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, 24 insertions, 0 deletions

diff --git a/target/arm/translate-vfp.c b/target/arm/translate-vfp.c
index 2316e105ac..d01e465821 100644
--- a/target/arm/translate-vfp.c
+++ b/target/arm/translate-vfp.c
@@ -3085,6 +3085,30 @@ static bool trans_VCVT_f64_f16(DisasContext *s, arg_VCVT_f64_f16 *a)
     return true;
 }
 
+static bool trans_VCVT_b16_f32(DisasContext *s, arg_VCVT_b16_f32 *a)
+{
+    TCGv_ptr fpst;
+    TCGv_i32 tmp;
+
+    if (!dc_isar_feature(aa32_bf16, s)) {
+        return false;
+    }
+
+    if (!vfp_access_check(s)) {
+        return true;
+    }
+
+    fpst = fpstatus_ptr(FPST_FPCR);
+    tmp = tcg_temp_new_i32();
+
+    vfp_load_reg32(tmp, a->vm);
+    gen_helper_bfcvt(tmp, tmp, fpst);
+    tcg_gen_st16_i32(tmp, cpu_env, vfp_f16_offset(a->vd, a->t));
+    tcg_temp_free_ptr(fpst);
+    tcg_temp_free_i32(tmp);
+    return true;
+}
+
 static bool trans_VCVT_f16_f32(DisasContext *s, arg_VCVT_f16_f32 *a)
 {
     TCGv_ptr fpst;