Reduce scope or eliminate temporary variables in jtag_add_statemove:

[openocd.git] / src / jtag / jtag.c

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index 751e53f96e1454d4f73f4118d05c4a1ce542b9c8..77f322578f6291fd86e186c15e4508d63308ec8a 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -2569,61 +2569,55 @@ static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char *
 }
 
 /**
- * Function jtag_add_statemove
- * moves from the current state to the goal \a state. This needs
+ * Moves from the current state to the goal \a state. This needs
  * to be handled according to the xsvf spec, see the XSTATE command
  * description.
+ *
+ * From the XSVF spec, pertaining to XSTATE:
+ *
+ * For special states known as stable states (Test-Logic-Reset,
+ * Run-Test/Idle, Pause-DR, Pause- IR), an XSVF interpreter follows
+ * predefined TAP state paths when the starting state is a stable state
+ * and when the XSTATE specifies a new stable state.  See the STATE
+ * command in the [Ref 5] for the TAP state paths between stable
+ * states.
+ *
+ * For non-stable states, XSTATE should specify a state that is only one
+ * TAP state transition distance from the current TAP state to avoid
+ * undefined TAP state paths. A sequence of multiple XSTATE commands can
+ * be issued to transition the TAP through a specific state path.
+ *
+ * @note Unless @a tms_bits holds a path that agrees with [Ref 5] in *
+ * above spec, then this code is not fully conformant to the xsvf spec.
+ * This puts a burden on tap_get_tms_path() function from the xsvf spec.
+ * If in doubt, you should confirm that that burden is being met.
+ *
+ * Otherwise, state must be immediately reachable in one clock cycle,
+ * and does not need to be a stable state.
  */
 int jtag_add_statemove(tap_state_t goal_state)
 {
-       int retval = ERROR_OK;
-
-       tap_state_t moves[8];
        tap_state_t cur_state = cmd_queue_cur_state;
-       int i;
-       int tms_bits;
-       int     tms_count;
 
        LOG_DEBUG( "cur_state=%s goal_state=%s",
                tap_state_name(cur_state),
                tap_state_name(goal_state) );
 
 
-       /*      From the XSVF spec, pertaining to XSTATE:
-
-               For special states known as stable states (Test-Logic-Reset,
-               Run-Test/Idle, Pause-DR, Pause- IR), an XSVF interpreter follows
-               predefined TAP state paths when the starting state is a stable state and
-               when the XSTATE specifies a new stable state (see the STATE command in
-               the [Ref 5] for the TAP state paths between stable states). For
-               non-stable states, XSTATE should specify a state that is only one TAP
-               state transition distance from the current TAP state to avoid undefined
-               TAP state paths. A sequence of multiple XSTATE commands can be issued to
-               transition the TAP through a specific state path.
-       */
-
        if (goal_state==cur_state )
                ;       /* nothing to do */
-
        else if( goal_state==TAP_RESET )
        {
                jtag_add_tlr();
        }
-
        else if( tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state) )
        {
-               /*      note: unless tms_bits holds a path that agrees with [Ref 5] in above
-                       spec, then this code is not fully conformant to the xsvf spec.  This
-                       puts a burden on tap_get_tms_path() function from the xsvf spec.
-                       If in doubt, you should confirm that that burden is being met.
-               */
-
-               tms_bits  = tap_get_tms_path(cur_state, goal_state);
-               tms_count = tap_get_tms_path_len(cur_state, goal_state);
+               unsigned tms_bits  = tap_get_tms_path(cur_state, goal_state);
+               unsigned tms_count = tap_get_tms_path_len(cur_state, goal_state);
+               tap_state_t moves[8];
+               assert(tms_count < DIM(moves));
 
-               assert( (unsigned) tms_count < DIM(moves) );
-
-               for (i=0;   i<tms_count;   i++, tms_bits>>=1)
+               for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
                {
                        bool bit = tms_bits & 1;
 
@@ -2633,24 +2627,16 @@ int jtag_add_statemove(tap_state_t goal_state)
 
                jtag_add_pathmove(tms_count, moves);
        }
-
-       /*      else state must be immediately reachable in one clock cycle, and does not
-               need to be a stable state.
-       */
        else if( tap_state_transition(cur_state, true)  == goal_state
                ||   tap_state_transition(cur_state, false) == goal_state )
        {
-               /* move a single state */
-               moves[0] = goal_state;
-               jtag_add_pathmove( 1, moves );
+               jtag_add_pathmove(1, &goal_state);
        }
 
        else
-       {
-               retval = ERROR_FAIL;
-       }
+               return ERROR_FAIL;
 
-       return retval;
+       return ERROR_OK;
 }
 
 void jtag_set_nsrst_delay(unsigned delay)