Initial commit based on common repo commit ffeb9c9b

libs/3rd-party/mseed/gswap.c

@@ -0,0 +1,150 @@
+/***************************************************************************
+ * gswap.c:
+ *
+ * Functions for generalized, in-pace byte swapping between LSBF and
+ * MSBF byte orders.
+ *
+ * Some standard integer types are needed, namely uint8_t and
+ * uint32_t, (these are normally declared by including inttypes.h or
+ * stdint.h).  Each function expects it's input to be a void pointer
+ * to a quantity of the appropriate size.
+ *
+ * There are two versions of most routines, one that works on
+ * quantities regardless of alignment (gswapX) and one that works on
+ * memory aligned quantities (gswapXa).  The memory aligned versions
+ * (gswapXa) are much faster than the other versions (gswapX), but the
+ * memory *must* be aligned.
+ *
+ * Written by Chad Trabant,
+ *   IRIS Data Management Center
+ *
+ * Version: 2010.006
+ ***************************************************************************/
+
+#include "lmplatform.h"
+
+/* Swap routines that work on any (aligned or not) quantities */
+
+void
+ms_gswap2 ( void *data2 )
+{
+  uint8_t temp;
+  
+  union
+  {
+    uint8_t  c[2];
+  } dat;
+  
+  memcpy( &dat, data2, 2 );
+  temp     = dat.c[0];
+  dat.c[0] = dat.c[1];
+  dat.c[1] = temp;
+  memcpy( data2, &dat, 2 );
+}
+
+
+void
+ms_gswap3 ( void *data3 )
+{
+  uint8_t temp;
+  
+  union
+  {
+    uint8_t  c[3];
+  } dat;
+  
+  memcpy( &dat, data3, 3 );
+  temp     = dat.c[0];
+  dat.c[0] = dat.c[2];
+  dat.c[2] = temp;
+  memcpy( data3, &dat, 3 );
+}
+
+
+void
+ms_gswap4 ( void *data4 )
+{
+  uint8_t temp;
+
+  union {
+    uint8_t c[4];
+  } dat;
+  
+  memcpy( &dat, data4, 4 );
+  temp     = dat.c[0];
+  dat.c[0] = dat.c[3];
+  dat.c[3] = temp;
+  temp     = dat.c[1];
+  dat.c[1] = dat.c[2];
+  dat.c[2] = temp;
+  memcpy( data4, &dat, 4 );
+}
+
+
+void
+ms_gswap8 ( void *data8 )
+{
+  uint8_t temp;
+  
+  union
+  {
+    uint8_t   c[8];
+  } dat;
+  
+  memcpy( &dat, data8, 8 );
+  temp     = dat.c[0];
+  dat.c[0] = dat.c[7];
+  dat.c[7] = temp;
+  
+  temp     = dat.c[1];
+  dat.c[1] = dat.c[6];
+  dat.c[6] = temp;
+  
+  temp     = dat.c[2];
+  dat.c[2] = dat.c[5];
+  dat.c[5] = temp;
+  
+  temp     = dat.c[3];
+  dat.c[3] = dat.c[4];
+  dat.c[4] = temp;
+  memcpy( data8, &dat, 8 );
+}
+
+/* Swap routines that work on memory aligned quantities */
+
+void
+ms_gswap2a ( void *data2 )
+{
+  uint16_t *data = data2;
+  
+  *data=(((*data>>8)&0xff) | ((*data&0xff)<<8));
+}
+
+
+void
+ms_gswap4a ( void *data4 )
+{
+  uint32_t *data = data4;
+  
+  *data=(((*data>>24)&0xff) | ((*data&0xff)<<24) |
+	 ((*data>>8)&0xff00) | ((*data&0xff00)<<8));
+}
+
+
+void
+ms_gswap8a ( void *data8 )
+{
+  uint32_t *data4 = data8;
+  uint32_t h0, h1;
+  
+  h0 = data4[0];
+  h0 = (((h0>>24)&0xff) | ((h0&0xff)<<24) |
+	((h0>>8)&0xff00) | ((h0&0xff00)<<8));
+  
+  h1 = data4[1];
+  h1 = (((h1>>24)&0xff) | ((h1&0xff)<<24) |
+	((h1>>8)&0xff00) | ((h1&0xff00)<<8));
+  
+  data4[0] = h1;
+  data4[1] = h0;
+}