@c Copyright (C) 1995-1999 Free Software Foundation, Inc. @c This is part of the G77 manual. @c For copying conditions, see the file g77.texi. @c The text of this file appears in the file NEWS @c in the G77 distribution, as well as in the G77 manual. @c Keep this the same as the dates above, since it's used @c in the standalone derivations of this file (e.g. NEWS). @set copyrights-news 1995-1999 @set last-update-news 1999-07-08 @include root.texi @ifset DOC-NEWS @c The immediately following lines apply to the NEWS file @c which is derived from this file. @emph{Note:} This file is automatically generated from the files @file{news0.texi} and @file{news.texi}. @file{NEWS} is @emph{not} a source file, although it is normally included within source distributions. This file lists news about the @value{which-g77} version (and some other versions) of the GNU Fortran compiler. Copyright (C) @value{copyrights-news} Free Software Foundation, Inc. You may copy, distribute, and modify it freely as long as you preserve this copyright notice and permission notice. @node Top,,, (dir) @chapter News About GNU Fortran @end ifset @ifset DOC-G77 @ifset USERVISONLY @node Changes @chapter User-visible Changes @cindex versions, recent @cindex recent versions @cindex changes, user-visible @cindex user-visible changes This chapter describes changes to @code{g77} that are visible to the programmers who actually write and maintain Fortran code they compile with @code{g77}. Information on changes to installation procedures, changes to the documentation, and bug fixes is not provided here, unless it is likely to affect how users use @code{g77}. @xref{News,,News About GNU Fortran}, for information on such changes to @code{g77}. @end ifset @ifclear USERVISONLY @node News @chapter News About GNU Fortran @cindex versions, recent @cindex recent versions @end ifclear @end ifset @ifclear USERVISONLY Changes made to recent versions of GNU Fortran are listed below, with the most recent version first. The changes are generally listed in order: @enumerate @item Code-generation and run-time-library bug-fixes @item Compiler and run-time-library crashes involving valid code that have been fixed @item New features @item Fixes and enhancements to existing features @item New diagnostics @item Internal improvements @item Miscellany @end enumerate This order is not strict---for example, some items involve a combination of these elements. @end ifclear Note that two variants of @code{g77} are tracked below. The @code{egcs} variant is described vis-a-vis previous versions of @code{egcs} and/or an official FSF version, as appropriate. Therefore, @code{egcs} versions sometimes have multiple listings to help clarify how they differ from other versions, though this can make getting a complete picture of what a particular @code{egcs} version contains somewhat more difficult. @ifset DOC-G77 For information on bugs in the @value{which-g77} version of @code{g77}, see @ref{Known Bugs,,Known Bugs In GNU Fortran}. @end ifset @ifset DOC-BUGS For information on bugs in the @value{which-g77} version of @code{g77}, see @file{@value{path-g77}/BUGS}. @end ifset @ifset DEVELOPMENT @emph{Warning:} The information below is still under development, and might not accurately reflect the @code{g77} code base of which it is a part. Efforts are made to keep it somewhat up-to-date, but they are particularly concentrated on any version of this information that is distributed as part of a @emph{released} @code{g77}. In particular, while this information is intended to apply to the @value{which-g77} version of @code{g77}, only an official @emph{release} of that version is expected to contain documentation that is most consistent with the @code{g77} product in that version. Nevertheless, information on @emph{previous} releases of @code{g77}, below, is likely to be more up-to-date and accurate than the equivalent information that accompanied those releases, assuming the last-updated date of the information below is later than the dates of those releases. That's due to attempts to keep this development version of news about previous @code{g77} versions up-to-date. @end ifset @ifclear USERVISONLY An online, ``live'' version of this document (derived directly from the mainline, development version of @code{g77} within @code{egcs}) is available at @uref{http://www.gnu.org/software/gcc/onlinedocs/g77_news.html}. @end ifclear The following information was last updated on @value{last-update-news}: @heading In development: @itemize @bullet @ifclear USERVISONLY @item The @code{TtyNam} intrinsics now set @var{Name} to all spaces (at run time) if the system has no @code{ttyname} implementation available. @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1999-06-28. This fixes a bug whereby input to a @code{NAMELIST} read involving a repeat count, such as @samp{K(5)=10*3}, was not properly handled by @code{libf2c}. The first item was written to @samp{K(5)}, but the remaining nine were written elsewhere (still within the array), not necessarily starting at @samp{K(6)}. @end ifclear @end itemize @heading In 0.5.25, @code{GCC} 2.95 (@code{EGCS} 1.2) versus @code{EGCS} 1.1.2: @itemize @bullet @ifclear USERVISONLY @item @code{g77} no longer generates bad code for assignments, or other conversions, of @code{REAL} or @code{COMPLEX} constant expressions to type @code{INTEGER(KIND=2)} (often referred to as @code{INTEGER*8}). For example, @samp{INTEGER*8 J; J = 4E10} now works as documented. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer truncates @code{INTEGER(KIND=2)} (usually @code{INTEGER*8}) subscript expressions when evaluating array references on systems with pointers widers than @code{INTEGER(KIND=1)} (such as Alphas). @end ifclear @ifclear USERVISONLY @item @code{g77} no longer generates bad code for an assignment to a @code{COMPLEX} variable or array that partially overlaps one or more of the sources of the same assignment (a very rare construction). It now assigns through a temporary, in cases where such partial overlap is deemed possible. @end ifclear @ifclear USERVISONLY @item @code{libg2c} (@code{libf2c}) no longer loses track of the file being worked on during a @code{BACKSPACE} operation. @end ifclear @ifclear USERVISONLY @item @code{libg2c} (@code{libf2c}) fixes a bug whereby input to a @code{NAMELIST} read involving a repeat count, such as @samp{K(5)=10*3}, was not properly handled by @code{libf2c}. The first item was written to @samp{K(5)}, but the remaining nine were written elsewhere (still within the array), not necessarily starting at @samp{K(6)}. @end ifclear @ifclear USERVISONLY @item @c Tim Prince reported this, regarding the TEST_FPU benchmark. Automatic arrays now seem to be working on HP-UX systems. @end ifclear @ifclear USERVISONLY @item The @code{Date} intrinsic now returns the correct result on big-endian systems. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} so it no longer crashes when compiling I/O statements using keywords that define @code{INTEGER} values, such as @samp{IOSTAT=@var{j}}, where @var{j} is other than default @code{INTEGER} (such as @code{INTEGER*2}). Instead, it issues a diagnostic. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} so it properly handles @samp{DATA A/@var{rpt}*@var{val}/}, where @var{rpt} is not default @code{INTEGER}, such as @code{INTEGER*2}, instead of producing a spurious diagnostic. Also fix @samp{DATA (A(I),I=1,N)}, where @samp{N} is not default @code{INTEGER} to work instead of crashing @code{g77}. @end ifclear @ifclear USERVISONLY @item The @samp{-ax} option is now obeyed when compiling Fortran programs. (It is passed to the @file{f771} driver.) @end ifclear @item The new @samp{-fbounds-check} option causes @code{g77} to compile run-time bounds checks of array subscripts, as well as of substring start and end points. @item @code{libg2c} now supports building as multilibbed library, which provides better support for systems that require options such as @samp{-mieee} to work properly. @item Source file names with the suffixes @samp{.FOR} and @samp{.FPP} now are recognized by @code{g77} as if they ended in @samp{.for} and @samp{.fpp}, respectively. @item The order of arguments to the @emph{subroutine} forms of the @code{CTime}, @code{DTime}, @code{ETime}, and @code{TtyNam} intrinsics has been swapped. The argument serving as the returned value for the corresponding function forms now is the @emph{second} argument, making these consistent with the other subroutine forms of @code{libU77} intrinsics. @item @code{g77} now warns about a reference to an intrinsic that has an interface that is not Year 2000 (Y2K) compliant. Also, @code{libg2c} has been changed to increase the likelihood of catching references to the implementations of these intrinsics using the @code{EXTERNAL} mechanism (which would avoid the new warnings). @ifset DOC-G77 @xref{Year 2000 (Y2K) Problems}, for more information. @end ifset @ifclear USERVISONLY @item @code{g77} now warns about a reference to a function when the corresponding @emph{subsequent} function program unit disagrees with the reference concerning the type of the function. @end ifclear @item @samp{-fno-emulate-complex} is now the default option. This should result in improved performance of code that uses the @code{COMPLEX} data type. @cindex alignment @cindex double-precision performance @cindex -malign-double @item The @samp{-malign-double} option now reliably aligns @emph{all} double-precision variables and arrays on Intel x86 targets. @ifclear USERVISONLY @item Even without the @samp{-malign-double} option, @code{g77} reliably aligns local double-precision variables that are not in @code{EQUIVALENCE} areas and not @code{SAVE}'d. @end ifclear @ifclear USERVISONLY @item @code{g77} now open-codes (``inlines'') division of @code{COMPLEX} operands instead of generating a run-time call to the @code{libf2c} routines @code{c_div} or @code{z_div}, unless the @samp{-Os} option is specified. @end ifclear @item @code{g77} no longer generates code to maintain @code{errno}, a C-language concept, when performing operations such as the @code{SqRt} intrinsic. @ifclear USERVISONLY @item @code{g77} developers can temporarily use the @samp{-fflatten-arrays} option to compare how the compiler handles code generation using C-like constructs as compared to the Fortran-like method constructs normally used. @end ifclear @ifclear USERVISONLY @item A substantial portion of the @code{g77} front end's code-generation component was rewritten. It now generates code using facilities more robustly supported by the @code{gcc} back end. One effect of this rewrite is that some codes no longer produce a spurious ``label @var{lab} used before containing binding contour'' message. @end ifclear @item Support for the @samp{-fugly} option has been removed. @ifclear USERVISONLY @item Improve documentation and indexing, including information on Year 2000 (Y2K) compliance, and providing more information on internals of the front end. @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1999-05-10. @end ifclear @end itemize @heading In 0.5.24 versus 0.5.23: There is no @code{g77} version 0.5.24 at this time, or planned. 