Documenting Cygnus and gcc compiler problems
Martin Buchholz
martin@xemacs.org
Tue Dec 7 15:29:00 GMT 1999
This ChangeLog intentionally left blank.
gcc maintainers: This is a patch to XEmacs, not gcc; but you might
want to document these problems yourself.
--- PROBLEMS 1999/09/22 23:43:39 1.26.2.12
+++ PROBLEMS 1999/12/07 23:24:32
@@ -41,14 +41,33 @@
There have been reports of egcs-1.1 not compiling XEmacs correctly on
Alpha Linux. There have also been reports that egcs-1.0.3a is O.K.
-*** Don't use -O2 with gcc 2.7.2 under Intel/XXX without also using
-`-fno-strength-reduce'.
+*** Don't use -O2 or -O3 with Cygwin 1.0, CodeFusion-99070 or gcc 2.7.2 on x86
+without also using `-fno-strength-reduce'.
gcc will generate incorrect code otherwise. This bug is present in at
least 2.6.x and 2.7.[0-2]. This bug has been fixed in GCC 2.7.2.1 and
later. This bug is O/S independent, but is limited to x86 architectures.
This problem is known to be fixed in egcs (or pgcc) 1.0 or later.
+
+Unfortunately, later releases of Cygnus-released compilers (not the
+Net-released ones) have a bug with the same `problem signature'.
+
+If you're lucky, you'll get an error while compiling that looks like:
+
+event-stream.c:3189: internal error--unrecognizable insn:
+(insn 256 14 15 (set (reg/v:SI 24)
+ (minus:SI (reg/v:SI 25)
+ (const_int 2))) -1 (insn_list 11 (nil))
+ (nil))
+ 0 0 [main]
+
+If you're unlucky, your code will simply execute incorrectly.
+
+*** Don't use gcc-2.95.2 with -mcpu=ultrasparc on Solaris 2.6.
+
+gcc will assume a 64-bit operating system, even though you've
+merely told it to assume a 64-bit instruction set.
*** Don't use -O2 with gcc 2.7.2 under Intel architectures without also
using `-fno-caller-saves'.
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