Re: [PATCH 4/4] hw/cpu: Call object_class_dynamic_cast() once in cpu_class_by_name()

[Gavin Shan]

On 9/8/23 21:22, Philippe Mathieu-Daudé wrote:
> Leverage the public CPUClass::cpu_resolving_type field and
> call object_class_dynamic_cast() once in cpu_class_by_name().
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   hw/core/cpu-common.c   | 3 ++-
>   target/alpha/cpu.c     | 3 +--
>   target/arm/cpu.c       | 4 +---
>   target/avr/cpu.c       | 4 +---
>   target/cris/cpu.c      | 4 +---
>   target/hexagon/cpu.c   | 4 +---
>   target/loongarch/cpu.c | 5 +----
>   target/m68k/cpu.c      | 4 +---
>   target/openrisc/cpu.c  | 4 +---
>   target/riscv/cpu.c     | 4 +---
>   target/rx/cpu.c        | 2 +-
>   target/tricore/cpu.c   | 4 +---
>   target/xtensa/cpu.c    | 4 +---
>   13 files changed, 14 insertions(+), 35 deletions(-)
>
> diff --git a/hw/core/cpu-common.c b/hw/core/cpu-common.c
> index 2d24261a6a..f4a2ccebea 100644
> --- a/hw/core/cpu-common.c
> +++ b/hw/core/cpu-common.c
> @@ -157,7 +157,8 @@ ObjectClass *cpu_class_by_name(const char *typename, const 
> char *cpu_model)
>       cc = CPU_CLASS(oc);
>       assert(cc->cpu_resolving_type && cc->class_by_name);
>       oc = cc->class_by_name(cpu_model);
> -    if (oc == NULL || object_class_is_abstract(oc)) {
> +    if (oc == NULL || object_class_is_abstract(oc)
> +                   || !object_class_dynamic_cast(oc, cc->cpu_resolving_type)) {
>           return NULL;
>       }
>       return oc;

Alignment.

    if (!oc || object_class_is_abstract(oc) ||
        !object_class_dynamic_cast(oc, cc->cpu_resolving_type)) {

> diff --git a/target/alpha/cpu.c b/target/alpha/cpu.c
> index 0ddea8004c..b184fcc123 100644
> --- a/target/alpha/cpu.c
> +++ b/target/alpha/cpu.c
> @@ -126,8 +126,7 @@ static ObjectClass *alpha_cpu_class_by_name(const char 
> *cpu_model)
>       int i;
>   
>       oc = object_class_by_name(cpu_model);
> -    if (oc != NULL && object_class_dynamic_cast(oc, TYPE_ALPHA_CPU) != NULL &&
> -        !object_class_is_abstract(oc)) {
> +    if (oc != NULL && !object_class_is_abstract(oc)) {
>           return oc;
>       }
>   

No, the check "!object_class_is_abstract(oc)" for this level can't be dropped.
The same check for the last level can be dropped because it's going to be
covered by hw/core/cpu-common.c::cpu_class_by_name().

> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 9e51bde170..d29040cd8c 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -2300,9 +2300,7 @@ static ObjectClass *arm_cpu_class_by_name(const char 
> *cpu_model)
>       oc = object_class_by_name(typename);
>       g_strfreev(cpuname);
>       g_free(typename);
> -    if (!oc || !object_class_dynamic_cast(oc, TYPE_ARM_CPU)) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/avr/cpu.c b/target/avr/cpu.c
> index f6004169ac..53735ff1dd 100644
> --- a/target/avr/cpu.c
> +++ b/target/avr/cpu.c
> @@ -159,9 +159,7 @@ static ObjectClass *avr_cpu_class_by_name(const char 
> *cpu_model)
>       ObjectClass *oc;
>   
>       oc = object_class_by_name(cpu_model);
> -    if (object_class_dynamic_cast(oc, TYPE_AVR_CPU) == NULL) {
> -        oc = NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/cris/cpu.c b/target/cris/cpu.c
> index adde4f599d..b307d0b9db 100644
> --- a/target/cris/cpu.c
> +++ b/target/cris/cpu.c
> @@ -95,9 +95,7 @@ static ObjectClass *cris_cpu_class_by_name(const char 
> *cpu_model)
>       typename = g_strdup_printf(CRIS_CPU_TYPE_NAME("%s"), cpu_model);
>       oc = object_class_by_name(typename);
>       g_free(typename);
> -    if (oc != NULL && !object_class_dynamic_cast(oc, TYPE_CRIS_CPU)) {
> -        oc = NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/hexagon/cpu.c b/target/hexagon/cpu.c
> index 2d4fed838d..4b8d63c4a7 100644
> --- a/target/hexagon/cpu.c
> +++ b/target/hexagon/cpu.c
> @@ -63,9 +63,7 @@ static ObjectClass *hexagon_cpu_class_by_name(const char 
> *cpu_model)
>       oc = object_class_by_name(typename);
>       g_strfreev(cpuname);
>       g_free(typename);
> -    if (!oc || !object_class_dynamic_cast(oc, TYPE_HEXAGON_CPU)) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
> index 189dfd32d1..1eb2c579eb 100644
> --- a/target/loongarch/cpu.c
> +++ b/target/loongarch/cpu.c
> @@ -646,10 +646,7 @@ static ObjectClass *loongarch_cpu_class_by_name(const char 
> *cpu_model)
>           }
>       }
>   
> -    if (object_class_dynamic_cast(oc, TYPE_LOONGARCH_CPU)) {
> -        return oc;
> -    }
> -    return NULL;
> +    return oc;
>   }
>   
>   void loongarch_cpu_dump_state(CPUState *cs, FILE *f, int flags)
> diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
> index bd7bb103d7..e8b86c80f1 100644
> --- a/target/m68k/cpu.c
> +++ b/target/m68k/cpu.c
> @@ -111,9 +111,7 @@ static ObjectClass *m68k_cpu_class_by_name(const char 
> *cpu_model)
>       typename = g_strdup_printf(M68K_CPU_TYPE_NAME("%s"), cpu_model);
>       oc = object_class_by_name(typename);
>       g_free(typename);
> -    if (oc != NULL && object_class_dynamic_cast(oc, TYPE_M68K_CPU) == NULL) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/openrisc/cpu.c b/target/openrisc/cpu.c
> index 5e1e0576e0..7aac9105bd 100644
> --- a/target/openrisc/cpu.c
> +++ b/target/openrisc/cpu.c
> @@ -168,9 +168,7 @@ static ObjectClass *openrisc_cpu_class_by_name(const char 
> *cpu_model)
>       typename = g_strdup_printf(OPENRISC_CPU_TYPE_NAME("%s"), cpu_model);
>       oc = object_class_by_name(typename);
>       g_free(typename);
> -    if (oc != NULL && !object_class_dynamic_cast(oc, TYPE_OPENRISC_CPU)) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index e8f04ef82b..0170e288e7 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -619,9 +619,7 @@ static ObjectClass *riscv_cpu_class_by_name(const char 
> *cpu_model)
>       oc = object_class_by_name(typename);
>       g_strfreev(cpuname);
>       g_free(typename);
> -    if (!oc || !object_class_dynamic_cast(oc, TYPE_RISCV_CPU)) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/rx/cpu.c b/target/rx/cpu.c
> index 2a6df418a8..879d4fcdef 100644
> --- a/target/rx/cpu.c
> +++ b/target/rx/cpu.c
> @@ -111,7 +111,7 @@ static ObjectClass *rx_cpu_class_by_name(const char 
> *cpu_model)
>       char *typename;
>   
>       oc = object_class_by_name(cpu_model);
> -    if (oc != NULL && object_class_dynamic_cast(oc, TYPE_RX_CPU) != NULL) {
> +    if (oc != NULL) {
>           return oc;
>       }
>       typename = g_strdup_printf(RX_CPU_TYPE_NAME("%s"), cpu_model);

Same as above. The check (object_class_dynamic_cast()) can't be dropped in
this level. Besides, the check object_class_is_abstract() is missed for this
level.

> diff --git a/target/tricore/cpu.c b/target/tricore/cpu.c
> index ffe5158786..f65b8761b0 100644
> --- a/target/tricore/cpu.c
> +++ b/target/tricore/cpu.c
> @@ -140,9 +140,7 @@ static ObjectClass *tricore_cpu_class_by_name(const char 
> *cpu_model)
>       typename = g_strdup_printf(TRICORE_CPU_TYPE_NAME("%s"), cpu_model);
>       oc = object_class_by_name(typename);
>       g_free(typename);
> -    if (!oc || !object_class_dynamic_cast(oc, TYPE_TRICORE_CPU)) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   
> diff --git a/target/xtensa/cpu.c b/target/xtensa/cpu.c
> index 13bed05d0c..6d96e5ab27 100644
> --- a/target/xtensa/cpu.c
> +++ b/target/xtensa/cpu.c
> @@ -141,9 +141,7 @@ static ObjectClass *xtensa_cpu_class_by_name(const char 
> *cpu_model)
>       typename = g_strdup_printf(XTENSA_CPU_TYPE_NAME("%s"), cpu_model);
>       oc = object_class_by_name(typename);
>       g_free(typename);
> -    if (oc == NULL || !object_class_dynamic_cast(oc, TYPE_XTENSA_CPU)) {
> -        return NULL;
> -    }
> +
>       return oc;
>   }
>   

Thanks,
Gavin