c/4048: gcc fails to self recompile with -fomit-frame-pointer

c/4048: gcc fails to self recompile with -fomit-frame-pointer

[Stanislav Brabec]

>Number:         4048
>Category:       c
>Synopsis:       gcc fails to self recompile with -O3 -fomit-frame-pointer
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Fri Aug 17 10:46:03 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     Stanislav Brabec
>Release:        3.0 and 3.0.1 20010807 (prerelease)
>Organization:
UTX
>Environment:
System: Linux utx 2.4.8-ac4 #5 St srp 15 11:49:33 CEST 2001 i686 unknown
Architecture: i686

host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with:
export CFLAGS=... CXXFLAGS=... (see lower for details)
./configure --prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --libexecdir=/usr/lib --datadir=/usr/share --sysconfdir=/etc --sharedstatedir=/var/cache --localstatedir=/var --libdir=/usr/lib --includedir=/usr/include --oldincludedir=/usr/include --infodir=/usr/share/info --mandir=/usr/share/man --enable-shared --disable-static --with-pic --with-system-zlib --verbose : (reconfigured) ./configure --prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --libexecdir=/usr/lib --datadir=/usr/share --sysconfdir=/etc --sharedstatedir=/var/cache --localstatedir=/var --libdir=/usr/lib --includedir=/usr/include --oldincludedir=/usr/include --infodir=/usr/share/info --mandir=/usr/share/man --enable-shared --with-pic --with-system-zlib --verbose
>Description:

Gcc fails self recompile with "-O3 -fomit-frame-pointer" or "-O2
-fomit-frame-pointer" compilation with "-O2" and "-O3" will succeed.

First compile done by gcc-2.95.3 will succeed with any option.

/usr/src/gcc/gcc/xgcc -B/usr/src/gcc/gcc/ -B/usr/i686-pc-linux-gnu/bin/ -B/usr/i686-pc-linux-gnu/lib/ -isystem /usr/i686-pc-linux-gnu/include -O2   -DIN_GCC    -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -isystem ./include  -fPIC -g1  -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED  -I. -I. -I. -I./. -I./config -I./../include -fexceptions -c ./unwind-dw2.c -o libgcc/./unwind-dw2.o
unwind-dw2.c: In function `extract_cie_info':
unwind-dw2.c:220: warning: implicit declaration of function `strlen'
unwind-dw2.c: In function `execute_stack_op':
unwind-dw2.c:303: warning: `result' might be used uninitialized in this functionunwind-dw2.c: In function `uw_frame_state_for':
unwind-dw2.c:889: warning: implicit declaration of function `memset'
unwind-dw2.c: In function `uw_install_context_1':
unwind-dw2.c:1167: warning: implicit declaration of function `memcpy'
unwind-dw2.c: At top level:
unwind-dw2.c:1187: Internal error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL: http://www.gnu.org/software/gcc/bugs.html > for instructions.


There is another piece of code, which generates bad result with "-O3
-fomit-frame-pointer", but correct one with "-O2": it is e2fsprogs -
http://e2fsprogs.sourceforge.net (tested with version e2fsprogs-1.23,
simply repeatable - 2 tests of "make check" are crashing).


Crash is repeatable on my both machines - Cyrix i686MX200 and
Athlon 1200/266.


Note: I have removed fixincluded files immediatelly after install.


>How-To-Repeat:
	See upper.
>Fix:

-- 
Stanislav Brabec
>Release-Note:
>Audit-Trail:
>Unformatted: