https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95028
Bug ID: 95028 Summary: ICE in g++ (Arch Linux 9.3.0-1) 9.3.0 with captured OMP reduce clause in lambda Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: fytch at protonmail dot com Target Milestone: --- Created attachment 48491 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48491&action=edit Code that causes the ICE (same as in the comment) Description: GCC seems to crash when writing this OpenMP clause within a lambda. Writing the loop outside the lambda is fine and defining the variable sum inside the lambda is also fine but this combination seems to crash GCC. Code: int main() { double sum; const auto task = [&] { #pragma omp parallel for reduction(+: sum) for(int i = 0; i < 1; ++i) sum += 1; }; task(); } Compiled with: g++ main.cpp -fopenmp Output: during RTL pass: expand main.cpp: In lambda function: main.cpp:4:17: internal compiler error: in make_decl_rtl, at varasm.c:1340 4 | #pragma omp parallel for reduction(+: sum) | ^~~ Please submit a full bug report, with preprocessed source if appropriate. See <https://bugs.archlinux.org/> for instructions. Output of g++ -v: Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-pkgversion='Arch Linux 9.3.0-1' --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared --enable-threads=posix --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 --enable-default-pie --enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc Thread model: posix gcc version 9.3.0 (Arch Linux 9.3.0-1)