From: Philippe Mathieu-Daudé <f4bug@amsat.org>

The three-operand MADD and MADDU are specific to Sony R5900 core,
and Toshiba TX19/TX39/TX79 cores as well.

The "32-Bit TX System RISC TX39 Family Architecture manual"
is available at https://wiki.qemu.org/File:DSAE0022432.pdf

Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Philippe Mathieu-Daudé<f4bug@amsat.org>
Signed-off-by: Fredrik Noring <noring@nocrew.org>
Tested-by: Fredrik Noring <noring@nocrew.org>
---
 target/mips/translate.c | 58 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index e3a5a73..3ad3b31 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -5027,8 +5027,8 @@ static void gen_muldiv(DisasContext *ctx, uint32_t opc,
 }
 
 /*
- * These MULT and MULTU instructions implemented in for example the
- * Toshiba/Sony R5900 and the Toshiba TX19, TX39 and TX79 core
+ * These MULT[U] and MADD[U] instructions implemented in for example
+ * the Toshiba/Sony R5900 and the Toshiba TX19, TX39 and TX79 core
  * architectures are special three-operand variants with the syntax
  *
  *     MULT[U][1] rd, rs, rt
@@ -5037,6 +5037,14 @@ static void gen_muldiv(DisasContext *ctx, uint32_t opc,
  *
  *     (rd, LO, HI) <- rs * rt
  *
+ * and
+ *
+ *     MADD[U]    rd, rs, rt
+ *
+ * such that
+ *
+ *     (rd, LO, HI) <- (LO, HI) + rs * rt
+ *
  * where the low-order 32-bits of the result is placed into both the
  * GPR rd and the special register LO. The high-order 32-bits of the
  * result is placed into the special register HI.
@@ -5093,8 +5101,48 @@ static void gen_mul_txx9(DisasContext *ctx, uint32_t opc,
             tcg_temp_free_i32(t3);
         }
         break;
+    case MMI_OPC_MADD:
+        {
+            TCGv_i64 t2 = tcg_temp_new_i64();
+            TCGv_i64 t3 = tcg_temp_new_i64();
+
+            tcg_gen_ext_tl_i64(t2, t0);
+            tcg_gen_ext_tl_i64(t3, t1);
+            tcg_gen_mul_i64(t2, t2, t3);
+            tcg_gen_concat_tl_i64(t3, cpu_LO[acc], cpu_HI[acc]);
+            tcg_gen_add_i64(t2, t2, t3);
+            tcg_temp_free_i64(t3);
+            gen_move_low32(cpu_LO[acc], t2);
+            gen_move_high32(cpu_HI[acc], t2);
+            if (rd) {
+                gen_move_low32(cpu_gpr[rd], t2);
+            }
+            tcg_temp_free_i64(t2);
+        }
+        break;
+    case MMI_OPC_MADDU:
+        {
+            TCGv_i64 t2 = tcg_temp_new_i64();
+            TCGv_i64 t3 = tcg_temp_new_i64();
+
+            tcg_gen_ext32u_tl(t0, t0);
+            tcg_gen_ext32u_tl(t1, t1);
+            tcg_gen_extu_tl_i64(t2, t0);
+            tcg_gen_extu_tl_i64(t3, t1);
+            tcg_gen_mul_i64(t2, t2, t3);
+            tcg_gen_concat_tl_i64(t3, cpu_LO[acc], cpu_HI[acc]);
+            tcg_gen_add_i64(t2, t2, t3);
+            tcg_temp_free_i64(t3);
+            gen_move_low32(cpu_LO[acc], t2);
+            gen_move_high32(cpu_HI[acc], t2);
+            if (rd) {
+                gen_move_low32(cpu_gpr[rd], t2);
+            }
+            tcg_temp_free_i64(t2);
+        }
+        break;
     default:
-        MIPS_INVAL("mul TXx9");
+        MIPS_INVAL("mul/madd TXx9");
         generate_exception_end(ctx, EXCP_RI);
         goto out;
     }
@@ -26703,6 +26751,8 @@ static void decode_mmi(CPUMIPSState *env, DisasContext *ctx)
         break;
     case MMI_OPC_MULT1:
     case MMI_OPC_MULTU1:
+    case MMI_OPC_MADD:
+    case MMI_OPC_MADDU:
         gen_mul_txx9(ctx, opc, rd, rs, rt);
         break;
     case MMI_OPC_DIV1:
@@ -26717,8 +26767,6 @@ static void decode_mmi(CPUMIPSState *env, DisasContext *ctx)
     case MMI_OPC_MFHI1:
         gen_HILO1_tx79(ctx, opc, rd);
         break;
-    case MMI_OPC_MADD:          /* TODO: MMI_OPC_MADD */
-    case MMI_OPC_MADDU:         /* TODO: MMI_OPC_MADDU */
     case MMI_OPC_PLZCW:         /* TODO: MMI_OPC_PLZCW */
     case MMI_OPC_MADD1:         /* TODO: MMI_OPC_MADD1 */
     case MMI_OPC_MADDU1:        /* TODO: MMI_OPC_MADDU1 */
-- 
2.7.4