[gcc r16-5154] LoongArch: Implement TARGET_COMPARE_VERSION_PRIORITY.

[LuluCheng]

https://gcc.gnu.org/g:8e4d9013007d160b51f6026b4b3e3b8220f2f683

commit r16-5154-g8e4d9013007d160b51f6026b4b3e3b8220f2f683
Author: Lulu Cheng <chenglulu@loongson.cn>
Date:   Wed Oct 15 16:51:21 2025 +0800

    LoongArch: Implement TARGET_COMPARE_VERSION_PRIORITY.
    
    gcc/ChangeLog:
    
            * config/loongarch/loongarch.cc
            (loongarch_compare_version_priority): Returns true if DECL1
            and DECL2 are versions of the same function.
            (TARGET_COMPARE_VERSION_PRIORITY): Define.

Diff:
---
 gcc/config/loongarch/loongarch.cc | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index edec88136554..a700e177dc86 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -12013,6 +12013,23 @@ loongarch_generate_version_dispatcher_body (void *node_p)
   return resolver_decl;
 }
 
+/* Compare priorities of two version decls. Return:
+    1: decl1 has a higher priority
+   -1: decl2 has a higher priority
+    0: decl1 and decl2 have the same priority.
+*/
+
+int
+loongarch_compare_version_priority (tree decl1, tree decl2)
+{
+  unsigned int prio1, prio2;
+  get_feature_mask_for_version (decl1, NULL, &prio1);
+  get_feature_mask_for_version (decl2, NULL, &prio2);
+
+  return prio1 == prio2 ? 0
+    : prio1 > prio2 ? 1 : -1;
+}
+
 /* Initialize the GCC target structure.  */
 #undef TARGET_ASM_ALIGNED_HI_OP
 #define TARGET_ASM_ALIGNED_HI_OP "\t.half\t"
@@ -12316,6 +12333,10 @@ loongarch_generate_version_dispatcher_body (void *node_p)
 #define TARGET_GENERATE_VERSION_DISPATCHER_BODY \
   loongarch_generate_version_dispatcher_body
 
+#undef TARGET_COMPARE_VERSION_PRIORITY
+#define TARGET_COMPARE_VERSION_PRIORITY \
+  loongarch_compare_version_priority
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-loongarch.h"