Vector distance.
float fast_distance(floatn p0, floatn p1);
Returns fast_length(3clc)(p0 - p1).
Built-in geometric functions operate component-wise. The description is per-component. floatn is float, float2, float3, or float4 and doublen is double, double2, double3, or double4. The built-in geometric functions are implemented using the round to nearest even rounding mode.
The geometric functions can be implemented using contractions such as mad(3clc) or fma(3clc).
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geometricFunctions(3clc)
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OpenCL Specification
page 262, section 6.12.5 - Geometric Functions