re PR fortran/37605 (Remarks on user manual for Gfortran)

2008-12-21  Arjen Markus  <arjen.markus@wldelft.nl>
	    Daniel Kraft  <d@domob.eu>

	PR fortran/37605
	* gfortran.texi: Fixed some typos and some minor style improvements.
	* intrinsic.texi: Some clarifications and typo-fixes.
	* invoke.texi: Better documenation of the behaviour of the
	-fdefault-*-8 options and some other fixes.

Co-Authored-By: Daniel Kraft <d@domob.eu>

From-SVN: r142866

gcc/fortran/ChangeLog

+2008-12-21  Arjen Markus  <arjen.markus@wldelft.nl>
+	    Daniel Kraft  <d@domob.eu>
+
+	PR fortran/37605
+	* gfortran.texi: Fixed some typos and some minor style improvements.
+	* intrinsic.texi: Some clarifications and typo-fixes.
+	* invoke.texi: Better documenation of the behaviour of the
+	-fdefault-*-8 options and some other fixes.
+
 2008-12-18  Daniel Kraft  <d@domob.eu>
 
 	PR fortran/31822

gcc/fortran/gfortran.texi

@@ -263,14 +263,13 @@ code designed to be efficiently translated and processed
 by a machine such as your computer.
 Humans usually aren't as good writing machine code
 as they are at writing Fortran (or C++, Ada, or Java),
-because is easy to make tiny mistakes writing machine code.
+because it is easy to make tiny mistakes writing machine code.
 
 @item
 Provide the user with information about the reasons why
 the compiler is unable to create a binary from the source code.
 Usually this will be the case if the source code is flawed.
-When writing Fortran, it is easy to make big mistakes.
-The Fortran 90 requires that the compiler can point out
+The Fortran 90 standard requires that the compiler can point out
 mistakes to the user.
 An incorrect usage of the language causes an @dfn{error message}.
 
@@ -986,8 +985,14 @@ equivalent to the standard-conforming declaration
       TYPESPEC(k) x,y,z
 @end smallexample
 @noindent
-where @code{k} is equal to @code{size} for most types, but is equal to
-@code{size/2} for the @code{COMPLEX} type.
+where @code{k} is the kind parameter suitable for the intended precision.  As
+kind parameters are implementation-dependent, use the @code{KIND},
+@code{SELECTED_INT_KIND} and @code{SELECTED_REAL_KIND} intrinsics to retrieve
+the correct value, for instance @code{REAL*8 x} can be replaced by:
+@smallexample
+INTEGER, PARAMETER :: dbl = KIND(1.0d0)
+REAL(KIND=dbl) :: x
+@end smallexample
 
 @node Old-style variable initialization
 @subsection Old-style variable initialization
@@ -1561,9 +1566,9 @@ worth a look.
 The long history of the Fortran language, its wide use and broad
 userbase, the large number of different compiler vendors and the lack of
 some features crucial to users in the first standards have lead to the
-existence of an important number of extensions to the language. While
+existence of a number of important extensions to the language.  While
 some of the most useful or popular extensions are supported by the GNU
-Fortran compiler, not all existing extensions are supported. This section
+Fortran compiler, not all existing extensions are supported.  This section
 aims at listing these extensions and offering advice on how best make
 code that uses them running with the GNU Fortran compiler.
 
@@ -1617,7 +1622,7 @@ store_catalog(7).id = 7831
 store_catalog(7).description = "milk bottle"
 store_catalog(7).price = 1.2
 
-! We can also manipulates the whole structure
+! We can also manipulate the whole structure
 store_catalog(12) = pear
 print *, store_catalog(12)
 @end example

gcc/fortran/invoke.texi

@@ -210,12 +210,12 @@ form is determined by the file extension.
 
 @item -fall-intrinsics
 @opindex @code{fall-intrinsics}
-Accept all of the intrinsic procedures provided in libgfortran 
-without regard to the setting of @option{-std}.  In particular, 
-this option can be quite useful with @option{-std=f95}.  Additionally,
-@command{gfortran} will ignore @option{-Wintrinsics-std} and will never try
-to link to an @code{EXTERNAL} version if the intrinsic is not included in the
-selected standard.
+This option causes all intrinsic procedures (including the GNU-specific
+extensions) to be accepted.  This can be useful with @option{-std=f95} to
+force standard-compliance but get access to the full range of intrinsics
+available with @command{gfortran}.  As a consequence, @option{-Wintrinsics-std}
+will be ignored and no user-defined procedure with the same name as any
+intrinsic will be called except when it is explicitly declared @code{EXTERNAL}.
 
 @item -fd-lines-as-code
 @item -fd-lines-as-comments
@@ -229,17 +229,26 @@ comment lines.
 
 @item -fdefault-double-8
 @opindex @code{fdefault-double-8}
-Set the @code{DOUBLE PRECISION} type to an 8 byte wide type.
+Set the @code{DOUBLE PRECISION} type to an 8 byte wide type.  If
+@option{-fdefault-real-8} is given, @code{DOUBLE PRECISION} would
+instead be promoted to 16 bytes if possible, and @option{-fdefault-double-8}
+can be used to prevent this.  The kind of real constants like @code{1.d0} will
+not be changed by @option{-fdefault-real-8} though, so also
+@option{-fdefault-double-8} does not affect it.
 
 @item -fdefault-integer-8
 @opindex @code{fdefault-integer-8}
 Set the default integer and logical types to an 8 byte wide type.
-Do nothing if this is already the default.
+Do nothing if this is already the default.  This option also affects
+the kind of integer constants like @code{42}.
 
 @item -fdefault-real-8
 @opindex @code{fdefault-real-8}
 Set the default real type to an 8 byte wide type.
-Do nothing if this is already the default.
+Do nothing if this is already the default.  This option also affects
+the kind of non-double real constants like @code{1.0}, and does promote
+the default width of @code{DOUBLE PRECISION} to 16 bytes if possible, unless
+@code{-fdefault-double-8} is given, too.
 
 @item -fdollar-ok
 @opindex @code{fdollar-ok}
@@ -861,7 +870,7 @@ zero), @samp{overflow} (overflow in a floating point operation),
 (operation produced a denormal value).
 
 Some of the routines in the Fortran runtime library, like
-@samp{CPU_TIME}, are likely to to trigger floating point exceptions when
+@samp{CPU_TIME}, are likely to trigger floating point exceptions when
 @code{ffpe-trap=precision} is used. For this reason, the use of 
 @code{ffpe-trap=precision} is not recommended.
 
@@ -1183,13 +1192,15 @@ by use of the @option{-ff2c} option.
 Enable generation of run-time checks for array subscripts
 and against the declared minimum and maximum values.  It also
 checks array indices for assumed and deferred
-shape arrays against the actual allocated bounds.
+shape arrays against the actual allocated bounds and ensures that all string
+lengths are equal for character array constructors without an explicit
+typespec.
 
 Some checks require that @option{-fbounds-check} is set for
 the compilation of the main program.
 
-In the future this may also include other forms of checking, e.g., checking
-substring references.
+Note: In the future this may also include other forms of checking, e.g.,
+checking substring references.
 
 
 @item fcheck-array-temporaries