I have reviewed the gcc web page for reporting bugs and this situation is not
covered.
I have a program that I have been compiling with the gcc 2.9 and 3.4 series.
In the past week I upgraded to gcc 4.0.0
I compiled the program and corrected the warning message about using "unsigned
char *" when the function prototype specified "char *" and vice versa.
The program files are compiled with the following command line in the make
file:
gcc -O3 -std=c99 -Wunused-variable -o $@ -lm $(OBJS)
There is no compiler output beyond reporting the command line invocation. No
warning messages, no compiler errors of any kind.
The program has run for many years with no problem. Under gcc 4.0.0, I get a
memory access error.
If I change the compile command in the make file to:
gcc -g -std=c99 -Wunused-variable -o $@ -lm $(OBJS)
The program runs with no error.
Changing the optimization option to "O" and compiling and the program again
runs with no error.
Only when I compile with an optimization level of "O2" or "O3" does the
program exit with a memory access error.
I have attempted to compile with "-g -O3" or "-g -O2" flags and then run under
Kdebug. This fails with an error message from Kdebug that gdb failed to load
the program. Thus, I am totally unable to debug the program and find the
exact problem with the optimization.
Thus, there appears to be a fatal error in the "O2" and "O3" levels of
optimization in gcc and a definite error in the debug output when the O2 or
O3 optimization level is specified.
compiler output below:
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o pipes.o pipes.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkpact.o awkpact.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkpcmp.o awkpcmp.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkpdo.o awkpdo.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkpfun.o awkpfun.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkplus.o awkplus.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkpmsc.o awkpmsc.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkprd.o awkprd.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o awkpwrt.o awkpwrt.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o date.o date.c
gcc -O3 -save-temps -std=c99 -Wunused-variable -c -o filefuncs.o filefuncs.c
linking
gcc -o qtawk -lm pipes.o qtawkcpy.o awkpact.o awkpcmp.o awkpdo.o awkpfun.o
awkplus.o awkpmsc.o awkprd.o awkpwrt.o date.o filefuncs.o getopt.o
compile_routines_short.o scan_routines.o
I have the "*.i" files as a tarred and bzip2 compressed file - need to know
where to send the file.
--
Summary: O2 and O3 memory access error - compiled program -
incorrect debug output
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: critical
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: fastsnip-gcc at yahoo dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21322
