Please configure GCC with --enable-checking=release to disable very slow extra compiler diagnostic checks

[Zartaj Majeed]

GCC on Cygwin is not configured with --enable-checking=release. This makes the compiler run very slow due to extra diagnostic checks.

I'm seeing C++ compile 10 times slower on Cygwin

Here's GCC configure options and the warning message about extra diagnostics on Cygwin compared to Ubuntu 24.04

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On Cygwin

gcc -v

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-cygwin/16/lto-wrapper.exe
Target: x86_64-pc-cygwin
Configured with: /mnt/share/packages/gccmake/gcc-16/gcc/gcc.x86_64/src/gcc-16-20250720/configure --srcdir=/mnt/share/packages/gccmake/gcc-16/gcc/gcc.x86_64/src/gcc-16-20250720 --prefix=/usr --exec-prefix=/usr --localstatedir=/var --sysconfdir=/etc --docdir=/usr/share/doc/gcc --htmldir=/usr/share/doc/gcc/html -C --build=x86_64-pc-cygwin --host=x86_64-pc-cygwin --target=x86_64-pc-cygwin --without-libiconv-prefix --without-libintl-prefix --libexecdir=/usr/lib --with-gcc-major-version-only --enable-shared --enable-shared-libgcc --enable-static --enable-version-specific-runtime-libs --enable-bootstrap --enable-__cxa_atexit --enable-clocale=newlib --with-dwarf2 --with-tune=generic --enable-languages=ada,c,c++,fortran,lto,objc,obj-c++,jit --enable-graphite --enable-threads=posix --enable-libatomic --enable-libgomp --enable-libquadmath --enable-libquadmath-support --disable-libssp --enable-libada --disable-symvers --disable-multilib --with-gnu-ld --with-gnu-as --with-cloog-include=/usr/include/cloog-isl --without-libiconv-prefix --without-libintl-prefix --with-system-zlib --enable-linker-build-id --with-default-libstdcxx-abi=gcc4-compatible --enable-libstdcxx-filesystem-ts
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.0 20250720 (experimental) (GCC)

gcc -xc -ftime-report -c -o empty.o - < <(echo "")

Time variable                                  wall           GGC
  phase setup                        :   0.01 ( 85%)  1994k ( 92%)
  TOTAL                              :   0.01         2176k
Extra diagnostic checks enabled; compiler may run slowly.
Configure with --enable-checking=release to disable checks.

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On Ubuntu 24.04

gcc -v

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-linux-gnu/14/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 14.2.0-4ubuntu2~24.04' --with-bugurl=file:///usr/share/doc/gcc-14/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2,rust --prefix=/usr --with-gcc-major-version-only --program-suffix=-14 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/libexec --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-libstdcxx-backtrace --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-14-ig5ci0/gcc-14-14.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-14-ig5ci0/gcc-14-14.2.0/debian/tmp-gcn/usr --enable-offload-defaulted --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.2.0 (Ubuntu 14.2.0-4ubuntu2~24.04)

gcc -xc -ftime-report -c -o empty.o - < <(echo "")

Time variable                                   usr           sys          wall           GGC
  phase setup                        :   0.00 (  0%)   0.00 (  0%)   0.00 (  0%)  1841k ( 92%)
  phase opt and generate             :   0.00 (  0%)   0.01 (100%)   0.01 (100%)  2104  (  0%)
  callgraph optimization             :   0.00 (  0%)   0.00 (  0%)   0.01 (100%)     0  (  0%)
  callgraph ipa passes               :   0.00 (  0%)   0.01 (100%)   0.01 (100%)  1952  (  0%)
  ipa free lang data                 :   0.00 (  0%)   0.01 (100%)   0.00 (  0%)     0  (  0%)
  TOTAL                              :   0.00          0.01          0.01         2002k

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Zartaj