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Compiler-specific Features
4.7.50 __qadd16 intrinsic
This intrinsic inserts a QADD16 instruction into the instruction stream generated by the
compiler. It enables you to perform two 16-bit integer arithmetic additions in parallel,
saturating the results to the 16-bit signed integer range -2 15 ≤ x ≤ 2 15 - 1.
unsigned int __qadd16(unsigned int val1, unsigned int val2)
Where:
val1
val2
holds the first two 16-bit summands
holds the second two 16-bit summands.
The __qadd16 intrinsic returns:
• the saturated addition of the low halfwords in the low halfword of the return value
• the saturated addition of the high halfwords in the high halfword of the return
value.
The returned results are saturated to the 16-bit signed integer range -2 15 ≤ x ≤ 2 15 - 1.
Example:
unsigned int add_halfwords(unsigned int val1, unsigned int val2)
{
unsigned int res;
}
res = __qadd16(val1, val2); /* res[15:0] = val1[15:0] + val2[15:0]
res[16:31] = val1[31:16] + val2[31:16]
*/
return res;
See also
• ARMv6 SIMD intrinsics on page 4-109
• Instruction summary on page 4-2 in the Assembler Guide
• Saturating instructions on page 4-93 in the Assembler Guide
• QADD, QSUB, QDADD, and QDSUB on page 4-94 in the Assembler Guide.
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