[compiler-rt] [builtins] Fix name of __aarch64_have_lse_atomics on Darwin

[sberg]

Summary

...where the name of that variable defined in
compiler-rt/lib/builtins/cpu_model.c is decorated with a leading underscore

[tambre]

The one in cpu_model.c has 2 underscores. Where do the three come from for non-Apple?

[sberg]

In D93390#2457554, @tambre wrote:

The one in cpu_model.c has 2 underscores. Where do the three come from for non-Apple?

It's the other way around, the third underscore is for Apple only, where C symbols are generally decorated with a leading underscore.

[ilinpv]

Thanks for fixing this.

compiler-rt/lib/builtins/aarch64/lse.S

 #ifdef __aarch64__
 
 #ifdef HAS_ASM_LSE
 .arch armv8-a+lse
 #else
 .arch armv8-a
 #endif
 
+#if !defined(__APPLE__)
 HIDDEN(__aarch64_have_lse_atomics)
+#else
+HIDDEN(___aarch64_have_lse_atomics)
+#endif
 
 // Generate mnemonics for
 // L_cas:                                 SIZE: 1,2,4,8,16 MODEL: 1,2,3,4
 // L_swp L_ldadd L_ldclr L_ldeor L_ldset: SIZE: 1,2,4,8    MODEL: 1,2,3,4
 
 #if SIZE == 1
 #define S b
 #define UXT uxtb

 #define tmp2 15
 
 // Macro for branch to label if no LSE available
 .macro JUMP_IF_NOT_LSE label
 #if !defined(__APPLE__)
         adrp    x(tmp0), __aarch64_have_lse_atomics
         ldrb    w(tmp0), [x(tmp0), :lo12:__aarch64_have_lse_atomics]
 #else
-        adrp    x(tmp0), __aarch64_have_lse_atomics@page
-        ldrb    w(tmp0), [x(tmp0), __aarch64_have_lse_atomics@pageoff]
+        adrp    x(tmp0), ___aarch64_have_lse_atomics@page
+        ldrb    w(tmp0), [x(tmp0), ___aarch64_have_lse_atomics@pageoff]
 #endif
         cbz     w(tmp0), \label
 .endm
 
 #ifdef L_cas
 DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(NAME(cas))
         JUMP_IF_NOT_LSE 8f
 #if SIZE < 16