12.46 __uhsub16 intrinsic

This intrinsic inserts a UHSUB16 instruction into the instruction stream generated by the compiler.

It enables you to perform two unsigned 16-bit integer subtractions, halving the results.

Syntax

unsigned int __uhsub16(unsigned int val1, unsigned int val2)
Where:
val1
holds the first two 16-bit operands
val2
holds the second two 16-bit operands.

Return value

The __uhsub16 intrinsic returns:
  • The halved subtraction of the low halfword in the second operand from the low halfword in the first operand, in the low halfword of the return value.
  • The halved subtraction of the high halfword in the second operand from the high halfword in the first operand, in the high halfword of the return value.

Examples

unsigned int subtract_and_halve(unsigned int val1, unsigned int val2)
{
    unsigned int res;
    res = __uhsub16(val1,val2); /* res[15:0] = (val1[15:0] + val2[15:0]) >> 1
                                   res[31:16] = (val1[31:16] - val2[31:16]) >> 1
                                 */
    return res;
}
Related reference
9.143 ARMv6 SIMD intrinsics
Related information
UHSUB16
ARM and Thumb instruction summary
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