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-rw-r--r--src/emu/cpu/rsp/vmac.h57
1 files changed, 57 insertions, 0 deletions
diff --git a/src/emu/cpu/rsp/vmac.h b/src/emu/cpu/rsp/vmac.h
new file mode 100644
index 00000000000..ecf921a261c
--- /dev/null
+++ b/src/emu/cpu/rsp/vmac.h
@@ -0,0 +1,57 @@
+// license:BSD-3-Clause
+// copyright-holders:Tyler J. Stachecki,Ryan Holtz
+
+inline rsp_vec_t vec_vmacf_vmacu(UINT32 iw, rsp_vec_t vs, rsp_vec_t vt, rsp_vec_t zero, rsp_vec_t *acc_lo, rsp_vec_t *acc_mid, rsp_vec_t *acc_hi)
+{
+ // Get the product and shift it over
+ // being sure to save the carries.
+ rsp_vec_t lo = _mm_mullo_epi16(vs, vt);
+ rsp_vec_t hi = _mm_mulhi_epi16(vs, vt);
+
+ rsp_vec_t mid = _mm_slli_epi16(hi, 1);
+ rsp_vec_t carry = _mm_srli_epi16(lo, 15);
+ hi = _mm_srai_epi16(hi, 15);
+ mid = _mm_or_si128(mid, carry);
+ lo = _mm_slli_epi16(lo, 1);
+
+ // Tricky part: start accumulating everything.
+ // Get/keep the carry as we'll add it in later.
+ rsp_vec_t overflow_mask = _mm_adds_epu16(*acc_lo, lo);
+ *acc_lo = _mm_add_epi16(*acc_lo, lo);
+
+ overflow_mask = _mm_cmpeq_epi16(*acc_lo, overflow_mask);
+ overflow_mask = _mm_cmpeq_epi16(overflow_mask, zero);
+
+ // Add in the carry. If the middle portion is
+ // already 0xFFFF and we have a carry, we have
+ // to carry the all the way up to hi.
+ mid = _mm_sub_epi16(mid, overflow_mask);
+ carry = _mm_cmpeq_epi16(mid, zero);
+ carry = _mm_and_si128(carry, overflow_mask);
+ hi = _mm_sub_epi16(hi, carry);
+
+ // Accumulate the middle portion.
+ overflow_mask = _mm_adds_epu16(*acc_mid, mid);
+ *acc_mid = _mm_add_epi16(*acc_mid, mid);
+
+ overflow_mask = _mm_cmpeq_epi16(*acc_mid, overflow_mask);
+ overflow_mask = _mm_cmpeq_epi16(overflow_mask, zero);
+
+ // Finish up the accumulation of the... accumulator.
+ *acc_hi = _mm_add_epi16(*acc_hi, hi);
+ *acc_hi = _mm_sub_epi16(*acc_hi, overflow_mask);
+
+ if (iw & 0x1) // VMACU
+ {
+ rsp_vec_t overflow_hi_mask = _mm_srai_epi16(*acc_hi, 15);
+ rsp_vec_t overflow_mid_mask = _mm_srai_epi16(*acc_mid, 15);
+ mid = _mm_or_si128(overflow_mid_mask, *acc_mid);
+ overflow_mask = _mm_cmpgt_epi16(*acc_hi, zero);
+ mid = _mm_andnot_si128(overflow_hi_mask, mid);
+ return _mm_or_si128(overflow_mask, mid);
+ }
+ else // VMACF
+ {
+ return sclamp_acc_to_mid(*acc_mid, *acc_hi);
+ }
+}