Re: [PATCH] target/mips: Introduce ase_3d_available() helper

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 21/10/24 11:58, Philippe Mathieu-Daudé wrote:
> Determine if the MIPS-3D ASE is implemented by checking
> the state of the 3D bit in the FIR CP1 control register.
> Remove the then unused ASE_MIPS3D definition.

I forgot to mention:

  "Note, this allows using MIPS-3D on the 20Kc model."

> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   target/mips/cpu.h                         | 6 ++++++
>   target/mips/mips-defs.h                   | 1 -
>   target/mips/tcg/translate.c               | 8 ++++++--
>   target/mips/cpu-defs.c.inc                | 4 ++--
>   target/mips/tcg/micromips_translate.c.inc | 5 ++++-
>   5 files changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/target/mips/cpu.h b/target/mips/cpu.h
> index a4a46ebbe98..6a4c4ea683a 100644
> --- a/target/mips/cpu.h
> +++ b/target/mips/cpu.h
> @@ -1319,6 +1319,12 @@ bool cpu_type_supports_cps_smp(const char *cpu_type);
>   bool cpu_supports_isa(const CPUMIPSState *env, uint64_t isa_mask);
>   bool cpu_type_supports_isa(const char *cpu_type, uint64_t isa);
>   
> +/* Check presence of MIPS-3D ASE */
> +static inline bool ase_3d_available(CPUMIPSState *env)
> +{
> +    return env->active_fpu.fcr0 & (1 << FCR0_3D);
> +}
> +
>   /* Check presence of MSA implementation */
>   static inline bool ase_msa_available(CPUMIPSState *env)
>   {
> diff --git a/target/mips/mips-defs.h b/target/mips/mips-defs.h
> index a6cebe0265c..6b5cd0d8f53 100644
> --- a/target/mips/mips-defs.h
> +++ b/target/mips/mips-defs.h
> @@ -26,7 +26,6 @@
>    *   bits 24-39: MIPS ASEs
>    */
>   #define ASE_MIPS16        0x0000000001000000ULL
> -#define ASE_MIPS3D        0x0000000002000000ULL
>   #define ASE_MDMX          0x0000000004000000ULL
>   #define ASE_DSP           0x0000000008000000ULL
>   #define ASE_DSP_R2        0x0000000010000000ULL
> diff --git a/target/mips/tcg/translate.c b/target/mips/tcg/translate.c
> index d92fc418edd..9e0c319bb23 100644
> --- a/target/mips/tcg/translate.c
> +++ b/target/mips/tcg/translate.c
> @@ -14952,7 +14952,9 @@ static bool decode_opc_legacy(CPUMIPSState *env, DisasContext *ctx)
>               } else {
>                   /* OPC_BC1ANY2 */
>                   check_cop1x(ctx);
> -                check_insn(ctx, ASE_MIPS3D);
> +                if (!ase_3d_available(env)) {
> +                    return false;
> +                }
>                   gen_compute_branch1(ctx, MASK_BC1(ctx->opcode),
>                                       (rt >> 2) & 0x7, imm << 2);
>               }
> @@ -14967,7 +14969,9 @@ static bool decode_opc_legacy(CPUMIPSState *env, DisasContext *ctx)
>               check_cp1_enabled(ctx);
>               check_insn_opc_removed(ctx, ISA_MIPS_R6);
>               check_cop1x(ctx);
> -            check_insn(ctx, ASE_MIPS3D);
> +            if (!ase_3d_available(env)) {
> +                return false;
> +            }
>               /* fall through */
>           case OPC_BC1:
>               check_cp1_enabled(ctx);
> diff --git a/target/mips/cpu-defs.c.inc b/target/mips/cpu-defs.c.inc
> index 19e2abac829..2728f4dba67 100644
> --- a/target/mips/cpu-defs.c.inc
> +++ b/target/mips/cpu-defs.c.inc
> @@ -663,7 +663,7 @@ const mips_def_t mips_defs[] =
>           .CP1_fcr31_rw_bitmask = 0xFF83FFFF,
>           .SEGBITS = 40,
>           .PABITS = 36,
> -        .insn_flags = CPU_MIPS64R1 | ASE_MIPS3D,
> +        .insn_flags = CPU_MIPS64R1,
>           .mmu_type = MMU_TYPE_R4000,
>       },
>       {
> @@ -692,7 +692,7 @@ const mips_def_t mips_defs[] =
>           .CP1_fcr31_rw_bitmask = 0xFF83FFFF,
>           .SEGBITS = 42,
>           .PABITS = 36,
> -        .insn_flags = CPU_MIPS64R2 | ASE_MIPS3D,
> +        .insn_flags = CPU_MIPS64R2,
>           .mmu_type = MMU_TYPE_R4000,
>       },
>       {
> diff --git a/target/mips/tcg/micromips_translate.c.inc b/target/mips/tcg/micromips_translate.c.inc
> index 3cbf53bf2b3..c479bec1081 100644
> --- a/target/mips/tcg/micromips_translate.c.inc
> +++ b/target/mips/tcg/micromips_translate.c.inc
> @@ -2484,7 +2484,10 @@ static void decode_micromips32_opc(CPUMIPSState *env, DisasContext *ctx)
>               mips32_op = OPC_BC1TANY4;
>           do_cp1mips3d:
>               check_cop1x(ctx);
> -            check_insn(ctx, ASE_MIPS3D);
> +            if (!ase_3d_available(env)) {
> +                gen_reserved_instruction(ctx);
> +                break;
> +            }
>               /* Fall through */
>           do_cp1branch:
>               if (env->CP0_Config1 & (1 << CP0C1_FP)) {