Speedup 'tb_find_slow' by using the same heuristic as during memory page lookup

Move the last found TB to the head of the list so it will be found more quickly next time it will be looked for.

Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: Pavel Yushchenko <pau@ispras.ru>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

diff --git a/cpu-exec.c b/cpu-exec.c
index dbdfdccd8cc3d788c2065e16fc1dc9679aaf539c..39e5eeaa8fc51ad839cd58006084b9f28061a58f 100644 (file)
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -167,6 +167,12 @@ static TranslationBlock *tb_find_slow(target_ulong pc,
     tb = tb_gen_code(env, pc, cs_base, flags, 0);
 
  found:
+    /* Move the last found TB to the head of the list */
+    if (likely(*ptb1)) {
+        *ptb1 = tb->phys_hash_next;
+        tb->phys_hash_next = tb_phys_hash[h];
+        tb_phys_hash[h] = tb;
+    }
     /* we add the TB in the virtual pc hash table */
     env->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;
     return tb;