0.5.24 is the version number designated for bug fixes and, perhaps, some new features added, to 0.5.23. Version 0.5.23 requires @code{gcc} 2.8.1, as 0.5.24 was planned to require. Due to @code{EGCS} becoming @code{GCC} (which is now an acronym for ``GNU Compiler Collection''), and @code{EGCS} 1.2 becoming officially designated @code{GCC} 2.95, there seems to be no need for an actual 0.5.24 release. To reduce the confusion already resulting from use of 0.5.24 to designate @code{g77} versions within @code{EGCS} versions 1.0 and 1.1, as well as in versions of @code{g77} documentation and notices during that period, ``mainline'' @code{g77} version numbering resumes at 0.5.25 with @code{GCC} 2.95 (@code{EGCS} 1.2), skipping over 0.5.24 as a placeholder version number. To repeat, there is no @code{g77} 0.5.24, but there is now a 0.5.25. Please remain calm and return to your keypunch units. @c 1999-03-15: EGCS 1.1.2 released. @heading In @code{EGCS} 1.1.2 versus @code{EGCS} 1.1.1: @ifclear USERVISONLY @itemize @bullet @item Fix the @code{IDate} intrinsic (VXT) (in @code{libg2c}) so the returned year is in the documented, non-Y2K-compliant range of 0-99, instead of being returned as 100 in the year 2000. @ifset DOC-G77 @xref{IDate Intrinsic (VXT)}, for more information. @end ifset @item Fix the @code{Date_and_Time} intrinsic (in @code{libg2c}) to return the milliseconds value properly in @var{Values}(8). @item Fix the @code{LStat} intrinsic (in @code{libg2c}) to return device-ID information properly in @var{SArray}(7). @item Improve documentation. @end itemize @end ifclear @c 1998-12-04: EGCS 1.1.1 released. @heading In @code{EGCS} 1.1.1 versus @code{EGCS} 1.1: @ifclear USERVISONLY @itemize @bullet @item Fix @code{libg2c} so it performs an implicit @code{ENDFILE} operation (as appropriate) whenever a @code{REWIND} is done. (This bug was introduced in 0.5.23 and @code{egcs} 1.1 in @code{g77}'s version of @code{libf2c}.) @item Fix @code{libg2c} so it no longer crashes with a spurious diagnostic upon doing any I/O following a direct formatted write. (This bug was introduced in 0.5.23 and @code{egcs} 1.1 in @code{g77}'s version of @code{libf2c}.) @item Fix @code{g77} so it no longer crashes compiling references to the @code{Rand} intrinsic on some systems. @item Fix @code{g77} portion of installation process so it works better on some systems (those with shells requiring @samp{else true} clauses on @code{if} constructs for the completion code to be set properly). @end itemize @end ifclear @c 1998-09-03: EGCS 1.1 released. @heading In @code{EGCS} 1.1 versus @code{EGCS} 1.0.3: @itemize @bullet @ifclear USERVISONLY @item Fix bugs in the @code{libU77} intrinsic @code{HostNm} that wrote one byte beyond the end of its @code{CHARACTER} argument, and in the @code{libU77} intrinsics @code{GMTime} and @code{LTime} that overwrote their arguments. @end ifclear @ifclear USERVISONLY @item Assumed arrays with negative bounds (such as @samp{REAL A(-1:*)}) no longer elicit spurious diagnostics from @code{g77}, even on systems with pointers having different sizes than integers. This bug is not known to have existed in any recent version of @code{gcc}. It was introduced in an early release of @code{egcs}. @end ifclear @ifclear USERVISONLY @item Valid combinations of @code{EXTERNAL}, passing that external as a dummy argument without explicitly giving it a type, and, in a subsequent program unit, referencing that external as an external function with a different type no longer crash @code{g77}. @end ifclear @ifclear USERVISONLY @item @code{CASE DEFAULT} no longer crashes @code{g77}. @end ifclear @ifclear USERVISONLY @item The @samp{-Wunused} option no longer issues a spurious warning about the ``master'' procedure generated by @code{g77} for procedures containing @code{ENTRY} statements. @end ifclear @item Support @samp{FORMAT(I<@var{expr}>)} when @var{expr} is a compile-time constant @code{INTEGER} expression. @item Fix @code{g77} @samp{-g} option so procedures that use @code{ENTRY} can be stepped through, line by line, in @code{gdb}. @item Allow any @code{REAL} argument to intrinsics @code{Second} and @code{CPU_Time}. @item Use @code{tempnam}, if available, to open scratch files (as in @samp{OPEN(STATUS='SCRATCH')}) so that the @code{TMPDIR} environment variable, if present, is used. @item @code{g77}'s version of @code{libf2c} separates out the setting of global state (such as command-line arguments and signal handling) from @file{main.o} into distinct, new library archive members. This should make it easier to write portable applications that have their own (non-Fortran) @code{main()} routine properly set up the @code{libf2c} environment, even when @code{libf2c} (now @code{libg2c}) is a shared library. @ifclear USERVISONLY @item @code{g77} no longer installs the @file{f77} command and @file{f77.1} man page in the @file{/usr} or @file{/usr/local} heirarchy, even if the @file{f77-install-ok} file exists in the source or build directory. See the installation documentation for more information. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer installs the @file{libf2c.a} library and @file{f2c.h} include file in the @file{/usr} or @file{/usr/local} heirarchy, even if the @file{f2c-install-ok} or @file{f2c-exists-ok} files exist in the source or build directory. See the installation documentation for more information. @end ifclear @ifclear USERVISONLY @item The @file{libf2c.a} library produced by @code{g77} has been renamed to @file{libg2c.a}. It is installed only in the @code{gcc} ``private'' directory heirarchy, @file{gcc-lib}. This allows system administrators and users to choose which version of the @code{libf2c} library from @code{netlib} they wish to use on a case-by-case basis. See the installation documentation for more information. @end ifclear @ifclear USERVISONLY @item The @file{f2c.h} include (header) file produced by @code{g77} has been renamed to @file{g2c.h}. It is installed only in the @code{gcc} ``private'' directory heirarchy, @file{gcc-lib}. This allows system administrators and users to choose which version of the include file from @code{netlib} they wish to use on a case-by-case basis. See the installation documentation for more information. @end ifclear @item The @code{g77} command now expects the run-time library to be named @code{libg2c.a} instead of @code{libf2c.a}, to ensure that a version other than the one built and installed as part of the same @code{g77} version is picked up. @ifclear USERVISONLY @item During the configuration and build process, @code{g77} creates subdirectories it needs only as it needs them. Other cleaning up of the configuration and build process has been performed as well. @end ifclear @ifclear USERVISONLY @item @code{install-info} now used to update the directory of Info documentation to contain an entry for @code{g77} (during installation). @end ifclear @item Some diagnostics have been changed from warnings to errors, to prevent inadvertent use of the resulting, probably buggy, programs. These mostly include diagnostics about use of unsupported features in the @code{OPEN}, @code{INQUIRE}, @code{READ}, and @code{WRITE} statements, and about truncations of various sorts of constants. @ifclear USERVISONLY @item Improve compilation of @code{FORMAT} expressions so that a null byte is appended to the last operand if it is a constant. This provides a cleaner run-time diagnostic as provided by @code{libf2c} for statements like @samp{PRINT '(I1', 42}. @end ifclear @ifclear USERVISONLY @item Improve documentation and indexing. @end ifclear @ifclear USERVISONLY @item The upgrade to @code{libf2c} as of 1998-06-18 should fix a variety of problems, including those involving some uses of the @code{T} format specifier, and perhaps some build (porting) problems as well. @end ifclear @end itemize @c 1998-09-03: EGCS 1.1 released. @heading In @code{EGCS} 1.1 versus @code{g77} 0.5.23: @itemize @bullet @ifclear USERVISONLY @cindex DNRM2 @cindex stack, 387 coprocessor @cindex Intel x86 @cindex -O2 @item Fix a code-generation bug that afflicted Intel x86 targets when @samp{-O2} was specified compiling, for example, an old version of the @code{DNRM2} routine. The x87 coprocessor stack was being mismanaged in cases involving assigned @code{GOTO} and @code{ASSIGN}. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer produces incorrect code and initial values for @code{EQUIVALENCE} and @code{COMMON} aggregates that, due to ``unnatural'' ordering of members vis-a-vis their types, require initial padding. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} crash compiling code containing the construct @samp{CMPLX(0.)} or similar. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer crashes when compiling code containing specification statements such as @samp{INTEGER(KIND=7) PTR}. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer crashes when compiling code such as @samp{J = SIGNAL(1, 2)}. @end ifclear @item @code{g77} now treats @samp{%LOC(@var{expr})} and @samp{LOC(@var{expr})} as ``ordinary'' expressions when they are used as arguments in procedure calls. This change applies only to global (filewide) analysis, making it consistent with how @code{g77} actually generates code for these cases. Previously, @code{g77} treated these expressions as denoting special ``pointer'' arguments for the purposes of filewide analysis. @ifclear USERVISONLY @item Fix @code{g77} crash (or apparently infinite run-time) when compiling certain complicated expressions involving @code{COMPLEX} arithmetic (especially multiplication). @end ifclear @cindex alignment @cindex double-precision performance @cindex -malign-double @item Align static double-precision variables and arrays on Intel x86 targets regardless of whether @samp{-malign-double} is specified. Generally, this affects only local variables and arrays having the @code{SAVE} attribute or given initial values via @code{DATA}. @item The @code{g77} driver now ensures that @samp{-lg2c} is specified in the link phase prior to any occurrence of @samp{-lm}. This prevents accidentally linking to a routine in the SunOS4 @samp{-lm} library when the generated code wants to link to the one in @code{libf2c} (@code{libg2c}). @item @code{g77} emits more debugging information when @samp{-g} is used. This new information allows, for example, @kbd{which __g77_length_a} to be used in @code{gdb} to determine the type of the phantom length argument supplied with @code{CHARACTER} variables. This information pertains to internally-generated type, variable, and other information, not to the longstanding deficiencies vis-a-vis @code{COMMON} and @code{EQUIVALENCE}. @item The F90 @code{Date_and_Time} intrinsic now is supported. @item The F90 @code{System_Clock} intrinsic allows the optional arguments (except for the @code{Count} argument) to be omitted. @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1998-06-18. @end ifclear @ifclear USERVISONLY @item