[svn-r8136] Purpose:

    Optimization

Description:
    Speed up various parts of the library by setting a global variable for the
endianness of the machine at library startup and use that variable instead of
repeatedly querying the endianness of the native int datatype.

Platforms tested:
    IBM p690 (copper)
    too minor to require h5committest

5 files changed, 29 insertions, 16 deletions

diff --git a/src/H5T.c b/src/H5T.c
index 6f670b0..f10752d 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -241,6 +241,9 @@ static struct {
     H5T_soft_t	*soft;		/*unsorted array of soft conversions	*/
 } H5T_g;
 
+/* The native endianess of the platform */
+H5T_order_t H5T_native_order_g = H5T_ORDER_ERROR;
+
 /* The overflow handler */
 H5T_overflow_t H5T_overflow_g = NULL;
 
@@ -514,7 +517,7 @@ H5T_init_inf(void)
     dst = &dst_p->u.atomic;
 
     /* Check that we can re-order the bytes correctly */
-    if (H5T_ORDER_LE!=dst->order && H5T_ORDER_BE!=dst->order)
+    if (H5T_ORDER_LE!=H5T_native_order_g && H5T_ORDER_BE!=H5T_native_order_g)
         HGOTO_ERROR (H5E_DATATYPE, H5E_UNSUPPORTED, FAIL, "unsupported byte order");
 
     /* +Inf */
@@ -524,7 +527,7 @@ H5T_init_inf(void)
     H5T_bit_set (d, dst->u.f.mpos, dst->u.f.msize, FALSE);
 
     /* Swap the bytes if the machine architecture is big-endian */
-    if (H5T_ORDER_BE==dst->order) {
+    if (H5T_ORDER_BE==H5T_native_order_g) {
         half_size = dst_p->size/2;
         for (u=0; u<half_size; u++) {
             uint8_t tmp = d[dst_p->size-(u+1)];
@@ -540,7 +543,7 @@ H5T_init_inf(void)
     H5T_bit_set (d, dst->u.f.mpos, dst->u.f.msize, FALSE);
 
     /* Swap the bytes if the machine architecture is big-endian */
-    if (H5T_ORDER_BE==dst->order) {
+    if (H5T_ORDER_BE==H5T_native_order_g) {
         half_size = dst_p->size/2;
         for (u=0; u<half_size; u++) {
             uint8_t tmp = d[dst_p->size-(u+1)];
@@ -555,7 +558,7 @@ H5T_init_inf(void)
     dst = &dst_p->u.atomic;
 
     /* Check that we can re-order the bytes correctly */
-    if (H5T_ORDER_LE!=dst->order && H5T_ORDER_BE!=dst->order)
+    if (H5T_ORDER_LE!=H5T_native_order_g && H5T_ORDER_BE!=H5T_native_order_g)
         HGOTO_ERROR (H5E_DATATYPE, H5E_UNSUPPORTED, FAIL, "unsupported byte order");
 
     /* +Inf */
@@ -565,7 +568,7 @@ H5T_init_inf(void)
     H5T_bit_set (d, dst->u.f.mpos, dst->u.f.msize, FALSE);
 
     /* Swap the bytes if the machine architecture is big-endian */
-    if (H5T_ORDER_BE==dst->order) {
+    if (H5T_ORDER_BE==H5T_native_order_g) {
         half_size = dst_p->size/2;
         for (u=0; u<half_size; u++) {
             uint8_t tmp = d[dst_p->size-(u+1)];
@@ -581,7 +584,7 @@ H5T_init_inf(void)
     H5T_bit_set (d, dst->u.f.mpos, dst->u.f.msize, FALSE);
 
     /* Swap the bytes if the machine architecture is big-endian */
-    if (H5T_ORDER_BE==dst->order) {
+    if (H5T_ORDER_BE==H5T_native_order_g) {
         half_size = dst_p->size/2;
         for (u=0; u<half_size; u++) {
             uint8_t tmp = d[dst_p->size-(u+1)];
diff --git a/src/H5Tbit.c b/src/H5Tbit.c
index f6e36c7..157da5d 100644
--- a/src/H5Tbit.c
+++ b/src/H5Tbit.c
@@ -189,7 +189,7 @@ H5T_bit_get_d (uint8_t *buf, size_t offset, size_t size)
     assert (8*sizeof(val)>=size);
 
