target-microblaze: impelemented swapx instructions

Implemented the swapb and swaph byte/halfword reversal instructions added
to microblaze v8.30
Signed-off-by: NPeter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

target-microblaze/translate.c

@@ -743,7 +743,7 @@ static void dec_bit(DisasContext *dc)
     unsigned int op;
     int mem_index = cpu_mmu_index(dc->env);
 
-    op = dc->ir & ((1 << 8) - 1);
+    op = dc->ir & ((1 << 9) - 1);
     switch (op) {
         case 0x21:
             /* src.  */
@@ -825,6 +825,16 @@ static void dec_bit(DisasContext *dc)
                 gen_helper_clz(cpu_R[dc->rd], cpu_R[dc->ra]);
             }
             break;
+        case 0x1e0:
+            /* swapb */
+            LOG_DIS("swapb r%d r%d\n", dc->rd, dc->ra);
+            tcg_gen_bswap32_i32(cpu_R[dc->rd], cpu_R[dc->ra]);
+            break;
+        case 0x1e1:
+            /*swaph */
+            LOG_DIS("swaph r%d r%d\n", dc->rd, dc->ra);
+            tcg_gen_rotri_i32(cpu_R[dc->rd], cpu_R[dc->ra], 16);
+            break;
         default:
             cpu_abort(dc->env, "unknown bit oc=%x op=%x rd=%d ra=%d rb=%d\n",
                      dc->pc, op, dc->rd, dc->ra, dc->rb);