[svn-r12091] Purpose: Support for VAX floating-point types.

Solution: Support VAX float and double types with new byte order. There're some
details not yet included,
1. the alignment detection for VAX order in H5detect.c.
2. support for special values in library conversion functions.
3. the infinity for VAX in H5T_init_inf.
4. support for VAX types in printing hexadecimal format.


Platforms tested: h5committest and fuss.

1 files changed, 44 insertions, 11 deletions

diff --git a/src/H5Odtype.c b/src/H5Odtype.c
index fc3f641..9aa2e85 100644
--- a/src/H5Odtype.c
+++ b/src/H5Odtype.c
@@ -61,15 +61,19 @@ const H5O_msg_class_t H5O_MSG_DTYPE[1] = {{
     H5O_dtype_debug		/* debug the message		*/
 }};
 
-/* This is the correct version to create all datatypes which don't contain
+/* This is the version bit to create all datatypes which don't contain
  * array datatypes (atomic types, compound datatypes without array fields,
- * vlen sequences of objects which aren't arrays, etc.) */
+ * vlen sequences of objects which aren't arrays, etc. 0x01) */
 #define H5O_DTYPE_VERSION_COMPAT	1
 
-/* This is the correct version to create all datatypes which contain H5T_ARRAY
- * class objects (array definitely, potentially compound & vlen sequences also) */
+/* This is the version bit to create all datatypes which contain H5T_ARRAY
+ * class objects (array definitely, potentially compound & vlen sequences also.
+ * 0x02) */
 #define H5O_DTYPE_VERSION_UPDATED	2
 
+/* This version bit represents H5T_ORDER_VAX (0x04) */
+#define H5O_DTYPE_VERSION_VAX           4
+
 
 /*-------------------------------------------------------------------------
  * Function:	H5O_dtype_decode_helper
@@ -84,12 +88,16 @@ const H5O_msg_class_t H5O_MSG_DTYPE[1] = {{
  * Modifications:
  *		Robb Matzke, Thursday, May 20, 1999
  *		Added support for bitfields and opaque datatypes.
+ *
+ *		Raymond Lu.  Monday, Mar 13, 2006
+ *		Added support for VAX floating-point types.
  *-------------------------------------------------------------------------
  */
 static herr_t
 H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
 {
-    unsigned		flags, version;
+    unsigned		flags;
+    unsigned            version = 0;
     unsigned		i, j;
     size_t		z;
     herr_t      ret_value=SUCCEED;       /* Return value */
@@ -103,7 +111,8 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
     /* decode */
     UINT32DECODE(*pp, flags);
     version = (flags>>4) & 0x0f;
-    if (version!=H5O_DTYPE_VERSION_COMPAT && version!=H5O_DTYPE_VERSION_UPDATED)
+    if (!(version & H5O_DTYPE_VERSION_COMPAT) && !(version & H5O_DTYPE_VERSION_UPDATED) &&
+            !(version & H5O_DTYPE_VERSION_VAX))
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTLOAD, FAIL, "bad version number for datatype message");
     dt->shared->type = (H5T_class_t)(flags & 0x0f);
     flags >>= 8;
@@ -151,6 +160,15 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
              * Floating-point types...
              */
             dt->shared->u.atomic.order = (flags & 0x1) ? H5T_ORDER_BE : H5T_ORDER_LE;
+            if(version & H5O_DTYPE_VERSION_VAX) {
+                /*Unsupported byte order*/
+                if((flags & 0x40) && !(flags & 0x1))
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_UNSUPPORTED, FAIL, "bad byte order for datatype message");
+
+                /*VAX order if both 1st and 6th bits are turned on*/
+                if(flags & 0x40)
+                    dt->shared->u.atomic.order = H5T_ORDER_VAX;
+            }
             dt->shared->u.atomic.lsb_pad = (flags & 0x2) ? H5T_PAD_ONE : H5T_PAD_ZERO;
             dt->shared->u.atomic.msb_pad = (flags & 0x4) ? H5T_PAD_ONE : H5T_PAD_ZERO;
             dt->shared->u.atomic.u.f.pad = (flags & 0x8) ? H5T_PAD_ONE : H5T_PAD_ZERO;
@@ -210,7 +228,7 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
                 /* Older versions of the library allowed a field to have
                  * intrinsic 'arrayness'.  Newer versions of the library
                  * use the separate array datatypes. */
-                if(version==H5O_DTYPE_VERSION_COMPAT) {
+                if(version & H5O_DTYPE_VERSION_COMPAT) {
                     /* Decode the number of dimensions */
                     ndims = *(*pp)++;
                     assert(ndims <= 4);
@@ -240,7 +258,7 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
                 }
 