     H5T_bit_copy ((uint8_t*)&val, 0, buf, offset, size);
-    switch (((H5T_t*)(H5I_object(H5T_NATIVE_INT_g)))->u.atomic.order) {
+    switch (H5T_native_order_g) {
         case H5T_ORDER_LE:
             break;
 
@@ -234,7 +234,7 @@ H5T_bit_set_d (uint8_t *buf, size_t offset, size_t size, hsize_t val)
     
     assert (8*sizeof(val)>=size);
 
-    switch (((H5T_t*)(H5I_object(H5T_NATIVE_INT_g)))->u.atomic.order) {
+    switch (H5T_native_order_g) {
         case H5T_ORDER_LE:
             break;
 
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 7c7b505..862c19a 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -683,15 +683,9 @@ H5T_conv_order_opt(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 
         /* Check for "no op" reference conversion */
         if(src->type==H5T_REFERENCE) {
-            H5T_t *native_int;          /* Native integer datatype */
-
             /* Sanity check */
             assert(dst->type==H5T_REFERENCE);
 
-            /* Get pointer to native integer type */
-            if (NULL==(native_int=H5I_object(H5T_NATIVE_INT_g)))
-                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype object");
-
             /* Check if we are on a little-endian machine (the order that
              * the addresses in the file must be) and just get out now, there
              * is no need to convert the object reference.  Yes, this is
@@ -701,7 +695,7 @@ H5T_conv_order_opt(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
              * "native" hobj_ref_t datatype and I think that would break a
              * lot of existing programs.  -QAK
              */
-            if(native_int->u.atomic.order == H5T_ORDER_LE)
+            if(H5T_native_order_g == H5T_ORDER_LE)
                 break;
         } /* end if */
 
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index d87cc2f..a01d995 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -232,6 +232,9 @@ typedef enum H5T_sdir_t {
     H5T_BIT_MSB				/*search msb toward lsb		     */
 } H5T_sdir_t;
 
+/* The native endianess of the platform */
+H5_DLLVAR H5T_order_t H5T_native_order_g;
+
 /* The overflow handler */
 H5_DLLVAR H5T_overflow_t H5T_overflow_g;
 
diff --git a/src/H5detect.c b/src/H5detect.c
index 670aed1..f3a5588 100644
--- a/src/H5detect.c
+++ b/src/H5detect.c
@@ -479,7 +479,7 @@ sigbus_handler(int UNUSED signo)
 static void
 print_results(int nd, detected_t *d, int na, malign_t *misc_align)
 {
-
+    int         byte_order;
     int		i, j;
 
     /* Include files */
@@ -523,6 +523,18 @@ H5TN_init_interface(void)\n\
 \n\
     FUNC_ENTER_NOAPI(H5TN_init_interface, FAIL);\n");
 
+    /* The native endianess of this machine */
+    /* (Use the byte-order of a reasonably large type) */
+    for (i = 0; i < nd; i++)
+        if(d[i].size>1) {
+            byte_order=d[i].perm[0];
+            break;
+        } /* end if */
+    printf("\n\
+    /* Set the native order for this machine */\n\
+    H5T_native_order_g = H5T_ORDER_%s;\n",
+	       byte_order ? "BE" : "LE");	/*byte order		*/
+
     for (i = 0; i < nd; i++) {
 
 	/* Print a comment to describe this section of definitions. */
@@ -548,6 +560,7 @@ H5TN_init_interface(void)\n\
 	       d[i].perm[0] ? "BE" : "LE",	/*byte order		*/
 	       d[i].offset,			/*offset		*/
 	       d[i].precision);			/*precision		*/
+    assert(d[i].size<2 || (d[i].perm[0]>0)==(byte_order>0));   /* Double-check that byte-order doesn't change */
 
 	if (0 == d[i].msize) {
 	    /* The part unique to fixed point types */