[PATCH 34/76] target/arm: Use FPST_FPCR_AH for BFCVT* insns

[Peter Maydell]

When FPCR.AH is 1, use FPST_FPCR_AH for:
 * AdvSIMD BFCVT, BFCVTN, BFCVTN2
 * SVE BFCVT, BFCVTNT

so that they get the required behaviour changes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/tcg/translate-a64.c | 27 +++++++++++++++++++++------
 target/arm/tcg/translate-sve.c |  6 ++++--
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 2a0c5e23e74..d53864ad794 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -8514,7 +8514,7 @@ TRANS(FRINTX_s, do_fp1_scalar, a, &f_scalar_frintx, -1)
 static const FPScalar1 f_scalar_bfcvt = {
     .gen_s = gen_helper_bfcvt,
 };
-TRANS_FEAT(BFCVT_s, aa64_bf16, do_fp1_scalar, a, &f_scalar_bfcvt, -1)
+TRANS_FEAT(BFCVT_s, aa64_bf16, do_fp1_scalar_ah, a, &f_scalar_bfcvt, -1)
 
 static const FPScalar1 f_scalar_frint32 = {
     NULL,
@@ -9290,12 +9290,27 @@ static void gen_bfcvtn_hs(TCGv_i64 d, TCGv_i64 n)
     tcg_gen_extu_i32_i64(d, tmp);
 }
 
-static ArithOneOp * const f_vector_bfcvtn[] = {
-    NULL,
-    gen_bfcvtn_hs,
-    NULL,
+static void gen_bfcvtn_ah_hs(TCGv_i64 d, TCGv_i64 n)
+{
+    TCGv_ptr fpst = fpstatus_ptr(FPST_FPCR_AH);
+    TCGv_i32 tmp = tcg_temp_new_i32();
+    gen_helper_bfcvt_pair(tmp, n, fpst);
+    tcg_gen_extu_i32_i64(d, tmp);
+}
+
+static ArithOneOp * const f_vector_bfcvtn[2][3] = {
+    {
+        NULL,
+        gen_bfcvtn_hs,
+        NULL,
+    }, {
+        NULL,
+        gen_bfcvtn_ah_hs,
+        NULL,
+    }
 };
-TRANS_FEAT(BFCVTN_v, aa64_bf16, do_2misc_narrow_vector, a, f_vector_bfcvtn)
+TRANS_FEAT(BFCVTN_v, aa64_bf16, do_2misc_narrow_vector, a,
+           f_vector_bfcvtn[s->fpcr_ah])
 
 static bool trans_SHLL_v(DisasContext *s, arg_qrr_e *a)
 {
diff --git a/target/arm/tcg/translate-sve.c b/target/arm/tcg/translate-sve.c
index 8ed8677baa8..4d77b55d545 100644
--- a/target/arm/tcg/translate-sve.c
+++ b/target/arm/tcg/translate-sve.c
@@ -3904,7 +3904,8 @@ TRANS_FEAT(FCVT_hs, aa64_sve, gen_gvec_fpst_arg_zpz,
            gen_helper_sve_fcvt_hs, a, 0, FPST_FPCR_F16_A64)
 
 TRANS_FEAT(BFCVT, aa64_sve_bf16, gen_gvec_fpst_arg_zpz,
-           gen_helper_sve_bfcvt, a, 0, FPST_FPCR_A64)
+           gen_helper_sve_bfcvt, a, 0,
+           s->fpcr_ah ? FPST_FPCR_AH : FPST_FPCR_A64)
 
 TRANS_FEAT(FCVT_dh, aa64_sve, gen_gvec_fpst_arg_zpz,
            gen_helper_sve_fcvt_dh, a, 0, FPST_FPCR_A64)
@@ -7054,7 +7055,8 @@ TRANS_FEAT(FCVTNT_ds, aa64_sve2, gen_gvec_fpst_arg_zpz,
            gen_helper_sve2_fcvtnt_ds, a, 0, FPST_FPCR_A64)
 
 TRANS_FEAT(BFCVTNT, aa64_sve_bf16, gen_gvec_fpst_arg_zpz,
-           gen_helper_sve_bfcvtnt, a, 0, FPST_FPCR_A64)
+           gen_helper_sve_bfcvtnt, a, 0,
+           s->fpcr_ah ? FPST_FPCR_AH : FPST_FPCR_A64)
 
 TRANS_FEAT(FCVTLT_hs, aa64_sve2, gen_gvec_fpst_arg_zpz,
            gen_helper_sve2_fcvtlt_hs, a, 0, FPST_FPCR_A64)
-- 
2.34.1