public inbox for gcc-prs@sourceware.org help / color / mirror / Atom feed
From: p.van-hoof@qub.ac.uk To: gcc-gnats@gcc.gnu.org Cc: p.van-hoof@qub.ac.uk Subject: optimization/10312: optimizer creates wrong code for loop Date: Fri, 04 Apr 2003 18:56:00 -0000 [thread overview] Message-ID: <200304041846.h34Ikxfo008166@scooby.star.fleet> (raw) >Number: 10312 >Category: optimization >Synopsis: optimizer creates wrong code for loop >Confidential: no >Severity: serious >Priority: medium >Responsible: unassigned >State: open >Class: wrong-code >Submitter-Id: net >Arrival-Date: Fri Apr 04 18:56:00 UTC 2003 >Closed-Date: >Last-Modified: >Originator: Peter van Hoof >Release: 3.4 20030403 (experimental) >Organization: Queen's University of Belfast >Environment: System: SunOS scooby 5.9 Generic_112233-04 sun4u sparc SUNW,Sun-Blade-100 Architecture: sun4 host: sparc-sun-solaris2.9 build: sparc-sun-solaris2.9 target: sparc-sun-solaris2.9 configured with: /scratch/gcc-repository/cvs/gcc/configure --prefix=/opt/local/gcc340 --enable-languages=c,c++,f77 --with-gnu-as --with-as=/opt/local/bin/gas >Description: The optimizer creates wrong code for the loop in the attached program. When compiled with -O2, the resulting code will generate a segfault. If the "double a" member of the struct is removed, the program will get stuck in an infinite loop, rather than crash. The program behaves correctly with gcc 3.2.2 and 3.3, so this is a regression. >How-To-Repeat: scooby> gcc -v -O2 c.c Reading specs from /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/specs Configured with: /scratch/gcc-repository/cvs/gcc/configure --prefix=/opt/local/gcc340 --enable-languages=c,c++,f77 --with-gnu-as --with-as=/opt/local/bin/gas Thread model: posix gcc version 3.4 20030403 (experimental) /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/cc1 -quiet -v -Dsparc -D__sparc__ -D__sparc -D__GCC_NEW_VARARGS__ -Acpu=sparc -Amachine=sparc c.c -quiet -dumpbase c.c -auxbase c -O2 -version -o /var/tmp//ccXLgTFq.s ignoring nonexistent directory "/opt/local/gcc340/sparc-sun-solaris2.9/include" #include "..." search starts here: #include <...> search starts here: /usr/local/include /opt/local/gcc340/include /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/include /usr/include End of search list. GNU C version 3.4 20030403 (experimental) (sparc-sun-solaris2.9) compiled by GNU C version 3.4 20030403 (experimental). GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 /opt/local/bin/gas -V -Qy -s -o /var/tmp//ccOfg7jT.o /var/tmp//ccXLgTFq.s GNU assembler version 2.13.2.1 (sparc-sun-solaris2.9) using BFD version 2.13.2.1 /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/collect2 -V -Y P,/usr/ccs/lib:/usr/lib -Qy /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/crt1.o /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/crti.o /usr/ccs/lib/values-Xa.o /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/crtbegin.o -L/opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4 -L/usr/ccs/bin -L/usr/ccs/lib -L/opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/../../.. /var/tmp//ccOfg7jT.o -lgcc -lgcc_eh -lc -lgcc -lgcc_eh -lc /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/crtend.o /opt/local/gcc340/lib/gcc-lib/sparc-sun-solaris2.9/3.4/crtn.o ld: Software Generation Utilities - Solaris Link Editors: 5.9-1.373 scooby> a.out Segmentation fault scooby> cat c.c struct { double a; int n[2]; } g = { 0., { 1, 2 } }; int k = 0; void b(int *j) {} int main() { int j; for( j=0; j < 2; j++ ) k = ( k > g.n[j] ) ? k : g.n[j]; k++; b(&j); return 0; } >Fix: Workaround: use lower level of optimization. >Release-Note: >Audit-Trail: >Unformatted:
next reply other threads:[~2003-04-04 18:56 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-04-04 18:56 p.van-hoof [this message] 2003-04-04 19:03 ebotcazou 2003-04-04 19:16 Peter van Hoof 2003-04-04 22:06 Eric Botcazou
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=200304041846.h34Ikxfo008166@scooby.star.fleet \ --to=p.van-hoof@qub.ac.uk \ --cc=gcc-gnats@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).