Make -fno-emulate-complex the default

From-SVN: r26161

gcc/f/ChangeLog

@@ -1,3 +1,11 @@
+Sat Apr  3 23:29:33 1999  Craig Burley  <craig@jcb-sc.com>
+
+	* bugs.texi, g77.texi, lang-options.h, news.texi, top.c:
+	Make -fno-emulate-complex the default, as COMPLEX support
+	in the back end is now believed to be working.
+
+	* version.c: Bump version.
+
 Fri Apr  2 13:33:16 1999  Craig Burley  <craig@jcb-sc.com>
 
 	* g77.texi: -malign-double now works.

gcc/f/bugs.texi

@@ -9,7 +9,7 @@
 @c in the standalone derivations of this file (e.g. BUGS).
 @set copyrights-bugs 1995-1999
 
-@set last-update-bugs 1999-03-15
+@set last-update-bugs 1999-04-03
 
 @include root.texi
 
@@ -247,23 +247,6 @@ This problem is largely resolved as of version 0.5.23.
 Version 0.6 should solve most or all remaining problems
 (such as cross-compiling involving 64-bit machines).
 
-@cindex COMPLEX support
-@cindex support, COMPLEX
-@item
-Maintainers of @code{gcc} report that the back end definitely has ``broken''
-support for @code{COMPLEX} types.
-Based on their input, it seems many of
-the problems affect only the more-general facilities for gcc's
-@code{__complex__} type, such as @code{__complex__ int}
-(where the real and imaginary parts are integers) that GNU
-Fortran does not use.
-
-Version 0.5.20 of @code{g77} works around this
-problem by not using the back end's support for @code{COMPLEX}.
-The new option @samp{-fno-emulate-complex} avoids the work-around,
-reverting to using the same ``broken'' mechanism as that used
-by versions of @code{g77} prior to 0.5.20.
-
 @cindex padding
 @cindex structures
 @cindex common blocks

gcc/f/g77.texi

@@ -2,7 +2,7 @@
 @c %**start of header
 @setfilename g77.info
 
-@set last-update 1999-04-02
+@set last-update 1999-04-03
 @set copyrights-g77 1995-1999
 
 @include root.texi
@@ -1466,7 +1466,7 @@ by type.  Explanations are in the following sections.
 -fpcc-struct-return  -freg-struct-return
 -fshort-double  -fno-common  -fpack-struct
 -fzeros  -fno-second-underscore
--fdebug-kludge  -fno-emulate-complex
+-fdebug-kludge  -femulate-complex
 -falias-check  -fargument-alias
 -fargument-noalias  -fno-argument-noalias-global
 -fno-globals
@@ -3253,44 +3253,36 @@ Current plans call for this to happen when published versions of @code{g77}
 and @code{gdb} exist that provide proper access to debugging information on
 @code{COMMON} and @code{EQUIVALENCE} members.
 
-@cindex -fno-emulate-complex option
-@cindex options, -fno-emulate-complex
-@item -fno-emulate-complex
-Implement @code{COMPLEX} arithmetic using the facilities in
+@cindex -femulate-complex option
+@cindex options, -femulate-complex
+@item -femulate-complex
+Implement @code{COMPLEX} arithmetic via emulation,
+instead of using the facilities of
 the @code{gcc} back end that provide direct support of
-@code{complex} arithmetic, instead of emulating the arithmetic.
+@code{complex} arithmetic.
 
-@code{gcc} has some known problems in its back-end support
+(@code{gcc} had some bugs in its back-end support
 for @code{complex} arithmetic, due primarily to the support not being
-completed as of version 2.7.2.2.
-Other front ends for the @code{gcc} back end avoid this problem
-by emulating @code{complex} arithmetic at a higher level, so the
-back end sees arithmetic on the real and imaginary components.
-To make @code{g77} more portable to systems where @code{complex}
-support in the @code{gcc} back end is particularly troublesome,
-@code{g77} now defaults to performing the same kinds of emulations
-done by these other front ends.
+completed as of version 2.8.1 and @code{egcs} 1.1.2.)
 
