[gcc(refs/vendors/ARM/heads/morello)] Use machine_mode enum values in switch cases

[gcc(refs/vendors/ARM/heads/morello)] Use machine_mode enum values in switch cases

[Matthew Malcomson]

https://gcc.gnu.org/g:4ffbe07f182bb39d35a578b5b42675f8c90f4c27

commit 4ffbe07f182bb39d35a578b5b42675f8c90f4c27
Author: Matthew Malcomson <matthew.malcomson@arm.com>
Date:   Fri Apr 8 16:25:42 2022 +0100

    Use machine_mode enum values in switch cases
    
    In `aarch64_split_atomic_op` we have a switch statement on a
    `machine_mode` value.  This switch statement has `case`s defined as
    `DImode` and `CADImode`.  These are macros defining a `scalar_int_mode`
    and `scalar_addr_mode` respectively.
    
    GCC 4.8 does not accept those classes as constant values that can be
    used in a case statement.  GCC prerequisites claim to build with GCC
    4.8.  Hence we can not use these classes in a case statement.
    
    Other switch statements on machine_mode's use the machine_mode enum
    values E_DImode and E_CADImode directly.  We update
    `aarch64_split_atomic_op` to follow that behaviour.  This allows
    building Morello GCC with GCC 4.8.

Diff:
---
 gcc/config/aarch64/aarch64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index a328e30db61..7fbc1970417 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -20899,11 +20899,11 @@ aarch64_split_atomic_op (enum rtx_code code, rtx old_out, rtx new_out, rtx mem,
   machine_mode arith_mode, subreg_mode;
   switch (mode)
     {
-      case DImode:
+      case E_DImode:
 	arith_mode = DImode;
 	subreg_mode = DImode;
 	break;
-      case CADImode:
+      case E_CADImode:
 	arith_mode = DImode;
 	subreg_mode = CADImode;
 	break;