diff options
Diffstat (limited to 'src/emu/cpu/rsp/vcr.h')
-rw-r--r-- | src/emu/cpu/rsp/vcr.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/emu/cpu/rsp/vcr.h b/src/emu/cpu/rsp/vcr.h new file mode 100644 index 00000000000..78f78c66244 --- /dev/null +++ b/src/emu/cpu/rsp/vcr.h @@ -0,0 +1,35 @@ +// license:BSD-3-Clause +// copyright-holders:Tyler J. Stachecki,Ryan Holtz + +inline rsp_vec_t vec_vcr(rsp_vec_t vs, rsp_vec_t vt, rsp_vec_t zero, rsp_vec_t *ge, rsp_vec_t *le) { + // sign = (vs ^ vt) < 0 + rsp_vec_t sign = _mm_xor_si128(vs, vt); + sign = _mm_srai_epi16(sign, 15); + + // Compute le + rsp_vec_t diff_lez = _mm_and_si128(vs, sign); + diff_lez = _mm_add_epi16(diff_lez, vt); + *le = _mm_srai_epi16(diff_lez, 15); + + // Compute ge + rsp_vec_t diff_gez = _mm_or_si128(vs, sign); + diff_gez = _mm_min_epi16(diff_gez, vt); + *ge = _mm_cmpeq_epi16(diff_gez, vt); + + // sign_notvt = sn ? ~vt : vt + rsp_vec_t sign_notvt = _mm_xor_si128(vt, sign); + + // Compute result: +#if (defined(__SSE4_1__) || defined(_MSC_VER)) + rsp_vec_t diff_sel_mask = _mm_blendv_epi8(*ge, *le, sign); + return _mm_blendv_epi8(vs, sign_notvt, diff_sel_mask); +#else + rsp_vec_t diff_sel_mask = _mm_sub_epi16(*le, *ge); + diff_sel_mask = _mm_and_si128(diff_sel_mask, sign); + diff_sel_mask = _mm_add_epi16(diff_sel_mask, *ge); + + zero = _mm_sub_epi16(sign_notvt, vs); + zero = _mm_and_si128(zero, diff_sel_mask); + return _mm_add_epi16(zero, vs); +#endif +} |