Rewrote the implementation of the SwapEndian_16() and SwapEndian_32() functions so...

[pub/USBasp.git] / LUFA / Common / Common.h

diff --git a/LUFA/Common/Common.h b/LUFA/Common/Common.h
index 7fd1555..76144f9 100644 (file)
--- a/LUFA/Common/Common.h
+++ b/LUFA/Common/Common.h
@@ -174,7 +174,21 @@
                        static inline uint16_t SwapEndian_16(uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
                        static inline uint16_t SwapEndian_16(uint16_t Word)
                        {
-                               return ((Word >> 8) | (Word << 8));                             
+                               uint8_t Temp;
+
+                               union
+                               {
+                                       uint16_t Word;
+                                       uint8_t  Bytes[2];
+                               } Data;
+                               
+                               Data.Word = Word;
+                               
+                               Temp = Data.Bytes[0];
+                               Data.Bytes[0] = Data.Bytes[1];
+                               Data.Bytes[1] = Temp;
+                               
+                               return Data.Word;
                        }
 
                        /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
@@ -186,10 +200,25 @@
                        static inline uint32_t SwapEndian_32(uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
                        static inline uint32_t SwapEndian_32(uint32_t DWord)
                        {
-                               return (((DWord & 0xFF000000) >> 24) |
-                                       ((DWord & 0x00FF0000) >> 8)  |
-                                               ((DWord & 0x0000FF00) << 8)  |
-                                               ((DWord & 0x000000FF) << 24));
+                               uint8_t Temp;
+
+                               union
+                               {
+                                       uint32_t DWord;
+                                       uint8_t  Bytes[4];
+                               } Data;
+                               
+                               Data.DWord = DWord;
+                               
+                               Temp = Data.Bytes[0];
+                               Data.Bytes[0] = Data.Bytes[3];
+                               Data.Bytes[3] = Temp;
+                               
+                               Temp = Data.Bytes[1];
+                               Data.Bytes[1] = Data.Bytes[2];
+                               Data.Bytes[2] = Temp;
+                               
+                               return Data.DWord;
                        }
 
                        /** Function to reverse the byte ordering of the individual bytes in a n byte number.