Compiler Reference Guide

__uadd8 intrinsic

ARM Compiler toolchain v5.02 for µVision Compiler Reference

Home > ARMv6 SIMD Instruction Intrinsics > __uadd8 intrinsic

`__uadd8` intrinsic

This intrinsic inserts a UADD8 instruction into the instruction stream generated by the compiler. It enables you to perform four unsigned 8-bit integer additions.

The GE bits in the APSR are set according to the results.

unsigned int __uadd8(unsigned int val1, unsigned int val2)

where:

val1: holds the first four 8-bit summands for each addition
val2: holds the second four 8-bit summands for each addition.

The __uadd8 intrinsic returns:

the addition of the first bytes in each operand, in the first byte of the return value
the addition of the second bytes in each operand, in the second byte of the return value
the addition of the third bytes in each operand, in the third byte of the return value
the addition of the fourth bytes in each operand, in the fourth byte of the return value.

Each bit in APSR.GE is set or cleared for each byte in the return value, depending on the results of the operation. If res is the return value, then:

if res[7:0] ≥ 0x100 then APSR.GE[0] = 1 else 0
if res[15:8] ≥ 0x100 then APSR.GE[1] = 1 else 0
if res[23:16] ≥ 0x100 then APSR.GE[2] = 1 else 0
if res[31:24] ≥ 0x100 then APSR.GE[3] = 1 else 0.

Example:

unsigned int add_bytes(unsigned int val1, unsigned int val2)
{
  unsigned int res;

    res = __uadd8(val1,val2); /* res[7:0] = val1[7:0] + val2[7:0]
                                 res[15:8] = val1[15:8] + val2[15:8]
                                 res[23:16] = val1[23:16] + val2[23:16]
                                 res[31:24] = val1[31:24] + val2[31:24]
                               */
    return res;
}

Compiler Reference Guide

__uadd8 intrinsic

`__uadd8` intrinsic

See also

Products

Development Tools

Hardware & Collateral

Downloads

Support

Contact

Important information