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Commit 3a3977a8 by Francois-Xavier Coudert Committed by François-Xavier Coudert
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* intrinsic.texi: Document new intrinsics. 

From-SVN: r115148
parent 95695ad3
Showing with 1510 additions and 296 deletions
gcc/fortran/ChangeLog
2006-07-03 Francois-Xavier Coudert <coudert@clipper.ens.fr>
* intrinsic.texi: Document new intrinsics.
2006-07-01 Tobias Schlüter <tobias.schlueter@physik.uni-muenchen.de> 2006-07-01 Tobias Schlüter <tobias.schlueter@physik.uni-muenchen.de>
PR fortran/19259 PR fortran/19259
...@@ -10,7 +14,7 @@ ...@@ -10,7 +14,7 @@
* check.c: Fix a comment typo. * check.c: Fix a comment typo.
2006-06-25 Paul Thomas <pault@gcc.gnu.org> 2006-06-25 Paul Thomas <pault@gcc.gnu.org>
PR fortran/25056 PR fortran/25056
* interface.c (compare_actual_formal): Signal an error if the formal * interface.c (compare_actual_formal): Signal an error if the formal
argument is a pure procedure and the actual is not pure. argument is a pure procedure and the actual is not pure.
......
gcc/fortran/intrinsic.texi
...@@ -59,7 +59,7 @@ and editing. All contributions and corrections are strongly encouraged. ...@@ -59,7 +59,7 @@ and editing. All contributions and corrections are strongly encouraged.
* @code{BIT_SIZE}: BIT_SIZE, Bit size inquiry function * @code{BIT_SIZE}: BIT_SIZE, Bit size inquiry function
* @code{BTEST}: BTEST, Bit test function * @code{BTEST}: BTEST, Bit test function
* @code{CEILING}: CEILING, Integer ceiling function * @code{CEILING}: CEILING, Integer ceiling function
* @code{CHAR}: CHAR, Character conversion function * @code{CHAR}: CHAR, Integer-to-character conversion function
* @code{CMPLX}: CMPLX, Complex conversion function * @code{CMPLX}: CMPLX, Complex conversion function
* @code{COMMAND_ARGUMENT_COUNT}: COMMAND_ARGUMENT_COUNT, Command line argument count * @code{COMMAND_ARGUMENT_COUNT}: COMMAND_ARGUMENT_COUNT, Command line argument count
* @code{CONJG}: CONJG, Complex conjugate function * @code{CONJG}: CONJG, Complex conjugate function
...@@ -90,20 +90,49 @@ and editing. All contributions and corrections are strongly encouraged. ...@@ -90,20 +90,49 @@ and editing. All contributions and corrections are strongly encouraged.
* @code{FDATE}: FDATE, Subroutine (or function) to get the current time as a string * @code{FDATE}: FDATE, Subroutine (or function) to get the current time as a string
* @code{FLOAT}: FLOAT, Convert integer to default real * @code{FLOAT}: FLOAT, Convert integer to default real
* @code{FLOOR}: FLOOR, Integer floor function * @code{FLOOR}: FLOOR, Integer floor function
* @code{FLUSH}: FLUSH, Flush I/O unit(s)
* @code{FNUM}: FNUM, File number function * @code{FNUM}: FNUM, File number function
* @code{FRACTION}: FRACTION, Fractional part of the model representation
* @code{FREE}: FREE, Memory de-allocation subroutine * @code{FREE}: FREE, Memory de-allocation subroutine
* @code{GETGID}: GETGID, Group ID function
* @code{GETPID}: GETPID, Process ID function
* @code{GETUID}: GETUID, User ID function
* @code{HUGE}: HUGE, Largest number of a kind
* @code{IACHAR}: IACHAR, Code in @acronym{ASCII} collating sequence
* @code{ICHAR}: ICHAR, Character-to-integer conversion function
* @code{IRAND}: IRAND, Integer pseudo-random number
* @code{KIND}: KIND, Kind of an entity
* @code{LOC}: LOC, Returns the address of a variable * @code{LOC}: LOC, Returns the address of a variable
* @code{LOG}: LOG, Logarithm function * @code{LOG}: LOG, Logarithm function
* @code{LOG10}: LOG10, Base 10 logarithm function * @code{LOG10}: LOG10, Base 10 logarithm function
* @code{MALLOC}: MALLOC, Dynamic memory allocation function * @code{MALLOC}: MALLOC, Dynamic memory allocation function
* @code{MAXEXPONENT}: MAXEXPONENT, Maximum exponent of a real kind
* @code{MINEXPONENT}: MINEXPONENT, Minimum exponent of a real kind
* @code{MOD}: MOD, Remainder function
* @code{MODULO}: MODULO, Modulo function
* @code{NEAREST}: NEAREST, Nearest representable number
* @code{NINT}: NINT, Nearest whole number
* @code{PRECISION}: PRECISION, Decimal precision of a real kind
* @code{RADIX}: RADIX, Base of a data model
* @code{RAND}: RAND, Real pseudo-random number
* @code{RANGE}: RANGE, Decimal exponent range of a real kind
* @code{REAL}: REAL, Convert to real type * @code{REAL}: REAL, Convert to real type
* @code{RRSPACING}: RRSPACING, Reciprocal of the relative spacing
* @code{SCALE}: SCALE, Scale a real value
* @code{SECNDS}: SECNDS, Time function * @code{SECNDS}: SECNDS, Time function
* @code{SELECTED_INT_KIND}: SELECTED_INT_KIND, Choose integer kind
* @code{SELECTED_REAL_KIND}: SELECTED_REAL_KIND, Choose real kind
* @code{SET_EXPONENT}: SET_EXPONENT, Set the exponent of the model
* @code{SIGN}: SIGN, Sign copying function
* @code{SIGNAL}: SIGNAL, Signal handling subroutine (or function) * @code{SIGNAL}: SIGNAL, Signal handling subroutine (or function)
* @code{SIN}: SIN, Sine function * @code{SIN}: SIN, Sine function
* @code{SINH}: SINH, Hyperbolic sine function * @code{SINH}: SINH, Hyperbolic sine function
* @code{SNGL}: SNGL, Convert double precision real to default real
* @code{SQRT}: SQRT, Square-root function * @code{SQRT}: SQRT, Square-root function
* @code{SRAND}: SRAND, Reinitialize the random number generator
* @code{TAN}: TAN, Tangent function * @code{TAN}: TAN, Tangent function
* @code{TANH}: TANH, Hyperbolic tangent function * @code{TANH}: TANH, Hyperbolic tangent function
* @code{TINY}: TINY, Smallest positive number of a real kind
@end menu @end menu
@node Introduction @node Introduction
...@@ -678,7 +707,7 @@ end program test_allocated ...@@ -678,7 +707,7 @@ end program test_allocated
@node ANINT @node ANINT
@section @code{ANINT} --- Imaginary part of complex number @section @code{ANINT} --- Nearest whole number
@findex @code{ANINT} intrinsic @findex @code{ANINT} intrinsic
@findex @code{DNINT} intrinsic @findex @code{DNINT} intrinsic
@cindex whole number @cindex whole number
...@@ -2755,42 +2784,6 @@ end program test_exponent ...@@ -2755,42 +2784,6 @@ end program test_exponent
@end table @end table
@node FREE
@section @code{FREE} --- Frees memory
@findex @code{FREE} intrinsic
@cindex FREE
@table @asis
@item @emph{Description}:
Frees memory previously allocated by @code{MALLOC()}. The @code{FREE}
intrinsic is an extension intended to be used with Cray pointers, and is
provided in @command{gfortran} to allow user to compile legacy code. For
new code using Fortran 95 pointers, the memory de-allocation intrinsic is
@code{DEALLOCATE}.
