blob: 33b21fd7312881810a3ede91b6ced323e465308d (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
// license:BSD-3-Clause
// copyright-holders:Tyler J. Stachecki,Ryan Holtz
inline rsp_vec_t vec_vadd(rsp_vec_t vs, rsp_vec_t vt, rsp_vec_t carry, rsp_vec_t *acc_lo)
{
// VCC uses unsaturated arithmetic.
rsp_vec_t vd = _mm_add_epi16(vs, vt);
*acc_lo = _mm_sub_epi16(vd, carry);
// VD is the signed sum of the two sources and the carry. Since we
// have to saturate the sum of all three, we have to be clever.
rsp_vec_t minimum = _mm_min_epi16(vs, vt);
rsp_vec_t maximum = _mm_max_epi16(vs, vt);
minimum = _mm_subs_epi16(minimum, carry);
return _mm_adds_epi16(minimum, maximum);
}
|