RealView Compilation Tools - ARM Information Center

Compiler-specific Features
4.7.88 __uhadd8 intrinsic
This intrinsic inserts a UHADD8 instruction into the instruction stream generated by the
compiler. It enables you to perform four unsigned 8-bit integer additions, halving the
results.
unsigned int __uhadd8(unsigned int val1, unsigned int val2)
Where:
val1
val2
holds the first four 8-bit summands
holds the second four 8-bit summands.
The __uhadd8 intrinsic returns:
• the halved addition of the first bytes in each operand, in the first byte of the return
value
• the halved addition of the second bytes in each operand, in the second byte of the
return value
• the halved addition of the third bytes in each operand, in the third byte of the
return value
• the halved addition of the fourth bytes in each operand, in the fourth byte of the
return value.
Example:
unsigned int add_bytes_then halve(unsigned int val1, unsigned int val2)
{
unsigned int res;
}
res = __uhadd8(val1,val2); /* res[7:0] = (val1[7:0] + val2[7:0])