From 102b920e11b6cd95addd59ea0eb08fac964fa8ad Mon Sep 17 00:00:00 2001
From: Jiri Gaisler <jiri@gaisler.se>
Date: Tue, 17 Mar 2015 22:02:41 +0100
Subject: [PATCH] sim/erc32: Use memory_iread() function for instruction
 fetching.

Use separate memory_iread() function for instruction fetching.
Speeds up execution and allows addition of an MMU at a later stage.
---
 sim/erc32/ChangeLog |  9 +++++++++
 sim/erc32/erc32.c   | 28 +++++++++++++++++++++++++++-
 sim/erc32/interf.c  |  5 ++---
 sim/erc32/sis.c     |  8 ++------
 sim/erc32/sis.h     |  2 ++
 5 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/sim/erc32/ChangeLog b/sim/erc32/ChangeLog
index 36fcbf4a690..1150e1c3c71 100644
--- a/sim/erc32/ChangeLog
+++ b/sim/erc32/ChangeLog
@@ -1,3 +1,12 @@
+2015-03-28  Jiri Gaisler  <jiri@gaisler.se>
+
+	* erc32.c (memory_iread): New function to fetch instructions.
+	(memory_read): Print message in verbose mode.
+	* interf.c (run_sim): Use memory_iread.
+	* sis.c (run_sim): As above.
+	* sis.h (memory_iread): New prototype.
+	(sregs): Declare.
+
 2015-03-28  Mike Frysinger  <vapier@gentoo.org>
 
 	* erc32.c (mec_read): Delete parenthesis around return statement.
diff --git a/sim/erc32/erc32.c b/sim/erc32/erc32.c
index 740d77821a1..7f24fb0ea75 100644
--- a/sim/erc32/erc32.c
+++ b/sim/erc32/erc32.c
@@ -1647,6 +1647,31 @@ store_bytes (mem, data, sz)
 
 /* Memory emulation */
 
+int
+memory_iread (uint32 addr, uint32 *data, int32 *ws)
+{
+    uint32          asi;
+    if ((addr >= mem_ramstart) && (addr < (mem_ramstart + mem_ramsz))) {
+	memcpy (data, &ramb[addr & mem_rammask & ~3], 4);
+	*ws = mem_ramr_ws;
+	return 0;
+    } else if (addr < mem_romsz) {
+	memcpy (data, &romb[addr & ~3], 4);
+	*ws = mem_romr_ws;
+	return 0;
+    }
+
+    if (sis_verbose)
+	printf ("Memory exception at %x (illegal address)\n", addr);
+    if (sregs.psr & 0x080)
+        asi = 9;
+    else
+        asi = 8;
+    set_sfsr (UIMP_ACC, addr, asi, 1);
+    *ws = MEM_EX_WS;
+    return 1;
+}
+
 int
 memory_read(asi, addr, data, sz, ws)
     int32           asi;
@@ -1712,7 +1737,8 @@ memory_read(asi, addr, data, sz, ws)
 
     }
 
-    printf("Memory exception at %x (illegal address)\n", addr);
+    if (sis_verbose)
+	printf ("Memory exception at %x (illegal address)\n", addr);
     set_sfsr(UIMP_ACC, addr, asi, 1);
     *ws = MEM_EX_WS;
     return 1;
diff --git a/sim/erc32/interf.c b/sim/erc32/interf.c
index f3764f1fd08..59fb635b9e9 100644
--- a/sim/erc32/interf.c
+++ b/sim/erc32/interf.c
@@ -95,9 +95,8 @@ run_sim(sregs, icount, dis)
             if (sregs->pc == 0 || sregs->npc == 0)
                 printf ("bogus pc or npc\n");
 #endif
-        mexc = memory_read(sregs->asi, sregs->pc, &sregs->inst,
-                           2, &sregs->hold);
-#if 1	/* DELETE ME! for debugging purposes only */
+        mexc = memory_iread (sregs->pc, &sregs->inst, &sregs->hold);
+#if 0	/* DELETE ME! for debugging purposes only */
         if (sis_verbose > 2)
             printf("pc %x, np %x, sp %x, fp %x, wm %x, cw %x, i %08x\n",
                    sregs->pc, sregs->npc,
diff --git a/sim/erc32/sis.c b/sim/erc32/sis.c
index c13b2465118..62590674ecd 100644
--- a/sim/erc32/sis.c
+++ b/sim/erc32/sis.c
@@ -75,7 +75,7 @@ run_sim(sregs, icount, dis)
     uint64          icount;
     int             dis;
 {
-    int             irq, mexc, deb, asi;
+    int             irq, mexc, deb;
 
     sregs->starttime = get_time();
     init_stdio();
@@ -84,11 +84,7 @@ run_sim(sregs, icount, dis)
     irq = 0;
     while (icount > 0) {
 
-	if (sregs->psr & 0x080)
-	    asi = 9;
-   	else
-	    asi = 8;
-	mexc = memory_read(asi, sregs->pc, &sregs->inst, 2, &sregs->hold);
+	mexc = memory_iread (sregs->pc, &sregs->inst, &sregs->hold);
 	sregs->icnt = 1;
 	if (sregs->annul) {
 	    sregs->annul = 0;
diff --git a/sim/erc32/sis.h b/sim/erc32/sis.h
index 74466aef8fe..d21bf49499a 100644
--- a/sim/erc32/sis.h
+++ b/sim/erc32/sis.h
@@ -169,6 +169,7 @@ extern void	sim_halt (void);
 extern void	exit_sim (void);
 extern void	init_stdio (void);
 extern void	restore_stdio (void);
+extern int	memory_iread (uint32 addr, uint32 *data, int32 *ws);
 extern int	memory_read (int32 asi, uint32 addr, uint32 *data,
 			     int32 sz, int32 *ws);
 extern int	memory_write (int32 asi, uint32 addr, uint32 *data,
@@ -179,6 +180,7 @@ extern int	sis_memory_read (uint32 addr, char *data,
 				 uint32 length);
 
 /* func.c */
+extern struct pstate  sregs;
 extern void	set_regi (struct pstate *sregs, int32 reg,
 			  uint32 rval);
 extern void	get_regi (struct pstate *sregs, int32 reg, char *buf);
-- 
2.30.2