12.17 __shasx intrinsic
This intrinsic inserts a
SHASX instruction into the instruction stream generated by the compiler.
you to exchange the two halfwords of one operand, perform one signed
16-bit integer addition and one signed 16-bit subtraction, and halve
unsigned int __shasx(unsigned int
, unsigned int
holds the first halfword operands
holds the second halfword operands.
__shasx intrinsic returns:
The halved subtraction of the high halfword in the
second operand from the low halfword in the first operand, in the
low halfword of the return value.
The halved subtraction of the low halfword in the
second operand from the high halfword in the first operand, in the
high halfword of the return value.
unsigned int exchange_add_subtract_halve(unsigned int val1, unsigned int val2)
unsigned int res;
res = __shasx(val1,val2); /* res[15:0] = (val1[15:0] - val2[31:16]) >> 1
res[31:16] = (val1[31:16] - val2[15:0]) >> 1