https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108500
--- