From 7ee91cf86136f4774a9143a3f745d37f314662da Mon Sep 17 00:00:00 2001
From: Damien George
Date: Tue, 6 Jan 2015 12:51:39 +0000
Subject: py: Add option to cache map lookup results in bytecode.

This is a simple optimisation inspired by JITing technology: we cache in
the bytecode (using 1 byte) the offset of the last successful lookup in
a map. This allows us next time round to check in that location in the
hash table (mp_map_t) for the desired entry, and if it's there use that
entry straight away.  Otherwise fallback to a normal map lookup.

Works for LOAD_NAME, LOAD_GLOBAL, LOAD_ATTR and STORE_ATTR opcodes.

On a few tests it gives >90% cache hit and greatly improves speed of
code.

Disabled by default.  Enabled for unix and stmhal ports.
---
 stmhal/mpconfigport.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'stmhal')

diff --git a/stmhal/mpconfigport.h b/stmhal/mpconfigport.h
index c01587f4f..d75102df3 100644
--- a/stmhal/mpconfigport.h
+++ b/stmhal/mpconfigport.h
@@ -40,6 +40,7 @@
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_MPZ)
 #define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_FLOAT)
 #define MICROPY_OPT_COMPUTED_GOTO   (1)
+#define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (1)
 /* Enable FatFS LFNs
     0: Disable LFN feature.
     1: Enable LFN with static working buffer on the BSS. Always NOT reentrant.
-- 
cgit v1.2.3