(mix_vm_reset_program) new function

(mix_vm_run, mix_vm_next) removed automatic reset of location pointer
when program halted

2 files changed, 26 insertions, 12 deletions

diff --git a/mixlib/mix_vm.c b/mixlib/mix_vm.c
index 2c41097..38ce5a9 100644
--- a/mixlib/mix_vm.c
+++ b/mixlib/mix_vm.c
@@ -308,6 +308,25 @@ mix_vm_get_prog_count (const mix_vm_t *vm)
   return get_loc_ (vm);
 }
 
+/* Reposition program counter and reset state so that a loaded
+   program can be restarted.
+*/
+void
+mix_vm_reset_program (mix_vm_t *vm)
+{
+  guint k;
+  g_return_if_fail (vm != NULL);
+  reset_loc_ (vm);
+  halt_ (vm, FALSE);
+  set_rA_ (vm, MIX_WORD_ZERO);
+  set_rX_ (vm, MIX_WORD_ZERO);
+  set_rJ_ (vm, MIX_WORD_ZERO);
+  for ( k = 1; k < IREG_NO_+1; ++k )
+    set_rI_ (vm, k, MIX_WORD_ZERO);
+  set_over_ (vm, FALSE);
+  set_cmp_ (vm, mix_EQ);
+}
+
 /* continue execution of instructions in memory */
 int
 mix_vm_run (mix_vm_t *vm)
@@ -315,12 +334,6 @@ mix_vm_run (mix_vm_t *vm)
   mix_ins_t ins;
   g_return_val_if_fail (vm != NULL, MIX_VM_ERROR);
   
-  if ( is_halted_ (vm) )
-    {
-      reset_loc_ (vm);	/* set current location to start address */
-      halt_ (vm, FALSE);
-    }
-  
   while ( !is_halted_ (vm) )
     {
       mix_word_to_ins_uncheck (get_cell_ (vm, get_loc_ (vm)), ins);
@@ -340,12 +353,7 @@ mix_vm_exec_next (mix_vm_t *vm)
   mix_ins_t ins;
   g_return_val_if_fail (vm != NULL, MIX_VM_ERROR);
   if (get_loc_ (vm) >= MIX_VM_CELL_NO) halt_ (vm, TRUE);
-  if (is_halted_ (vm))
-    {
-      reset_loc_ (vm);	/* set current location to start address */
-      halt_ (vm, FALSE);
-      return MIX_VM_HALT;
-    }
+  if (is_halted_ (vm)) return MIX_VM_HALT;
   mix_word_to_ins_uncheck (get_cell_ (vm, get_loc_ (vm)), ins);
   if (!(*ins_handlers_[ins.opcode]) (vm, &ins))
     return MIX_VM_ERROR;
diff --git a/mixlib/mix_vm.h b/mixlib/mix_vm.h
index cf4965c..62ba34d 100644
--- a/mixlib/mix_vm.h
+++ b/mixlib/mix_vm.h
@@ -127,6 +127,12 @@ mix_vm_get_symbol_table (const mix_vm_t *vm);
 extern mix_address_t 
 mix_vm_get_prog_count (const mix_vm_t *vm);
 
+/* Reposition program counter and reset state so that a loaded
+   program can be restarted.
+*/
+extern void
+mix_vm_reset_program (mix_vm_t *vm);
+
 /* continue execution of instructions in memory */
 /* Possible outcomes */
 enum {