[Mesa-dev] [PATCH 23/59] intel/compiler: Extended Math is limited to SIMD8 on half-float

[Pohjolainen, Topi]

On Tue, Dec 04, 2018 at 08:16:47AM +0100, Iago Toral Quiroga wrote:
> From the Skylake PRM, Extended Math Function:
> 
>   "The execution size must be no more than 8 when half-floats
>    are used in source or destination operand."
> 
> Earlier generations do not support Extended Math with half-float.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen at intel.com>

> ---
>  src/intel/compiler/brw_fs.cpp | 30 +++++++++++++++++++++++-------
>  1 file changed, 23 insertions(+), 7 deletions(-)
> 
> diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
> index 43b920ae33d..509c6febf38 100644
> --- a/src/intel/compiler/brw_fs.cpp
> +++ b/src/intel/compiler/brw_fs.cpp
> @@ -5386,18 +5386,34 @@ get_lowered_simd_width(const struct gen_device_info *devinfo,
>     case SHADER_OPCODE_EXP2:
>     case SHADER_OPCODE_LOG2:
>     case SHADER_OPCODE_SIN:
> -   case SHADER_OPCODE_COS:
> +   case SHADER_OPCODE_COS: {
>        /* Unary extended math instructions are limited to SIMD8 on Gen4 and
>         * Gen6.
>         */
> -      return (devinfo->gen >= 7 ? MIN2(16, inst->exec_size) :
> -              devinfo->gen == 5 || devinfo->is_g4x ? MIN2(16, inst->exec_size) :
> -              MIN2(8, inst->exec_size));
> +      unsigned max_width =
> +         (devinfo->gen >= 7 ? MIN2(16, inst->exec_size) :
> +          devinfo->gen == 5 || devinfo->is_g4x ? MIN2(16, inst->exec_size) :
> +          MIN2(8, inst->exec_size));
>  
> -   case SHADER_OPCODE_POW:
> +      /* Extended Math Function is limited to SIMD8 with half-float */
> +      if (inst->dst.type == BRW_REGISTER_TYPE_HF)
> +         max_width = MIN2(max_width, 8);
> +
> +      return max_width;
> +   }
> +
> +   case SHADER_OPCODE_POW: {
>        /* SIMD16 is only allowed on Gen7+. */
> -      return (devinfo->gen >= 7 ? MIN2(16, inst->exec_size) :
> -              MIN2(8, inst->exec_size));
> +      unsigned max_width =
> +          (devinfo->gen >= 7 ? MIN2(16, inst->exec_size) :
> +           MIN2(8, inst->exec_size));
> +
> +      /* Extended Math Function is limited to SIMD8 with half-float */
> +      if (inst->dst.type == BRW_REGISTER_TYPE_HF)
> +         max_width = MIN2(max_width, 8);
> +
> +      return max_width;
> +   }
>  
>     case SHADER_OPCODE_INT_QUOTIENT:
>     case SHADER_OPCODE_INT_REMAINDER:
> -- 
> 2.17.1
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev