hdf5/hdf5-ldouble-ppc64le.patch

diff -rupN hdf5-1.8.16.orig/configure hdf5-1.8.16/configure
--- hdf5-1.8.16.orig/configure	2015-11-10 15:01:10.000000000 +0100
+++ hdf5-1.8.16/configure	2016-01-28 13:44:58.136709651 +0100
@@ -27347,6 +27347,14 @@ main ()
                 unsigned char       s2[8];
                 int                 ret = 1;
 
+#if defined __powerpc64__ && defined _LITTLE_ENDIAN
+                /* Don't bother checking on ppc64le, we know it'll work, and
+                   that what hdf5 calls 'special algorithm' simply is
+                   IBM ldouble 128 (i.e. two seperately scaled doubles).
+                   The check below assumes big endian.  */
+                ret = 0;
+#endif
+
                 if(sizeof(long double) == 16 && sizeof(long) == 8) {
                     /*make sure the long double type has 16 bytes in size and
                      * 11 bits of exponent.  If it is,
@@ -27464,6 +27472,14 @@ main ()
                 unsigned char       s[16];
                 int                 flag=0, ret=1;
 
+#if defined __powerpc64__ && defined _LITTLE_ENDIAN
+                /* Don't bother checking on ppc64le, we know it'll work, and
+                   that what hdf5 calls 'special algorithm' simply is
+                   IBM ldouble 128 (i.e. two seperately scaled doubles).
+                   The check below assumes big endian.  */
+                ret = 0;
+#endif
+
                 /*Determine if long double has 16 byte in size, 11 bit exponent, and
                  *the bias is 0x3ff */
                 if(sizeof(long double) == 16) {
diff -rupN hdf5-1.8.16.orig/configure.ac hdf5-1.8.16/configure.ac
--- hdf5-1.8.16.orig/configure.ac	2015-11-04 23:29:55.000000000 +0100
+++ hdf5-1.8.16/configure.ac	2016-01-28 13:44:58.144709750 +0100
@@ -2277,7 +2277,15 @@ else
                 unsigned char       s[16];
                 unsigned char       s2[8];
                 int                 ret = 1;
-                
+
+#if defined __powerpc64__ && defined _LITTLE_ENDIAN
+                /* Don't bother checking on ppc64le, we know it'll work, and
+                   that what hdf5 calls 'special algorithm' simply is
+                   IBM ldouble 128 (i.e. two seperately scaled doubles).
+                   The check below assumes big endian.  */
+                ret = 0;
+#endif
+
                 if(sizeof(long double) == 16 && sizeof(long) == 8) {
                     /*make sure the long double type has 16 bytes in size and 
                      * 11 bits of exponent.  If it is,
@@ -2354,6 +2362,14 @@ else
                 unsigned long       ull;
                 unsigned char       s[16];
                 int                 flag=0, ret=1;
+
+#if defined __powerpc64__ && defined _LITTLE_ENDIAN
+                /* Don't bother checking on ppc64le, we know it'll work, and
+                   that what hdf5 calls 'special algorithm' simply is
+                   IBM ldouble 128 (i.e. two seperately scaled doubles).
+                   The check below assumes big endian.  */
+                ret = 0;
+#endif
             
                 /*Determine if long double has 16 byte in size, 11 bit exponent, and
                  *the bias is 0x3ff */ 
diff -rupN hdf5-1.8.16.orig/test/dt_arith.c hdf5-1.8.16/test/dt_arith.c
--- hdf5-1.8.16.orig/test/dt_arith.c	2015-10-24 07:13:43.000000000 +0200
+++ hdf5-1.8.16/test/dt_arith.c	2016-01-28 13:44:58.153709861 +0100
@@ -3010,7 +3010,18 @@ test_conv_flt_1 (const char *name, int r
                         buf, saved, nelmts);
 #if H5_SIZEOF_LONG_DOUBLE!=H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE!=0
             } else if(src_type == FLT_LDOUBLE) {
-                 INIT_FP_SPECIAL(src_size, src_nbits, sendian, LDBL_MANT_DIG, dst_size,
+		 size_t mant_dig = LDBL_MANT_DIG;
+		 if (mant_dig >= src_nbits) {
+		     /* This happens for IBM long double in little endian.
+		        The macro LDBL_MANT_DIG says 106 mantissa bits, but the
+			HDF5 detection code actually represents it as a normal 64bit
+			double (52 bit mantissa) with the upper double being 
+			unspec bits (which is sort of okay as the testsuite
+			wouldn't deal with that format correctly anyway).  So
+			override the mantissa size.  */
+		     mant_dig = 52;
+		 }
+                 INIT_FP_SPECIAL(src_size, src_nbits, sendian, mant_dig, dst_size,
                         buf, saved, nelmts);
 #endif
             } else
@@ -3663,7 +3674,18 @@ test_conv_int_fp(const char *name, int r
             INIT_FP_DENORM(long double, LDBL_MANT_DIG, src_size, src_nbits, sendian, dst_size,
                     buf, saved, nelmts);
         } else {
-            INIT_FP_SPECIAL(src_size, src_nbits, sendian, LDBL_MANT_DIG, dst_size, buf, saved, nelmts);
+	    size_t mant_dig = LDBL_MANT_DIG;
+	    if (mant_dig >= src_nbits) {
+		/* This happens for IBM long double in little endian.
+		   The macro LDBL_MANT_DIG says 106 mantissa bits, but the
+		   HDF5 detection code actually represents it as a normal 64bit
+		   double (52 bit mantissa) with the upper double being 
+		   unspec bits (which is sort of okay as the testsuite
+		   wouldn't deal with that format correctly anyway).  So
+		   override the mantissa size.  */
+		mant_dig = 52;
+	    }
+            INIT_FP_SPECIAL(src_size, src_nbits, sendian, mant_dig, dst_size, buf, saved, nelmts);
         }
 #endif
     } else