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| Home > ARMv6 SIMD Instruction Intrinsics > __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 intval1, unsigned intval2)
Where:
val1holds the first four 8-bit summands for each addition
val2holds 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 is
the return value, then:res
if [7:0]
≥ 0x100 then APSR.GE[0] = 1 else 0res
if [15:8]
≥ 0x100 then APSR.GE[1] = 1 else 0res
if [23:16]
≥ 0x100 then APSR.GE[2] = 1 else 0res
if [31:24]
≥ 0x100 then APSR.GE[3] = 1 else 0.res
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;
}
Instruction summary in the Assembler Reference
Parallel add and subtract in the Assembler Reference.