Improve documentation and indexing. @end ifclear @end itemize @ifset DOC-NEWS @heading In previous versions: Information on previous versions is not provided in this @file{@value{path-g77}/NEWS} file, to keep it short. See @file{@value{path-g77}/news.texi}, or any of its other derivations (Info, HTML, dvi forms) for such information. @end ifset @ifclear DOC-NEWS @c 1998-05-20: 0.5.23 released. @heading In 0.5.23 versus 0.5.22: @itemize @bullet @item This release contains several regressions against version 0.5.22 of @code{g77}, due to using the ``vanilla'' @code{gcc} back end instead of patching it to fix a few bugs and improve performance in a few cases. Features that have been dropped from this version of @code{g77} due to their being implemented via @code{g77}-specific patches to the @code{gcc} back end in previous releases include: @itemize @minus @item Support for @code{__restrict__} keyword, the options @samp{-fargument-alias}, @samp{-fargument-noalias}, and @samp{-fargument-noalias-global}, and the corresponding alias-analysis code. (@code{egcs} has the alias-analysis code, but not the @code{__restrict__} keyword. @code{egcs} @code{g77} users benefit from the alias-analysis code despite the lack of the @code{__restrict__} keyword, which is a C-language construct.) @item Support for the GNU compiler options @samp{-fmove-all-movables}, @samp{-freduce-all-givs}, and @samp{-frerun-loop-opt}. (@code{egcs} supports these options. @code{g77} users of @code{egcs} benefit from them even if they are not explicitly specified, because the defaults are optimized for @code{g77} users.) @item Support for the @samp{-W} option warning about integer division by zero. @item The Intel x86-specific option @samp{-malign-double} applying to stack-allocated data as well as statically-allocate data. @end itemize @ifclear USERVISONLY Note that the @file{gcc/f/gbe/} subdirectory has been removed from this distribution as a result of @code{g77} no longer including patches for the @code{gcc} back end. @end ifclear @ifclear USERVISONLY @item Fix bugs in the @code{libU77} intrinsic @code{HostNm} that wrote one byte beyond the end of its @code{CHARACTER} argument, and in the @code{libU77} intrinsics @code{GMTime} and @code{LTime} that overwrote their arguments. @end ifclear @item Support @code{gcc} version 2.8, and remove support for prior versions of @code{gcc}. @cindex -@w{}-driver option @cindex @code{g77} options, -@w{}-driver @cindex options, -@w{}-driver @item Remove support for the @samp{--driver} option, as @code{g77} now does all the driving, just like @code{gcc}. @ifclear USERVISONLY @item @code{CASE DEFAULT} no longer crashes @code{g77}. @end ifclear @ifclear USERVISONLY @item Valid combinations of @code{EXTERNAL}, passing that external as a dummy argument without explicitly giving it a type, and, in a subsequent program unit, referencing that external as an external function with a different type no longer crash @code{g77}. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer installs the @file{f77} command and @file{f77.1} man page in the @file{/usr} or @file{/usr/local} heirarchy, even if the @file{f77-install-ok} file exists in the source or build directory. See the installation documentation for more information. @end ifclear @ifclear USERVISONLY @item @code{g77} no longer installs the @file{libf2c.a} library and @file{f2c.h} include file in the @file{/usr} or @file{/usr/local} heirarchy, even if the @file{f2c-install-ok} or @file{f2c-exists-ok} files exist in the source or build directory. See the installation documentation for more information. @end ifclear @ifclear USERVISONLY @item The @file{libf2c.a} library produced by @code{g77} has been renamed to @file{libg2c.a}. It is installed only in the @code{gcc} ``private'' directory heirarchy, @file{gcc-lib}. This allows system administrators and users to choose which version of the @code{libf2c} library from @code{netlib} they wish to use on a case-by-case basis. See the installation documentation for more information. @end ifclear @ifclear USERVISONLY @item The @file{f2c.h} include (header) file produced by @code{g77} has been renamed to @file{g2c.h}. It is installed only in the @code{gcc} ``private'' directory heirarchy, @file{gcc-lib}. This allows system administrators and users to choose which version of the include file from @code{netlib} they wish to use on a case-by-case basis. See the installation documentation for more information. @end ifclear @item The @code{g77} command now expects the run-time library to be named @code{libg2c.a} instead of @code{libf2c.a}, to ensure that a version other than the one built and installed as part of the same @code{g77} version is picked up. @ifclear USERVISONLY @item The @samp{-Wunused} option no longer issues a spurious warning about the ``master'' procedure generated by @code{g77} for procedures containing @code{ENTRY} statements. @end ifclear @item @code{g77}'s version of @code{libf2c} separates out the setting of global state (such as command-line arguments and signal handling) from @file{main.o} into distinct, new library archive members. This should make it easier to write portable applications that have their own (non-Fortran) @code{main()} routine properly set up the @code{libf2c} environment, even when @code{libf2c} (now @code{libg2c}) is a shared library. @ifclear USERVISONLY @item During the configuration and build process, @code{g77} creates subdirectories it needs only as it needs them, thus avoiding unnecessary creation of, for example, @file{stage1/f/runtime} when doing a non-bootstrap build. Other cleaning up of the configuration and build process has been performed as well. @end ifclear @ifclear USERVISONLY @item @code{install-info} now used to update the directory of Info documentation to contain an entry for @code{g77} (during installation). @end ifclear @item Some diagnostics have been changed from warnings to errors, to prevent inadvertent use of the resulting, probably buggy, programs. These mostly include diagnostics about use of unsupported features in the @code{OPEN}, @code{INQUIRE}, @code{READ}, and @code{WRITE} statements, and about truncations of various sorts of constants. @ifclear USERVISONLY @item Improve documentation and indexing. @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1998-04-20. This should fix a variety of problems, including those involving some uses of the @code{T} format specifier, and perhaps some build (porting) problems as well. @end ifclear @end itemize @c 1998-03-16: 0.5.22 released. @heading In 0.5.22 versus 0.5.21: @itemize @bullet @ifclear USERVISONLY @item Fix code generation for iterative @code{DO} loops that have one or more references to the iteration variable, or to aliases of it, in their control expressions. For example, @samp{DO 10 J=2,J} now is compiled correctly. @end ifclear @ifclear USERVISONLY @cindex DNRM2 @cindex stack, 387 coprocessor @cindex Intel x86 @cindex -O2 @item Fix a code-generation bug that afflicted Intel x86 targets when @samp{-O2} was specified compiling, for example, an old version of the @code{DNRM2} routine. The x87 coprocessor stack was being mismanaged in cases involving assigned @code{GOTO} and @code{ASSIGN}. @end ifclear @ifclear USERVISONLY @item Fix @code{DTime} intrinsic so as not to truncate results to integer values (on some systems). @end ifclear @item Fix @code{Signal} intrinsic so it offers portable support for 64-bit systems (such as Digital Alphas running GNU/Linux). @ifclear USERVISONLY @item Fix run-time crash involving @code{NAMELIST} on 64-bit machines such as Alphas. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} version of @code{libf2c} so it no longer produces a spurious @samp{I/O recursion} diagnostic at run time when an I/O operation (such as @samp{READ *,I}) is interrupted in a manner that causes the program to be terminated via the @code{f_exit} routine (such as via @kbd{C-c}). @end ifclear @ifclear USERVISONLY @item Fix @code{g77} crash triggered by @code{CASE} statement with an omitted lower or upper bound. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} crash compiling references to @code{CPU_Time} intrinsic. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} crash (or apparently infinite run-time) when compiling certain complicated expressions involving @code{COMPLEX} arithmetic (especially multiplication). @end ifclear @ifclear USERVISONLY @item Fix @code{g77} crash on statements such as @samp{PRINT *, (REAL(Z(I)),I=1,2)}, where @samp{Z} is @code{DOUBLE COMPLEX}. @end ifclear @ifclear USERVISONLY @item Fix a @code{g++} crash. @end ifclear @item Support @samp{FORMAT(I<@var{expr}>)} when @var{expr} is a compile-time constant @code{INTEGER} expression. @item Fix @code{g77} @samp{-g} option so procedures that use @code{ENTRY} can be stepped through, line by line, in @code{gdb}. @ifclear USERVISONLY @item Fix a profiling-related bug in @code{gcc} back end for Intel x86 architecture. @end ifclear @item Allow any @code{REAL} argument to intrinsics @code{Second} and @code{CPU_Time}. @item Allow any numeric argument to intrinsics @code{Int2} and @code{Int8}. @item Use @code{tempnam}, if available, to open scratch files (as in @samp{OPEN(STATUS='SCRATCH')}) so that the @code{TMPDIR} environment variable, if present, is used. @item Rename the @code{gcc} keyword @code{restrict} to @code{__restrict__}, to avoid rejecting valid, existing, C programs. Support for @code{restrict} is now more like support for @code{complex}. @ifclear USERVISONLY @item Fix @samp{-fpedantic} to not reject procedure invocations such as @samp{I=J()} and @samp{CALL FOO()}. @end ifclear @item Fix @samp{-fugly-comma} to affect invocations of only external procedures. Restore rejection of gratuitous trailing omitted arguments to intrinsics, as in @samp{I=MAX(3,4,,)}. @item Fix compiler so it accepts @samp{-fgnu-intrinsics-*} and @samp{-fbadu77-intrinsics-*} options. @ifclear USERVISONLY @item Improve diagnostic messages from @code{libf2c} so it is more likely that the printing of the active format string is limited to the string, with no trailing garbage being printed. (Unlike @code{f2c}, @code{g77} did not append a null byte to its compiled form of every format string specified via a @code{FORMAT} statement. However, @code{f2c} would exhibit the problem anyway for a statement like @samp{PRINT '(I)garbage', 1} by printing @samp{(I)garbage} as the format string.) @end ifclear @ifclear USERVISONLY @item Improve compilation of @code{FORMAT} expressions so that a null byte is appended to the last operand if it is a constant. This provides a cleaner run-time diagnostic as provided by @code{libf2c} for statements like @samp{PRINT '(I1', 42}. @end ifclear @ifclear USERVISONLY @item Fix various crashes involving code with diagnosed errors. @end ifclear @ifclear USERVISONLY @item Fix cross-compilation bug when configuring @code{libf2c}. @end ifclear @ifclear USERVISONLY @item Improve diagnostics. @end ifclear @ifclear USERVISONLY @item Improve documentation and indexing. @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1997-09-23. This fixes a formatted-I/O bug that afflicted 64-bit systems with 32-bit integers (such as Digital Alpha running GNU/Linux). @end ifclear @end itemize @c 1998-03-18: EGCS 1.0.2 released. @heading In @code{EGCS} 1.0.2 versus @code{EGCS} 1.0.1: @itemize @bullet @ifclear USERVISONLY @item Fix @code{g77} crash triggered by @code{CASE} statement with an omitted lower or upper bound. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} crash on statements such as @samp{PRINT *, (REAL(Z(I)),I=1,2)}, where @samp{Z} is @code{DOUBLE COMPLEX}. @end ifclear @ifclear USERVISONLY @cindex ELF support @cindex support, ELF @cindex -fPIC option @cindex options, -fPIC @item Fix @samp{-fPIC} (such as compiling for ELF targets) on the Intel x86 architecture target so invalid assembler code is no longer produced. @end ifclear @ifclear USERVISONLY @item Fix @samp{-fpedantic} to not reject procedure invocations such as @samp{I=J()} and @samp{CALL FOO()}. @end ifclear @ifclear USERVISONLY @item Fix @samp{-fugly-comma} to affect invocations of only external procedures. Restore rejection of gratuitous trailing omitted arguments to intrinsics, as in @samp{I=MAX(3,4,,)}. @end ifclear @item Fix compiler so it accepts @samp{-fgnu-intrinsics-*} and @samp{-fbadu77-intrinsics-*} options. @end itemize @c 1998-01-06: EGCS 1.0.1 released. @heading In @code{EGCS} 1.0.1 versus @code{EGCS} 1.0: @ifclear USERVISONLY @itemize @bullet @item Fix run-time crash involving @code{NAMELIST} on 64-bit machines such as Alphas. @end itemize @end ifclear @c 1997-12-03: EGCS 1.0 released. @heading In @code{EGCS} 1.0 versus @code{g77} 0.5.21: @itemize @bullet @item Version 1.0 of @code{egcs} contains several regressions against version 0.5.21 of @code{g77}, due to using the ``vanilla'' @code{gcc} back end instead of patching it to fix a few bugs and improve performance in a few cases. Features that have been dropped from this version of @code{g77} due to their being implemented via @code{g77}-specific patches to the @code{gcc} back end in previous releases include: @itemize @minus @item Support for the C-language @code{restrict} keyword. @item Support for the @samp{-W} option warning about integer division by zero. @item The Intel x86-specific option @samp{-malign-double} applying to stack-allocated data as well as statically-allocate data. @end itemize @ifclear USERVISONLY Note that the @file{gcc/f/gbe/} subdirectory has been removed from this distribution as a result of @code{g77} being fully integrated with the @code{egcs} variant of the @code{gcc} back end. @end ifclear @ifclear USERVISONLY @item Fix code generation for iterative @code{DO} loops that have one or more references to the iteration variable, or to aliases of it, in their control expressions. For example, @samp{DO 10 J=2,J} now is compiled correctly. @end ifclear @ifclear USERVISONLY @item Fix @code{DTime} intrinsic so as not to truncate results to integer values (on some systems). @end ifclear @ifclear USERVISONLY @item @c Toon Moene discovered these. Some Fortran code, miscompiled by @code{g77} built on @code{gcc} version 2.8.1 on m68k-next-nextstep3 configurations when using the @samp{-O2} option, is now compiled correctly. It is believed that a C function known to miscompile on that configuration when using the @samp{-O2 -funroll-loops} options also is now compiled correctly. @end ifclear @ifclear USERVISONLY @item Remove support for non-@code{egcs} versions of @code{gcc}. @end ifclear @cindex -@w{}-driver option @cindex @code{g77} options, -@w{}-driver @cindex options, -@w{}-driver @item Remove support for the @samp{--driver} option, as @code{g77} now does all the driving, just like @code{gcc}. @item Allow any numeric argument to intrinsics @code{Int2} and @code{Int8}. @ifclear USERVISONLY @item Improve diagnostic messages from @code{libf2c} so it is more likely that the printing of the active format string is limited to the string, with no trailing garbage being printed. (Unlike @code{f2c}, @code{g77} did not append a null byte to its compiled form of every format string specified via a @code{FORMAT} statement. However, @code{f2c} would exhibit the problem anyway for a statement like @samp{PRINT '(I)garbage', 1} by printing @samp{(I)garbage} as the format string.) @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1997-09-23. This fixes a formatted-I/O bug that afflicted 64-bit systems with 32-bit integers (such as Digital Alpha running GNU/Linux). @end ifclear @end itemize @c 1997-09-09: 0.5.21 released. @heading In 0.5.21: @itemize @bullet @ifclear USERVISONLY @item Fix a code-generation bug introduced by 0.5.20 caused by loop unrolling (by specifying @samp{-funroll-loops} or similar). This bug afflicted all code compiled by version 2.7.2.2.f.2 of @code{gcc} (C, C++, Fortran, and so on). @end ifclear @ifclear USERVISONLY @item Fix a code-generation bug manifested when combining local @code{EQUIVALENCE} with a @code{DATA} statement that follows the first executable statement (or is treated as an executable-context statement as a result of using the @samp{-fpedantic} option). @end ifclear @ifclear USERVISONLY @item Fix a compiler crash that occured when an integer division by a constant zero is detected. Instead, when the @samp{-W} option is specified, the @code{gcc} back end issues a warning about such a case. This bug afflicted all code compiled by version 2.7.2.2.f.2 of @code{gcc} (C, C++, Fortran, and so on). @end ifclear @ifset USERVISONLY @item When the @samp{-W} option is specified, @code{gcc}, @code{g77}, and other GNU compilers that incorporate the @code{gcc} back end as modified by @code{g77}, issue a warning about integer division by constant zero. @end ifset @ifclear USERVISONLY @item Fix a compiler crash that occurred in some cases of procedure inlining. (Such cases became more frequent in 0.5.20.) @end ifclear @ifclear USERVISONLY @item Fix a compiler crash resulting from using @code{DATA} or similar to initialize a @code{COMPLEX} variable or array to zero. @end ifclear @ifclear USERVISONLY @item Fix compiler crashes involving use of @code{AND}, @code{OR}, or @code{XOR} intrinsics. @end ifclear @ifclear USERVISONLY @item Fix compiler bug triggered when using a @code{COMMON} or @code{EQUIVALENCE} variable as the target of an @code{ASSIGN} or assigned-@code{GOTO} statement. @end ifclear @ifclear USERVISONLY @item Fix compiler crashes due to using the name of a some non-standard intrinsics (such as @code{FTell} or @code{FPutC}) as such and as the name of a procedure or common block. Such dual use of a name in a program is allowed by the standard. @end ifclear @c @code{g77}'s version of @code{libf2c} has been modified @c so that the external names of library's procedures do not @c conflict with names used for Fortran procedures compiled @c by @code{g77}. @c An additional layer of jacket procedures has been added @c to @code{libf2c} to map the old names to the new names, @c for automatic use by programs that interface to the @c library procedures via the external-procedure mechanism. @c @c For example, the intrinsic @code{FPUTC} previously was @c implemented by @code{g77} as a call to the @code{libf2c} @c routine @code{fputc_}. @c This would conflict with a Fortran procedure named @code{FPUTC} @c (using default compiler options), and this conflict @c would cause a crash under certain circumstances. @c @c Now, the intrinsic @code{FPUTC} calls @code{G77_fputc_0}, @c which does not conflict with the @code{fputc_} external @c that implements a Fortran procedure named @code{FPUTC}. @c @c Programs that refer to @code{FPUTC} as an external procedure @c without supplying their own implementation will link to @c the new @code{libf2c} routine @code{fputc_}, which is @c simply a jacket routine that calls @code{G77_fputc_0}. @ifclear USERVISONLY @item Place automatic arrays on the stack, even if @code{SAVE} or the @samp{-fno-automatic} option is in effect. This avoids a compiler crash in some cases. @end ifclear @ifclear USERVISONLY @item The @samp{-malign-double} option now reliably aligns @code{DOUBLE PRECISION} optimally on Pentium and Pentium Pro architectures (586 and 686 in @code{gcc}). @end ifclear @item New option @samp{-Wno-globals} disables warnings about ``suspicious'' use of a name both as a global name and as the implicit name of an intrinsic, and warnings about disagreements over the number or natures of arguments passed to global procedures, or the natures of the procedures themselves. The default is to issue such warnings, which are new as of this version of @code{g77}. @item New option @samp{-fno-globals} disables diagnostics about potentially fatal disagreements analysis problems, such as disagreements over the number or natures of arguments passed to global procedures, or the natures of those procedures themselves. The default is to issue such diagnostics and flag the compilation as unsuccessful. With this option, the diagnostics are issued as warnings, or, if @samp{-Wno-globals} is specified, are not issued at all. This option also disables inlining of global procedures, to avoid compiler crashes resulting from coding errors that these diagnostics normally would identify. @ifclear USERVISONLY @item Diagnose cases where a reference to a procedure disagrees with the type of that procedure, or where disagreements about the number or nature of arguments exist. This avoids a compiler crash. @end ifclear @ifclear USERVISONLY @item Fix parsing bug whereby @code{g77} rejected a second initialization specification immediately following the first's closing @samp{/} without an intervening comma in a @code{DATA} statement, and the second specification was an implied-DO list. @end ifclear @ifclear USERVISONLY @item Improve performance of the @code{gcc} back end so certain complicated expressions involving @code{COMPLEX} arithmetic (especially multiplication) don't appear to take forever to compile. @end ifclear @ifclear USERVISONLY @item Fix a couple of profiling-related bugs in @code{gcc} back end. @end ifclear @ifclear USERVISONLY @item Integrate GNU Ada's (GNAT's) changes to the back end, which consist almost entirely of bug fixes. These fixes are circa version 3.10p of GNAT. @end ifclear @ifclear USERVISONLY @item Include some other @code{gcc} fixes that seem useful in @code{g77}'s version of @code{gcc}. (See @file{gcc/ChangeLog} for details---compare it to that file in the vanilla @code{gcc-2.7.2.3.tar.gz} distribution.) @end ifclear @item Fix @code{libU77} routines that accept file and other names to strip trailing blanks from them, for consistency with other implementations. Blanks may be forcibly appended to such names by appending a single null character (@samp{CHAR(0)}) to the significant trailing blanks. @item Fix @code{CHMOD} intrinsic to work with file names that have embedded blanks, commas, and so on. @item Fix @code{SIGNAL} intrinsic so it accepts an optional third @code{Status} argument. @ifclear USERVISONLY @item Fix @code{IDATE()} intrinsic subroutine (VXT form) so it accepts arguments in the correct order. Documentation