@item @emph{Option}:
gnu
@item @emph{Class}:
subroutine
@item @emph{Syntax}:
@code{FREE(PTR)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{PTR} @tab The type shall be @code{INTEGER}. It represents the
location of the memory that should be de-allocated.
@end multitable
@item @emph{Return value}:
None
@item @emph{Example}:
See @code{MALLOC} for an example.
@end table
@node FDATE @node FDATE
@section @code{FDATE} --- Get the current time as a string @section @code{FDATE} --- Get the current time as a string
@findex @code{FDATE} intrinsic @findex @code{FDATE} intrinsic
...@@ -2919,6 +2912,38 @@ end program test_floor ...@@ -2919,6 +2912,38 @@ end program test_floor
@node FLUSH
@section @code{FLUSH} --- Flush I/O unit(s)
@findex @code{FLUSH}
@cindex flush
@table @asis
@item @emph{Description}:
Flushes Fortran unit(s) currently open for output. Without the optional
argument, all units are flushed, otherwise just the unit specified.
@item @emph{Option}:
gnu
@item @emph{Class}:
non-elemental subroutine
@item @emph{Syntax}:
@code{CALL FLUSH(UNIT)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{UNIT} @tab (Optional) The type shall be @code{INTEGER}.
@end multitable
@item @emph{Note}:
Beginning with the Fortran 2003 standard, there is a @code{FLUSH}
statement that should be prefered over the @code{FLUSH} intrinsic.
@end table
@node FNUM @node FNUM
@section @code{FNUM} --- File number function @section @code{FNUM} --- File number function
@findex @code{FNUM} intrinsic @findex @code{FNUM} intrinsic
...@@ -2958,57 +2983,192 @@ end program test_fnum ...@@ -2958,57 +2983,192 @@ end program test_fnum
@end smallexample @end smallexample
@end table @end table
@node LOC
@section @code{LOC} --- Returns the address of a variable
@findex @code{LOC} intrinsic @node FRACTION
@cindex loc @section @code{FRACTION} --- Fractional part of the model representation
@findex @code{FRACTION} intrinsic
@cindex fractional part
@table @asis @table @asis
@item @emph{Description}: @item @emph{Description}:
@code{LOC(X)} returns the address of @var{X} as an integer. @code{FRACTION(X)} returns the fractional part of the model
representation of @code{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{Y = FRACTION(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab The type of the argument shall be a @code{REAL}.
@end multitable
@item @emph{Return value}:
The return value is of the same type and kind as the argument.
The fractional part of the model representation of @code{X} is returned;
it is @code{X * RADIX(X)**(-EXPONENT(X))}.
@item @emph{Example}:
@smallexample
program test_fraction
real :: x
x = 178.1387e-4
print *, fraction(x), x * radix(x)**(-exponent(x))
end program test_fraction
@end smallexample
@end table
@node FREE
@section @code{FREE} --- Frees memory
@findex @code{FREE} intrinsic
@cindex FREE
@table @asis
@item @emph{Description}:
Frees memory previously allocated by @code{MALLOC()}. The @code{FREE}
intrinsic is an extension intended to be used with Cray pointers, and is
provided in @command{gfortran} to allow user to compile legacy code. For
new code using Fortran 95 pointers, the memory de-allocation intrinsic is
@code{DEALLOCATE}.
@item @emph{Option}: @item @emph{Option}:
gnu gnu
@item @emph{Class}: @item @emph{Class}:
inquiry function subroutine
@item @emph{Syntax}: @item @emph{Syntax}:
@code{I = LOC(X)} @code{FREE(PTR)}
@item @emph{Arguments}: @item @emph{Arguments}:
@multitable @columnfractions .15 .80 @multitable @columnfractions .15 .80
@item @var{X} @tab Variable of any type. @item @var{PTR} @tab The type shall be @code{INTEGER}. It represents the
location of the memory that should be de-allocated.
@end multitable @end multitable
@item @emph{Return value}: @item @emph{Return value}:
The return value is of type @code{INTEGER(n)}, where @code{n} is the None
size (in bytes) of a memory address on the target machine.
@item @emph{Example}:
See @code{MALLOC} for an example.
@end table
@node GETGID
@section @code{GETGID} --- Group ID function
@findex @code{GETGID} intrinsic
@cindex GETGID
@table @asis
@item @emph{Description}:
Returns the numerical group ID of the current process.
@item @emph{Option}:
gnu
@item @emph{Class}:
function
@item @emph{Syntax}:
@code{I = GETGID()}
@item @emph{Return value}:
The return value of @code{GETGID} is an @code{INTEGER} of the default
kind.
@item @emph{Example}:
See @code{GETPID} for an example.
@end table
@node GETPID
@section @code{GETPID} --- Process ID function
@findex @code{GETPID} intrinsic
@cindex GETPID
@table @asis
@item @emph{Description}:
Returns the process numerical identificator of the current process.
@item @emph{Option}:
gnu
@item @emph{Class}:
function
@item @emph{Syntax}:
@code{I = GETPID()}
@item @emph{Return value}:
The return value of @code{GETPID} is an @code{INTEGER} of the default
kind.
@item @emph{Example}: @item @emph{Example}:
@smallexample @smallexample
program test_loc program info
integer :: i print *, "The current process ID is ", getpid()
real :: r print *, "Your numerical user ID is ", getuid()
i = loc(r) print *, "Your numerical group ID is ", getgid()
print *, i end program info
end program test_loc
@end smallexample @end smallexample
@end table @end table
@node LOG
@section @code{LOG} --- Logarithm function
@findex @code{LOG} intrinsic @node GETUID
@findex @code{ALOG} intrinsic @section @code{GETUID} --- User ID function
@findex @code{DLOG} intrinsic @findex @code{GETUID} intrinsic
@findex @code{CLOG} intrinsic @cindex GETUID
@findex @code{ZLOG} intrinsic
@findex @code{CDLOG} intrinsic
@cindex logarithm
@table @asis @table @asis
@item @emph{Description}: @item @emph{Description}:
@code{LOG(X)} computes the logarithm of @var{X}. Returns the numerical user ID of the current process.
@item @emph{Option}:
gnu
@item @emph{Class}:
function
@item @emph{Syntax}:
@code{GETUID()}
@item @emph{Return value}:
The return value of @code{GETUID} is an @code{INTEGER} of the default
kind.
@item @emph{Example}:
See @code{GETPID} for an example.
@end table
@node HUGE
@section @code{HUGE} --- Largest number of a kind
@findex @code{HUGE} intrinsic
@cindex huge
@table @asis
@item @emph{Description}:
@code{HUGE(X)} returns the largest number that is not an infinity in
the model of the type of @code{X}.
@item @emph{Option}: @item @emph{Option}:
f95, gnu f95, gnu
...@@ -3017,51 +3177,76 @@ f95, gnu ...@@ -3017,51 +3177,76 @@ f95, gnu
elemental function elemental function
@item @emph{Syntax}: @item @emph{Syntax}:
@code{X = LOG(X)} @code{Y = HUGE(X)}
@item @emph{Arguments}: @item @emph{Arguments}:
@multitable @columnfractions .15 .80 @multitable @columnfractions .15 .80
@item @var{X} @tab The type shall be @code{REAL(*)} or @item @var{X} @tab shall be of type @code{REAL} or @code{INTEGER}.
@code{COMPLEX(*)}.
@end multitable @end multitable
@item @emph{Return value}: @item @emph{Return value}:
The return value is of type @code{REAL(*)} or @code{COMPLEX(*)}. The return value is of the same type and kind as @var{X}
The kind type parameter is the same as @var{X}.
@item @emph{Example}: @item @emph{Example}:
@smallexample @smallexample
program test_log program test_huge_tiny
real(8) :: x = 1.0_8 print *, huge(0), huge(0.0), huge(0.0d0)
complex :: z = (1.0, 2.0) print *, tiny(0.0), tiny(0.0d0)
x = log(x) end program test_huge_tiny
z = log(z)
end program test_log
@end smallexample @end smallexample
@end table
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Argument @tab Return type @tab Option @node IACHAR
@item @code{ALOG(X)} @tab @code{REAL(4) X} @tab @code{REAL(4)} @tab f95, gnu @section @code{IACHAR} --- Code in @acronym{ASCII} collating sequence
@item @code{DLOG(X)} @tab @code{REAL(8) X} @tab @code{REAL(8)} @tab f95, gnu @findex @code{IACHAR} intrinsic
@item @code{CLOG(X)} @tab @code{COMPLEX(4) X} @tab @code{COMPLEX(4)} @tab f95, gnu @cindex @acronym{ASCII} collating sequence
@item @code{ZLOG(X)} @tab @code{COMPLEX(8) X} @tab @code{COMPLEX(8)} @tab f95, gnu
@item @code{CDLOG(X)} @tab @code{COMPLEX(8) X} @tab @code{COMPLEX(8)} @tab f95, gnu @table @asis
@item @emph{Description}:
@code{IACHAR(C)} returns the code for the @acronym{ASCII} character
in the first character position of @code{C}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{I = IACHAR(C)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{C} @tab Shall be a scalar @code{CHARACTER}, with @code{INTENT(IN)}
@end multitable @end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER} and of the default integer
kind.
@item @emph{Example}:
@smallexample
program test_iachar
integer i
i = iachar(' ')
end program test_iachar
@end smallexample
@end table @end table
@node LOG10 @node ICHAR
@section @code{LOG10} --- Base 10 logarithm function @section @code{ICHAR} --- Character-to-integer conversion function
@findex @code{LOG10} intrinsic @findex @code{ICHAR} intrinsic
@findex @code{ALOG10} intrinsic
@findex @code{DLOG10} intrinsic
@cindex logarithm
@table @asis @table @asis
@item @emph{Description}: @item @emph{Description}:
@code{LOG10(X)} computes the base 10 logarithm of @var{X}. @code{ICHAR(C)} returns the code for the character in the first character
position of @code{C} in the system's native character set.
The correspondence between character and their codes is not necessarily
the same between GNU Fortran implementations.
@item @emph{Option}: @item @emph{Option}:
f95, gnu f95, gnu
...@@ -3070,153 +3255,1181 @@ f95, gnu ...@@ -3070,153 +3255,1181 @@ f95, gnu
elemental function elemental function
@item @emph{Syntax}: @item @emph{Syntax}:
@code{X = LOG10(X)} @code{I = ICHAR(C)}
@item @emph{Arguments}: @item @emph{Arguments}:
@multitable @columnfractions .15 .80 @multitable @columnfractions .15 .80
@item @var{X} @tab The type shall be @code{REAL(*)} or @item @var{C} @tab Shall be a scalar @code{CHARACTER}, with @code{INTENT(IN)}
@code{COMPLEX(*)}. @end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER} and of the default integer
kind.
@item @emph{Example}:
@smallexample
program test_ichar
integer i
i = ichar(' ')
end program test_ichar
@end smallexample
@item @emph{Note}:
No intrinsic exists to convert a printable character string to a numerical
value. For example, there is no intrinsic that, given the @code{CHARACTER}
value 154, returns an @code{INTEGER} or @code{REAL} value with the
value 154.
Instead, you can use internal-file I/O to do this kind of conversion. For
example:
@smallexample
program read_val
integer value
character(len=10) string
string = '154'
read (string,'(I10)') value
print *, value
end program read_val
@end smallexample
@end table
@node IRAND
@section @code{IRAND} --- Integer pseudo-random number
@findex @code{IRAND} intrinsic
@cindex random number
@table @asis
@item @emph{Description}:
@code{IRAND(FLAG)} returns a pseudo-random number from a uniform
distribution between 0 and a system-dependent limit (which is in most
cases 2147483647). If @var{FLAG} is 0, the next number
in the current sequence is returned; if @var{FLAG} is 1, the generator
is restarted by @code{CALL SRAND(0)}; if @var{FLAG} has any other value,
it is used as a new seed with @code{SRAND}.
@item @emph{Option}:
gnu
@item @emph{Class}:
non-elemental function
@item @emph{Syntax}:
@code{I = IRAND(FLAG)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{FLAG} @tab shall be a scalar @code{INTEGER} of kind 4.
@end multitable
@item @emph{Return value}:
The return value is of @code{INTEGER(kind=4)} type.
@item @emph{Example}:
@smallexample
program test_irand
integer,parameter :: seed = 86456
call srand(seed)
print *, irand(), irand(), irand(), irand()
print *, irand(seed), irand(), irand(), irand()
end program test_irand
@end smallexample
@end table
@node KIND
@section @code{KIND} --- Kind of an entity
@findex @code{KIND} intrinsic
@table @asis
@item @emph{Description}:
@code{KIND(X)} returns the kind value of the entity @var{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
inquiry function
@item @emph{Syntax}:
@code{K = KIND(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab Shall be of type @code{LOGICAL}, @code{INTEGER},
@code{REAL}, @code{COMPLEX} or @code{CHARACTER}.
@end multitable
@item @emph{Return value}:
The return value is a scalar of type @code{INTEGER} and of the default
integer kind.
@item @emph{Example}:
@smallexample
program test_kind
integer,parameter :: kc = kind(' ')
integer,parameter :: kl = kind(.true.)
print *, "The default character kind is ", kc
print *, "The default logical kind is ", kl
end program test_kind
@end smallexample
@end table
@node LOC
@section @code{LOC} --- Returns the address of a variable
@findex @code{LOC} intrinsic
@cindex loc
@table @asis
@item @emph{Description}:
@code{LOC(X)} returns the address of @var{X} as an integer.
@item @emph{Option}:
gnu
@item @emph{Class}:
inquiry function
@item @emph{Syntax}:
@code{I = LOC(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab Variable of any type.
@end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER(n)}, where @code{n} is the
size (in bytes) of a memory address on the target machine.
@item @emph{Example}:
@smallexample
program test_loc
integer :: i
real :: r
i = loc(r)
print *, i
end program test_loc
@end smallexample
@end table
@node LOG
@section @code{LOG} --- Logarithm function
@findex @code{LOG} intrinsic
@findex @code{ALOG} intrinsic
@findex @code{DLOG} intrinsic
@findex @code{CLOG} intrinsic
@findex @code{ZLOG} intrinsic
@findex @code{CDLOG} intrinsic
@cindex logarithm
@table @asis
@item @emph{Description}:
@code{LOG(X)} computes the logarithm of @var{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{X = LOG(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab The type shall be @code{REAL(*)} or
@code{COMPLEX(*)}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{REAL(*)} or @code{COMPLEX(*)}.
The kind type parameter is the same as @var{X}.
@item @emph{Example}:
@smallexample
program test_log
real(8) :: x = 1.0_8
complex :: z = (1.0, 2.0)
x = log(x)
z = log(z)
end program test_log
@end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Argument @tab Return type @tab Option
@item @code{ALOG(X)} @tab @code{REAL(4) X} @tab @code{REAL(4)} @tab f95, gnu
@item @code{DLOG(X)} @tab @code{REAL(8) X} @tab @code{REAL(8)} @tab f95, gnu
@item @code{CLOG(X)} @tab @code{COMPLEX(4) X} @tab @code{COMPLEX(4)} @tab f95, gnu
@item @code{ZLOG(X)} @tab @code{COMPLEX(8) X} @tab @code{COMPLEX(8)} @tab f95, gnu
@item @code{CDLOG(X)} @tab @code{COMPLEX(8) X} @tab @code{COMPLEX(8)} @tab f95, gnu
@end multitable
@end table
@node LOG10
@section @code{LOG10} --- Base 10 logarithm function
@findex @code{LOG10} intrinsic
@findex @code{ALOG10} intrinsic
@findex @code{DLOG10} intrinsic
@cindex logarithm
@table @asis
@item @emph{Description}:
@code{LOG10(X)} computes the base 10 logarithm of @var{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{X = LOG10(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab The type shall be @code{REAL(*)} or
@code{COMPLEX(*)}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{REAL(*)} or @code{COMPLEX(*)}.
The kind type parameter is the same as @var{X}.
@item @emph{Example}:
@smallexample
program test_log10
real(8) :: x = 10.0_8
x = log10(x)
end program test_log10
@end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Argument @tab Return type @tab Option
@item @code{ALOG10(X)} @tab @code{REAL(4) X} @tab @code{REAL(4)} @tab f95, gnu
@item @code{DLOG10(X)} @tab @code{REAL(8) X} @tab @code{REAL(8)} @tab f95, gnu
@end multitable
@end table
@node MALLOC
@section @code{MALLOC} --- Allocate dynamic memory
@findex @code{MALLOC} intrinsic
@cindex MALLOC
@table @asis
@item @emph{Description}:
@code{MALLOC(SIZE)} allocates @var{SIZE} bytes of dynamic memory and
returns the address of the allocated memory. The @code{MALLOC} intrinsic
is an extension intended to be used with Cray pointers, and is provided
in @command{gfortran} to allow user to compile legacy code. For new code
using Fortran 95 pointers, the memory allocation intrinsic is
@code{ALLOCATE}.
@item @emph{Option}:
gnu
@item @emph{Class}:
non-elemental function
@item @emph{Syntax}:
@code{PTR = MALLOC(SIZE)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{SIZE} @tab The type shall be @code{INTEGER(*)}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER(K)}, with @var{K} such that
variables of type @code{INTEGER(K)} have the same size as
C pointers (@code{sizeof(void *)}).
@item @emph{Example}:
The following example demonstrates the use of @code{MALLOC} and
@code{FREE} with Cray pointers. This example is intended to run on
32-bit systems, where the default integer kind is suitable to store
pointers; on 64-bit systems, ptr_x would need to be declared as
@code{integer(kind=8)}.
@smallexample
program test_malloc
integer i
integer ptr_x
real*8 x(*), z
pointer(ptr_x,x)
ptr_x = malloc(20*8)
do i = 1, 20
x(i) = sqrt(1.0d0 / i)
end do
z = 0
do i = 1, 20
z = z + x(i)
print *, z
end do
call free(ptr_x)
end program test_malloc
@end smallexample
@end table
@node MAXEXPONENT
@section @code{MAXEXPONENT} --- Maximum exponent of a real kind
@findex @code{MAXEXPONENT} intrinsic
@cindex MAXEXPONENT
@table @asis
@item @emph{Description}:
@code{MAXEXPONENT(X)} returns the maximum exponent in the model of the
type of @code{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{I = MAXEXPONENT(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER} and of the default integer
kind.
@item @emph{Example}:
@smallexample
program exponents
real(kind=4) :: x
real(kind=8) :: y
print *, minexponent(x), maxexponent(x)
print *, minexponent(y), maxexponent(y)
end program exponents
@end smallexample
@end table
@node MINEXPONENT
@section @code{MINEXPONENT} --- Minimum exponent of a real kind
@findex @code{MINEXPONENT} intrinsic
@cindex MINEXPONENT
@table @asis
@item @emph{Description}:
@code{MINEXPONENT(X)} returns the minimum exponent in the model of the
type of @code{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{I = MINEXPONENT(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER} and of the default integer
kind.
@item @emph{Example}:
See @code{MAXEXPONENT} for an example.
@end table
@node MOD
@section @code{MOD} --- Remainder function
@findex @code{MOD} intrinsic
@findex @code{AMOD} intrinsic
@findex @code{DMOD} intrinsic
@cindex remainder
@table @asis
@item @emph{Description}:
@code{MOD(A,P)} computes the remainder of the division of A by P. It is
calculated as @code{A - (INT(A/P) * P)}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{X = MOD(A,P)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{A} @tab shall be a scalar of type @code{INTEGER} or @code{REAL}
@item @var{P} @tab shall be a scalar of the same type as @var{A} and not
equal to zero
@end multitable
@item @emph{Return value}:
The kind of the return value is the result of cross-promoting
the kinds of the arguments.
@item @emph{Example}:
@smallexample
program test_mod
print *, mod(17,3)
print *, mod(17.5,5.5)
print *, mod(17.5d0,5.5)
print *, mod(17.5,5.5d0)
print *, mod(-17,3)
print *, mod(-17.5,5.5)
print *, mod(-17.5d0,5.5)
print *, mod(-17.5,5.5d0)
print *, mod(17,-3)
print *, mod(17.5,-5.5)
print *, mod(17.5d0,-5.5)
print *, mod(17.5,-5.5d0)
end program test_mod
@end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Arguments @tab Return type @tab Option
@item @code{AMOD(A,P)} @tab @code{REAL(4)} @tab @code{REAL(4)} @tab f95, gnu
@item @code{DMOD(A,P)} @tab @code{REAL(8)} @tab @code{REAL(8)} @tab f95, gnu
@end multitable
@end table
@node MODULO
@section @code{MODULO} --- Modulo function
@findex @code{MODULO} intrinsic
@cindex modulo
@table @asis
@item @emph{Description}:
@code{MODULO(A,P)} computes the @var{A} modulo @var{P}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{X = MODULO(A,P)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{A} @tab shall be a scalar of type @code{INTEGER} or @code{REAL}
@item @var{P} @tab shall be a scalar of the same type and kind as @var{A}
@end multitable
@item @emph{Return value}:
The type and kind of the result are those of the arguments.
@table @asis
@item If @var{A} and @var{P} are of type @code{INTEGER}:
@code{MODULO(A,P)} has the value @var{R} such that @code{A=Q*P+R}, where
@var{Q} is an integer and @var{R} is between 0 (inclusive) and @var{P}
(exclusive).
@item If @var{A} and @var{P} are of type @code{REAL}:
@code{MODULO(A,P)} has the value of @code{A - FLOOR (A / P) * P}.
@end table
In all cases, if @var{P} is zero the result is processor-dependent.
@item @emph{Example}:
@smallexample
program test_mod
print *, modulo(17,3)
print *, modulo(17.5,5.5)
print *, modulo(-17,3)
print *, modulo(-17.5,5.5)
print *, modulo(17,-3)
print *, modulo(17.5,-5.5)
end program test_mod
@end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Arguments @tab Return type @tab Option
@item @code{AMOD(A,P)} @tab @code{REAL(4)} @tab @code{REAL(4)} @tab f95, gnu
@item @code{DMOD(A,P)} @tab @code{REAL(8)} @tab @code{REAL(8)} @tab f95, gnu
@end multitable
@end table
@node NEAREST
@section @code{NEAREST} --- Nearest representable number
@findex @code{NEAREST} intrinsic
@cindex processor-representable number
@table @asis
@item @emph{Description}:
@code{NEAREST(X, S)} returns the processor-representable number nearest
to @code{X} in the direction indicated by the sign of @code{S}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{Y = NEAREST(X, S)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL}.
@item @var{S} @tab (Optional) shall be of type @code{REAL} and
not equal to zero.
@end multitable
@item @emph{Return value}:
The return value is of the same type as @code{X}. If @code{S} is
positive, @code{NEAREST} returns the processor-representable number
greater than @code{X} and nearest to it. If @code{S} is negative,
@code{NEAREST} returns the processor-representable number smaller than
@code{X} and nearest to it.
@item @emph{Example}:
@smallexample
program test_nearest
real :: x, y
x = nearest(42.0, 1.0)
y = nearest(42.0, -1.0)
write (*,"(3(G20.15))") x, y, x - y
end program test_nearest
@end smallexample
@end table
@node NINT
@section @code{NINT} --- Nearest whole number
@findex @code{NINT} intrinsic
@findex @code{IDNINT} intrinsic
@cindex whole number
@table @asis
@item @emph{Description}:
@code{NINT(X)} rounds its argument to the nearest whole number.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{X = NINT(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab The type of the argument shall be @code{REAL}.
@end multitable
@item @emph{Return value}:
Returns @var{A} with the fractional portion of its magnitude eliminated by
rounding to the nearest whole number and with its sign preserved,
converted to an @code{INTEGER} of the default kind.
@item @emph{Example}:
@smallexample
program test_nint
real(4) x4
real(8) x8
x4 = 1.234E0_4
x8 = 4.321_8
print *, nint(x4), idnint(x8)
end program test_nint
@end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .33 .33 .33
@item Name @tab Argument @tab Option
@item @code{IDNINT(X)} @tab @code{REAL(8)} @tab f95, gnu
@end multitable
@end table
@node PRECISION
@section @code{PRECISION} --- Decimal precision of a real kind
@findex @code{PRECISION} intrinsic
@cindex PRECISION
@table @asis
@item @emph{Description}:
@code{PRECISION(X)} returns the decimal precision in the model of the
type of @code{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{I = PRECISION(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL} or @code{COMPLEX}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER} and of the default integer
kind.
@item @emph{Example}:
@smallexample
program prec_and_range
real(kind=4) :: x(2)
complex(kind=8) :: y
print *, precision(x), range(x)
print *, precision(y), range(y)
end program prec_and_range
@end smallexample
@end table
@node RADIX
@section @code{RADIX} --- Base of a model number
@findex @code{RADIX} intrinsic
@cindex base
@table @asis
@item @emph{Description}:
@code{RADIX(X)} returns the base of the model representing the entity @var{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
inquiry function
@item @emph{Syntax}:
@code{R = RADIX(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab Shall be of type @code{INTEGER} or @code{REAL}
@end multitable
@item @emph{Return value}:
The return value is a scalar of type @code{INTEGER} and of the default
integer kind.
@item @emph{Example}:
@smallexample
program test_radix
print *, "The radix for the default integer kind is", radix(0)
print *, "The radix for the default real kind is", radix(0.0)
end program test_radix
@end smallexample
@end table
@node RAND
@section @code{RAND} --- Real pseudo-random number
@findex @code{RAND} intrinsic
@findex @code{RAN} intrinsic
@cindex random number
@table @asis
@item @emph{Description}:
@code{RAND(FLAG)} returns a pseudo-random number from a uniform
distribution between 0 and 1. If @var{FLAG} is 0, the next number
in the current sequence is returned; if @var{FLAG} is 1, the generator
is restarted by @code{CALL SRAND(0)}; if @var{FLAG} has any other value,
it is used as a new seed with @code{SRAND}.
@item @emph{Option}:
gnu
@item @emph{Class}:
non-elemental function
@item @emph{Syntax}:
@code{X = RAND(FLAG)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{FLAG} @tab shall be a scalar @code{INTEGER} of kind 4.
@end multitable
@item @emph{Return value}:
The return value is of @code{REAL} type and the default kind.
@item @emph{Example}:
@smallexample
program test_rand
integer,parameter :: seed = 86456
call srand(seed)
print *, rand(), rand(), rand(), rand()
print *, rand(seed), rand(), rand(), rand()
end program test_rand
@end smallexample
@item @emph{Note}:
For compatibility with HP FORTRAN 77/iX, the @code{RAN} intrinsic is
provided as an alias for @code{RAND}.
@end table
@node RANGE
@section @code{RANGE} --- Decimal exponent range of a real kind
@findex @code{RANGE} intrinsic
@cindex RANGE
@table @asis
@item @emph{Description}:
@code{RANGE(X)} returns the decimal exponent range in the model of the
type of @code{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{I = RANGE(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL} or @code{COMPLEX}.
@end multitable
@item @emph{Return value}:
The return value is of type @code{INTEGER} and of the default integer
kind.
@item @emph{Example}:
See @code{PRECISION} for an example.
@end table
@node REAL
@section @code{REAL} --- Convert to real type
@findex @code{REAL} intrinsic
@findex @code{REALPART} intrinsic
@cindex true values
@table @asis
@item @emph{Description}:
@code{REAL(X [, KIND])} converts its argument @var{X} to a real type. The
@code{REALPART(X)} function is provided for compatibility with @command{g77},
and its use is strongly discouraged.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
transformational function
@item @emph{Syntax}:
@multitable @columnfractions .30 .80
@item @code{X = REAL(X)}
@item @code{X = REAL(X, KIND)}
@item @code{X = REALPART(Z)}
@end multitable
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be @code{INTEGER(*)}, @code{REAL(*)}, or
@code{COMPLEX(*)}.
@item @var{KIND} @tab (Optional) @var{KIND} shall be a scalar integer.
@end multitable
@item @emph{Return value}:
These functions return the a @code{REAL(*)} variable or array under
the following rules:
@table @asis
@item (A)
@code{REAL(X)} is converted to a default real type if @var{X} is an
integer or real variable.
@item (B)
@code{REAL(X)} is converted to a real type with the kind type parameter
of @var{X} if @var{X} is a complex variable.
@item (C)
@code{REAL(X, KIND)} is converted to a real type with kind type
parameter @var{KIND} if @var{X} is a complex, integer, or real
variable.
@end table
@item @emph{Example}:
@smallexample
program test_real
complex :: x = (1.0, 2.0)
print *, real(x), real(x,8), realpart(x)
end program test_real
@end smallexample
@end table
@node RRSPACING
@section @code{RRSPACING} --- Reciprocal of the relative spacing
@findex @code{RRSPACING} intrinsic
@table @asis
@item @emph{Description}:
@code{RRSPACING(X)} returns the reciprocal of the relative spacing of
model numbers near @var{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{Y = RRSPACING(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL}.
@end multitable
@item @emph{Return value}:
The return value is of the same type and kind as @var{X}.
The value returned is equal to
@code{ABS(FRACTION(X)) * FLOAT(RADIX(X))**DIGITS(X)}.
@end table
@node SCALE
@section @code{SCALE} --- Scale a real value
@findex @code{SCALE} intrinsic
@table @asis
@item @emph{Description}:
@code{SCALE(X,I)} returns @code{X * RADIX(X)**I}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{Y = SCALE(X, I)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab The type of the argument shall be a @code{REAL}.
@item @var{I} @tab The type of the argument shall be a @code{INTEGER}.
@end multitable
@item @emph{Return value}:
The return value is of the same type and kind as @var{X}.
Its value is @code{X * RADIX(X)**I}.
@item @emph{Example}:
@smallexample
program test_scale
real :: x = 178.1387e-4
integer :: i = 5
print *, scale(x,i), x*radix(x)**i
end program test_scale
@end smallexample
@end table
@node SELECTED_INT_KIND
@section @code{SELECTED_INT_KIND} --- Choose integer kind
@findex @code{SELECTED_INT_KIND} intrinsic
@cindex integer kind
@table @asis
@item @emph{Description}:
@code{SELECTED_INT_KIND(I)} return the kind value of the smallest integer
type that can represent all values ranging from @math{-10^I} (exclusive)
to @math{10^I} (exclusive). If there is no integer kind that accomodates
this range, @code{SELECTED_INT_KIND} returns @math{-1}.
@item @emph{Option}:
f95
@item @emph{Class}:
transformational function
@item @emph{Syntax}:
@multitable @columnfractions .30 .80
@item @code{J = SELECTED_INT_KIND(I)}
@end multitable
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{I} @tab shall be a scalar and of type @code{INTEGER}.
@end multitable
@item @emph{Example}:
@smallexample
program large_integers
integer,parameter :: k5 = selected_int_kind(5)
integer,parameter :: k15 = selected_int_kind(15)
integer(kind=k5) :: i5
integer(kind=k15) :: i15
print *, huge(i5), huge(i15)
! The following inequalities are always true
print *, huge(i5) >= 10_k5**5-1
print *, huge(i15) >= 10_k15**15-1
end program large_integers
@end smallexample
@end table
@node SELECTED_REAL_KIND
@section @code{SELECTED_REAL_KIND} --- Choose real kind
@findex @code{SELECTED_REAL_KIND} intrinsic
@cindex real kind
@table @asis
@item @emph{Description}:
@code{SELECTED_REAL_KIND(P,R)} return the kind value of a real data type
with decimal precision greater of at least @code{P} digits and exponent
range greater at least @code{R}.
@item @emph{Option}:
f95
@item @emph{Class}:
transformational function
@item @emph{Syntax}:
@multitable @columnfractions .30 .80
@item @code{I = SELECTED_REAL_KIND(P,R)}
@end multitable
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{P} @tab (Optional) shall be a scalar and of type @code{INTEGER}.
@item @var{R} @tab (Optional) shall be a scalar and of type @code{INTEGER}.
@end multitable
At least one argument shall be present.
@item @emph{Return value}:
@code{SELECTED_REAL_KIND} returns the value of the kind type parameter of
a real data type with decimal precision of at least @code{P} digits and a
decimal exponent range of at least @code{R}. If more than one real data
type meet the criteria, the kind of the data type with the smallest
decimal precision is returned. If no real data type matches the criteria,
the result is
@table @asis
@item -1 if the processor does not support a real data type with a
precision greater than or equal to @code{P}
@item -2 if the processor does not support a real type with an exponent
range greater than or equal to @code{R}
@item -3 if neither is supported.
@end table
@item @emph{Example}:
@smallexample
program real_kinds
integer,parameter :: p6 = selected_real_kind(6)
integer,parameter :: p10r100 = selected_real_kind(10,100)
integer,parameter :: r400 = selected_real_kind(r=400)
real(kind=p6) :: x
real(kind=p10r100) :: y
real(kind=r400) :: z
print *, precision(x), range(x)
print *, precision(y), range(y)
print *, precision(z), range(z)
end program real_kinds
@end smallexample
@end table
@node SECNDS
@section @code{SECNDS} --- Time subroutine
@findex @code{SECNDS} intrinsic
@cindex SECNDS
@table @asis
@item @emph{Description}:
@code{SECNDS(X)} gets the time in seconds from the real-time system clock.
@var{X} is a reference time, also in seconds. If this is zero, the time in
seconds from midnight is returned. This function is non-standard and its
use is discouraged.
@item @emph{Option}:
gnu
@item @emph{Class}:
function
@item @emph{Syntax}:
@code{T = SECNDS (X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item Name @tab Type
@item @var{T} @tab REAL(4)
@item @var{X} @tab REAL(4)
@end multitable @end multitable
@item @emph{Return value}: @item @emph{Return value}:
The return value is of type @code{REAL(*)} or @code{COMPLEX(*)}. None
The kind type parameter is the same as @var{X}.
@item @emph{Example}: @item @emph{Example}:
@smallexample @smallexample
program test_log10 program test_secnds
real(8) :: x = 10.0_8 real(4) :: t1, t2
x = log10(x) print *, secnds (0.0) ! seconds since midnight
end program test_log10 t1 = secnds (0.0) ! reference time
do i = 1, 10000000 ! do something
end do
t2 = secnds (t1) ! elapsed time
print *, "Something took ", t2, " seconds."
end program test_secnds
@end smallexample @end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Argument @tab Return type @tab Option
@item @code{ALOG10(X)} @tab @code{REAL(4) X} @tab @code{REAL(4)} @tab f95, gnu
@item @code{DLOG10(X)} @tab @code{REAL(8) X} @tab @code{REAL(8)} @tab f95, gnu
@end multitable
@end table @end table
@node MALLOC
@section @code{MALLOC} --- Allocate dynamic memory @node SET_EXPONENT
@findex @code{MALLOC} intrinsic @section @code{SET_EXPONENT} --- Set the exponent of the model
@cindex MALLOC @findex @code{SET_EXPONENT} intrinsic
@cindex exponent
@table @asis @table @asis
@item @emph{Description}: @item @emph{Description}:
@code{MALLOC(SIZE)} allocates @var{SIZE} bytes of dynamic memory and @code{SET_EXPONENT(X, I)} returns the real number whose fractional part
returns the address of the allocated memory. The @code{MALLOC} intrinsic is that that of @var{X} and whose exponent part if @var{I}.
is an extension intended to be used with Cray pointers, and is provided
in @command{gfortran} to allow user to compile legacy code. For new code
using Fortran 95 pointers, the memory allocation intrinsic is
@code{ALLOCATE}.
@item @emph{Option}: @item @emph{Option}:
gnu f95, gnu
@item @emph{Class}: @item @emph{Class}:
non-elemental function elemental function
@item @emph{Syntax}: @item @emph{Syntax}:
@code{PTR = MALLOC(SIZE)} @code{Y = SET_EXPONENT(X, I)}
@item @emph{Arguments}: @item @emph{Arguments}:
@multitable @columnfractions .15 .80 @multitable @columnfractions .15 .80
@item @var{SIZE} @tab The type shall be @code{INTEGER(*)}. @item @var{X} @tab shall be of type @code{REAL}.
@item @var{I} @tab shall be of type @code{INTEGER}.
@end multitable @end multitable
@item @emph{Return value}: @item @emph{Return value}:
The return value is of type @code{INTEGER(K)}, with @var{K} such that The return value is of the same type and kind as @var{X}.
variables of type @code{INTEGER(K)} have the same size as The real number whose fractional part
C pointers (@code{sizeof(void *)}). is that that of @var{X} and whose exponent part if @var{I} is returned;
it is @code{FRACTION(X) * RADIX(X)**I}.
@item @emph{Example}: @item @emph{Example}:
The following example demonstrates the use of @code{MALLOC} and
@code{FREE} with Cray pointers. This example is intended to run on
32-bit systems, where the default integer kind is suitable to store
pointers; on 64-bit systems, ptr_x would need to be declared as
@code{integer(kind=8)}.
@smallexample @smallexample
program test_malloc program test_setexp
integer i real :: x = 178.1387e-4
integer ptr_x integer :: i = 17
real*8 x(*), z print *, set_exponent(x), fraction(x) * radix(x)**i
pointer(ptr_x,x) end program test_setexp
ptr_x = malloc(20*8)
do i = 1, 20
x(i) = sqrt(1.0d0 / i)
end do
z = 0
do i = 1, 20
z = z + x(i)
print *, z
end do
call free(ptr_x)
end program test_malloc
@end smallexample @end smallexample
@end table @end table
@node REAL
@section @code{REAL} --- Convert to real type @node SIGN
@findex @code{REAL} intrinsic @section @code{SIGN} --- Sign copying function
@findex @code{REALPART} intrinsic @findex @code{SIGN} intrinsic
@cindex true values @findex @code{ISIGN} intrinsic
@findex @code{DSIGN} intrinsic
@cindex sign copying
@table @asis @table @asis
@item @emph{Description}: @item @emph{Description}:
@code{REAL(X [, KIND])} converts its argument @var{X} to a real type. The @code{SIGN(A,B)} returns the value of @var{A} with the sign of @var{B}.
@code{REALPART(X)} function is provided for compatibility with @command{g77},
and its use is strongly discouraged.
@item @emph{Option}: @item @emph{Option}:
f95, gnu f95, gnu
@item @emph{Class}: @item @emph{Class}:
transformational function elemental function
@item @emph{Syntax}: @item @emph{Syntax}:
@multitable @columnfractions .30 .80 @code{X = SIGN(A,B)}
@item @code{X = REAL(X)}
@item @code{X = REAL(X, KIND)}
@item @code{X = REALPART(Z)}
@end multitable
@item @emph{Arguments}: @item @emph{Arguments}:
@multitable @columnfractions .15 .80 @multitable @columnfractions .15 .80
@item @var{X} @tab shall be @code{INTEGER(*)}, @code{REAL(*)}, or @item @var{A} @tab shall be a scalar of type @code{INTEGER} or @code{REAL}
@code{COMPLEX(*)}. @item @var{B} @tab shall be a scalar of the same type and kind as @var{A}
@item @var{KIND} @tab (Optional) @var{KIND} shall be a scalar integer.
@end multitable @end multitable
@item @emph{Return value}: @item @emph{Return value}:
These functions return the a @code{REAL(*)} variable or array under The kind of the return value is that of @var{A} and @var{B}.
the following rules: If @math{B\ge 0} then the result is @code{ABS(A)}, else
it is @code{-ABS(A)}.
@table @asis
@item (A)
@code{REAL(X)} is converted to a default real type if @var{X} is an
integer or real variable.
@item (B)
@code{REAL(X)} is converted to a real type with the kind type parameter
of @var{X} if @var{X} is a complex variable.
@item (C)
@code{REAL(X, KIND)} is converted to a real type with kind type
parameter @var{KIND} if @var{X} is a complex, integer, or real
variable.
@end table
@item @emph{Example}: @item @emph{Example}:
@smallexample @smallexample
program test_real program test_sign
complex :: x = (1.0, 2.0) print *, sign(-12,1)
print *, real(x), real(x,8), realpart(x) print *, sign(-12,0)
end program test_real print *, sign(-12,-1)
print *, sign(-12.,1.)
print *, sign(-12.,0.)
print *, sign(-12.,-1.)
end program test_sign
@end smallexample @end smallexample
@item @emph{Specific names}:
@multitable @columnfractions .24 .24 .24 .24
@item Name @tab Arguments @tab Return type @tab Option
@item @code{ISIGN(A,P)} @tab @code{INTEGER(4)} @tab @code{INTEGER(4)} @tab f95, gnu
@item @code{DSIGN(A,P)} @tab @code{REAL(8)} @tab @code{REAL(8)} @tab f95, gnu
@end multitable
@end table @end table
...@@ -3280,53 +4493,6 @@ end program test_signal ...@@ -3280,53 +4493,6 @@ end program test_signal
@node SECNDS
@section @code{SECNDS} --- Time subroutine
@findex @code{SECNDS} intrinsic
@cindex SECNDS
@table @asis
@item @emph{Description}:
@code{SECNDS(X)} gets the time in seconds from the real-time system clock.
@var{X} is a reference time, also in seconds. If this is zero, the time in
seconds from midnight is returned. This function is non-standard and its
use is discouraged.
@item @emph{Option}:
gnu
@item @emph{Class}:
function
@item @emph{Syntax}:
@code{T = SECNDS (X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item Name @tab Type
@item @var{T} @tab REAL(4)
@item @var{X} @tab REAL(4)
@end multitable
@item @emph{Return value}:
None
@item @emph{Example}:
@smallexample
program test_secnds
real(4) :: t1, t2
print *, secnds (0.0) ! seconds since midnight
t1 = secnds (0.0) ! reference time
do i = 1, 10000000 ! do something
end do
t2 = secnds (t1) ! elapsed time
print *, "Something took ", t2, " seconds."
end program test_secnds
@end smallexample
@end table
@node SIN @node SIN
@section @code{SIN} --- Sine function @section @code{SIN} --- Sine function
@findex @code{SIN} intrinsic @findex @code{SIN} intrinsic
...@@ -3421,6 +4587,38 @@ end program test_sinh ...@@ -3421,6 +4587,38 @@ end program test_sinh
@node SNGL
@section @code{SNGL} --- Convert double precision real to default real
@findex @code{SNGL} intrinsic
@cindex sngl
@table @asis
@item @emph{Description}:
@code{SNGL(A)} converts the double precision real @var{A}
to a default real value. This is an archaic form of @code{REAL}
that is specific to one type for @var{A}.
@item @emph{Option}:
gnu
@item @emph{Class}:
function
@item @emph{Syntax}:
@code{X = SNGL(A)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{A} @tab The type shall be a double precision @code{REAL}.
