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* [Bug c/35900] New: typecast (sign extension) missing @ 2008-04-10 12:39 holger dot hopp at sap dot com 2008-04-10 13:46 ` [Bug c/35900] " rguenth at gcc dot gnu dot org 2008-04-10 16:15 ` holger dot hopp at sap dot com 0 siblings, 2 replies; 3+ messages in thread From: holger dot hopp at sap dot com @ 2008-04-10 12:39 UTC (permalink / raw) To: gcc-bugs In the following example the typecast (sign extension) from int (32bit) to long (64bit) is missing. Before the compare the signed i1 is < 0 and unsigned u2 is > 0 and this should be kept when casting to 64bit long. Same issue for long long (also 64bit). So we get correct ov=1 with gcc version <= 4.2, but wrong ov=0 with gcc version >= 4.3. This issue occurs with and without optimization. gcc version: gcc-4_3_branch and trunk svn revision 133752 (gcc-4_2 and below runs fine) int main() { int ov; unsigned u2; int i1; i1 = 0; u2 = (unsigned)2147483647 + 1 ; (i1) += (u2); if ( (long)(i1)<(long)(u2) ) ov = 1; else ov = 0; return !ov; } -- Summary: typecast (sign extension) missing Product: gcc Version: 4.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: holger dot hopp at sap dot com GCC build triplet: x86_64-unknown-linux-gnu GCC host triplet: x86_64-unknown-linux-gnu GCC target triplet: x86_64-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35900 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c/35900] typecast (sign extension) missing 2008-04-10 12:39 [Bug c/35900] New: typecast (sign extension) missing holger dot hopp at sap dot com @ 2008-04-10 13:46 ` rguenth at gcc dot gnu dot org 2008-04-10 16:15 ` holger dot hopp at sap dot com 1 sibling, 0 replies; 3+ messages in thread From: rguenth at gcc dot gnu dot org @ 2008-04-10 13:46 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from rguenth at gcc dot gnu dot org 2008-04-10 13:45 ------- I belive this was fixed by Author: rguenth Date: Tue Apr 8 22:03:33 2008 New Revision: 134110 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=134110 Log: 2008-04-08 Richard Guenther <rguenther@suse.de> * fold-const.c (fold_widened_comparison): Do not allow sign-changes that change the result. * gcc.c-torture/execute/20080408-1.c: New testcase. Added: branches/gcc-4_3-branch/gcc/testsuite/gcc.c-torture/execute/20080408-1.c - copied unchanged from r134108, trunk/gcc/testsuite/gcc.c-torture/execute/20080408-1.c Modified: branches/gcc-4_3-branch/gcc/ChangeLog branches/gcc-4_3-branch/gcc/fold-const.c branches/gcc-4_3-branch/gcc/testsuite/ChangeLog -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |FIXED Target Milestone|--- |4.3.1 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35900 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c/35900] typecast (sign extension) missing 2008-04-10 12:39 [Bug c/35900] New: typecast (sign extension) missing holger dot hopp at sap dot com 2008-04-10 13:46 ` [Bug c/35900] " rguenth at gcc dot gnu dot org @ 2008-04-10 16:15 ` holger dot hopp at sap dot com 1 sibling, 0 replies; 3+ messages in thread From: holger dot hopp at sap dot com @ 2008-04-10 16:15 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from holger dot hopp at sap dot com 2008-04-10 16:15 ------- You're right! Great - the fix is faster available than expected! Thank you. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35900 ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2008-04-10 16:15 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2008-04-10 12:39 [Bug c/35900] New: typecast (sign extension) missing holger dot hopp at sap dot com 2008-04-10 13:46 ` [Bug c/35900] " rguenth at gcc dot gnu dot org 2008-04-10 16:15 ` holger dot hopp at sap dot com
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