Initial commit

libsst-os/SST_Endian.c

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+/*
+	SST_Endian.c
+	Author: Chris Ertel <crertel@762studios.com>
+	Created: 1/16/2012
+
+	Purpose: 
+
+	libsst-os endian and byte reordering routines.
+
+	License:
+
+	This program is free software. It comes without any warranty, to
+	the extent permitted by applicable law. You can redistribute it
+	and/or modify it under the terms of the Do What The Fuck You Want
+	To Public License, Version 2, as published by Sam Hocevar. See
+	http://sam.zoy.org/wtfpl/COPYING for more details.
+
+*/
+
+#include <SST/SST_Endian.h>
+#include <pstdint.h>
+
+static SST_ByteOrder machineByteOrder;
+
+void __libsst_init_endian()
+{
+	const uint16_t testSeq = 0x55FE;
+	const uint8_t* c = (const uint8_t*)&testSeq;
+
+	if(c[0] == 0x55)
+		machineByteOrder = SST_BIG_ENDIAN;
+	else
+		machineByteOrder = SST_LITTLE_ENDIAN;
+}
+
+SST_ByteOrder SST_OS_GetHostEndianness( void )
+{
+	return machineByteOrder;
+}
+
+uint16_t SST_OS_ByteSwap16( uint16_t _toSwap)
+{
+	return (_toSwap >> 8) | (_toSwap << 8);
+}
+
+uint32_t SST_OS_ByteSwap32( uint32_t _toSwap)
+{
+	uint32_t a = (_toSwap & 0x000000ff);
+	uint32_t b = (_toSwap & 0x0000ff00) >> 8;
+	uint32_t c = (_toSwap & 0x00ff0000) >> 16;
+	uint32_t d = (_toSwap & 0xff000000) >> 24;
+
+	uint32_t ret = (a << 24) | (b << 16) | (c << 8) | (d);
+	return ret;
+}
+
+uint64_t SST_OS_ByteSwap64( uint64_t _toSwap)
+{
+	uint64_t a = (_toSwap & 0x00000000000000ffull);
+	uint64_t b = (_toSwap & 0x000000000000ff00ull) >> 8;
+	uint64_t c = (_toSwap & 0x0000000000ff0000ull) >> 16;
+	uint64_t d = (_toSwap & 0x00000000ff000000ull) >> 24;
+	uint64_t e = (_toSwap & 0x000000ff00000000ull) >> 32;
+	uint64_t f = (_toSwap & 0x0000ff0000000000ull) >> 40;
+	uint64_t g = (_toSwap & 0x00ff000000000000ull) >> 48;
+	uint64_t h = (_toSwap & 0xff00000000000000ull) >> 56;
+
+	uint64_t ret = (a << 56) | (b << 48) | (c << 40) | (d << 32) | (e << 24) | (f << 16) | (g << 8) | h;
+	return ret;
+}