target-arm: Give the FPSCR rounding modes names

When setting rounding modes we currently just hardcode the numeric values
for rounding modes in a big switch statement.

With AArch64 support coming, we will need to refer to these rounding modes
at different places throughout the code though, so let's better give them
names so we don't get confused by accident.

Signed-off-by: Alexander Graf <agraf@suse.de>
[WN: Commit message tweak, use names from ARM ARM.]
Signed-off-by: Will Newton <will.newton@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index 6c84e22..1a32907 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -487,6 +487,15 @@
     vfp_set_fpscr(env, new_fpscr);
 }
 
+enum arm_fprounding {
+    FPROUNDING_TIEEVEN,
+    FPROUNDING_POSINF,
+    FPROUNDING_NEGINF,
+    FPROUNDING_ZERO,
+    FPROUNDING_TIEAWAY,
+    FPROUNDING_ODD
+};
+
 enum arm_cpu_mode {
   ARM_CPU_MODE_USR = 0x10,
   ARM_CPU_MODE_FIQ = 0x11,
diff --git a/target-arm/helper.c b/target-arm/helper.c
index d1ed6b0..b157c55 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -3815,16 +3815,16 @@
     if (changed & (3 << 22)) {
         i = (val >> 22) & 3;
         switch (i) {
-        case 0:
+        case FPROUNDING_TIEEVEN:
             i = float_round_nearest_even;
             break;
-        case 1:
+        case FPROUNDING_POSINF:
             i = float_round_up;
             break;
-        case 2:
+        case FPROUNDING_NEGINF:
             i = float_round_down;
             break;
-        case 3:
+        case FPROUNDING_ZERO:
             i = float_round_to_zero;
             break;
         }