From 02a3d77940d9b9dcf3af3e8ca9672145155fbfe6 Mon Sep 17 00:00:00 2001
From: Wojciech Siewierski <wojciech.siewierski@onet.pl>
Date: Wed, 13 Apr 2016 22:24:42 +0200
Subject: [PATCH] Optimize source_layers_cache for the cache memory
Swapping the array indices should increase the locality of the memory access.
---
tmk_core/common/action_layer.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tmk_core/common/action_layer.c b/tmk_core/common/action_layer.c
index fc721a732..e817c0d51 100644
--- a/tmk_core/common/action_layer.c
+++ b/tmk_core/common/action_layer.c
@@ -111,7 +111,7 @@ void layer_debug(void)
#endif
#if !defined(NO_ACTION_LAYER) && defined(PREVENT_STUCK_MODIFIERS)
-uint8_t source_layers_cache[MAX_LAYER_BITS][(MATRIX_ROWS * MATRIX_COLS + 7) / 8] = {0};
+uint8_t source_layers_cache[(MATRIX_ROWS * MATRIX_COLS + 7) / 8][MAX_LAYER_BITS] = {0};
void update_source_layers_cache(keypos_t key, uint8_t layer)
{
@@ -120,9 +120,9 @@ void update_source_layers_cache(keypos_t key, uint8_t layer)
const uint8_t storage_bit = key_number % 8;
for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
- source_layers_cache[bit_number][storage_row] ^=
+ source_layers_cache[storage_row][bit_number] ^=
(-((layer & (1U << bit_number)) != 0)
- ^ source_layers_cache[bit_number][storage_row])
+ ^ source_layers_cache[storage_row][bit_number])
& (1U << storage_bit);
}
}
@@ -136,7 +136,7 @@ uint8_t read_source_layers_cache(keypos_t key)
for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
layer |=
- ((source_layers_cache[bit_number][storage_row]
+ ((source_layers_cache[storage_row][bit_number]
& (1U << storage_bit)) != 0)
<< bit_number;
}