>Submitter-Id: net >Originator: Konstantin Kivi >Organization: >Confidential: no >Synopsis: wrong code generation wthile optimization >Severity: serious >Priority: medium >Category: optimization >Class: wrong-code >Release: 3.0.4 (Debian testing/unstable) >Environment: System: Linux konst 2.4.20 #4 SMP ðÎÄ óÅÎ 22 18:41:18 MSD 2003 i686 unknown Architecture: i686
host: i386-pc-linux-gnu build: i386-pc-linux-gnu target: i386-pc-linux-gnu configured with: ../src/configure -v --enable-languages=c,c++,java,f77,proto,objc --prefix=/usr --infodir=/share/info --mandir=/share/man --enable-shared --with-gnu-as --with-gnu-ld --with-system-zlib --enable-long-long --enable-nls --without-included-gettext --disable-checking --enable-threads=posix --enable-java-gc=boehm --with-cpp-install-dir=bin --enable-objc-gc i386-linux >Description: wrong code generation in the example below >How-To-Repeat: Script started on Fri May 14 15:57:37 2004 [EMAIL PROTECTED]://.../Bug>cat bbug.c struct a { char t[2]; int b; } ; struct aa { char t[2]; } ; int main() { struct a A; struct aa AA; A.t[0]=0xFF; A.t[1]=0xF9; if((unsigned char )A.t[0]==0xFF && (unsigned char)A.t[1]==0xF9 ) { puts("A Ok"); } AA.t[0]=0xFF; AA.t[1]=0xF9; if((unsigned char )AA.t[0]==0xFF && (unsigned char)AA.t[1]==0xF9 ) { puts("AA Ok"); } return 0; } [EMAIL PROTECTED]://.../Bug>cat makefile .PHONY: good bad all all: good bad good: gcc -Wall bbug.c -o good_prog bad: gcc -Wall -O bbug.c -o bad_prog [EMAIL PROTECTED]://.../Bug>make gcc -Wall bbug.c -o good_prog bbug.c: In function `main': bbug.c:23: warning: implicit declaration of function `puts' gcc -Wall -O bbug.c -o bad_prog bbug.c: In function `main': bbug.c:22: warning: comparison is always 0 bbug.c:23: warning: implicit declaration of function `puts' [EMAIL PROTECTED]://.../Bug>./good_prog A Ok AA Ok [EMAIL PROTECTED]://.../Bug>./bad_prog AA Ok [EMAIL PROTECTED]://.../Bug>gcc -v Reading specs from /usr/lib/gcc-lib/i386-linux/2.95.4/specs gcc version 2.95.4 20011002 (Debian prerelease) [EMAIL PROTECTED]://.../Bug>exit Script done on Fri May 14 15:58:25 2004 Script started on Fri May 14 16:03:25 2004 [EMAIL PROTECTED]://.../konst>ssh tnuma DYNIX/ptx(R) V4.5.3 #4 (root): Sat Jun 21 14:39:42 MSD 2003 Copyright 1988 - 2001 Sequent Computer Systems, Inc. Patents No. 5,185,861; 5,261,053; 5,442,758; 5,608,893; 5,655,122; 5,727,209 No mail. DYNIX/ptx(R) V4.5.3 #4 (root): Sat Jun 21 14:39:42 MSD 2003 Copyright 1988 - 2001 Sequent Computer Systems, Inc. Patents No. 5,185,861; 5,261,053; 5,442,758; 5,608,893; 5,655,122; 5,727,209 [EMAIL PROTECTED]://...konst>cd Bug [EMAIL PROTECTED]://...Bug>make gcc -Wall bbug.c -o good_prog bbug.c: In function `main': bbug.c:23: warning: implicit declaration of function `puts' gcc -Wall -O bbug.c -o bad_prog bbug.c: In function `main': bbug.c:22: warning: comparison is always 0 bbug.c:23: warning: implicit declaration of function `puts' [EMAIL PROTECTED]://...Bug>./good_prog A Ok AA Ok [EMAIL PROTECTED]://...Bug>./bad_prog AA Ok [EMAIL PROTECTED]://...Bug>gcc -v Reading specs from /usr/local/lib/gcc-lib/i386-sequent-sysv4/3.3.2/specs Configured with: ../gcc-3.3.2/configure --with-gnu-as --with-gas --with-gnu-ld --enable-languages=c,c++ --with-stubs Thread model: single gcc version 3.3.2 [EMAIL PROTECTED]://...Bug>exit logout Connection to tnuma closed. Script done on Fri May 14 16:04:10 2004 >Fix: