To easily convert MXU code to decodetree, extract decode_ase_mxu()
from decode_opc_mxu(), making it return a boolean.
We will keep decode_opc_mxu() in the translate.c unit because it
calls gen_arith().

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 target/mips/translate.c | 45 ++++++++++++++++++++++++-----------------
 1 file changed, 26 insertions(+), 19 deletions(-)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index 9e875fa4a25..6f853fcdcce 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -25777,34 +25777,18 @@ static void decode_opc_mxu__pool19(DisasContext *ctx)
     }
 }
 
-/*
- * Main MXU decoding function
- */
-static void decode_opc_mxu(DisasContext *ctx, uint32_t insn)
+static bool decode_ase_mxu(DisasContext *ctx, uint32_t insn)
 {
     uint32_t opcode = extract32(insn, 0, 6);
 
-    if (opcode == OPC__MXU_MUL) {
-        uint32_t  rs, rt, rd, op1;
-
-        rs = extract32(insn, 21, 5);
-        rt = extract32(insn, 16, 5);
-        rd = extract32(insn, 11, 5);
-        op1 = MASK_SPECIAL2(insn);
-
-        gen_arith(ctx, op1, rd, rs, rt);
-
-        return;
-    }
-
     if (opcode == OPC_MXU_S32M2I) {
         gen_mxu_s32m2i(ctx);
-        return;
+        return true;
     }
 
     if (opcode == OPC_MXU_S32I2M) {
         gen_mxu_s32i2m(ctx);
-        return;
+        return true;
     }
 
     {
@@ -25845,6 +25829,29 @@ static void decode_opc_mxu(DisasContext *ctx, uint32_t insn)
         gen_set_label(l_exit);
         tcg_temp_free(t_mxu_cr);
     }
+
+    return true;
+}
+
+/*
+ * Main MXU decoding function
+ */
+static void decode_opc_mxu(DisasContext *ctx, uint32_t insn)
+{
+    if (extract32(insn, 0, 6) == OPC__MXU_MUL) {
+        uint32_t  rs, rt, rd, op1;
+
+        rs = extract32(insn, 21, 5);
+        rt = extract32(insn, 16, 5);
+        rd = extract32(insn, 11, 5);
+        op1 = MASK_SPECIAL2(insn);
+
+        gen_arith(ctx, op1, rd, rs, rt);
+
+        return;
+    }
+
+    decode_ase_mxu(ctx, insn);
 }
 
 #endif /* !defined(TARGET_MIPS64) */
-- 
2.26.2

On 2/22/21 2:38 PM, Philippe Mathieu-Daudé wrote:
> To easily convert MXU code to decodetree, extract decode_ase_mxu()
> from decode_opc_mxu(), making it return a boolean.
> We will keep decode_opc_mxu() in the translate.c unit because it
> calls gen_arith().
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  target/mips/translate.c | 45 ++++++++++++++++++++++++-----------------
>  1 file changed, 26 insertions(+), 19 deletions(-)

I guess the split is fine until you can just call gen_mul() from a trans() from
the mxu decodetree.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

On 2/24/21 2:25 AM, Richard Henderson wrote:
> On 2/22/21 2:38 PM, Philippe Mathieu-Daudé wrote:
>> To easily convert MXU code to decodetree, extract decode_ase_mxu()
>> from decode_opc_mxu(), making it return a boolean.
>> We will keep decode_opc_mxu() in the translate.c unit because it
>> calls gen_arith().
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>  target/mips/translate.c | 45 ++++++++++++++++++++++++-----------------
>>  1 file changed, 26 insertions(+), 19 deletions(-)
> 
> I guess the split is fine until you can just call gen_mul() from a trans() from
> the mxu decodetree.

I expect mxu decodetree to not cover MUL and return false, so it is
handled in the base ISA decoder.

> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Thanks :)