@end multitable
@item @emph{Return value}:
The return value is of type default @code{REAL}.
@end table
@node SQRT @node SQRT
@section @code{SQRT} --- Square-root function @section @code{SQRT} --- Square-root function
@findex @code{SQRT} intrinsic @findex @code{SQRT} intrinsic
...@@ -3475,6 +4673,50 @@ end program test_sqrt ...@@ -3475,6 +4673,50 @@ end program test_sqrt
@node SRAND
@section @code{SRAND} --- Reinitialize the random number generator
@findex @code{SRAND} intrinsic
@cindex random number
@table @asis
@item @emph{Description}:
@code{SRAND} reinitializes the pseudo-random number generator
called by @code{RAND} and @code{IRAND}. The new seed used by the
generator is specified by the required argument @var{SEED}.
@item @emph{Option}:
gnu
@item @emph{Class}:
non-elemental subroutine
@item @emph{Syntax}:
@code{CALL SRAND(SEED)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{SEED} @tab shall be a scalar @code{INTEGER(kind=4)}.
@end multitable
@item @emph{Return value}:
Does not return.
@item @emph{Example}:
See @code{RAND} and @code{IRAND} for examples.
@item @emph{Notes}:
The Fortran 2003 standard specifies the intrinsic @code{RANDOM_SEED} to
initialize the pseudo-random numbers generator and @code{RANDOM_NUMBER}
to generate pseudo-random numbers. Please note that in
@command{gfortran}, these two sets of intrinsics (@code{RAND},
@code{IRAND} and @code{SRAND} on the one hand, @code{RANDOM_NUMBER} and
@code{RANDOM_SEED} on the other hand) access two independent
pseudo-random numbers generators.
@end table
@node TAN @node TAN
@section @code{TAN} --- Tangent function @section @code{TAN} --- Tangent function
@findex @code{TAN} intrinsic @findex @code{TAN} intrinsic
...@@ -3565,10 +4807,39 @@ end program test_tanh ...@@ -3565,10 +4807,39 @@ end program test_tanh
@comment sub flush @node TINY
@comment @section @code{TINY} --- Smallest positive number of a real kind
@comment gen fraction @findex @code{TINY} intrinsic
@comment @cindex tiny
@table @asis
@item @emph{Description}:
@code{TINY(X)} returns the smallest positive (non zero) number
in the model of the type of @code{X}.
@item @emph{Option}:
f95, gnu
@item @emph{Class}:
elemental function
@item @emph{Syntax}:
@code{Y = TINY(X)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .80
@item @var{X} @tab shall be of type @code{REAL}.
@end multitable
@item @emph{Return value}:
The return value is of the same type and kind as @var{X}
@item @emph{Example}:
See @code{HUGE} for an example.
@end table
@comment gen fstat @comment gen fstat
@comment sub fstat @comment sub fstat
@comment @comment
...@@ -3579,22 +4850,12 @@ end program test_tanh ...@@ -3579,22 +4850,12 @@ end program test_tanh
@comment @comment
@comment sub getenv @comment sub getenv
@comment @comment
@comment gen getgid
@comment
@comment gen getpid
@comment
@comment gen getuid
@comment
@comment sub get_command @comment sub get_command
@comment @comment
@comment sub get_command_argument @comment sub get_command_argument
@comment @comment
@comment sub get_environment_variable @comment sub get_environment_variable
@comment @comment
@comment gen huge
@comment
@comment gen iachar
@comment
@comment gen iand @comment gen iand
@comment @comment
@comment gen iargc @comment gen iargc
...@@ -3605,8 +4866,6 @@ end program test_tanh ...@@ -3605,8 +4866,6 @@ end program test_tanh
@comment @comment
@comment gen ibset @comment gen ibset
@comment @comment
@comment gen ichar
@comment
@comment gen ieor @comment gen ieor
@comment @comment
@comment gen index @comment gen index
...@@ -3617,14 +4876,10 @@ end program test_tanh ...@@ -3617,14 +4876,10 @@ end program test_tanh
@comment @comment
@comment gen ior @comment gen ior
@comment @comment
@comment gen irand
@comment
@comment gen ishft @comment gen ishft
@comment @comment
@comment gen ishftc @comment gen ishftc
@comment @comment
@comment gen kind
@comment
@comment gen lbound @comment gen lbound
@comment @comment
@comment gen len @comment gen len
...@@ -3650,8 +4905,6 @@ end program test_tanh ...@@ -3650,8 +4905,6 @@ end program test_tanh
@comment max1 @comment max1
@comment dmax1 @comment dmax1
@comment @comment
@comment gen maxexponent
@comment
@comment gen maxloc @comment gen maxloc
@comment @comment
@comment gen maxval @comment gen maxval
...@@ -3665,85 +4918,45 @@ end program test_tanh ...@@ -3665,85 +4918,45 @@ end program test_tanh
@comment min1 @comment min1
@comment dmin1 @comment dmin1
@comment @comment
@comment gen minexponent
@comment
@comment gen minloc @comment gen minloc
@comment @comment
@comment gen minval @comment gen minval
@comment @comment
@comment gen mod
@comment amod
@comment dmod
@comment
@comment gen modulo
@comment
@comment sub mvbits @comment sub mvbits
@comment @comment
@comment gen nearest
@comment
@comment gen nint
@comment idnint
@comment
@comment gen not @comment gen not
@comment @comment
@comment gen null @comment gen null
@comment @comment
@comment gen pack @comment gen pack
@comment @comment
@comment gen precision @comment gen perror
@comment @comment
@comment gen present @comment gen present
@comment @comment
@comment gen product @comment gen product
@comment @comment
@comment gen radix
@comment
@comment gen rand
@comment ran
@comment
@comment sub random_number @comment sub random_number
@comment @comment
@comment sub random_seed @comment sub random_seed
@comment @comment
@comment gen range
@comment
@comment gen real
@comment float
@comment sngl
@comment
@comment gen repeat @comment gen repeat
@comment @comment
@comment gen reshape @comment gen reshape
@comment @comment
@comment gen rrspacing
@comment
@comment gen scale
@comment
@comment gen scan @comment gen scan
@comment @comment
@comment gen second @comment gen second
@comment sub second @comment sub second
@comment @comment
@comment gen selected_int_kind
@comment
@comment gen selected_real_kind
@comment
@comment gen set_exponent
@comment
@comment gen shape @comment gen shape
@comment @comment
@comment gen sign
@comment isign
@comment dsign
@comment
@comment gen size @comment gen size
@comment @comment
@comment gen spacing @comment gen spacing
@comment @comment
@comment gen spread @comment gen spread
@comment @comment
@comment sub srand
@comment
@comment gen stat @comment gen stat
@comment sub stat @comment sub stat
@comment @comment
...@@ -3754,8 +4967,6 @@ end program test_tanh ...@@ -3754,8 +4967,6 @@ end program test_tanh
@comment @comment
@comment sub system_clock @comment sub system_clock
@comment @comment
@comment gen tiny
@comment
@comment gen transfer @comment gen transfer
@comment @comment
@comment gen transpose @comment gen transpose
...@@ -3773,4 +4984,3 @@ end program test_tanh ...@@ -3773,4 +4984,3 @@ end program test_tanh
@comment gen unpack @comment gen unpack
@comment @comment
@comment gen verify @comment gen verify
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