runtime/lib/clear_cache.c

/* ===-- clear_cache.c - Implement __clear_cache ---------------------------===
 *
 *                     The LLVM Compiler Infrastructure
 *
 * This file is distributed under the University of Illinois Open Source
 * License. See LICENSE.TXT for details.
 *
 * ===----------------------------------------------------------------------===
 */

#include <stdlib.h>

#if __APPLE__
  #include <libkern/OSCacheControl.h>
#endif

/*
 * The compiler generates calls to __clear_cache() when creating 
 * trampoline functions on the stack for use with nested functions.
 * It is expected to invalidate the instruction cache for the 
 * specified range.
 */

void __clear_cache(void* start, void* end)
{
#if __i386__ || __x86_64__
/*
 * Intel processors have a unified instruction and data cache
 * so there is nothing to do
 */
#else
    #if __APPLE__
        /* On Darwin, sys_icache_invalidate() provides this functionality */
        sys_icache_invalidate(start, end-start);
    #else
        abort();
    #endif
#endif
}