https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71885
Bug ID: 71885
Summary: Incorrect code generated with -01, function calls are
missing
Product: gcc
Version: 6.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: eric at baculasystems dot com
Target Milestone: ---
Created attachment 38905
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38905&action=edit
.ii file generated with -O1 option
I overload the new operator in a class (to initialize the memory to 0 and track
memory leaks), and after the upgrade from GCC 5.x to 6.1, my program stopped to
work correctly.
If I tweak a little bit the new operator (I add a printf() inside, or I do all
operations in one line memset(malloc()) instead of malloc() ; memset();) the
code is generated correctly.
I have a small test file, not sure this is the best example.
In my little program, I have two set of classes, one that is properly
generated, and an other one that is buggy. The only difference between the two
is a "printf()" in a function. The good result should be a == 0
# g++ -Wall -00 new.c
# ./a.out
new is called from new.c:81 and it works!
test_ok a == 0
test a == 0
# g++ -Wall -01 new.c
# ./a.out
test_ok a == 0
test a == 1431655765
I'm running Archlinux.
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc-multilib/src/gcc/configure --prefix=/usr
--libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared
--enable-threads=posix --enable-libmpx --with-system-zlib --with-isl
--enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu
--disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object
--enable-linker-build-id --enable-lto --enable-plugin
--enable-install-libiberty --with-linker-hash-style=gnu
--enable-gnu-indirect-function --enable-multilib --disable-werror
--enable-checking=release
Thread model: posix
gcc version 6.1.1 20160707 (GCC)
Thanks
