[Beignet] [PATCH] fix built-in function "fast_normalize"

[Lu, Guanqun]

hi homer,

how about if x is NaN, according to the opencl-1.2 spec.

  "normalize ( v ) returns a vector full of NaNs if any element is a NaN."

so i would assume that if x is NaN, the result should be NaN. HOw do you think?


--guanqun



> -----Original Message-----
> From: beignet-bounces+guanqun.lu=intel.com at lists.freedesktop.org
> [mailto:beignet-bounces+guanqun.lu=intel.com at lists.freedesktop.org] On
> Behalf Of Homer Hsing
> Sent: Monday, October 28, 2013 9:03 AM
> To: beignet at lists.freedesktop.org
> Subject: [Beignet] [PATCH] fix built-in function "fast_normalize"
> 
> if the parameter is zero, then return zero
> if the parameter is positive, then return 1.
> for other cases, return -1.
> 
> Signed-off-by: Homer Hsing <homer.xing at intel.com>
> ---
>  backend/src/ocl_stdlib.tmpl.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/backend/src/ocl_stdlib.tmpl.h b/backend/src/ocl_stdlib.tmpl.h
> index a3bf0a0..38d1ab0 100644
> --- a/backend/src/ocl_stdlib.tmpl.h
> +++ b/backend/src/ocl_stdlib.tmpl.h
> @@ -1779,7 +1779,7 @@ INLINE_OVERLOADABLE float fast_distance(float x,
> float y) { return length(x-y);
>  INLINE_OVERLOADABLE float fast_distance(float2 x, float2 y) { return
> length(x-y); }
>  INLINE_OVERLOADABLE float fast_distance(float3 x, float3 y) { return
> length(x-y); }
>  INLINE_OVERLOADABLE float fast_distance(float4 x, float4 y) { return
> length(x-y); }
> -INLINE_OVERLOADABLE float fast_normalize(float x) { return 1.f; }
> +INLINE_OVERLOADABLE float fast_normalize(float x) { return x > 0 ? 1.f : (x <
> 0 ? -1.f : 0.f); }
>  INLINE_OVERLOADABLE float2 fast_normalize(float2 x) { return x * rsqrt(dot(x,
> x)); }
>  INLINE_OVERLOADABLE float3 fast_normalize(float3 x) { return x * rsqrt(dot(x,
> x)); }
>  INLINE_OVERLOADABLE float4 fast_normalize(float4 x) { return x * rsqrt(dot(x,
> x)); }
> --
> 1.8.3.2
> 
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