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From: "jan.kratochvil at redhat dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug debug/49888] New: VTA: -O2 -g variable value changes, it does not change in the source Date: Thu, 28 Jul 2011 18:04:00 -0000 [thread overview] Message-ID: <bug-49888-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49888 Summary: VTA: -O2 -g variable value changes, it does not change in the source Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: debug AssignedTo: unassigned@gcc.gnu.org ReportedBy: jan.kratochvil@redhat.com CC: aoliva@gcc.gnu.org Target: x86_64-unknown-linux-gnu static int v; static void __attribute__((noinline, noclone)) f (int *p) { int c = *p; v = c; *p = 2; v = 0; /* break-here */ } int main () { int v = 2; f (&v); return 0; } -------------------------------------------------------------------------------- FAIL: gcc (GCC) 4.5.4 20110728 (prerelease) FAIL: gcc (GCC) 4.6.2 20110728 (prerelease) FAIL: gcc (GCC) 4.7.0 20110728 (experimental) -Wall -g -O2 -------------------------------------------------------------------------------- Breakpoint 1, f (p=0x7fffffffda44) at 8.c:7 7 *p = 2; (gdb) disass Dump of assembler code for function f: => 0x0000000000400480 <+0>: movl $0x2,(%rdi) 0x0000000000400486 <+6>: movl $0x0,0x2003e8(%rip) # 0x600878 <v> 0x0000000000400490 <+16>: retq End of assembler dump. (gdb) p c $1 = 1 (gdb) stepi 8 v = 0; /* break-here */ (gdb) p c Actual: $2 = 2 Expected: $2 = 1 `c' is never changed in the source code, it should not change in runtime. <63> DW_AT_location : 2 byte block: 75 0 (DW_OP_breg5 (rdi): 0) <optimized out> would be better than a wrong value.
next reply other threads:[~2011-07-28 18:04 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-07-28 18:04 jan.kratochvil at redhat dot com [this message] 2012-05-23 9:36 ` [Bug debug/49888] " aoliva at gcc dot gnu.org 2012-06-13 21:44 ` aoliva at gcc dot gnu.org 2012-06-13 21:58 ` aoliva at gcc dot gnu.org 2012-06-13 22:10 ` jan.kratochvil at redhat dot com 2012-06-22 1:31 ` aoliva at gcc dot gnu.org 2012-06-22 1:34 ` aoliva at gcc dot gnu.org 2012-06-28 7:41 ` aoliva at gcc dot gnu.org 2012-07-06 11:37 ` aoliva at gcc dot gnu.org 2012-11-08 2:57 ` aoliva at gcc dot gnu.org 2013-01-16 4:32 ` aoliva at gcc dot gnu.org 2013-01-18 10:59 ` aoliva at gcc dot gnu.org 2013-01-18 11:01 ` aoliva at gcc dot gnu.org
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