Mark __assert_fail as _Noreturn.

This eliminates a performance regression caused in the box2d benchmark by switching to the musl headers. Without this being _Noreturn, clang / llvm generates much worse code involving phis and extra loads.
wsmind · Sep 24, 2013 · baa4d38 · baa4d38
1 parent 4db5a7e
commit baa4d38
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diff --git a/system/include/libc/assert.h b/system/include/libc/assert.h
@@ -12,7 +12,7 @@
 extern "C" {
 #endif
 
-void __assert_fail (const char *, const char *, int, const char *);
+_Noreturn void __assert_fail (const char *, const char *, int, const char *);
 
 #ifdef __cplusplus
 }

diff --git a/system/lib/libc/musl/readme.txt b/system/lib/libc/musl/readme.txt
@@ -6,3 +6,4 @@ Differences from upstream musl include:
 * various 64 bit types are 32 bit instead including off_t,
   ino_t, dev_t, blkcnt_t, fsblkcnt_t, fsfilcnt_t, rlim_t.
 * We don't define _POSIX_SHARED_MEMORY_OBJECTS.
+* We flag __assert_fail as _Noreturn.