[PR68432 16/22] Use code,alternative attributes for nds32

[Richard Sandiford]

Tested as described in the covering note.  I plan to commit this as obvious
if the prerequisites are approved.

gcc/
        * config/nds32/nds32.md (is_16bit): Turn into a code,alternative
        attribute.
        (enabled): Likewise.

diff --git a/gcc/config/nds32/nds32.md b/gcc/config/nds32/nds32.md
index 89c0391..dbe2a2d 100644
--- a/gcc/config/nds32/nds32.md
+++ b/gcc/config/nds32/nds32.md
@@ -57,7 +57,7 @@
 
 
 ;; True if the instruction requires TARGET_16_BIT.
-(define_attr "is_16bit" "no,yes" (const_string "no"))
+(define_attr "is_16bit" "no,yes" (const_string "no") "code,alternative")
 
 
 ;; Length, in bytes, default is 4-bytes.
@@ -76,7 +76,8 @@
   (cond [(and (eq_attr "is_16bit" "yes")
              (match_test "!TARGET_16_BIT"))
         (const_int 0)]
-       (const_int 1)))
+       (const_int 1))
+  "code,alternative")
 
 
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