fixed accordingly, and for @code{GMTIME()} and @code{LTIME()} as well. @end ifclear @item Make many changes to @code{libU77} intrinsics to support existing code more directly. Such changes include allowing both subroutine and function forms of many routines, changing @code{MCLOCK()} and @code{TIME()} to return @code{INTEGER(KIND=1)} values, introducing @code{MCLOCK8()} and @code{TIME8()} to return @code{INTEGER(KIND=2)} values, and placing functions that are intended to perform side effects in a new intrinsic group, @code{badu77}. @ifclear USERVISONLY @item Improve @code{libU77} so it is more portable. @end ifclear @item Add options @samp{-fbadu77-intrinsics-delete}, @samp{-fbadu77-intrinsics-hide}, and so on. @ifclear USERVISONLY @item Fix crashes involving diagnosed or invalid code. @end ifclear @ifclear USERVISONLY @item @code{g77} and @code{gcc} now do a somewhat better job detecting and diagnosing arrays that are too large to handle before these cause diagnostics during the assembler or linker phase, a compiler crash, or generation of incorrect code. @end ifclear @ifclear USERVISONLY @item Make some fixes to alias analysis code. @end ifclear @ifclear USERVISONLY @item Add support for @code{restrict} keyword in @code{gcc} front end. @end ifclear @ifclear USERVISONLY @item Support @code{gcc} version 2.7.2.3 (modified by @code{g77} into version 2.7.2.3.f.1), and remove support for prior versions of @code{gcc}. @end ifclear @ifclear USERVISONLY @item Incorporate GNAT's patches to the @code{gcc} back end into @code{g77}'s, so GNAT users do not need to apply GNAT's patches to build both GNAT and @code{g77} from the same source tree. @end ifclear @ifclear USERVISONLY @item Modify @code{make} rules and related code so that generation of Info documentation doesn't require compilation using @code{gcc}. Now, any ANSI C compiler should be adequate to produce the @code{g77} documentation (in particular, the tables of intrinsics) from scratch. @end ifclear @item Add @code{INT2} and @code{INT8} intrinsics. @item Add @code{CPU_TIME} intrinsic. @item Add @code{ALARM} intrinsic. @item @code{CTIME} intrinsic now accepts any @code{INTEGER} argument, not just @code{INTEGER(KIND=2)}. @ifclear USERVISONLY @item Warn when explicit type declaration disagrees with the type of an intrinsic invocation. @end ifclear @ifclear USERVISONLY @item Support @samp{*f771} entry in @code{gcc} @file{specs} file. @end ifclear @ifclear USERVISONLY @item Fix typo in @code{make} rule @code{g77-cross}, used only for cross-compiling. @end ifclear @ifclear USERVISONLY @item Fix @code{libf2c} build procedure to re-archive library if previous attempt to archive was interrupted. @end ifclear @ifclear USERVISONLY @item Change @code{gcc} to unroll loops only during the last invocation (of as many as two invocations) of loop optimization. @end ifclear @ifclear USERVISONLY @item Improve handling of @samp{-fno-f2c} so that code that attempts to pass an intrinsic as an actual argument, such as @samp{CALL FOO(ABS)}, is rejected due to the fact that the run-time-library routine is, effectively, compiled with @samp{-ff2c} in effect. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} driver to recognize @samp{-fsyntax-only} as an option that inhibits linking, just like @samp{-c} or @samp{-S}, and to recognize and properly handle the @samp{-nostdlib}, @samp{-M}, @samp{-MM}, @samp{-nodefaultlibs}, and @samp{-Xlinker} options. @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1997-08-16. @end ifclear @ifclear USERVISONLY @item Modify @code{libf2c} to consistently and clearly diagnose recursive I/O (at run time). @end ifclear @item @code{g77} driver now prints version information (such as produced by @kbd{g77 -v}) to @code{stderr} instead of @code{stdout}. @item The @samp{.r} suffix now designates a Ratfor source file, to be preprocessed via the @code{ratfor} command, available separately. @ifclear USERVISONLY @item Fix some aspects of how @code{gcc} determines what kind of system is being configured and what kinds are supported. For example, GNU Linux/Alpha ELF systems now are directly supported. @end ifclear @ifclear USERVISONLY @item Improve diagnostics. @end ifclear @ifclear USERVISONLY @item Improve documentation and indexing. @end ifclear @ifclear USERVISONLY @item Include all pertinent files for @code{libf2c} that come from @code{netlib.bell-labs.com}; give any such files that aren't quite accurate in @code{g77}'s version of @code{libf2c} the suffix @samp{.netlib}. @end ifclear @ifclear USERVISONLY @item Reserve @code{INTEGER(KIND=0)} for future use. @end ifclear @end itemize @c 1997-02-28: 0.5.20 released. @heading In 0.5.20: @itemize @bullet @item The @samp{-fno-typeless-boz} option is now the default. This option specifies that non-decimal-radix constants using the prefixed-radix form (such as @samp{Z'1234'}) are to be interpreted as @code{INTEGER(KIND=1)} constants. Specify @samp{-ftypeless-boz} to cause such constants to be interpreted as typeless. (Version 0.5.19 introduced @samp{-fno-typeless-boz} and its inverse.) @ifset DOC-G77 @xref{Fortran Dialect Options,,Options Controlling Fortran Dialect}, for information on the @samp{-ftypeless-boz} option. @end ifset @item Options @samp{-ff90-intrinsics-enable} and @samp{-fvxt-intrinsics-enable} now are the defaults. Some programs might use names that clash with intrinsic names defined (and now enabled) by these options or by the new @code{libU77} intrinsics. Users of such programs might need to compile them differently (using, for example, @samp{-ff90-intrinsics-disable}) or, better yet, insert appropriate @code{EXTERNAL} statements specifying that these names are not intended to be names of intrinsics. @item The @code{ALWAYS_FLUSH} macro is no longer defined when building @code{libf2c}, which should result in improved I/O performance, especially over NFS. @emph{Note:} If you have code that depends on the behavior of @code{libf2c} when built with @code{ALWAYS_FLUSH} defined, you will have to modify @code{libf2c} accordingly before building it from this and future versions of @code{g77}. @ifset DOC-G77 @xref{Output Assumed To Flush}, for more information. @end ifset @item Dave Love's implementation of @code{libU77} has been added to the version of @code{libf2c} distributed with and built as part of @code{g77}. @code{g77} now knows about the routines in this library as intrinsics. @item New option @samp{-fvxt} specifies that the source file is written in VXT Fortran, instead of GNU Fortran. @ifset DOC-G77 @xref{VXT Fortran}, for more information on the constructs recognized when the @samp{-fvxt} option is specified. @end ifset @item The @samp{-fvxt-not-f90} option has been deleted, along with its inverse, @samp{-ff90-not-vxt}. If you used one of these deleted options, you should re-read the pertinent documentation to determine which options, if any, are appropriate for compiling your code with this version of @code{g77}. @ifset DOC-G77 @xref{Other Dialects}, for more information. @end ifset @item The @samp{-fugly} option now issues a warning, as it likely will be removed in a future version. (Enabling all the @samp{-fugly-*} options is unlikely to be feasible, or sensible, in the future, so users should learn to specify only those @samp{-fugly-*} options they really need for a particular source file.) @item The @samp{-fugly-assumed} option, introduced in version 0.5.19, has been changed to better accommodate old and new code. @ifset DOC-G77 @xref{Ugly Assumed-Size Arrays}, for more information. @end ifset @ifclear USERVISONLY @item Make a number of fixes to the @code{g77} front end and the @code{gcc} back end to better support Alpha (AXP) machines. This includes providing at least one bug-fix to the @code{gcc} back end for Alphas. @end ifclear @item Related to supporting Alpha (AXP) machines, the @code{LOC()} intrinsic and @code{%LOC()} construct now return values of @code{INTEGER(KIND=0)} type, as defined by the GNU Fortran language. This type is wide enough (holds the same number of bits) as the character-pointer type on the machine. On most machines, this won't make a difference, whereas, on Alphas and other systems with 64-bit pointers, the @code{INTEGER(KIND=0)} type is equivalent to @code{INTEGER(KIND=2)} (often referred to as @code{INTEGER*8}) instead of the more common @code{INTEGER(KIND=1)} (often referred to as @code{INTEGER*4}). @item Emulate @code{COMPLEX} arithmetic in the @code{g77} front end, to avoid bugs in @code{complex} support in the @code{gcc} back end. New option @samp{-fno-emulate-complex} causes @code{g77} to revert the 0.5.19 behavior. @ifclear USERVISONLY @item Fix bug whereby @samp{REAL A(1)}, for example, caused a compiler crash if @samp{-fugly-assumed} was in effect and @var{A} was a local (automatic) array. That case is no longer affected by the new handling of @samp{-fugly-assumed}. @end ifclear @ifclear USERVISONLY @item Fix @code{g77} command driver so that @samp{g77 -o foo.f} no longer deletes @file{foo.f} before issuing other diagnostics, and so the @samp{-x} option is properly handled. @end ifclear @ifclear USERVISONLY @item Enable inlining of subroutines and functions by the @code{gcc} back end. This works as it does for @code{gcc} itself---program units may be inlined for invocations that follow them in the same program unit, as long as the appropriate compile-time options are specified. @end ifclear @item Dummy arguments are no longer assumed to potentially alias (overlap) other dummy arguments or @code{COMMON} areas when any of these are defined (assigned to) by Fortran code. This can result in faster and/or smaller programs when compiling with optimization enabled, though on some systems this effect is observed only when @samp{-fforce-addr} also is specified. New options @samp{-falias-check}, @samp{-fargument-alias}, @samp{-fargument-noalias}, and @samp{-fno-argument-noalias-global} control the way @code{g77} handles potential aliasing. @ifset DOC-G77 @xref{Aliasing Assumed To Work}, for detailed information on why the new defaults might result in some programs no longer working the way they did when compiled by previous versions of @code{g77}. @end ifset @ifclear USERVISONLY @item The @code{CONJG()} and @code{DCONJG()} intrinsics now are compiled in-line. @end ifclear @ifclear USERVISONLY @item The bug-fix for 0.5.19.1 has been re-done. The @code{g77} compiler has been changed back to assume @code{libf2c} has no aliasing problems in its implementations of the @code{COMPLEX} (and @code{DOUBLE COMPLEX}) intrinsics. The @code{libf2c} has been changed to have no such problems. As a result, 0.5.20 is expected to offer improved performance over 0.5.19.1, perhaps as good as 0.5.19 in most or all cases, due to this change alone. @emph{Note:} This change requires version 0.5.20 of @code{libf2c}, at least, when linking code produced by any versions of @code{g77} other than 0.5.19.1. Use @samp{g77 -v} to determine the version numbers of the @code{libF77}, @code{libI77}, and @code{libU77} components of the @code{libf2c} library. (If these version numbers are not printed---in particular, if the linker complains about unresolved references to names like @samp{g77__fvers__}---that strongly suggests your installation has an obsolete version of @code{libf2c}.) @end ifclear @item New option @samp{-fugly-assign} specifies that the same memory locations are to be used to hold the values assigned by both statements @samp{I = 3} and @samp{ASSIGN 10 TO I}, for example. (Normally, @code{g77} uses a separate memory location to hold assigned statement labels.) @ifset DOC-G77 @xref{Ugly Assigned Labels}, for more information. @end ifset @item @code{FORMAT} and @code{ENTRY} statements now are allowed to precede @code{IMPLICIT NONE} statements. @ifclear USERVISONLY @item Produce diagnostic for unsupported @code{SELECT CASE} on @code{CHARACTER} type, instead of crashing, at compile time. @end ifclear @ifclear USERVISONLY @item Fix crashes involving diagnosed or invalid code. @end ifclear @ifclear USERVISONLY @item Change approach to building @code{libf2c} archive (@file{libf2c.a}) so that members are added to it only when truly necessary, so the user that installs an already-built @code{g77} doesn't need to have write access to the build tree (whereas the user doing the build might not have access to install new software on the system). @end ifclear @ifclear USERVISONLY @item Support @code{gcc} version 2.7.2.2 (modified by @code{g77} into version 2.7.2.2.f.2), and remove support for prior versions of @code{gcc}. @end ifclear @ifclear USERVISONLY @item Upgrade to @code{libf2c} as of 1997-02-08, and fix up some of the build procedures. @end ifclear @ifclear USERVISONLY @item Improve general build procedures for @code{g77}, fixing minor bugs (such as deletion of any file named @file{f771} in the parent directory of @code{gcc/}). @end ifclear @item Enable full support of @code{INTEGER(KIND=2)} (often referred to as @code{INTEGER*8}) available in @code{libf2c} and @file{f2c.h} so that @code{f2c} users may make full use of its features via the @code{g77} version of @file{f2c.h} and the @code{INTEGER(KIND=2)} support routines in the @code{g77} version of @code{libf2c}. @item Improve @code{g77} driver and @code{libf2c} so that @samp{g77 -v} yields version information on the library. @item The @code{SNGL} and @code{FLOAT} intrinsics now are specific intrinsics, instead of synonyms for the generic intrinsic @code{REAL}. @item New intrinsics have been added. These are @code{REALPART}, @code{IMAGPART}, @code{COMPLEX}, @code{LONG}, and @code{SHORT}. @item A new group of intrinsics, @code{gnu}, has been added to contain the new @code{REALPART}, @code{IMAGPART}, and @code{COMPLEX} intrinsics. An old group, @code{dcp}, has been removed. @item Complain about industry-wide ambiguous references @samp{REAL(@var{expr})} and @samp{AIMAG(@var{expr})}, where @var{expr} is @code{DOUBLE COMPLEX} (or any complex type other than @code{COMPLEX}), unless @samp{-ff90} option specifies Fortran 90 interpretation or new @samp{-fugly-complex} option, in conjunction with @samp{-fnot-f90}, specifies @code{f2c} interpretation. @ifclear USERVISONLY @item Make improvements to diagnostics. @end ifclear @ifclear USERVISONLY @item Speed up compiler a bit. @end ifclear @ifclear USERVISONLY @item Improvements to documentation and indexing, including a new chapter containing information on one, later more, diagnostics that users are directed to pull up automatically via a message in the diagnostic itself. (Hence the menu item @code{M} for the node @code{Diagnostics} in the top-level menu of the Info documentation.) @end ifclear @end itemize @ifclear DOC-OLDNEWS @heading In previous versions: Information on previous versions is archived in @file{@value{path-g77}/news.texi} following the test of the @code{DOC-OLDNEWS} macro. @end ifclear @ifset DOC-OLDNEWS @c 1997-02-01: 0.5.19.1 released. @heading In 0.5.19.1: @itemize @bullet @item Code-generation bugs afflicting operations on complex data have been fixed. These bugs occurred when assigning the result of an operation to a complex variable (or array element) that also served as an input to that operation. The operations affected by this bug were: @code{CONJG()}, @code{DCONJG()}, @code{CCOS()}, @code{CDCOS()}, @code{CLOG()}, @code{CDLOG()}, @code{CSIN()}, @code{CDSIN()}, @code{CSQRT()}, @code{CDSQRT()}, complex division, and raising a @code{DOUBLE COMPLEX} operand to an @code{INTEGER} power. (The related generic and @samp{Z}-prefixed intrinsics, such as @code{ZSIN()}, also were affected.) For example, @samp{C = CSQRT(C)}, @samp{Z = Z/C}, and @samp{Z = Z**I} (where @samp{C} is @code{COMPLEX} and @samp{Z} is @code{DOUBLE COMPLEX}) have been fixed. @end itemize @c 1996-12-07: 0.5.19 released. @heading In 0.5.19: @itemize @bullet @item Fix @code{FORMAT} statement parsing so negative values for specifiers such as @code{P} (e.g. @samp{FORMAT(-1PF8.1)}) are correctly processed as negative. @item Fix @code{SIGNAL} intrinsic so it once again accepts a procedure as its second argument. @item A temporary kludge option provides bare-bones information on @code{COMMON} and @code{EQUIVALENCE} members at debug time. @item New @samp{-fonetrip} option specifies FORTRAN-66-style one-trip @code{DO} loops. @item New @samp{-fno-silent} option causes names of program units to be printed as they are compiled, in a fashion similar to UNIX @code{f77} and @code{f2c}. @item New @samp{-fugly-assumed} option specifies that arrays dimensioned via @samp{DIMENSION X(1)}, for example, are to be treated as assumed-size. @item New @samp{-fno-typeless-boz} option specifies that non-decimal-radix constants using the prefixed-radix form (such as @samp{Z'1234'}) are to be interpreted as @code{INTEGER} constants. @item New @samp{-ff66} option is a ``shorthand'' option that specifies behaviors considered appropriate for FORTRAN 66 programs. @item New @samp{-ff77} option is a ``shorthand'' option that specifies behaviors considered appropriate for UNIX @code{f77} programs. @item New @samp{-fugly-comma} and @samp{-fugly-logint} options provided to perform some of what @samp{-fugly} used to do. @samp{-fugly} and @samp{-fno-ugly} are now ``shorthand'' options, in that they do nothing more than enable (or disable) other @samp{-fugly-*} options. @item Fix parsing of assignment statements involving targets that are substrings of elements of @code{CHARACTER} arrays having names such as @samp{READ}, @samp{WRITE}, @samp{GOTO}, and @samp{REALFUNCTIONFOO}. @item Fix crashes involving diagnosed code. @item Fix handling of local @code{EQUIVALENCE} areas so certain cases of valid Fortran programs are not misdiagnosed as improperly extending the area backwards. @item Support @code{gcc} version 2.7.2.1. @item Upgrade to @code{libf2c} as of 1996-09-26, and fix up some of the build procedures. @item Change code generation for list-directed I/O so it allows for new versions of @code{libf2c} that might return non-zero status codes for some operations previously assumed to always return zero. This change not only affects how @code{IOSTAT=} variables are set by list-directed I/O, it also affects whether @code{END=} and @code{ERR=} labels are reached by these operations. @item Add intrinsic support for new @code{FTELL} and @code{FSEEK} procedures in @code{libf2c}. @item Modify @code{fseek_()} in @code{libf2c} to be more portable (though, in practice, there might be no systems where this matters) and to catch invalid @code{whence} arguments. @item Some useless warnings from the @samp{-Wunused} option have been eliminated. @item Fix a problem building the @file{f771} executable on AIX systems by linking with the @samp{-bbigtoc} option. @item Abort configuration if @code{gcc} has not been patched using the patch file provided in the @file{gcc/f/gbe/} subdirectory. @item Add options @samp{--help} and @samp{--version} to the @code{g77} command, to conform to GNU coding guidelines. Also add printing of @code{g77} version number when the @samp{--verbose} (@samp{-v}) option is used. @item Change internally generated name for local @code{EQUIVALENCE} areas to one based on the alphabetically sorted first name in the list of names for entities placed at the beginning of the areas. @item Improvements to documentation and indexing. @end itemize @c 1996-04-01: 0.5.18 released. @heading In 0.5.18: @itemize @bullet @item Add some rudimentary support for @code{INTEGER*1}, @code{INTEGER*2}, @code{INTEGER*8}, and their @code{LOGICAL} equivalents. (This support works on most, maybe all, @code{gcc} targets.) Thanks to Scott Snyder (@email{snyder@@d0sgif.fnal.gov}) for providing the patch for this! Among the missing elements from the support for these features are full intrinsic support and constants. @item Add some rudimentary support for the @code{BYTE} and @code{WORD} type-declaration statements. @code{BYTE} corresponds to @code{INTEGER*1}, while @code{WORD} corresponds to @code{INTEGER*2}. Thanks to Scott Snyder (@email{snyder@@d0sgif.fnal.gov}) for providing the patch for this! @item The compiler code handling intrinsics has been largely rewritten to accommodate the new types. No new intrinsics or arguments for existing intrinsics have been added, so there is, at this point, no intrinsic to convert to @code{INTEGER*8}, for example. @item Support automatic arrays in procedures. @item Reduce space/time requirements for handling large @emph{sparsely} initialized aggregate arrays. This improvement applies to only a subset of the general problem to be addressed in 0.6. @item Treat initial values of zero as if they weren't specified (in DATA and type-declaration statements). The initial values will be set to zero anyway, but the amount of compile time processing them will be reduced, in some cases significantly (though, again, this is only a subset of the general problem to be addressed in 0.6). A new option, @samp{-fzeros}, is introduced to enable the traditional treatment of zeros as any other value. @item With @samp{-ff90} in force, @code{g77} incorrectly interpreted @samp{REAL(Z)} as returning a @code{REAL} result, instead of as a @code{DOUBLE PRECISION} result. (Here, @samp{Z} is @code{DOUBLE COMPLEX}.) With @samp{-fno-f90} in force, the interpretation remains unchanged, since this appears to be how at least some F77 code using the @code{DOUBLE COMPLEX} extension expected it to work. Essentially, @samp{REAL(Z)} in F90 is the same as @samp{DBLE(Z)}, while in extended F77, it appears to be the same as @samp{REAL(REAL(Z))}. @item An expression involving exponentiation, where both operands were type @code{INTEGER} and the right-hand operand was negative, was erroneously evaluated. @item Fix bugs involving @code{DATA} implied-@code{DO} constructs (these involved an errant diagnostic and a crash, both on good code, one involving subsequent statement-function definition). @item Close @code{INCLUDE} files after processing them, so compiling source files with lots of @code{INCLUDE} statements does not result in being unable to open @code{INCLUDE} files after all the available file descriptors are used up. @item Speed up compiling, especially of larger programs, and perhaps slightly reduce memory utilization while compiling (this is @emph{not} the improvement planned for 0.6 involving large aggregate areas)---these improvements result from simply turning off some low-level code to do self-checking that hasn't been triggered in a long time. @item Introduce three new options that implement optimizations in the @code{gcc} back end (GBE). These options are @samp{-fmove-all-movables}, @samp{-freduce-all-givs}, and @samp{-frerun-loop-opt}, which are enabled, by default, for Fortran compilations. These optimizations are intended to help toon Fortran programs. @item Patch the GBE to do a better job optimizing certain kinds of references to array elements. @item Due to patches to the GBE, the version number of @code{gcc} also is patched to make it easier to manage installations, especially useful if it turns out a @code{g77} change to the GBE has a bug. The @code{g77}-modified version number is the @code{gcc} version number with the string @samp{.f.@var{n}} appended, where @samp{f} identifies the version as enhanced for Fortran, and @var{n} is @samp{1} for the first Fortran patch for that version of @code{gcc}, @samp{2} for the second, and so on. So, this introduces version 2.7.2.f.1 of @code{gcc}. @item Make several improvements and fixes to diagnostics, including the removal of two that were inappropriate or inadequate. @item Warning about two successive arithmetic operators, produced by @samp{-Wsurprising}, now produced @emph{only} when both operators are, indeed, arithmetic (not relational/boolean). @item @samp{-Wsurprising} now warns about the remaining cases of using non-integral variables for implied-@code{DO} loops, instead of these being rejected unless @samp{-fpedantic} or @samp{-fugly} specified. @item Allow @code{SAVE} of a local variable or array, even after it has been given an initial value via @code{DATA}, for example. @item Introduce an Info version of @code{g77} documentation, which supercedes @file{gcc/f/CREDITS}, @file{gcc/f/DOC}, and @file{gcc/f/PROJECTS}. These files will be removed in a future release. The files @file{gcc/f/BUGS}, @file{gcc/f/INSTALL}, and @file{gcc/f/NEWS} now are automatically built from the texinfo source when distributions are made. This effort was inspired by a first pass at translating @file{g77-0.5.16/f/DOC} that was contributed to Craig by David Ronis (@email{ronis@@onsager.chem.mcgill.ca}). @item New @samp{-fno-second-underscore} option to specify that, when @samp{-funderscoring} is in effect, a second underscore is not to be appended to Fortran names already containing an underscore. @item Change the way iterative @code{DO} loops work to follow the F90 standard. In particular, calculation of the iteration count is still done by converting the start, end, and increment parameters to the type of the @code{DO} variable, but the result of the calculation is always converted to the default @code{INTEGER} type. (This should have no effect on existing code compiled by @code{g77}, but code written to assume that use of a @emph{wider} type for the @code{DO} variable will result in an iteration count being fully calculated using that wider type (wider than default @code{INTEGER}) must be rewritten.) @item Support @code{gcc} version 2.7.2. @item Upgrade to @code{libf2c} as of 1996-03-23, and fix up some of the build procedures. Note that the email addresses related to @code{f2c} have changed---the distribution site now is named @code{netlib.bell-labs.com}, and the maintainer's new address is @email{dmg@@bell-labs.com}. @end itemize @c 1995-11-18: 0.5.17 released. @heading In 0.5.17: @itemize @bullet @item @strong{Fix serious bug} in @samp{g77 -v} command that can cause removal of a system's @file{/dev/null} special file if run by user @code{root}. @strong{All users} of version 0.5.16 should ensure that they have not removed @file{/dev/null} or replaced it with an ordinary file (e.g. by comparing the output of @samp{ls -l /dev/null} with @samp{ls -l /dev/zero}. If the output isn't basically the same, contact your system administrator about restoring @file{/dev/null} to its proper status). This bug is particularly insidious because removing @file{/dev/null} as a special file can go undetected for quite a while, aside from various applications and programs exhibiting sudden, strange behaviors. I sincerely apologize for not realizing the implications of the fact that when @samp{g77 -v} runs the @code{ld} command with @samp{-o /dev/null} that @code{ld} tries to @emph{remove} the executable it is supposed to build (especially if it reports unresolved references, which it should in this case)! @item Fix crash on @samp{CHARACTER*(*) FOO} in a main or block data program unit. @item Fix crash that can occur when diagnostics given outside of any program unit (such as when input file contains @samp{@@foo}). @item Fix crashes, infinite loops (hangs), and such involving diagnosed code. @item Fix @code{ASSIGN}'ed variables so they can be @code{SAVE}'d or dummy arguments, and issue clearer error message in cases where target of @code{ASSIGN} or @code{ASSIGN}ed @code{GOTO}/@code{FORMAT} is too small (which should never happen). @item Make @code{libf2c} build procedures work on more systems again by eliminating unnecessary invocations of @samp{ld -r -x} and @code{mv}. @item Fix omission of @samp{-funix-intrinsics-@dots{}} options in list of permitted options to compiler. @item Fix failure to always diagnose missing type declaration for @code{IMPLICIT NONE}. @item Fix compile-time performance problem (which could sometimes crash the compiler, cause a hang, or whatever, due to a bug in the back end) involving exponentiation with a large @code{INTEGER} constant for the right-hand operator (e.g. @samp{I**32767}). @item Fix build procedures so cross-compiling @code{g77} (the @code{fini} utility in particular) is properly built using the host compiler. @item Add new @samp{-Wsurprising} option to warn about constructs that are interpreted by the Fortran standard (and @code{g77}) in ways that are surprising to many programmers. @item Add @code{ERF()} and @code{ERFC()} as generic intrinsics mapping to existing @code{ERF}/@code{DERF} and @code{ERFC}/@code{DERFC} specific intrinsics. @emph{Note:} You should specify @samp{INTRINSIC ERF,ERFC} in any code where you might use these as generic intrinsics, to improve likelihood of diagnostics (instead of subtle run-time bugs) when using a compiler that doesn't support these as intrinsics (e.g. @code{f2c}). @item Remove from @samp{-fno-pedantic} the diagnostic about @code{DO} with non-@code{INTEGER} index variable; issue that under @samp{-Wsurprising} instead. @item Clarify some diagnostics that say things like ``ignored'' when that's misleading. @item Clarify diagnostic on use of @code{.EQ.}/@code{.NE.} on @code{LOGICAL} operands. @item Minor improvements to code generation for various operations on @code{LOGICAL} operands. @item Minor improvement to code generation for some @code{DO} loops on some machines. @item Support @code{gcc} version 2.7.1. @item Upgrade to @code{libf2c} as of 1995-11-15. @end itemize @c 1995-08-30: 0.5.16 released. @heading In 0.5.16: @itemize @bullet @item Fix a code-generation bug involving complicated @code{EQUIVALENCE} statements not involving @code{COMMON}. @item Fix code-generation bugs involving invoking ``gratis'' library procedures in @code{libf2c} from code compiled with @samp{-fno-f2c} by making these procedures known to @code{g77} as intrinsics (not affected by -fno-f2c). This is known to fix code invoking @code{ERF()}, @code{ERFC()}, @code{DERF()}, and @code{DERFC()}. @item Update @code{libf2c} to include netlib patches through 1995-08-16, and @code{#define} @code{WANT_LEAD_0} to 1 to make @code{g77}-compiled code more consistent with other Fortran implementations by outputting leading zeros in formatted and list-directed output. @item Fix a code-generation bug involving adjustable dummy arrays with high bounds whose primaries are changed during procedure execution, and which might well improve code-generation performance for such arrays compared to @code{f2c} plus @code{gcc} (but apparently only when using @file{gcc-2.7.0} or later). @item Fix a code-generation bug involving invocation of @code{COMPLEX} and @code{DOUBLE COMPLEX} @code{FUNCTION}s and doing @code{COMPLEX} and @code{DOUBLE COMPLEX} divides, when the result of the invocation or divide is assigned directly to a variable that overlaps one or more of the arguments to the invocation or divide. @item Fix crash by not generating new optimal code for @samp{X**I} if @samp{I} is nonconstant and the expression is used to dimension a dummy array, since the @code{gcc} back end does not support the necessary mechanics (and the @code{gcc} front end rejects the equivalent construct, as it turns out). @item Fix crash on expressions like @samp{COMPLEX**INTEGER}. @item Fix crash on expressions like @samp{(1D0,2D0)**2}, i.e. raising a @code{DOUBLE COMPLEX} constant to an @code{INTEGER} constant power. @item Fix crashes and such involving diagnosed code. @item Diagnose, instead of crashing on, statement function definitions having duplicate dummy argument names. @item Fix bug causing rejection of good code involving statement function definitions. @item Fix bug resulting in debugger not knowing size of local equivalence area when any member of area has initial value (via @code{DATA}, for example). @item Fix installation bug that prevented installation of @code{g77} driver. Provide for easy selection of whether to install copy of @code{g77} as @code{f77} to replace the broken code. @item Fix @code{gcc} driver (affects @code{g77} thereby) to not gratuitously invoke the @code{f771} program (e.g. when @samp{-E} is specified). @item Fix diagnostic to point to correct source line when it immediately follows an @code{INCLUDE} statement. @item Support more compiler options in @code{gcc}/@code{g77} when compiling Fortran files. These options include @samp{-p}, @samp{-pg}, @samp{-aux-info}, @samp{-P}, correct setting of version-number macros for preprocessing, full recognition of @samp{-O0}, and automatic insertion of configuration-specific linker specs. @item Add new intrinsics that interface to existing routines in @code{libf2c}: @code{ABORT}, @code{DERF}, @code{DERFC}, @code{ERF}, @code{ERFC}, @code{EXIT}, @code{FLUSH}, @code{GETARG}, @code{GETENV}, @code{IARGC}, @code{SIGNAL}, and @code{SYSTEM}. Note that @code{ABORT}, @code{EXIT}, @code{FLUSH}, @code{SIGNAL}, and @code{SYSTEM} are intrinsic subroutines, not functions (since they have side effects), so to get the return values from @code{SIGNAL} and @code{SYSTEM}, append a final argument specifying an @code{INTEGER} variable or array element (e.g. @samp{CALL SYSTEM('rm foo',ISTAT)}). @item Add new intrinsic group named @code{unix} to contain the new intrinsics, and by default enable this new group. @item Move @code{LOC()} intrinsic out of the @code{vxt} group to the new @code{unix} group. @item Improve @code{g77} so that @samp{g77 -v} by itself (or with