Re: [Qemu-devel] [PATCH 23/40] Add vspltis{b,h,w} instructions.

[Aurelien Jarno <aurelien@aurel32.net>]

On Tue, Dec 30, 2008 at 07:10:05PM -0800, Nathan Froyd wrote:
> 
> Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
> ---
>  target-ppc/helper.h    |    3 +++
>  target-ppc/op_helper.c |   17 +++++++++++++++++
>  target-ppc/translate.c |    4 ++++
>  3 files changed, 24 insertions(+), 0 deletions(-)
> 
> diff --git a/target-ppc/helper.h b/target-ppc/helper.h
> index 02e3c10..9fbcc4a 100644
> --- a/target-ppc/helper.h
> +++ b/target-ppc/helper.h
> @@ -179,6 +179,9 @@ DEF_HELPER_3(vrlw, void, avr, avr, avr)
>  DEF_HELPER_3(vsl, void, avr, avr, avr)
>  DEF_HELPER_3(vsr, void, avr, avr, avr)
>  DEF_HELPER_4(vsldoi, void, avr, avr, avr, i32)
> +DEF_HELPER_2(vspltisb, void, avr, i32)
> +DEF_HELPER_2(vspltish, void, avr, i32)
> +DEF_HELPER_2(vspltisw, void, avr, i32)
>  
>  DEF_HELPER_1(efscfsi, i32, i32)
>  DEF_HELPER_1(efscfui, i32, i32)
> diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
> index d0748b2..55f341f 100644
> --- a/target-ppc/op_helper.c
> +++ b/target-ppc/op_helper.c
> @@ -2302,6 +2302,23 @@ void helper_vslo (ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b)
>  #endif
>  }
>  
> +#define VSPLTI(suffix, element, splat_type)                     \
> +    void helper_vspltis##suffix (ppc_avr_t *r, uint32_t splat)  \
> +    {                                                           \
> +        splat_type x = (splat_type)splat;                       \
> +        int i;                                                  \
> +        /* 5-bit sign extension.  */                            \
> +        if (x & 0x10)                                           \
> +            x -= 0x20;                                          \

I don't really like this way of doing a sign extension. I would prefer
to avoid a test and do something like:
splat_type x = (int8_t)(splat << 3) >> 3;

> +        for (i = 0; i < ARRAY_SIZE(r->element); i++) {          \
> +            r->element[i] = x;                                  \
> +        }                                                       \
> +    }
> +VSPLTI(b, s8, int8_t)
> +VSPLTI(h, s16, int16_t)
> +VSPLTI(w, s32, int32_t)
> +#undef VSPLTI
> +
>  #define VSR(suffix, element)                                            \
>      void helper_vsr##suffix (ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b)  \
>      {                                                                   \
> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
> index e590476..d9c1e60 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -6339,6 +6339,10 @@ GEN_VXFORM(vsr, 2, 11);
>          tcg_temp_free_ptr(rd);                                          \
>      }
>  
> +GEN_VXFORM_SIMM(vspltisb, 6, 12);
> +GEN_VXFORM_SIMM(vspltish, 6, 13);
> +GEN_VXFORM_SIMM(vspltisw, 6, 14);
> +
>  #define GEN_VXRFORM1(opname, name, str, opc2, opc3)                     \
>      GEN_HANDLER2(name, str, 0x4, opc2, opc3, 0x00000000, PPC_ALTIVEC)   \
>      {                                                                   \
> -- 
> 1.6.0.5
> 
> 
> 
> 

-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   aurel32@debian.org         | aurelien@aurel32.net
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