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From: jonathan.sambrook@dsvr.co.uk To: gcc-gnats@gcc.gnu.org Subject: c/10426: -O2 messes with ordering of pointer dereferencing Date: Thu, 17 Apr 2003 11:56:00 -0000 [thread overview] Message-ID: <20030417115334.16780.qmail@sources.redhat.com> (raw) >Number: 10426 >Category: c >Synopsis: -O2 messes with ordering of pointer dereferencing >Confidential: no >Severity: serious >Priority: medium >Responsible: unassigned >State: open >Class: sw-bug >Submitter-Id: net >Arrival-Date: Thu Apr 17 11:56:00 UTC 2003 >Closed-Date: >Last-Modified: >Originator: jonathan.sambrook@dsvr.co.uk >Release: 3.2.2 (don't know when from, but after 2.96 which works fine) >Organization: >Environment: Linux 2.4.20 gcc 3.2.2 >Description: Expected o/p : "abcde", but with -O2 get "bcde": int main( int argc, char ** argv ) { char str[17]; sprintf( str, "ABCDE" ); char * p = str; for( ;*p ; ) *p++ = tolower(*p); printf( "'%s'\n", str ); return 0; } Yes it's nasty coding; no *I* didn't write it in its wild form :) [.i file redundant] >How-To-Repeat: Works: gcc -o test test.c Doesn't: gcc -O2 -o test test.c >Fix: >Release-Note: >Audit-Trail: >Unformatted: ----gnatsweb-attachment---- Content-Type: application/octet-stream; name="gcc_-v_output" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="gcc_-v_output" Z2NjIC12IC1zYXZlLXRlbXBzIC1PMiAtbyB0ZXN0IHRlc3QuYwpSZWFkaW5nIHNwZWNzIGZyb20g L3Vzci9saWIvZ2NjLWxpYi9pMzg2LXJlZGhhdC1saW51eC8zLjIuMi9zcGVjcwpDb25maWd1cmVk IHdpdGg6IC4uL2NvbmZpZ3VyZSAtLXByZWZpeD0vdXNyIC0tbWFuZGlyPS91c3Ivc2hhcmUvbWFu IC0taW5mb2Rpcj0vdXNyL3NoYXJlL2luZm8gLS1lbmFibGUtc2hhcmVkIC0tZW5hYmxlLXRocmVh ZHM9cG9zaXggLS1kaXNhYmxlLWNoZWNraW5nIC0td2l0aC1zeXN0ZW0temxpYiAtLWVuYWJsZS1f X2N4YV9hdGV4aXQgLS1ob3N0PWkzODYtcmVkaGF0LWxpbnV4ClRocmVhZCBtb2RlbDogcG9zaXgK Z2NjIHZlcnNpb24gMy4yLjIgMjAwMzAyMTcgKFJlZCBIYXQgTGludXggOC4wIDMuMi4yLTIpCiAv dXNyL2xpYi9nY2MtbGliL2kzODYtcmVkaGF0LWxpbnV4LzMuMi4yL2NwcDAgLWxhbmctYyAtdiAt RF9fR05VQ19fPTMgLURfX0dOVUNfTUlOT1JfXz0yIC1EX19HTlVDX1BBVENITEVWRUxfXz0yIC1E X19HWFhfQUJJX1ZFUlNJT049MTAyIC1EX19FTEZfXyAtRHVuaXggLURfX2dudV9saW51eF9fIC1E bGludXggLURfX0VMRl9fIC1EX191bml4X18gLURfX2dudV9saW51eF9fIC1EX19saW51eF9fIC1E