> ## Name

> exp - returns the base-e exponential of scalars and vectors

> ## Synopsis

>     float  exp(float a);
>     float1 exp(float1 a);
>     float2 exp(float2 a);
>     float3 exp(float3 a);
>     float4 exp(float4 a);

>     half   exp(half a);
>     half1  exp(half1 a);
>     half2  exp(half2 a);
>     half3  exp(half3 a);
>     half4  exp(half4 a);

>     fixed  exp(fixed a);
>     fixed1 exp(fixed1 a);
>     fixed2 exp(fixed2 a);
>     fixed3 exp(fixed3 a);
>     fixed4 exp(fixed4 a);

> ## Parameters

> a
>   Vector or scalar of which to determine the base-e exponential. The value e is approximately 2.71828182845904523536.

> ## Description

> Returns the base-e exponential a.

> For vectors, the returned vector contains the base-e exponential of each element of the input vector.

> ## Reference Implementation

>     float3 exp(float3 a)
>     {
>       float3 rv;
>       int i;

>       for (i=0; i<3; i++) {
>         rv[i] = exp(a[i]);  // this is the ANSI C standard library exp()
>       }
>       return rv;
>     }

> exp is typically implemented with either a native base-2 exponentional instruction or pow.

> ## Profile Support

> exp is fully supported in all profiles unless otherwise specified.

> Support in the fp20 is limited to constant compile-time evaluation.

> ## See Also

> exp2, log, pow