> ## Name

> isinf - test whether or not a scalar or each vector component is infinite

> ## Synopsis

>     bool  isinf(float x);
>     bool1 isinf(float1 x);
>     bool2 isinf(float2 x);
>     bool3 isinf(float3 x);
>     bool4 isinf(float4 x);

>     bool   isinf(half x);
>     bool1  isinf(half1 x);
>     bool2  isinf(half2 x);
>     bool3  isinf(half3 x);
>     bool4  isinf(half4 x);

>     bool  isinf(fixed x);
>     bool1 isinf(fixed1 x);
>     bool2 isinf(fixed2 x);
>     bool3 isinf(fixed3 x);
>     bool4 isinf(fixed4 x);

> ## Parameters

> x
>   Vector or scalar to test if infinite.

> ## Description

> Returns whether or not a scalar or each vector component is a (negative or positive) infinite value. Finite and not-a-number (NaN) values are not infinite.

> ## Reference Implementation

> isinf for float3 vectors could be implemented like this.

>     bool3 isinf(float3 s)
>     {
>       // By IEEE 754 rule, 2*Inf equals Inf
>       return (2*s == s) && (s != 0);
>     }

> ## Profile Support

> isinf is supported in all profiles except fp20.

> ## See Also

> isfinite, isnan