[svn-r17505] Description:

	Bring r17416:17496 from trunk to revise_chunks branch

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers w/default API=1.6.x,
                                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in debug mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.5.8 (amazon) in debug mode
        Mac OS X/32 10.5.8 (amazon) w/C++ & FORTRAN, w/threadsafe,
                                in production mode
	

14 files changed, 108 insertions, 322 deletions

diff --git a/tools/h5diff/testfiles/h5diff_10.txt b/tools/h5diff/testfiles/h5diff_10.txt
index 38246d9..4788a79 100644
--- a/tools/h5diff/testfiles/h5diff_10.txt
+++ b/tools/h5diff/testfiles/h5diff_10.txt
@@ -11,13 +11,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_600.txt b/tools/h5diff/testfiles/h5diff_600.txt
index 17af208..82c5240 100644
--- a/tools/h5diff/testfiles/h5diff_600.txt
+++ b/tools/h5diff/testfiles/h5diff_600.txt
@@ -11,13 +11,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_603.txt b/tools/h5diff/testfiles/h5diff_603.txt
index 30fe246..e115114 100644
--- a/tools/h5diff/testfiles/h5diff_603.txt
+++ b/tools/h5diff/testfiles/h5diff_603.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_604.txt b/tools/h5diff/testfiles/h5diff_604.txt
index 9357b26..554f2ed 100644
--- a/tools/h5diff/testfiles/h5diff_604.txt
+++ b/tools/h5diff/testfiles/h5diff_604.txt
@@ -1,63 +1,2 @@
-<-d 0> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]] 
-  file1                    File name of the first HDF5 file
-  file2                    File name of the second HDF5 file
-  [obj1]                   Name of an HDF5 object, in absolute path
-  [obj2]                   Name of an HDF5 object, in absolute path
-  OPTIONS
-   -h, --help              Print a usage message and exit
-   -V, --version           Print version number and exit
-   -r, --report            Report mode. Print differences
-   -v, --verbose           Verbose mode. Print differences, list of objects
-   -q, --quiet             Quiet mode. Do not do output
-   -c, --compare           List objects that are not comparable
-   -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
-
- Modes of output:
-
-  Default mode: print the number of differences found and where they occured
-  -r Report mode: print the above plus the differences
-  -v Verbose mode: print the above plus a list of objects and warnings
-  -q Quiet mode: do not print output
-
- Compare criteria
-
- If no objects [obj1[obj2]] are specified, h5diff only compares objects
-   with the same absolute path in both files
-
- The compare criteria is:
-   1) datasets: numerical array differences 2) groups: name string difference
-   3) datatypes: the return value of H5Tequal 4) links: name string difference
-   of the linked value
-
- Return exit code:
-
-  1 if differences found, 0 if no differences, 2 if error
-
- Examples of use:
-
- 1) h5diff file1 file2 /g1/dset1 /g1/dset2
-
-    Compares object '/g1/dset1' in file1 with '/g1/dset2' in file2
-
- 2) h5diff file1 file2 /g1/dset1
-
-    Compares object '/g1/dset1' in both files
-
- 3) h5diff file1 file2
-
-    Compares all objects in both files
-
- Note)  file1 and file2 can be the same file. Use
-
-    h5diff file1 file1 /g1/dset1 /g1/dset2
-
-    to compare '/g1/dset1' and '/g1/dset2' in the same file
-
+dataset: </g1/dset3> and </g1/dset4>
+6 differences found
diff --git a/tools/h5diff/testfiles/h5diff_605.txt b/tools/h5diff/testfiles/h5diff_605.txt
index 1c99713..554f2ed 100644
--- a/tools/h5diff/testfiles/h5diff_605.txt
+++ b/tools/h5diff/testfiles/h5diff_605.txt
@@ -1,63 +1,2 @@
-<-d u> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]] 
-  file1                    File name of the first HDF5 file
-  file2                    File name of the second HDF5 file
-  [obj1]                   Name of an HDF5 object, in absolute path
-  [obj2]                   Name of an HDF5 object, in absolute path
-  OPTIONS
-   -h, --help              Print a usage message and exit
-   -V, --version           Print version number and exit
-   -r, --report            Report mode. Print differences
-   -v, --verbose           Verbose mode. Print differences, list of objects
-   -q, --quiet             Quiet mode. Do not do output
-   -c, --compare           List objects that are not comparable
-   -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
-
- Modes of output:
-
-  Default mode: print the number of differences found and where they occured
-  -r Report mode: print the above plus the differences
-  -v Verbose mode: print the above plus a list of objects and warnings
-  -q Quiet mode: do not print output
-
- Compare criteria
-
- If no objects [obj1[obj2]] are specified, h5diff only compares objects
-   with the same absolute path in both files
-
- The compare criteria is:
-   1) datasets: numerical array differences 2) groups: name string difference
-   3) datatypes: the return value of H5Tequal 4) links: name string difference
-   of the linked value
-
- Return exit code:
-
-  1 if differences found, 0 if no differences, 2 if error
-
- Examples of use:
-
- 1) h5diff file1 file2 /g1/dset1 /g1/dset2
-
-    Compares object '/g1/dset1' in file1 with '/g1/dset2' in file2
-
- 2) h5diff file1 file2 /g1/dset1
-
-    Compares object '/g1/dset1' in both files
-
- 3) h5diff file1 file2
-
-    Compares all objects in both files
-
- Note)  file1 and file2 can be the same file. Use
-
-    h5diff file1 file1 /g1/dset1 /g1/dset2
-
-    to compare '/g1/dset1' and '/g1/dset2' in the same file
-
+dataset: </g1/dset3> and </g1/dset4>
+6 differences found
diff --git a/tools/h5diff/testfiles/h5diff_606.txt b/tools/h5diff/testfiles/h5diff_606.txt
index 0567106..db361fd 100644
--- a/tools/h5diff/testfiles/h5diff_606.txt
+++ b/tools/h5diff/testfiles/h5diff_606.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_612.txt b/tools/h5diff/testfiles/h5diff_612.txt
index 505705b..bbd6b00 100644
--- a/tools/h5diff/testfiles/h5diff_612.txt
+++ b/tools/h5diff/testfiles/h5diff_612.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_613.txt b/tools/h5diff/testfiles/h5diff_613.txt
index 1a89746..554f2ed 100644
--- a/tools/h5diff/testfiles/h5diff_613.txt
+++ b/tools/h5diff/testfiles/h5diff_613.txt
@@ -1,63 +1,2 @@
-<-p 0> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]] 
-  file1                    File name of the first HDF5 file
-  file2                    File name of the second HDF5 file
-  [obj1]                   Name of an HDF5 object, in absolute path
-  [obj2]                   Name of an HDF5 object, in absolute path
-  OPTIONS
-   -h, --help              Print a usage message and exit
-   -V, --version           Print version number and exit
-   -r, --report            Report mode. Print differences
-   -v, --verbose           Verbose mode. Print differences, list of objects
-   -q, --quiet             Quiet mode. Do not do output
-   -c, --compare           List objects that are not comparable
-   -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
-
- Modes of output:
-
-  Default mode: print the number of differences found and where they occured
-  -r Report mode: print the above plus the differences
-  -v Verbose mode: print the above plus a list of objects and warnings
-  -q Quiet mode: do not print output
-
- Compare criteria
-
- If no objects [obj1[obj2]] are specified, h5diff only compares objects
-   with the same absolute path in both files
-
- The compare criteria is:
-   1) datasets: numerical array differences 2) groups: name string difference
-   3) datatypes: the return value of H5Tequal 4) links: name string difference
-   of the linked value
-
- Return exit code:
-
-  1 if differences found, 0 if no differences, 2 if error
-
- Examples of use:
-
- 1) h5diff file1 file2 /g1/dset1 /g1/dset2
-
-    Compares object '/g1/dset1' in file1 with '/g1/dset2' in file2
-
- 2) h5diff file1 file2 /g1/dset1
-
-    Compares object '/g1/dset1' in both files
-
- 3) h5diff file1 file2
-
-    Compares all objects in both files
-
- Note)  file1 and file2 can be the same file. Use
-
-    h5diff file1 file1 /g1/dset1 /g1/dset2
-
-    to compare '/g1/dset1' and '/g1/dset2' in the same file
-
+dataset: </g1/dset3> and </g1/dset4>
+6 differences found
diff --git a/tools/h5diff/testfiles/h5diff_614.txt b/tools/h5diff/testfiles/h5diff_614.txt
index ec12818..554f2ed 100644
--- a/tools/h5diff/testfiles/h5diff_614.txt
+++ b/tools/h5diff/testfiles/h5diff_614.txt
@@ -1,63 +1,2 @@
-<-p u> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]] 
-  file1                    File name of the first HDF5 file
-  file2                    File name of the second HDF5 file
-  [obj1]                   Name of an HDF5 object, in absolute path
-  [obj2]                   Name of an HDF5 object, in absolute path
-  OPTIONS
-   -h, --help              Print a usage message and exit
-   -V, --version           Print version number and exit
-   -r, --report            Report mode. Print differences
-   -v, --verbose           Verbose mode. Print differences, list of objects
-   -q, --quiet             Quiet mode. Do not do output
-   -c, --compare           List objects that are not comparable
-   -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
-
- Modes of output:
-
-  Default mode: print the number of differences found and where they occured
-  -r Report mode: print the above plus the differences
-  -v Verbose mode: print the above plus a list of objects and warnings
-  -q Quiet mode: do not print output
-
- Compare criteria
-
- If no objects [obj1[obj2]] are specified, h5diff only compares objects
-   with the same absolute path in both files
-
- The compare criteria is:
-   1) datasets: numerical array differences 2) groups: name string difference
-   3) datatypes: the return value of H5Tequal 4) links: name string difference
-   of the linked value
-
- Return exit code:
-
-  1 if differences found, 0 if no differences, 2 if error
-
- Examples of use:
-
- 1) h5diff file1 file2 /g1/dset1 /g1/dset2
-
-    Compares object '/g1/dset1' in file1 with '/g1/dset2' in file2
-
- 2) h5diff file1 file2 /g1/dset1
-
-    Compares object '/g1/dset1' in both files
-
- 3) h5diff file1 file2
-
-    Compares all objects in both files
-
- Note)  file1 and file2 can be the same file. Use
-
-    h5diff file1 file1 /g1/dset1 /g1/dset2
-
-    to compare '/g1/dset1' and '/g1/dset2' in the same file
-
+dataset: </g1/dset3> and </g1/dset4>
+6 differences found
diff --git a/tools/h5diff/testfiles/h5diff_615.txt b/tools/h5diff/testfiles/h5diff_615.txt
index 8528c0e..9c8f0c7 100644
--- a/tools/h5diff/testfiles/h5diff_615.txt
+++ b/tools/h5diff/testfiles/h5diff_615.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_621.txt b/tools/h5diff/testfiles/h5diff_621.txt
index 96d6c3f..79eebed 100644
--- a/tools/h5diff/testfiles/h5diff_621.txt
+++ b/tools/h5diff/testfiles/h5diff_621.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_622.txt b/tools/h5diff/testfiles/h5diff_622.txt
index 9dc3751..09de51d 100644
--- a/tools/h5diff/testfiles/h5diff_622.txt
+++ b/tools/h5diff/testfiles/h5diff_622.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_623.txt b/tools/h5diff/testfiles/h5diff_623.txt
index a02f5ea..dc60b94 100644
--- a/tools/h5diff/testfiles/h5diff_623.txt
+++ b/tools/h5diff/testfiles/h5diff_623.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output:
 
diff --git a/tools/h5diff/testfiles/h5diff_624.txt b/tools/h5diff/testfiles/h5diff_624.txt
index 396a007..016ab77 100644
--- a/tools/h5diff/testfiles/h5diff_624.txt
+++ b/tools/h5diff/testfiles/h5diff_624.txt
@@ -12,13 +12,16 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[obj2]]
    -q, --quiet             Quiet mode. Do not do output
    -c, --compare           List objects that are not comparable
    -N, --nan               Avoid NaNs detection
-   -n C, --count=C         Print differences up to C number
-   -d D, --delta=D         Print difference when greater than limit D
-   -p R, --relative=R      Print difference when greater than relative limit R
-
-  C - is a positive integer
-  D - is a positive number. Compare criteria is |a - b| > D
-  R - is a positive number. Compare criteria is |(b-a)/a| > R
+   -n C, --count=C         Print differences up to C number, C is a positive integer.
+   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive number.
+   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive number.
+   --use-system-epsilon    Print difference if (|a-b| > EPSILON),
+                           where EPSILON (FLT_EPSILON or FLT_EPSILON) is the system epsilon value. 
+                           If the system epsilon is not defined, use the value below:
+                               FLT_EPSILON = 1.19209E-07 for float
+                               DBL_EPSILON = 2.22045E-16 for double
+                           -d, -p, and --use-system-epsilon options are used for comparing floating point values.
+                           By default, strict equality is used. Use -p or -d to set specific tolerance.
 
  Modes of output: