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Grayscale lib: Using a 32x32->32 bit multiplication is better on ARM, as 16x16->32 bit isn't a single instruction. Renamed the macro for pointing out that it's not necessarily 16 bit anymore, and to avoid collisions with similar macros in plugins.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11436 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2006-11-05 14:40:14 +00:00
parent 0b9e266b1e
commit 32c69452d6
4 changed files with 96 additions and 92 deletions
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10
apps/plugins/lib/gray.h
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@ -113,9 +113,13 @@ void gray_ub_scroll_down(int count);
#define _GRAY_RUNNING 0x0001 /* greyscale overlay is running */
#define _GRAY_DEFERRED_UPDATE 0x0002 /* lcd_update() requested */
/* unsigned 16 bit multiplication (a single instruction on the SH) */
#define MULU16(a, b) ((unsigned long) \
(((unsigned short) (a)) * ((unsigned short) (b))))
/* fast unsigned multiplication (16x16bit->32bit or 32x32bit->32bit,
* whichever is faster for the architecture) */
#ifdef CPU_ARM
#define _GRAY_MULUQ(a, b) ((uint32_t) (((uint32_t) (a)) * ((uint32_t) (b))))
#else
#define _GRAY_MULUQ(a, b) ((uint32_t) (((uint16_t) (a)) * ((uint16_t) (b))))
#endif
/* The grayscale buffer management structure */
struct _gray_info