target/arm: Implement scalar float32 to bfloat16 conversion

This is the 64-bit BFCVT and the 32-bit VCVT{B,T}.BF16.F32.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525225817.400336-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 95c2853f39..b335ca8735 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -6280,6 +6280,9 @@ static void handle_fp_1src_single(DisasContext *s, int opcode, int rd, int rn)
     case 0x3: /* FSQRT */
         gen_helper_vfp_sqrts(tcg_res, tcg_op, cpu_env);
         goto done;
+    case 0x6: /* BFCVT */
+        gen_fpst = gen_helper_bfcvt;
+        break;
     case 0x8: /* FRINTN */
     case 0x9: /* FRINTP */
     case 0xa: /* FRINTM */
@@ -6557,6 +6560,22 @@ static void disas_fp_1src(DisasContext *s, uint32_t insn)
         }
         break;
 
+    case 0x6:
+        switch (type) {
+        case 1: /* BFCVT */
+            if (!dc_isar_feature(aa64_bf16, s)) {
+                goto do_unallocated;
+            }
+            if (!fp_access_check(s)) {
+                return;
+            }
+            handle_fp_1src_single(s, opcode, rd, rn);
+            break;
+        default:
+            goto do_unallocated;
+        }
+        break;
+
     default:
     do_unallocated:
         unallocated_encoding(s);