-Use @samp{-fno-emulate-complex} to try the @code{complex} support
-in the @code{gcc} back end, in case it works and produces faster
-programs.
-So far, all the known bugs seem to involve compile-time crashes,
-rather than the generation of incorrect code.
+Use @samp{-femulate-complex} if you suspect code-generation bugs,
+or experience compiler crashes,
+that might result from @code{g77} using the @code{COMPLEX} support
+in the @code{gcc} back end.
+If using that option fixes the bugs or crashes you are seeing,
+that indicates a likely @code{g77} bugs
+(though, all compiler crashes are considered bugs),
+so, please report it.
+(Note that the known bugs, now believed fixed, produced compiler crashes
+rather than causing the generation of incorrect code.)
 
 Use of this option should not affect how Fortran code compiled
 by @code{g77} works in terms of its interfaces to other code,
 e.g. that compiled by @code{f2c}.
 
-@emph{Caution:} Future versions of @code{g77} are likely to change
-the default for this option to
-@samp{-fno-emulate-complex}, and perhaps someday ignore both forms
+@emph{Caution:} Future versions of @code{g77} might ignore both forms
 of this option.
 
-Also, it is possible that use of the @samp{-fno-emulate-complex} option
-could result in incorrect code being silently produced by @code{g77}.
-But, this is generally true of compilers anyway, so, as usual, test
-the programs you compile before assuming they are working.
-
 @cindex -falias-check option
 @cindex options, -falias-check
 @cindex -fargument-alias option
@@ -8896,11 +8888,6 @@ mode afterward.
 (In @code{gdb}, this is accomplished via @samp{set lang c} and
 either @samp{set lang fortran} or @samp{set lang auto}.)
 
-@emph{Note:} Compiling with the @samp{-fno-emulate-complex} option
-avoids the debugging problem, but is known to cause other problems
-like compiler crashes and generation of incorrect code, so it is
-not recommended.
-
 @node Arrays
 @section Arrays (DIMENSION)
 @cindex DIMENSION statement

gcc/f/lang-options.h

@@ -81,8 +81,8 @@ FTNOPT( "-finit-local-zero", "Initialize local vars and arrays to zero" )
 FTNOPT( "-fno-init-local-zero", "" )
 FTNOPT( "-fbackslash", "" )
 FTNOPT( "-fno-backslash", "Backslashes in character/hollerith constants not special (C-style)" )
-FTNOPT( "-femulate-complex", "" )
-FTNOPT( "-fno-emulate-complex", "Have compiler back end cope with COMPLEX arithmetic" )
+FTNOPT( "-femulate-complex", "Have front end emulate COMPLEX arithmetic to avoid bugs" )
+FTNOPT( "-fno-emulate-complex", "" )
 FTNOPT( "-funderscoring", "" )
 FTNOPT( "-fno-underscoring", "Disable the appending of underscores to externals" )
 FTNOPT( "-fsecond-underscore", "" )

gcc/f/news.texi

@@ -9,7 +9,7 @@
 @c in the standalone derivations of this file (e.g. NEWS).
 @set copyrights-news 1995-1999
 
-@set last-update-news 1999-04-02
+@set last-update-news 1999-04-03
 
 @include root.texi
 
@@ -204,6 +204,11 @@ when the corresponding @emph{subsequent} function program unit
 disagrees with the reference concerning the type of the function.
 @end ifclear
 
+@item
+@code{-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

gcc/f/top.c

@@ -65,7 +65,7 @@ bool ffe_is_do_internal_checks_ = FALSE;
 bool ffe_is_90_ = FFETARGET_defaultIS_90;
 bool ffe_is_automatic_ = FFETARGET_defaultIS_AUTOMATIC;
 bool ffe_is_backslash_ = FFETARGET_defaultIS_BACKSLASH;
-bool ffe_is_emulate_complex_ = TRUE;
+bool ffe_is_emulate_complex_ = FALSE;
 bool ffe_is_underscoring_ = FFETARGET_defaultEXTERNAL_UNDERSCORED
   || FFETARGET_defaultUNDERSCORED_EXTERNAL_UNDERSCORED;
 bool ffe_is_second_underscore_ = FFETARGET_defaultUNDERSCORED_EXTERNAL_UNDERSCORED;

gcc/f/version.c

@@ -1 +1 @@
-const char *ffe_version_string = "0.5.24-19990313";
+const char *ffe_version_string = "0.5.24-19990403";