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* [Bug c/53480] New: warning "may be used uninitialized" issued with -m32 but not with -m64
@ 2012-05-24 19:35 gbburkhardt at verizon dot net
2012-05-24 19:46 ` [Bug tree-optimization/53480] " pinskia at gcc dot gnu.org
2012-05-26 18:09 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: gbburkhardt at verizon dot net @ 2012-05-24 19:35 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53480
Bug #: 53480
Summary: warning "may be used uninitialized" issued with -m32
but not with -m64
Classification: Unclassified
Product: gcc
Version: 4.6.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: gbburkhardt@verizon.net
For the following program, a warning is issued with "-m32", but not with
"-m64".
armis@armis-00:~$ gcc -c -O2 -g -Wall -m32 -std=gnu99 tt.c
tt.c: In function ‘sub’:
tt.c:18:29: warning: ‘v0.minValue’ may be used uninitialized in this function
[-Wuninitialized]
tt.c:21:29: warning: ‘v0.maxValue’ may be used uninitialized in this function
[-Wuninitialized]
armis@armis-00:~$ gcc -c -O2 -g -Wall -m64 -std=gnu99 tt.c
armis@armis-00:~$
#include <stdio.h>
typedef struct {
double minValue, maxValue;
} Range;
void getNewRange(Range*);
void sub()
{
Range v0, v1;
for (int i=0; i < 2; i++) {
getNewRange(&v1);
if (i == 0) {
v0.minValue = v1.minValue;
v0.maxValue = v1.minValue;
} else {
if (v0.minValue > v1.minValue)
v0.minValue = v1.minValue;
if (v0.maxValue < v1.maxValue)
v0.maxValue = v1.maxValue;
}
}
printf("min=%f, max=%f\n", v0.minValue, v0.maxValue);
}
armis@armis-00:~$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6.1/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.6.1-9ubuntu3' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr
--program-suffix=-4.6 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin
--enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3)
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/53480] warning "may be used uninitialized" issued with -m32 but not with -m64
2012-05-24 19:35 [Bug c/53480] New: warning "may be used uninitialized" issued with -m32 but not with -m64 gbburkhardt at verizon dot net
@ 2012-05-24 19:46 ` pinskia at gcc dot gnu.org
2012-05-26 18:09 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2012-05-24 19:46 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53480
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|c |tree-optimization
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-05-24 19:41:07 UTC ---
This warning depends on optimization. In this case, it depends on sra doing
something.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/53480] warning "may be used uninitialized" issued with -m32 but not with -m64
2012-05-24 19:35 [Bug c/53480] New: warning "may be used uninitialized" issued with -m32 but not with -m64 gbburkhardt at verizon dot net
2012-05-24 19:46 ` [Bug tree-optimization/53480] " pinskia at gcc dot gnu.org
@ 2012-05-26 18:09 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2012-05-26 18:09 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53480
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |diagnostic
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-05-26 18:08:11 UTC ---
In GCC 4.7.0 and above, it does not warn with -m32 or -m64.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-05-26 18:08 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2012-05-24 19:35 [Bug c/53480] New: warning "may be used uninitialized" issued with -m32 but not with -m64 gbburkhardt at verizon dot net
2012-05-24 19:46 ` [Bug tree-optimization/53480] " pinskia at gcc dot gnu.org
2012-05-26 18:09 ` pinskia at gcc dot gnu.org
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