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-rw-r--r--src/devices/cpu/rsp/vcl.h65
1 files changed, 65 insertions, 0 deletions
diff --git a/src/devices/cpu/rsp/vcl.h b/src/devices/cpu/rsp/vcl.h
new file mode 100644
index 00000000000..e09a13d5a8e
--- /dev/null
+++ b/src/devices/cpu/rsp/vcl.h
@@ -0,0 +1,65 @@
+// license:BSD-3-Clause
+// copyright-holders:Tyler J. Stachecki,Ryan Holtz
+
+inline rsp_vec_t vec_vcl(rsp_vec_t vs, rsp_vec_t vt, rsp_vec_t zero, rsp_vec_t *ge, rsp_vec_t *le, rsp_vec_t eq, rsp_vec_t sign, rsp_vec_t vce)
+{
+ // sign_negvt = sign ? -vt : vt
+ rsp_vec_t sign_negvt = _mm_xor_si128(vt, sign);
+ sign_negvt = _mm_sub_epi16(sign_negvt, sign);
+
+ // Compute diff, diff_zero, ncarry, and nvce:
+ // Note: diff = sign ? (vs + vt) : (vs - vt).
+ rsp_vec_t diff = _mm_sub_epi16(vs, sign_negvt);
+ rsp_vec_t ncarry = _mm_adds_epu16(vs, vt);
+ ncarry = _mm_cmpeq_epi16(diff, ncarry);
+ rsp_vec_t nvce = _mm_cmpeq_epi16(vce, zero);
+ rsp_vec_t diff_zero = _mm_cmpeq_epi16(diff, zero);
+
+ // Compute results for if (sign && ne):
+ rsp_vec_t le_case1 = _mm_and_si128(diff_zero, ncarry);
+ le_case1 = _mm_and_si128(nvce, le_case1);
+ rsp_vec_t le_case2 = _mm_or_si128(diff_zero, ncarry);
+ le_case2 = _mm_and_si128(vce, le_case2);
+ rsp_vec_t le_eq = _mm_or_si128(le_case1, le_case2);
+
+ // Compute results for if (!sign && ne):
+ rsp_vec_t ge_eq = _mm_subs_epu16(vt, vs);
+ ge_eq = _mm_cmpeq_epi16(ge_eq, zero);
+
+ // Blend everything together. Caveat: we don't update
+ // the results of ge/le if ne is false, so be careful.
+ rsp_vec_t do_le = _mm_andnot_si128(eq, sign);
+#if (defined(__SSE4_1__) || defined(_MSC_VER))
+ *le = _mm_blendv_epi8(*le, le_eq, do_le);
+#else
+ le_eq = _mm_and_si128(do_le, le_eq);
+ *le = _mm_andnot_si128(do_le, *le);
+ *le = _mm_or_si128(le_eq, *le);
+#endif
+
+ rsp_vec_t do_ge = _mm_or_si128(sign, eq);
+#if (defined(__SSE4_1__) || defined(_MSC_VER))
+ *ge = _mm_blendv_epi8(ge_eq, *ge, do_ge);
+#else
+ *ge = _mm_and_si128(do_ge, *ge);
+ ge_eq = _mm_andnot_si128(do_ge, ge_eq);
+ *ge = _mm_or_si128(ge_eq, *ge);
+#endif
+
+ // Mux the result based on the value of sign.
+#if (defined(__SSE4_1__) || defined(_MSC_VER))
+ rsp_vec_t mux_mask = _mm_blendv_epi8(*ge, *le, sign);
+#else
+ do_le = _mm_and_si128(sign, *le);
+ do_ge = _mm_andnot_si128(sign, *ge);
+ rsp_vec_t mux_mask = _mm_or_si128(do_le, do_ge);
+#endif
+
+#if (defined(__SSE4_1__) || defined(_MSC_VER))
+ return _mm_blendv_epi8(vs, sign_negvt, mux_mask);
+#else
+ sign_negvt = _mm_and_si128(mux_mask, sign_negvt);
+ vs = _mm_andnot_si128(mux_mask, vs);
+ return _mm_or_si128(sign_negvt, vs);
+#endif
+}