GMISC invsqrt() function.

Fix a 64bit processor bug.
Add support for processors where the floating point and integer endianness don't match.
Add support for processors with a non-standard floating point format.
Update gdisp_streaming demo with extra comments to reflect the above changes.

1 files changed, 26 insertions, 1 deletions

diff --git a/include/gmisc/options.h b/include/gmisc/options.h
index 73b41800..9c309487 100644
--- a/include/gmisc/options.h
+++ b/include/gmisc/options.h
@@ -44,9 +44,34 @@
 /**

  * @}

  *

- * @name    GMISC Optional Sizing Parameters

+ * @name    GMISC Optional Parameters

  * @{

  */

+	/**

+	 * @brief	Modifies the @p invsqrt() function to assume a different integer to floating point endianness.

+	 * @note	Normally the floating point format and the integer format have

+	 * 			the same endianness. Unfortunately there are some strange

+	 * 			processors that don't eg. some very early ARM devices.

+	 * 			For those where the endianness doesn't match you can fix it by

+	 * 			defining GDISP_INVSQRT_MIXED_ENDIAN.

+	 * @note	This still assumes the processor is using an ieee floating point format.

+	 *

+	 * If you have a software floating point that uses a non-standard

+	 * floating point format (or very strange hardware) then define

+	 * GDISP_INVSQRT_REAL_SLOW and it will do it the hard way.

+	 */

+	#ifndef GDISP_INVSQRT_MIXED_ENDIAN

+		#define GDISP_INVSQRT_MIXED_ENDIAN	FALSE

+	#endif

+	/**

+	 * @brief	Modifies the @p invsqrt() function to do things the long slow way.

+	 * @note	This causes the @p invsqrt() function to work regardless of the

+	 * 			processor floating point format.

+	 * @note	This makes the @p invsqrt() function very slow.

+	 */

+	#ifndef GDISP_INVSQRT_REAL_SLOW

+		#define GDISP_INVSQRT_REAL_SLOW		FALSE

+	#endif

 /** @} */

 

 #endif /* _GMISC_OPTIONS_H */