Integer Built-In Functions
Click an item in the table below for details about that function.
| abs | |x| |
| abs_diff | |x-y| without modulo overflow |
| add_sat | x+y and saturate result |
| hadd | (x+y) >> 1.
The intermediate sum does not modulo overflow |
| rhadd | (x+y+1) >> 1.
The intermediate sum does not modulo overflow. |
| clamp |
min(max(
x, minval), maxval)
|
| clz | Number of leading 0-bits in x |
| ctz | Number of trailing 0-bits in x |
| mad_hi | mul_hi(a,b)+c |
| mad24 | (Fast integer function.) Multiply 24-bit integer then add the 32-bit result to 32-bit integer |
| mad_sat | a*b+c
and saturate the result |
| max | The greater of x or y |
| min | The lesser of x or y |
| mul_hi | High half of the product of x and y |
| mul24 | (Fast integer function.) Multiply 24-bit integer values
a and b |
| rotate | result[indx]=v[indx]<<
i[indx] |
| sub_sat | x - y and saturate the result |
| upsample | result[i] = ((gentype)hi[i] << 8|16|32) |
lo[i] |
| popcount | Returns the number of non-zero bits in x. |
Description
Built-in integer functions take scalar or vector arguments. The vector versions of the integer functions operate component-wise. The description is per component.
We use the generic type name gentype to indicate that the function can take char, char{2|3|4|8|16}, uchar, uchar{2|3|4|8|16}, short, short{2|3|4|8|16}, ushort, ushort{2|3|4|8|16}, int, int{2|3|4|8|16}, uint, uint{2|3|4|8|16}, long, long{2|3|4|8|16}, ulong, or ulong{2|3|4|8|16} as the type for the arguments. We use the generic type name ugentype to refer to unsigned versions of gentype. For example, if gentype is char4, ugentype is uchar4.
We also use the generic type name sgentype to indicate that the function can take a scalar data type i.e. char, uchar, short, ushort, int, uint, long, or ulong as the type for the arguments. For built-in integer functions that take gentype and sgentype arguments, the gentype argument must be a vector or scalar version of the sgentype argument. For example, if sgentype is uchar, gentype must be uchar or uchar{2|3|4|8|16}. For vector versions, sgentype is implicitly widened to gentype as described in section 6.3.a of the OpenCL specification.
For any specific use of a function, the actual type has to be the same for all arguments and the return type unless otherwise specified.
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