target/arm: Implement bfloat16 dot product (indexed)

This is BFDOT for both AArch64 AdvSIMD and SVE,
and VDOT.BF16 for AArch32 NEON.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525225817.400336-8-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/target/arm/vec_helper.c b/target/arm/vec_helper.c
index 7eefcd06ea..74a497f38c 100644
--- a/target/arm/vec_helper.c
+++ b/target/arm/vec_helper.c
@@ -2452,3 +2452,23 @@ void HELPER(gvec_bfdot)(void *vd, void *vn, void *vm, void *va, uint32_t desc)
     }
     clear_tail(d, opr_sz, simd_maxsz(desc));
 }
+
+void HELPER(gvec_bfdot_idx)(void *vd, void *vn, void *vm,
+                            void *va, uint32_t desc)
+{
+    intptr_t i, j, opr_sz = simd_oprsz(desc);
+    intptr_t index = simd_data(desc);
+    intptr_t elements = opr_sz / 4;
+    intptr_t eltspersegment = MIN(16 / 4, elements);
+    float32 *d = vd, *a = va;
+    uint32_t *n = vn, *m = vm;
+
+    for (i = 0; i < elements; i += eltspersegment) {
+        uint32_t m_idx = m[i + H4(index)];
+
+        for (j = i; j < i + eltspersegment; j++) {
+            d[j] = bfdotadd(a[j], n[j], m_idx);
+        }
+    }
+    clear_tail(d, opr_sz, simd_maxsz(desc));
+}