[PATCH v1 08/11] target/arm: Implement bfloat16 matrix multiply accumulate

[Richard Henderson]

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

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.h             |  3 +++
 target/arm/neon-shared.decode   |  2 ++
 target/arm/sve.decode           |  6 +++--
 target/arm/translate-a64.c      | 10 +++++++++
 target/arm/translate-sve.c      | 12 ++++++++++
 target/arm/vec_helper.c         | 40 +++++++++++++++++++++++++++++++++
 target/arm/translate-neon.c.inc |  9 ++++++++
 7 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/target/arm/helper.h b/target/arm/helper.h
index af0ee8f693..74f8bc766f 100644
--- a/target/arm/helper.h
+++ b/target/arm/helper.h
@@ -1008,6 +1008,9 @@ DEF_HELPER_FLAGS_5(gvec_bfdot, TCG_CALL_NO_RWG,
 DEF_HELPER_FLAGS_5(gvec_bfdot_idx, TCG_CALL_NO_RWG,
                    void, ptr, ptr, ptr, ptr, i32)
 
+DEF_HELPER_FLAGS_5(gvec_bfmmla, TCG_CALL_NO_RWG,
+                   void, ptr, ptr, ptr, ptr, i32)
+
 #ifdef TARGET_AARCH64
 #include "helper-a64.h"
 #include "helper-sve.h"
diff --git a/target/arm/neon-shared.decode b/target/arm/neon-shared.decode
index fa3cf14e3a..4e0a25d27c 100644
--- a/target/arm/neon-shared.decode
+++ b/target/arm/neon-shared.decode
@@ -67,6 +67,8 @@ VUMMLA         1111 1100 0.10 .... .... 1100 .1.1 .... \
                vm=%vm_dp vn=%vn_dp vd=%vd_dp
 VUSMMLA        1111 1100 1.10 .... .... 1100 .1.0 .... \
                vm=%vm_dp vn=%vn_dp vd=%vd_dp
+VMMLA_b16      1111 1100 0.00 .... .... 1100 .1.0 .... \
+               vm=%vm_dp vn=%vn_dp vd=%vd_dp
 
 VCMLA_scalar   1111 1110 0 . rot:2 .... .... 1000 . q:1 index:1 0 vm:4 \
                vn=%vn_dp vd=%vd_dp size=1
diff --git a/target/arm/sve.decode b/target/arm/sve.decode
index d5e1e5d400..aa8d5e4b8f 100644
--- a/target/arm/sve.decode
+++ b/target/arm/sve.decode
@@ -1519,8 +1519,10 @@ SQRDCMLAH_zzzz  01000100 esz:2 0 rm:5 0011 rot:2 rn:5 
rd:5  ra=%reg_movprfx
 USDOT_zzzz      01000100 .. 0 ..... 011 110 ..... .....  @rda_rn_rm
 
 ### SVE2 floating point matrix multiply accumulate
-
-FMMLA           01100100 .. 1 ..... 111001 ..... .....  @rda_rn_rm
+{
+  BFMMLA        01100100 01 1 ..... 111 001 ..... .....  @rda_rn_rm_e0
+  FMMLA         01100100 .. 1 ..... 111 001 ..... .....  @rda_rn_rm
+}
 
 ### SVE2 Memory Gather Load Group
 
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index f60afbbd06..8636eac4a8 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -12243,6 +12243,13 @@ static void 
disas_simd_three_reg_same_extra(DisasContext *s, uint32_t insn)
         }
         feature = dc_isar_feature(aa64_fcma, s);
         break;
+    case 0x1d: /* BFMMLA */
+        if (size != MO_16 || !is_q) {
+            unallocated_encoding(s);
+            return;
+        }
+        feature = dc_isar_feature(aa64_bf16, s);
+        break;
     case 0x1f: /* BFDOT */
         switch (size) {
         case 1:
@@ -12336,6 +12343,9 @@ static void 
disas_simd_three_reg_same_extra(DisasContext *s, uint32_t insn)
         }
         return;
 
+    case 0xd: /* BFMMLA */
+        gen_gvec_op4_ool(s, is_q, rd, rn, rm, rd, 0, gen_helper_gvec_bfmmla);
+        return;
     case 0xf: /* BFDOT */
         switch (size) {
         case 1:
diff --git a/target/arm/translate-sve.c b/target/arm/translate-sve.c
index ef6828c632..9ade521705 100644
--- a/target/arm/translate-sve.c
+++ b/target/arm/translate-sve.c
@@ -8610,3 +8610,15 @@ static bool trans_BFDOT_zzxz(DisasContext *s, 
arg_rrxr_esz *a)
     }
     return true;
 }
+
+static bool trans_BFMMLA(DisasContext *s, arg_rrrr_esz *a)
+{
+    if (!dc_isar_feature(aa64_sve_bf16, s)) {
+        return false;
+    }
+    if (sve_access_check(s)) {
+        gen_gvec_ool_zzzz(s, gen_helper_gvec_bfmmla,
+                          a->rd, a->rn, a->rm, a->ra, 0);
+    }
+    return true;
+}
diff --git a/target/arm/vec_helper.c b/target/arm/vec_helper.c
index 3e26fb0e5f..623a0872f3 100644
--- a/target/arm/vec_helper.c
+++ b/target/arm/vec_helper.c
@@ -2715,3 +2715,43 @@ 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));
+}
diff --git a/target/arm/translate-neon.c.inc b/target/arm/translate-neon.c.inc
index bb0adf4756..7ce65f691f 100644
--- a/target/arm/translate-neon.c.inc
+++ b/target/arm/translate-neon.c.inc
@@ -4117,3 +4117,12 @@ static bool trans_VUSMMLA(DisasContext *s, arg_VUSMMLA 
*a)
     return do_neon_ddda(s, 7, a->vd, a->vn, a->vm, 0,
                         gen_helper_gvec_usmmla_b);
 }
+
+static bool trans_VMMLA_b16(DisasContext *s, arg_VMMLA_b16 *a)
+{
+    if (!dc_isar_feature(aa32_bf16, s)) {
+        return false;
+    }
+    return do_neon_ddda(s, 7, a->vd, a->vn, a->vm, 0,
+                        gen_helper_gvec_bfmmla);
+}
-- 
2.25.1