target/arm: Implement bfloat16 matrix multiply accumulate

This is BFMMLA for both AArch64 AdvSIMD and SVE,
and VMMLA.BF16 for AArch32 NEON.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525225817.400336-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 41 insertions, 1 deletions

diff --git a/target/arm/vec_helper.c b/target/arm/vec_helper.c
index 74a497f38c..27e9bdd329 100644
--- a/target/arm/vec_helper.c
+++ b/target/arm/vec_helper.c
@@ -2385,7 +2385,7 @@ static void do_mmla_b(void *vd, void *vn, void *vm, void *va, uint32_t desc,
          * Process the entire segment at once, writing back the
          * results only after we've consumed all of the inputs.
          *
-         * Key to indicies by column:
+         * Key to indices by column:
          *          i   j                  i             j
          */
         sum0 = a[H4(0 + 0)];
@@ -2472,3 +2472,43 @@ void HELPER(gvec_bfdot_idx)(void *vd, void *vn, void *vm,
     }
     clear_tail(d, opr_sz, simd_maxsz(desc));
 }
+
+void HELPER(gvec_bfmmla)(void *vd, void *vn, void *vm, void *va, uint32_t desc)
+{
+    intptr_t s, opr_sz = simd_oprsz(desc);
+    float32 *d = vd, *a = va;
+    uint32_t *n = vn, *m = vm;
+
+    for (s = 0; s < opr_sz / 4; s += 4) {
+        float32 sum00, sum01, sum10, sum11;
+
+        /*
+         * Process the entire segment at once, writing back the
+         * results only after we've consumed all of the inputs.
+         *
+         * Key to indicies by column:
+         *               i   j           i   k             j   k
+         */
+        sum00 = a[s + H4(0 + 0)];
+        sum00 = bfdotadd(sum00, n[s + H4(0 + 0)], m[s + H4(0 + 0)]);
+        sum00 = bfdotadd(sum00, n[s + H4(0 + 1)], m[s + H4(0 + 1)]);
+
+        sum01 = a[s + H4(0 + 1)];
+        sum01 = bfdotadd(sum01, n[s + H4(0 + 0)], m[s + H4(2 + 0)]);
+        sum01 = bfdotadd(sum01, n[s + H4(0 + 1)], m[s + H4(2 + 1)]);
+
+        sum10 = a[s + H4(2 + 0)];
+        sum10 = bfdotadd(sum10, n[s + H4(2 + 0)], m[s + H4(0 + 0)]);
+        sum10 = bfdotadd(sum10, n[s + H4(2 + 1)], m[s + H4(0 + 1)]);
+
+        sum11 = a[s + H4(2 + 1)];
+        sum11 = bfdotadd(sum11, n[s + H4(2 + 0)], m[s + H4(2 + 0)]);
+        sum11 = bfdotadd(sum11, n[s + H4(2 + 1)], m[s + H4(2 + 1)]);
+
+        d[s + H4(0 + 0)] = sum00;
+        d[s + H4(0 + 1)] = sum01;
+        d[s + H4(2 + 0)] = sum10;
+        d[s + H4(2 + 1)] = sum11;
+    }
+    clear_tail(d, opr_sz, simd_maxsz(desc));
+}