https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81818
--- Comment #10 from Andrew Roberts <andrewm.roberts at sky dot com> ---
I've attached the output for gcc 7.2.0 with -fmem-report (as
gcc-7.2.0-fmem-report.tar.bz2).
g++ -Ox -fmem-report -c testmap.cpp
where -Ox is one of: -O0, -O1, -O2, -O3, or -O1 -fgcse
This is across: x64 (x86-64) , arm, aarch64-rpi3 (aarch64)
Both Raspbery Pi 3 systems are identical, one has 32 bit OS, other has 64 bit
OS (Arch Linux ARM)
The files are named: gcc-7.2.0-[arch]-[opt].txt.
The original issue was large memory usage increase for aarch64 vs arm, on -O2
and above. So looking at -O1 vs -O2 for the above.
There seem to be leaks in the Bitmaps:
Total Memory Percentage
Memory Leaked Leaked
arm -O1: 54067992 10582346 19.57%
arm -O2: 43536148 15595746 35.82%
aarch64 -O1: 39788848 9005047 22.63%
aarch64 -O2: 74521688 42694630 57.29% <= big increase on aarch64 at -O2
47% of the leaks at -O2 on aarch64 are in:
df-problems.c:1912 (df_mir_alloc) 543920: 0.7% 202813600
10167911: 23.8% 0 0 heap
df-problems.c:1913 (df_mir_alloc) 544080: 0.7% 202798720
10167165: 23.8% 0 0 heap
32% of the leaks at -O2 on x86-64 are also in the same place, so I guess this
is a 64bit code path.
I don't see anything else which stands out as being different between arm and
aarch64 as they move from -O1 to -O2.
There are plenty of other leaks though, although how significant these are I
have no idea.
The arm gcc is configured with:
/usr/local/gcc/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/usr/local/gcc/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/gcc-7.2.0/libexec/gcc/armv7l-unknown-linux-gnueabihf/7.2.0/lto-wrapper
Target: armv7l-unknown-linux-gnueabihf
Configured with: ../gcc-7.2.0/configure --prefix=/usr/local/gcc-7.2.0
--program-suffix= --disable-werror --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-linker-hash-style=gnu --enable-plugin
--enable-gnu-indirect-function --enable-lto --with-isl
--enable-languages=c,c++,fortran --disable-libgcj --enable-clocale=gnu
--disable-libstdcxx-pch --enable-install-libiberty --disable-multilib
--disable-libssp --host=armv7l-unknown-linux-gnueabihf
--build=armv7l-unknown-linux-gnueabihf --with-arch=armv7-a --with-float=hard
--with-fpu=vfpv3-d16 --disable-bootstrap --enable-gather-detailed-mem-stats
Thread model: posix
gcc version 7.2.0 (GCC)
The aarch64 gcc is configured with:
/usr/local/gcc/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/usr/local/gcc/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/gcc-7.2.0/libexec/gcc/aarch64-unknown-linux-gnu/7.2.0/lto-wrapper
Target: aarch64-unknown-linux-gnu
Configured with: ../gcc-7.2.0/configure --prefix=/usr/local/gcc-7.2.0
--program-suffix= --disable-werror --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-linker-hash-style=gnu --enable-plugin
--enable-gnu-indirect-function --enable-lto --with-isl
--enable-languages=c,c++,fortran --disable-libgcj --enable-clocale=gnu
--disable-libstdcxx-pch --enable-install-libiberty --disable-multilib
--enable-shared --enable-clocale=gnu --with-arch-directory=aarch64
--enable-multiarch --disable-libssp --host=aarch64-unknown-linux-gnu
--build=aarch64-unknown-linux-gnu --with-arch=armv8-a --disable-bootstrap
--enable-gather-detailed-mem-stats
Thread model: posix
gcc version 7.2.0 (GCC)
The x86-64 gcc is configured with:
/usr/local/gcc/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/usr/local/gcc/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/gcc-7.2.0/libexec/gcc/x86_64-unknown-linux-gnu/7.2.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-7.2.0/configure --prefix=/usr/local/gcc-7.2.0
--program-suffix= --disable-werror --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-linker-hash-style=gnu --enable-plugin
--enable-initfini-array --enable-gnu-indirect-function --with-isl
--enable-languages=c,c++,fortran,lto --disable-libgcj --enable-lto
--enable-multilib --with-tune=generic --with-arch_32=i686
--host=x86_64-unknown-linux-gnu --build=x86_64-unknown-linux-gnu
--with-ld=/usr/local/bin/ld --with-gnu-ld --with-as=/usr/local/bin/as
--with-gnu-as --disable-bootstrap --enable-gather-detailed-mem-stats
Thread model: posix
gcc version 7.2.0 (GCC)
