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authorWilliam Wilgus <me.theuser@yahoo.com>2017-11-09 18:03:33 +0100
committerWilliam Wilgus <me.theuser@yahoo.com>2018-10-18 13:29:32 +0200
commitb977b77fb7ea75895ac65d64d99b056d95435bfc (patch)
tree8a4ba6adeb13e2af3c975479d90a4395a1b911db /firmware
parentdd40c46d50f9f22643b828e80783d3576b9c1d50 (diff)
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Optimize is_diacritic
is_diacritic is used for pretty much all of the text display sizing Timing here matters, so important it uses a priority buffer in order to cut down on searching the database. This patch is verified functionally equlivalent but saves 80 bytes and is ~20% faster for the clip+ I tested it on Several things were done: Optimizing the copy loop for the priority buffer Globbing some operations together but the main one has to do with the database structure its self -- Rather than a bit packed struct it combines the lower 8 bytes into one value [info] and uses flags to access the values instead Change-Id: I475073419b647639ef1eeaa3b9213e4e1067c0db
Diffstat (limited to 'firmware')
-rw-r--r--firmware/common/diacritic.c49
1 files changed, 29 insertions, 20 deletions
diff --git a/firmware/common/diacritic.c b/firmware/common/diacritic.c
index aa2726c5fb..eca7b07b6e 100644
--- a/firmware/common/diacritic.c
+++ b/firmware/common/diacritic.c
@@ -10,6 +10,7 @@
* Copyright (C) 2009 Phinitnun Chanasabaeng
* Initial work
* Copyright (C) 2009 Tomer Shalev
+ * Copyright (C) 2018 William Wilgus
*
* Rockbox diacritic positioning
* Based on initial work by Phinitnun Chanasabaeng
@@ -27,19 +28,23 @@
#include "system.h"
#define DIAC_NUM_RANGES (ARRAYLEN(diac_ranges))
+#define DIAC_RTL (1 << 7)
+#define DIAC_CNT (0xFF ^ DIAC_RTL)
/* Each diac_range_ struct defines a Unicode range that begins with
* N diacritic characters, and continues with non-diacritic characters up to the
- * base of the next item in the array */
+ * base of the next item in the array, [info] packs RTL status and the count of
+ * diacritic chars after [base]. RTL occupies the MSB and CNT the (7) lower bits
+ */
+
struct diac_range
{
- unsigned base : 16;
- unsigned num_diacritics : 7;
- unsigned is_rtl : 1;
+ uint16_t base;
+ uint8_t info; /* [RTL:1 CNT:7] */
};
#define DIAC_RANGE_ENTRY(first_diac, first_non_diac, is_rtl) \
- { first_diac, first_non_diac - first_diac, is_rtl }
+ { first_diac, ((first_non_diac - first_diac) & DIAC_CNT) | (is_rtl * DIAC_RTL)}
/* Sorted by Unicode value */
static const struct diac_range diac_ranges[] =
@@ -190,22 +195,28 @@ static const struct diac_range diac_ranges[] =
#define MRU_MAX_LEN 32
-static unsigned short mru_len = 0;
-static unsigned short diacritic_mru[MRU_MAX_LEN];
-
bool is_diacritic(const unsigned short char_code, bool *is_rtl)
{
- unsigned short mru, i;
+ static uint8_t mru_len = 0;
+ static uint8_t diacritic_mru[MRU_MAX_LEN];
+
+ uint8_t i, itmp;
+ uint8_t info, mru;
+
const struct diac_range *diac;
/* Search in MRU */
- for (mru = 0; mru < mru_len; mru++)
+ for (mru = 0, i = 0; mru < mru_len; mru++)
{
+
+ /* Items shifted >> 1 */
+ itmp = i;
i = diacritic_mru[mru];
+ diacritic_mru[mru] = itmp;
/* Found in MRU */
- if (diac_ranges[i].base <= char_code &&
- char_code < diac_ranges[i + 1].base)
+ if ((char_code >= (diac = &diac_ranges[i])->base)
+ && (char_code < (++diac)->base))
{
goto Found;
}
@@ -219,23 +230,21 @@ bool is_diacritic(const unsigned short char_code, bool *is_rtl)
break;
}
- /* Add MRU entry, or overwrite LRU if MRU array is full */
+ /* Add MRU entry */
if (mru_len < MRU_MAX_LEN)
mru_len++;
- else
- mru--;
Found:
+
/* Promote MRU item to top of MRU */
- for ( ; mru > 0; mru--)
- diacritic_mru[mru] = diacritic_mru[mru - 1];
diacritic_mru[0] = i;
diac = &diac_ranges[i];
+ info = diac->info;
/* Update RTL */
if (is_rtl)
- *is_rtl = diac->is_rtl;
+ *is_rtl = ((DIAC_RTL & info) == DIAC_RTL);
- return (char_code < diac->base + diac->num_diacritics);
-}
+ return (char_code < diac->base + (info & DIAC_CNT));
+} \ No newline at end of file