[Bug sanitizer/104718] New: Leak reported for elided static variable
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104718 Bug ID: 104718 Summary: Leak reported for elided static variable Product: gcc Version: 9.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: sanitizer Assignee: unassigned at gcc dot gnu.org Reporter: dlong at cadence dot com CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org, jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at gcc dot gnu.org Target Milestone: --- Created attachment 52523 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52523&action=edit test case showing incorrect leak report This is a case where g++ is able to detect that a section of code is not used, and as a result it seems to be more-or-less eliding a static variable that references some dynamically allocated storage. It seems that this is confusing the leak sanitizer, which reports the storage for that variable as leaked. Normally, static variables which reference dynamically allocated memory at program exit are not shown as leaks. If you compile the attached test with: g++-9.3.0 -std=c++17 -O2 -fsanitize=address -DUSE2=true lsantest.cc -o lsantest so that the mutex mut2 is not elided and then run ./lsantest, the program exits cleanly and reports no leaks. If you compile it with: g++-9.3.0 -std=c++17 -O2 -fsanitize=address -DUSE2=false lsantest.cc -o lsantest so that mut2 can be elided and then run ./lsantest, the sanitizer will report a leak at exit. mut1 is never elided and never reported as a leak. mut2 will not be reported as a leak if use2 is just static bool instead of static bool const. Nor will it be reported as a leak if mut2 is not declared static.
[Bug c++/105071] New: Incorrect code with -Os and complex
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105071
Bug ID: 105071
Summary: Incorrect code with -Os and complex
Product: gcc
Version: 9.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dlong at cadence dot com
Target Milestone: ---
Created attachment 52691
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52691&action=edit
.ii file for test case
64-bit Intel, RedHat Enterprise Linux 7.4
$ cat foo.cc
#include
#include
using namespace std;
void broken(complex x)
{
complex x2=x*x;
complex x3=x2*x;
complex x4=x3*x;
complex x5=x4*x;
complex d=1.0+2.0/x+4.0/x2+8.0/x3+16.0/x4+32.0/x5;
fprintf(stderr, "%e%+ej\n", real(d), imag(d));
}
int main(int argc, char **argv) {
broken(complex(1.0, 0.00e+00));
return 0;
}
$ g++-9 -Wall -o foo foo.cc && ./foo # correct
6.30e+01+0.00e+00j
$ g++-9 -Wall -O2 -o foo foo.cc && ./foo # also correct
6.30e+01+0.00e+00j
$ g++-9 -Wall -Os -o foo foo.cc && ./foo # wrong
1.00e+00+0.00e+00j
If the +32.0/x5 at the end of the computation of d is
omitted, then -Os also gives the correct result.
$ g++-9 -v
Using built-in specs.
COLLECT_GCC=g++-9
COLLECT_LTO_WRAPPER=/grid/common/pkgsData/gcc-v9.3.0p3/Linux/RHEL7.0-2017-x86_64/libexec/gcc/x86_64-redhat-linux/9.3.0/lto-wrapper
Target: x86_64-redhat-linux
Configured with: /tmp/gcc-v9.3.0p3/gcc.source/configure
--prefix=/grid/common/pkgsData/gcc-v9.3.0p3/Linux/RHEL7.0-2017-x86_64
--with-pkgversion=Cadence --disable-libgcj --enable-threads=posix
--enable-shared --enable-checking=release --with-system-zlib
--enable-__cxa_atexit --disable-libunwind-exceptions
--with-linker-hash-style=gnu --enable-languages=c,c++,fortran --disable-nls
--enable-gnu-unique-object --enable-bootstrap --enable-plugin
--enable-initfini-array --enable-linker-build-id --enable-gnu-indirect-function
--enable-install-libiberty
--with-ld=/grid/common/pkgsData/gcc-v9.3.0p3/Linux/RHEL7.0-2017-x86_64/bin/ld
--with-as=/grid/common/pkgsData/gcc-v9.3.0p3/Linux/RHEL7.0-2017-x86_64/bin/as
--build=x86_64-redhat-linux --host=x86_64-redhat-linux --with-tune=generic
--enable-multiarch
Thread model: posix
gcc version 9.3.0 (Cadence)
[Bug sanitizer/103519] New: Address sanitizer check missing for AVX512 masked load
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103519
Bug ID: 103519
Summary: Address sanitizer check missing for AVX512 masked load
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: dlong at cadence dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
Example with generated assembly available here: https://godbolt.org/z/WTo5sGThb
In this:
#include
__m512d v;
void
access(float const *addr)
{
__m512d val;
__m256 val1;
__mmask8 const k3 = 0x3f;
val1=_mm256_maskz_loadu_ps(k3, addr);
val=_mm512_cvtps_pd(val1);
_mm512_storeu_pd((double *)&v, val);
}
when compiled with AVX512 instructions and -fsanitize=address, no address check
is generated for the maskz_load.
(FWIW, if the mask is folded into the conversion using maskz_cvtps_pd instead
then a check is generated. However it's a check for a full 32-byte access even
though the CPU will only actually access 24-bytes due to the mask.)
[Bug sanitizer/103519] Address sanitizer check missing for AVX512 masked load
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103519 David Long changed: What|Removed |Added CC||dlong at cadence dot com --- Comment #1 from David Long --- (In case the godbolt link happens to disappear at some point, compilation options are -mavx512f -mavx512vl -mfma -mbmi2 -O -fsanitize=address)