X191bml4IC1EX19saW51eCAtQXN5c3RlbT1wb3NpeCAtRF9fT1BUSU1JWkVfXyAtRF9fU1REQ19I T1NURURfXz0xIC1BY3B1PWkzODYgLUFtYWNoaW5lPWkzODYgLURpMzg2IC1EX19pMzg2IC1EX19p Mzg2X18gLURfX3R1bmVfaTM4Nl9fIHRlc3QuYyB0ZXN0LmkKR05VIENQUCB2ZXJzaW9uIDMuMi4y IDIwMDMwMjE3IChSZWQgSGF0IExpbnV4IDguMCAzLjIuMi0yKSAoY3BwbGliKSAoaTM4NiBMaW51 eC9FTEYpCmlnbm9yaW5nIG5vbmV4aXN0ZW50IGRpcmVjdG9yeSAiL3Vzci9pMzg2LXJlZGhhdC1s aW51eC9pbmNsdWRlIgojaW5jbHVkZSAiLi4uIiBzZWFyY2ggc3RhcnRzIGhlcmU6CiNpbmNsdWRl IDwuLi4+IHNlYXJjaCBzdGFydHMgaGVyZToKIC91c3IvbG9jYWwvaW5jbHVkZQogL3Vzci9saWIv Z2NjLWxpYi9pMzg2LXJlZGhhdC1saW51eC8zLjIuMi9pbmNsdWRlCiAvdXNyL2luY2x1ZGUKRW5k IG9mIHNlYXJjaCBsaXN0LgogL3Vzci9saWIvZ2NjLWxpYi9pMzg2LXJlZGhhdC1saW51eC8zLjIu Mi9jYzEgLWZwcmVwcm9jZXNzZWQgdGVzdC5pIC1xdWlldCAtZHVtcGJhc2UgdGVzdC5jIC1PMiAt dmVyc2lvbiAtbyB0ZXN0LnMKR05VIENQUCB2ZXJzaW9uIDMuMi4yIDIwMDMwMjE3IChSZWQgSGF0 IExpbnV4IDguMCAzLjIuMi0yKSAoY3BwbGliKSAoaTM4NiBMaW51eC9FTEYpCkdOVSBDIHZlcnNp b24gMy4yLjIgMjAwMzAyMTcgKFJlZCBIYXQgTGludXggOC4wIDMuMi4yLTIpIChpMzg2LXJlZGhh dC1saW51eCkKICAgICAgICBjb21waWxlZCBieSBHTlUgQyB2ZXJzaW9uIDMuMi4yIDIwMDMwMjE3 IChSZWQgSGF0IExpbnV4IDguMCAzLjIuMi0yKS4KIGFzIC1WIC1ReSAtbyB0ZXN0Lm8gdGVzdC5z CkdOVSBhc3NlbWJsZXIgdmVyc2lvbiAyLjEzLjkwLjAuMTggKGk2ODYtcmVkaGF0LWxpbnV4KSB1 c2luZyBCRkQgdmVyc2lvbiAyLjEzLjkwLjAuMTggMjAwMzAyMDYKIC91c3IvbGliL2djYy1saWIv aTM4Ni1yZWRoYXQtbGludXgvMy4yLjIvY29sbGVjdDIgLS1laC1mcmFtZS1oZHIgLW0gZWxmX2kz ODYgLWR5bmFtaWMtbGlua2VyIC9saWIvbGQtbGludXguc28uMiAtbyB0ZXN0IC91c3IvbGliL2dj Yy1saWIvaTM4Ni1yZWRoYXQtbGludXgvMy4yLjIvLi4vLi4vLi4vY3J0MS5vIC91c3IvbGliL2dj Yy1saWIvaTM4Ni1yZWRoYXQtbGludXgvMy4yLjIvLi4vLi4vLi4vY3J0aS5vIC91c3IvbGliL2dj Yy1saWIvaTM4Ni1yZWRoYXQtbGludXgvMy4yLjIvY3J0YmVnaW4ubyAtTC91c3IvbGliL2djYy1s aWIvaTM4Ni1yZWRoYXQtbGludXgvMy4yLjIgLUwvdXNyL2xpYi9nY2MtbGliL2kzODYtcmVkaGF0 LWxpbnV4LzMuMi4yLy4uLy4uLy4uIHRlc3QubyAtbGdjYyAtbGdjY19laCAtbGMgLWxnY2MgLWxn Y2NfZWggL3Vzci9saWIvZ2NjLWxpYi9pMzg2LXJlZGhhdC1saW51eC8zLjIuMi9jcnRlbmQubyAv dXNyL2xpYi9nY2MtbGliL2kzODYtcmVkaGF0LWxpbnV4LzMuMi4yLy4uLy4uLy4uL2NydG4ubwo=
next reply other threads:[~2003-04-17 11:56 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-04-17 11:56 jonathan.sambrook [this message] 2003-04-17 14:24 ebotcazou
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