https://gcc.gnu.org/g:955217839f5cff7b64202eb08496e16a29d7acc4
commit r16-4252-g955217839f5cff7b64202eb08496e16a29d7acc4 Author: Sam James <[email protected]> Date: Wed Aug 14 13:15:30 2024 +0100 doc: mention STAGE1_CFLAGS STAGE1_CFLAGS can be used to accelerate the just-built stage1 compiler which especially improves its performance on some of the large generated files during bootstrap. It defaults to nothing (i.e. -O0). The downside is that if the native compiler is buggy, there's a greater risk of a failed bootstrap. Those with a modern native compiler, ideally a recent version of GCC, should be able to use -O1 or -O2 without issue to get a faster build. PR rtl-optimization/111619 * doc/install.texi (Building a native compiler): Discuss STAGE1_CFLAGS. Diff: --- gcc/doc/install.texi | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi index fc771448274a..576b7eead5ec 100644 --- a/gcc/doc/install.texi +++ b/gcc/doc/install.texi @@ -3125,6 +3125,13 @@ Again, if the native compiler miscompiles the stage1 compiler, you may need to work around this by avoiding non-working parts of the stage1 compiler. Use @code{STAGE1_TFLAGS} to this end. +You can use @code{STAGE1_CFLAGS} to set the flags passed to the host compiler +when building the stage1 compiler. The default is to pass @option{-g}, but when +the host compiler is GCC, this results in a non-optimized build of the stage1 +compiler. You can speed up the bootstrap by using @samp{STAGE1_CFLAGS='-O2'} +at the increased risk of miscompiling the stage1 compiler when the host +compiler is buggy. + If you used the flag @option{--enable-languages=@dots{}} to restrict the compilers to be built, only those you've actually enabled will be built. This will of course only build those runtime libraries, for
