[Bug c++/106041] New: Long/infinite compile time for Arm SIMD -O1 or -O2 but not -O0

[jan.wassenberg at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106041

            Bug ID: 106041
           Summary: Long/infinite compile time for Arm SIMD -O1 or -O2 but
                    not -O0
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jan.wassenberg at gmail dot com
  Target Milestone: ---

Created attachment 53179
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53179&action=edit
Zipped preprocessed source

Long (overnight) compile time for Arm target, vs 28sec for Clang.

Repro: time aarch64-linux-gnu-g++-12 -O2 memory_test.cc.ii

Output: none, not even with -ftime-report. Commenting out the contents of
TestLoadStoreInterleaved3 and TestLoadStoreInterleaved4 avoids the problem.

-v output:
Using built-in specs.
COLLECT_GCC=aarch64-linux-gnu-g++-12
COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/aarch64-linux-gnu/12/lto-wrapper
Target: aarch64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 12-20220302-1'
--with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-12 --enable-shared
--enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-libquadmath --disable-libquadmath-support --enable-plugin
--enable-default-pie --with-system-zlib --enable-libphobos-checking=release
--without-target-system-zlib --enable-multiarch --enable-fix-cortex-a53-843419
--disable-werror --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=aarch64-linux-gnu
--program-prefix=aarch64-linux-gnu- --includedir=/usr/aarch64-linux-gnu/include
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.1 20220302 (experimental) [master r12-7448-g58394373a70]
(Debian 12-20220302-1)