certain other options, including @samp{-B}, @samp{-b}, @samp{-i}, @samp{-nostdlib}, and @samp{-V}) reports lots more useful version info, and so that long-form options @code{gcc} accepts are understood by @code{g77} as well (even in truncated, unambiguous forms). @item Add new @code{g77} option @samp{--driver=name} to specify driver when default, @code{gcc}, isn't appropriate. @item Add support for @samp{#} directives (as output by the preprocessor) in the compiler, and enable generation of those directives by the preprocessor (when compiling @samp{.F} files) so diagnostics and debugging info are more useful to users of the preprocessor. @item Produce better diagnostics, more like @code{gcc}, with info such as @samp{In function `foo':} and @samp{In file included from...:}. @item Support @code{gcc}'s @samp{-fident} and @samp{-fno-ident} options. @item When @samp{-Wunused} in effect, don't warn about local variables used as statement-function dummy arguments or @code{DATA} implied-@code{DO} iteration variables, even though, strictly speaking, these are not uses of the variables themselves. @item When @samp{-W -Wunused} in effect, don't warn about unused dummy arguments at all, since there's no way to turn this off for individual cases (@code{g77} might someday start warning about these)---applies to @code{gcc} versions 2.7.0 and later, since earlier versions didn't warn about unused dummy arguments. @item New option @samp{-fno-underscoring} that inhibits transformation of names (by appending one or two underscores) so users may experiment with implications of such an environment. @item Minor improvement to @file{gcc/f/info} module to make it easier to build @code{g77} using the native (non-@code{gcc}) compiler on certain machines (but definitely not all machines nor all non-@code{gcc} compilers). Please do not report bugs showing problems compilers have with macros defined in @file{gcc/f/target.h} and used in places like @file{gcc/f/expr.c}. @item Add warning to be printed for each invocation of the compiler if the target machine @code{INTEGER}, @code{REAL}, or @code{LOGICAL} size is not 32 bits, since @code{g77} is known to not work well for such cases. @item Lots of new documentation (though work is still needed to put it into canonical GNU format). @item Build @code{libf2c} with @samp{-g0}, not @samp{-g2}, in effect (by default), to produce smaller library without lots of debugging clutter. @end itemize @c 1995-05-19: 0.5.15 released. @heading In 0.5.15: @itemize @bullet @item Fix bad code generation involving @samp{X**I} and temporary, internal variables generated by @code{g77} and the back end (such as for @code{DO} loops). @item Fix crash given @samp{CHARACTER A;DATA A/.TRUE./}. @item Replace crash with diagnostic given @samp{CHARACTER A;DATA A/1.0/}. @item Fix crash or other erratic behavior when null character constant (@samp{''}) is encountered. @item Fix crash or other erratic behavior involving diagnosed code. @item Fix code generation for external functions returning type @code{REAL} when the @samp{-ff2c} option is in force (which it is by default) so that @code{f2c} compatibility is indeed provided. @item Disallow @samp{COMMON I(10)} if @samp{I} has previously been specified with an array declarator. @item New @samp{-ffixed-line-length-@var{n}} option, where @var{n} is the maximum length of a typical fixed-form line, defaulting to 72 columns, such that characters beyond column @var{n} are ignored, or @var{n} is @samp{none}, meaning no characters are ignored. does not affect lines with @samp{&} in column 1, which are always processed as if @samp{-ffixed-line-length-none} was in effect. @item No longer generate better code for some kinds of array references, as @code{gcc} back end is to be fixed to do this even better, and it turned out to slow down some code in some cases after all. @item In @code{COMMON} and @code{EQUIVALENCE} areas with any members given initial values (e.g. via @code{DATA}), uninitialized members now always initialized to binary zeros (though this is not required by the standard, and might not be done in future versions of @code{g77}). Previously, in some @code{COMMON}/@code{EQUIVALENCE} areas (essentially those with members of more than one type), the uninitialized members were initialized to spaces, to cater to @code{CHARACTER} types, but it seems no existing code expects that, while much existing code expects binary zeros. @end itemize @heading In 0.5.14: @itemize @bullet @item Don't emit bad code when low bound of adjustable array is nonconstant and thus might vary as an expression at run time. @item Emit correct code for calculation of number of trips in @code{DO} loops for cases where the loop should not execute at all. (This bug affected cases where the difference between the begin and end values was less than the step count, though probably not for floating-point cases.) @item Fix crash when extra parentheses surround item in @code{DATA} implied-@code{DO} list. @item Fix crash over minor internal inconsistencies in handling diagnostics, just substitute dummy strings where necessary. @item Fix crash on some systems when compiling call to @code{MVBITS()} intrinsic. @item Fix crash on array assignment @samp{TYPE@var{ddd}(@dots{})=@dots{}}, where @var{ddd} is a string of one or more digits. @item Fix crash on @code{DCMPLX()} with a single @code{INTEGER} argument. @item Fix various crashes involving code with diagnosed errors. @item Support @samp{-I} option for @code{INCLUDE} statement, plus @code{gcc}'s @file{header.gcc} facility for handling systems like MS-DOS. @item Allow @code{INCLUDE} statement to be continued across multiple lines, even allow it to coexist with other statements on the same line. @item Incorporate Bellcore fixes to @code{libf2c} through 1995-03-15---this fixes a bug involving infinite loops reading EOF with empty list-directed I/O list. @item Remove all the @code{g77}-specific auto-configuration scripts, code, and so on, except for temporary substitutes for bsearch() and strtoul(), as too many configure/build problems were reported in these areas. People will have to fix their systems' problems themselves, or at least somewhere other than @code{g77}, which expects a working ANSI C environment (and, for now, a GNU C compiler to compile @code{g77} itself). @item Complain if initialized common redeclared as larger in subsequent program unit. @item Warn if blank common initialized, since its size can vary and hence related warnings that might be helpful won't be seen. @item New @samp{-fbackslash} option, on by default, that causes @samp{\} within @code{CHARACTER} and Hollerith constants to be interpreted a la GNU C. Note that this behavior is somewhat different from @code{f2c}'s, which supports only a limited subset of backslash (escape) sequences. @item Make @samp{-fugly-args} the default. @item New @samp{-fugly-init} option, on by default, that allows typeless/Hollerith to be specified as initial values for variables or named constants (@code{PARAMETER}), and also allows character<->numeric conversion in those contexts---turn off via @samp{-fno-ugly-init}. @item New @samp{-finit-local-zero} option to initialize local variables to binary zeros. This does not affect whether they are @code{SAVE}d, i.e. made automatic or static. @item New @samp{-Wimplicit} option to warn about implicitly typed variables, arrays, and functions. (Basically causes all program units to default to @code{IMPLICIT NONE}.) @item @samp{-Wall} now implies @samp{-Wuninitialized} as with @code{gcc} (i.e. unless @samp{-O} not specified, since @samp{-Wuninitialized} requires @samp{-O}), and implies @samp{-Wunused} as well. @item @samp{-Wunused} no longer gives spurious messages for unused @code{EXTERNAL} names (since they are assumed to refer to block data program units, to make use of libraries more reliable). @item Support @code{%LOC()} and @code{LOC()} of character arguments. @item Support null (zero-length) character constants and expressions. @item Support @code{f2c}'s @code{IMAG()} generic intrinsic. @item Support @code{ICHAR()}, @code{IACHAR()}, and @code{LEN()} of character expressions that are valid in assignments but not normally as actual arguments. @item Support @code{f2c}-style @samp{&} in column 1 to mean continuation line. @item Allow @code{NAMELIST}, @code{EXTERNAL}, @code{INTRINSIC}, and @code{VOLATILE} in @code{BLOCK DATA}, even though these are not allowed by the standard. @item Allow @code{RETURN} in main program unit. @item Changes to Hollerith-constant support to obey Appendix C of the standard: @itemize @minus @item Now padded on the right with zeros, not spaces. @item Hollerith ``format specifications'' in the form of arrays of non-character allowed. @item Warnings issued when non-space truncation occurs when converting to another type. @item When specified as actual argument, now passed by reference to @code{INTEGER} (padded on right with spaces if constant too small, otherwise fully intact if constant wider the @code{INTEGER} type) instead of by value. @end itemize @strong{Warning:} @code{f2c} differs on the interpretation of @samp{CALL FOO(1HX)}, which it treats exactly the same as @samp{CALL FOO('X')}, but which the standard and @code{g77} treat as @samp{CALL FOO(%REF('X '))} (padded with as many spaces as necessary to widen to @code{INTEGER}), essentially. @item Changes and fixes to typeless-constant support: @itemize @minus @item Now treated as a typeless double-length @code{INTEGER} value. @item Warnings issued when overflow occurs. @item Padded on the left with zeros when converting to a larger type. @item Should be properly aligned and ordered on the target machine for whatever type it is turned into. @item When specified as actual argument, now passed as reference to a default @code{INTEGER} constant. @end itemize @item @code{%DESCR()} of a non-@code{CHARACTER} expression now passes a pointer to the expression plus a length for the expression just as if it were a @code{CHARACTER} expression. For example, @samp{CALL FOO(%DESCR(D))}, where @samp{D} is @code{REAL*8}, is the same as @samp{CALL FOO(D,%VAL(8)))}. @item Name of multi-entrypoint master function changed to incorporate the name of the primary entry point instead of a decimal value, so the name of the master function for @samp{SUBROUTINE X} with alternate entry points is now @samp{__g77_masterfun_x}. @item Remove redundant message about zero-step-count @code{DO} loops. @item Clean up diagnostic messages, shortening many of them. @item Fix typo in @code{g77} man page. @item Clarify implications of constant-handling bugs in @file{f/BUGS}. @item Generate better code for @samp{**} operator with a right-hand operand of type @code{INTEGER}. @item Generate better code for @code{SQRT()} and @code{DSQRT()}, also when @samp{-ffast-math} specified, enable better code generation for @code{SIN()} and @code{COS()}. @item Generate better code for some kinds of array references. @item Speed up lexing somewhat (this makes the compilation phase noticeably faster). @end itemize @end ifset @end ifclear