target/arm: Improve arm_rmode_to_sf

Use proper enumeration types for input and output.
Use a const array to perform the mapping, with an
assert that the input is valid.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

3 files changed, 18 insertions, 29 deletions

diff --git a/target/arm/internals.h b/target/arm/internals.h
index b1ef059..673519a 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -193,16 +193,22 @@ void arm_restore_state_to_opc(CPUState *cs,
 void arm_cpu_synchronize_from_tb(CPUState *cs, const TranslationBlock *tb);
 #endif /* CONFIG_TCG */
 
-enum arm_fprounding {
+typedef enum ARMFPRounding {
     FPROUNDING_TIEEVEN,
     FPROUNDING_POSINF,
     FPROUNDING_NEGINF,
     FPROUNDING_ZERO,
     FPROUNDING_TIEAWAY,
     FPROUNDING_ODD
-};
+} ARMFPRounding;
+
+extern const FloatRoundMode arm_rmode_to_sf_map[6];
 
-int arm_rmode_to_sf(int rmode);
+static inline FloatRoundMode arm_rmode_to_sf(ARMFPRounding rmode)
+{
+    assert((unsigned)rmode < ARRAY_SIZE(arm_rmode_to_sf_map));
+    return arm_rmode_to_sf_map[rmode];
+}
 
 static inline void aarch64_save_sp(CPUARMState *env, int el)
 {
diff --git a/target/arm/tcg/translate-mve.c b/target/arm/tcg/translate-mve.c
index 798b4fd..9744bf3 100644
--- a/target/arm/tcg/translate-mve.c
+++ b/target/arm/tcg/translate-mve.c
@@ -588,7 +588,7 @@ DO_VCVT(VCVT_FS, vcvt_hs, vcvt_fs)
 DO_VCVT(VCVT_FU, vcvt_hu, vcvt_fu)
 
 static bool do_vcvt_rmode(DisasContext *s, arg_1op *a,
-                          enum arm_fprounding rmode, bool u)
+                          ARMFPRounding rmode, bool u)
 {
     /*
      * Handle VCVT fp to int with specified rounding mode.
diff --git a/target/arm/vfp_helper.c b/target/arm/vfp_helper.c
index 90cc324..36906db 100644
--- a/target/arm/vfp_helper.c
+++ b/target/arm/vfp_helper.c
@@ -1104,31 +1104,14 @@ float64 HELPER(rintd)(float64 x, void *fp_status)
 }
 
 /* Convert ARM rounding mode to softfloat */
-int arm_rmode_to_sf(int rmode)
-{
-    switch (rmode) {
-    case FPROUNDING_TIEAWAY:
-        rmode = float_round_ties_away;
-        break;
-    case FPROUNDING_ODD:
-        rmode = float_round_to_odd;
-        break;
-    case FPROUNDING_TIEEVEN:
-    default:
-        rmode = float_round_nearest_even;
-        break;
-    case FPROUNDING_POSINF:
-        rmode = float_round_up;
-        break;
-    case FPROUNDING_NEGINF:
-        rmode = float_round_down;
-        break;
-    case FPROUNDING_ZERO:
-        rmode = float_round_to_zero;
-        break;
-    }
-    return rmode;
-}
+const FloatRoundMode arm_rmode_to_sf_map[] = {
+    [FPROUNDING_TIEEVEN] = float_round_nearest_even,
+    [FPROUNDING_POSINF] = float_round_up,
+    [FPROUNDING_NEGINF] = float_round_down,
+    [FPROUNDING_ZERO] = float_round_to_zero,
+    [FPROUNDING_TIEAWAY] = float_round_ties_away,
+    [FPROUNDING_ODD] = float_round_to_odd,
+};
 
 /*
  * Implement float64 to int32_t conversion without saturation;