                 /* Go create the array datatype now, for older versions of the datatype message */
-                if(version==H5O_DTYPE_VERSION_COMPAT) {
+                if(version & H5O_DTYPE_VERSION_COMPAT) {
                     /* Check if this member is an array field */
                     if(ndims>0) {
                         /* Set up the permutation vector for the array create */
@@ -450,16 +468,21 @@ done:
  * Modifications:
  *		Robb Matzke, Thursday, May 20, 1999
  *		Added support for bitfields and opaque types.
+ *
+ *		Raymond Lu.  Monday, Mar 13, 2006
+ *		Added support for VAX floating-point types.
  *-------------------------------------------------------------------------
  */
 static herr_t
 H5O_dtype_encode_helper(uint8_t **pp, const H5T_t *dt)
 {
-    htri_t has_array=FALSE;       /* Whether a compound datatype has an array inside it */
+    htri_t              has_array=FALSE; /* Whether a compound datatype has an array inside it */
+    htri_t              has_vax=FALSE;   /* Whether VAX floating number exists */
     unsigned		flags = 0;
     char		*hdr = (char *)*pp;
     unsigned		i, j;
     size_t		n, z, aligned;
+    uint8_t             version;         /* version number */
     herr_t      ret_value=SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5O_dtype_encode_helper);
@@ -579,10 +602,14 @@ H5O_dtype_encode_helper(uint8_t **pp, const H5T_t *dt)
              */
             switch (dt->shared->u.atomic.order) {
                 case H5T_ORDER_LE:
-                    break;		/*nothing */
+                    break;		/*nothing*/
                 case H5T_ORDER_BE:
                     flags |= 0x01;
                     break;
+                case H5T_ORDER_VAX:     /*turn on 1st and 6th (reserved before adding VAX) bits*/ 
+                    flags |= 0x41;
+                    has_vax = TRUE;
+                    break;
                 default:
                     HGOTO_ERROR(H5E_DATATYPE, H5E_UNSUPPORTED, FAIL, "byte order is not supported in file format yet");
             }
@@ -793,7 +820,13 @@ H5O_dtype_encode_helper(uint8_t **pp, const H5T_t *dt)
     }
 
     /* Encode the type's class, version and bit field */
-    *hdr++ = ((unsigned)(dt->shared->type) & 0x0f) | (((dt->shared->type==H5T_COMPOUND && has_array) ? H5O_DTYPE_VERSION_UPDATED : H5O_DTYPE_VERSION_COMPAT )<<4);
+    version &= 0x00; 
+    /* Four combination exist for version number, compact, compact+vax, updated, and updated+vax. */
+    version = (dt->shared->type==H5T_COMPOUND && has_array) ? H5O_DTYPE_VERSION_UPDATED : H5O_DTYPE_VERSION_COMPAT;
+    if(has_vax)
+        version |= H5O_DTYPE_VERSION_VAX;
+
+    *hdr++ = ((unsigned)(dt->shared->type) & 0x0f) | (version<<4);
     *hdr++ = (flags >> 0) & 0xff;
     *hdr++ = (flags >> 8) & 0xff;
     *hdr++ = (flags >> 16) & 0xff;