCPE_ARG;
+if (r != SCPE_OK)
+    return sim_messagef (SCPE_ARG, "Invalid Numeric Value: %s\n", gbuf);
+if (lnt && (lnt < HIST_MIN))
+    return sim_messagef (SCPE_ARG, "%d is less than the minumum history value of %d\n", lnt, HIST_MIN);
 hst_p = 0;
 if (hst_lnt) {
     free (hst);
     hst_lnt = 0;
     hst = NULL;
+    if (hst_log) {
+        fclose (hst_log);
+        hst_log = NULL;
+        }
     }
 if (lnt) {
     hst = (InstHistory *) calloc (lnt, sizeof (InstHistory));
     if (hst == NULL)
             return SCPE_MEM;
     hst_lnt = lnt;
+    hst_switches = sim_switches;
+    if (cptr && *cptr) {
+        hst_log = sim_fopen (cptr, "w");
+        if (hst_log)
+            cpu_show_hist_records (hst_log, TRUE, 0, 0);
+        else {
+            free (hst);
+            hst_lnt = 0;
+            hst = NULL;
+            return sim_messagef(SCPE_OPENERR, "Unable to open file '%s': %s\n", cptr, strerror (errno));
+            }            
+        }
     }
 return SCPE_OK;
 }
@@ -3420,12 +3459,9 @@ return SCPE_OK;
 
 t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
 {
-int32 i, k, di, lnt, numspec;
+int32 di, lnt;
 char *cptr = (char *) desc;
 t_stat r;
-InstHistory *h;
-extern const char *opcode[];
-extern t_value *sim_eval;
 
 if (hst_lnt == 0)                                       /* enabled? */
     return SCPE_NOFNC;
@@ -3438,11 +3474,29 @@ else lnt = hst_lnt;
 di = hst_p - lnt;                                       /* work forward */
 if (di < 0)
     di = di + hst_lnt;
-fprintf (st, "PC       PSL       IR\n\n");
+return cpu_show_hist_records (st, TRUE, di, lnt);
-for (k = 0; k < lnt; k++) {                             /* print specified */
+}
-    h = &hst[(di++) % hst_lnt];                         /* entry pointer */
+
+t_stat cpu_show_hist_records (FILE *st, t_bool do_header, int32 start, int32 count)
+{
+int32 i, k, numspec;
+InstHistory *h;
+extern const char *opcode[];
+extern t_value *sim_eval;
+
+if (hst_lnt == 0)                                       /* enabled? */
+    return SCPE_NOFNC;
+if (do_header) {
+    if (hst_switches & SWMASK('T'))
+        fprintf (st," TIME       ");
+    fprintf (st, "PC       PSL       IR\n\n");
+    }
+for (k = 0; k < count; k++) {                           /* print specified */
+    h = &hst[(start++) % hst_lnt];                      /* entry pointer */
     if (h->iPC == 0)                                    /* filled in? */
         continue;
+    if (hst_switches & SWMASK('T'))                     /* sim_time */
+        fprintf(st, "%10.0f  ", h->time);
     fprintf(st, "%08X %08X| ", h->iPC, h->PSL);         /* PC, PSL */
     numspec = drom[h->opc][0] & DR_NSPMASK;             /* #specifiers */
     if (opcode[h->opc] == NULL)                         /* undefined? */
@@ -3466,6 +3520,7 @@ for (k = 0; k < lnt; k++) {                             /* print specified */
         }                                               /* end else */
     fputc ('\n', st);                                   /* end line */
     }                                                   /* end for */
+fflush (st);
 return SCPE_OK;
 }
 
@@ -3477,6 +3532,8 @@ t_bool more;
 
 numspec = drom[h->opc][0] & DR_NSPMASK;                 /* #specifiers */
 fputs ("\n                  ", st);                     /* space */
+if (hst_switches & SWMASK('T'))
+    fputs ("            ", st);
 for (i = 1, j = 0, more = FALSE; i <= numspec; i++) {   /* loop thru specs */
     disp = drom[h->opc][i];                             /* specifier type */
     if (disp == RG)                                     /* fix specials */
@@ -3639,9 +3696,13 @@ fprintf (st, "The CPU can maintain a history of the most recently executed instr
 fprintf (st, "This is controlled by the SET CPU HISTORY and SHOW CPU HISTORY commands:\n\n");
 fprintf (st, "   sim> SET CPU HISTORY                 clear history buffer\n");
 fprintf (st, "   sim> SET CPU HISTORY=0               disable history\n");
-fprintf (st, "   sim> SET CPU HISTORY=n               enable history, length = n\n");
+fprintf (st, "   sim> SET CPU {-T} HISTORY=n{:file}   enable history, length = n\n");
 fprintf (st, "   sim> SHOW CPU HISTORY                print CPU history\n");
 fprintf (st, "   sim> SHOW CPU HISTORY=n              print first n entries of CPU history\n\n");
-fprintf (st, "The maximum length for the history is 65536 entries.\n\n");
+fprintf (st, "The -T switch causes simulator time to be recorded (and displayed)\n");
+fprintf (st, "with each history entry.\n");
+fprintf (st, "When writing history to a file (SET CPU HISTORY=n:file), 'n' specifies\n");
+fprintf (st, "the buffer flush frequency.  Warning: prodigious amounts of disk space\n");
+fprintf (st, "may be comsumed.  The maximum length for the history is %d entries.\n\n", HIST_MAX);
 return SCPE_OK;
 }