Bug 1275204 - mozjemalloc: Use the JS arm64 allocator on Linux/sparc6…

…4. r=glandium

memory/mozjemalloc/jemalloc.c

@@ -2419,7 +2419,7 @@ static void *
 pages_map(void *addr, size_t size)
 {
 	void *ret;
-#if defined(__ia64__)
+#if defined(__ia64__) || (defined(__sparc__) && defined(__arch64__) && defined(__linux__))
         /*
          * The JS engine assumes that all allocated pointers have their high 17 bits clear,
          * which ia64's mmap doesn't support directly. However, we can emulate it by passing
@@ -2440,18 +2440,40 @@ pages_map(void *addr, size_t size)
 	}
 #endif
 
+#if defined(__sparc__) && defined(__arch64__) && defined(__linux__)
+    const uintptr_t start = 0x0000070000000000ULL;
+    const uintptr_t end   = 0x0000800000000000ULL;
+
+    /* Copied from js/src/gc/Memory.cpp and adapted for this source */
+
+    uintptr_t hint;
+    void* region = MAP_FAILED;
+    for (hint = start; region == MAP_FAILED && hint + size <= end; hint += chunksize) {
+           region = mmap((void*)hint, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
+           if (region != MAP_FAILED) {
+                   if (((size_t) region + (size - 1)) & 0xffff800000000000) {
+                           if (munmap(region, size)) {
+                                   MOZ_ASSERT(errno == ENOMEM);
+                           }
+                           region = MAP_FAILED;
+                   }
+           }
+    }
+    ret = region;
+#else
+
 	/*
 	 * We don't use MAP_FIXED here, because it can cause the *replacement*
 	 * of existing mappings, and we only want to create new mappings.
 	 */
 	ret = mmap(addr, size, PROT_READ | PROT_WRITE,
 		MAP_PRIVATE | MAP_ANON, -1, 0);
 	assert(ret != NULL);
-
+#endif
 	if (ret == MAP_FAILED) {
 		ret = NULL;
 	}
-#if defined(__ia64__)
+#if defined(__ia64__) || (defined(__sparc__) && defined(__arch64__) && defined(__linux__))
         /*
          * If the allocated memory doesn't have its upper 17 bits clear, consider it
          * as out of memory.
@@ -2484,7 +2506,7 @@ pages_map(void *addr, size_t size)
 		MozTagAnonymousMemory(ret, size, "jemalloc");
 	}
 
-#if defined(__ia64__)
+#if defined(__ia64__) || (defined(__sparc__) && defined(__arch64__) && defined(__linux__))
 	assert(ret == NULL || (!check_placement && ret != NULL)
 	    || (check_placement && ret == addr));
 #else