Re: [Qemu-devel] [PATCH 08/40] Add vcmpequ{b, h, w} and vcmpgt{s, u}{b, h, w} instructions.

[Aurelien Jarno]

On Tue, Dec 30, 2008 at 07:09:50PM -0800, Nathan Froyd wrote:
> 
> Signed-off-by: Nathan Froyd <address@hidden>
> ---
>  target-ppc/helper.h    |    9 +++++++++
>  target-ppc/op_helper.c |   34 ++++++++++++++++++++++++++++++++++
>  target-ppc/translate.c |   10 ++++++++++
>  3 files changed, 53 insertions(+), 0 deletions(-)
> 
> diff --git a/target-ppc/helper.h b/target-ppc/helper.h
> index 196106e..efe7a1a 100644
> --- a/target-ppc/helper.h
> +++ b/target-ppc/helper.h
> @@ -123,6 +123,15 @@ DEF_HELPER_3(vminuw, void, avr, avr, avr)
>  DEF_HELPER_3(vmaxub, void, avr, avr, avr)
>  DEF_HELPER_3(vmaxuh, void, avr, avr, avr)
>  DEF_HELPER_3(vmaxuw, void, avr, avr, avr)
> +DEF_HELPER_3(vcmpequb, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpequh, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpequw, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpgtub, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpgtuh, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpgtuw, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpgtsb, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpgtsh, i32, avr, avr, avr)
> +DEF_HELPER_3(vcmpgtsw, i32, avr, avr, avr)
>  
>  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 367c366..5daa62f 100644
> --- a/target-ppc/op_helper.c
> +++ b/target-ppc/op_helper.c
> @@ -2007,6 +2007,40 @@ VAVG(w, s32, int64_t, u32, uint64_t)
>  #undef VAVG_DO
>  #undef VAVG
>  
> +#define VCMP(suffix, compare, element)                                  \
> +    uint32_t helper_vcmp##suffix (ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b) \
> +    {                                                                   \
> +        uint32_t ones = (sizeof (a->element[0]) == 4                    \
> +                         ? 0xffffffff                                   \
> +                         : (sizeof (a->element[0]) == 2                 \
> +                            ? 0xffff                                    \
> +                            : 0xff));                                   \
> +        uint32_t all = ones;                                            \
> +        uint32_t none = 0;                                              \
> +        int i;                                                          \
> +        for (i = 0; i < ARRAY_SIZE(r->element); i++) {                  \
> +            uint32_t result = (a->element[i] compare b->element[i] ? ones : 
> 0x0); \
> +            switch (sizeof (a->element[0])) {                           \
> +            case 4: r->u32[i] = result; break;                          \
> +            case 2: r->u16[i] = result; break;                          \
> +            case 1: r->u8[i] = result; break;                           \
> +            }                                                           \
> +            all &= result;                                              \
> +            none |= result;                                             \
> +        }                                                               \

The part defining the ones looks a bit complicated. You may want to
define result as int32_t, and put either -1 or 0. Then you can just cast
the value:
               case 4: r->u32[i] = (int32_t)result; break;
               case 2: r->u16[i] = (int16_t)result; break;
               case 1: r->u8[i] = (int8_t)result; break;

> +        return ((all != 0) << 3) | ((none == 0) << 1);                  \
> +    }
> +VCMP(equb, ==, u8)
> +VCMP(equh, ==, u16)
> +VCMP(equw, ==, u32)
> +VCMP(gtub, >, u8)
> +VCMP(gtuh, >, u16)
> +VCMP(gtuw, >, u32)
> +VCMP(gtsb, >, s8)
> +VCMP(gtsh, >, s16)
> +VCMP(gtsw, >, s32)
> +#undef VCMP
> +
>  #define VMINMAX_DO(name, compare, element)                              \
>      void helper_v##name (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 967d9da..7ebdb21 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -6233,6 +6233,16 @@ GEN_VXFORM(vavgsw, 1, 22);
>      GEN_VXRFORM1(name, name, #name, opc2, opc3)                      \
>      GEN_VXRFORM1(name, name##_, #name ".", opc2, (opc3 | (0x1 << 4)))
>  
> +GEN_VXRFORM(vcmpequb, 3, 0)
> +GEN_VXRFORM(vcmpequh, 3, 1)
> +GEN_VXRFORM(vcmpequw, 3, 2)
> +GEN_VXRFORM(vcmpgtsb, 3, 12)
> +GEN_VXRFORM(vcmpgtsh, 3, 13)
> +GEN_VXRFORM(vcmpgtsw, 3, 14)
> +GEN_VXRFORM(vcmpgtub, 3, 8)
> +GEN_VXRFORM(vcmpgtuh, 3, 9)
> +GEN_VXRFORM(vcmpgtuw, 3, 10)
> +
>  /***                           SPE extension                               
> ***/
>  /* Register moves */
>  
> -- 
> 1.6.0.5
> 
> 
> 
> 

-- 
  .''`.  Aurelien Jarno             | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   address@hidden         | address@hidden
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