target/mips: Add emulation of MMI instruction PCPYLD

Add emulation of MMI instruction PCPYLD. The emulation is implemented
using TCG front end operations directly to achieve better performance.
Signed-off-by: NMateja Marjanovic <mateja.marjanovic@rt-rk.com>
Signed-off-by: NAleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: NAleksandar Rikalo <arikalo@wavecomp.com>
Message-Id: <1551712405-2530-3-git-send-email-mateja.marjanovic@rt-rk.com>

target/mips/translate.c

@@ -24419,6 +24419,45 @@ static void gen_mmi_pcpyh(DisasContext *ctx)
     }
 }
 
+/*
+ *  PCPYLD rd, rs, rt
+ *
+ *    Parallel Copy Lower Doubleword
+ *
+ *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ *  +-----------+---------+---------+---------+---------+-----------+
+ *  |    MMI    |   rs    |   rt    |   rd    | PCPYLD  |    MMI2   |
+ *  +-----------+---------+---------+---------+---------+-----------+
+ */
+static void gen_mmi_pcpyld(DisasContext *ctx)
+{
+    uint32_t rs, rt, rd;
+    uint32_t opcode;
+
+    opcode = ctx->opcode;
+
+    rs = extract32(opcode, 21, 5);
+    rt = extract32(opcode, 16, 5);
+    rd = extract32(opcode, 11, 5);
+
+    if (rd == 0) {
+        /* nop */
+    } else {
+        if (rs == 0) {
+            tcg_gen_movi_i64(cpu_mmr[rd], 0);
+        } else {
+            tcg_gen_mov_i64(cpu_mmr[rd], cpu_gpr[rs]);
+        }
+        if (rt == 0) {
+            tcg_gen_movi_i64(cpu_gpr[rd], 0);
+        } else {
+            if (rd != rt) {
+                tcg_gen_mov_i64(cpu_gpr[rd], cpu_gpr[rt]);
+            }
+        }
+    }
+}
+
 #endif
 
 
@@ -27433,7 +27472,6 @@ static void decode_mmi2(CPUMIPSState *env, DisasContext *ctx)
     case MMI_OPC_2_PINTH:     /* TODO: MMI_OPC_2_PINTH */
     case MMI_OPC_2_PMULTW:    /* TODO: MMI_OPC_2_PMULTW */
     case MMI_OPC_2_PDIVW:     /* TODO: MMI_OPC_2_PDIVW */
-    case MMI_OPC_2_PCPYLD:    /* TODO: MMI_OPC_2_PCPYLD */
     case MMI_OPC_2_PMADDH:    /* TODO: MMI_OPC_2_PMADDH */
     case MMI_OPC_2_PHMADH:    /* TODO: MMI_OPC_2_PHMADH */
     case MMI_OPC_2_PAND:      /* TODO: MMI_OPC_2_PAND */
@@ -27448,6 +27486,9 @@ static void decode_mmi2(CPUMIPSState *env, DisasContext *ctx)
     case MMI_OPC_2_PROT3W:    /* TODO: MMI_OPC_2_PROT3W */
         generate_exception_end(ctx, EXCP_RI); /* TODO: MMI_OPC_CLASS_MMI2 */
         break;
+    case MMI_OPC_2_PCPYLD:
+        gen_mmi_pcpyld(ctx);
+        break;
     default:
         MIPS_INVAL("TX79 MMI class MMI2");
         generate_exception_end(ctx, EXCP_RI);