target/arm: Introduce fp_access_check_scalar_hsd

Provide a simple way to check for float64, float32,
and float16 support, as well as the fpu enabled.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 32 insertions, 30 deletions

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 9c6365f..4e47b8a 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -1240,6 +1240,27 @@ static bool fp_access_check(DisasContext *s)
 }
 
 /*
+ * Return <0 for non-supported element sizes, with MO_16 controlled by
+ * FEAT_FP16; return 0 for fp disabled; otherwise return >0 for success.
+ */
+static int fp_access_check_scalar_hsd(DisasContext *s, MemOp esz)
+{
+    switch (esz) {
+    case MO_64:
+    case MO_32:
+        break;
+    case MO_16:
+        if (!dc_isar_feature(aa64_fp16, s)) {
+            return -1;
+        }
+        break;
+    default:
+        return -1;
+    }
+    return fp_access_check(s);
+}
+
+/*
  * Check that SVE access is enabled.  If it is, return true.
  * If not, emit code to generate an appropriate exception and return false.
  * This function corresponds to CheckSVEEnabled().
@@ -6628,22 +6649,10 @@ static bool trans_FCSEL(DisasContext *s, arg_FCSEL *a)
 {
     TCGv_i64 t_true, t_false;
     DisasCompare64 c;
+    int check = fp_access_check_scalar_hsd(s, a->esz);
 
-    switch (a->esz) {
-    case MO_32:
-    case MO_64:
-        break;
-    case MO_16:
-        if (!dc_isar_feature(aa64_fp16, s)) {
-            return false;
-        }
-        break;
-    default:
-        return false;
-    }
-
-    if (!fp_access_check(s)) {
-        return true;
+    if (check <= 0) {
+        return check == 0;
     }
 
     /* Zero extend sreg & hreg inputs to 64 bits now.  */
@@ -6894,22 +6903,15 @@ TRANS(FMINV_s, do_fp_reduction, a, gen_helper_vfp_mins)
 
 static bool trans_FMOVI_s(DisasContext *s, arg_FMOVI_s *a)
 {
-    switch (a->esz) {
-    case MO_32:
-    case MO_64:
-        break;
-    case MO_16:
-        if (!dc_isar_feature(aa64_fp16, s)) {
-            return false;
-        }
-        break;
-    default:
-        return false;
-    }
-    if (fp_access_check(s)) {
-        uint64_t imm = vfp_expand_imm(a->esz, a->imm);
-        write_fp_dreg(s, a->rd, tcg_constant_i64(imm));
+    int check = fp_access_check_scalar_hsd(s, a->esz);
+    uint64_t imm;
+
+    if (check <= 0) {
+        return check == 0;
     }
+
+    imm = vfp_expand_imm(a->esz, a->imm);
+    write_fp_dreg(s, a->rd, tcg_constant_i64(imm));
     return true;
 }