12.52 __uqsub16 intrinsic

This intrinsic inserts a UQSUB16 instruction into the instruction stream generated by the compiler.

It enables you to perform two unsigned 16-bit integer subtractions, saturating the results to the 16-bit unsigned integer range 0 ≤ x ≤ 216 - 1.

Syntax

unsigned int __uqsub16(unsigned int val1, unsigned int val2)
Where:
val1
holds the first halfword operands for each subtraction
val2
holds the second halfword operands for each subtraction.

Return value

The __uqsub16 intrinsic returns:
  • The 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 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.
The results are saturated to the 16-bit unsigned integer range 0 ≤ x ≤ 216 - 1.

Examples

unsigned int subtract_halfwords(unsigned int val1, unsigned int val2)
{
    unsigned int res;
    res = __uqsub16(val1,val2); /* res[15:0] = val1[15:0] - val2[15:0]
                                   res[31:16] = val1[31:16] - val2[31:16]
                                */
    return res;
}
Related reference
9.143 ARMv6 SIMD intrinsics
Related information
UQSUB16
ARM and Thumb instruction summary
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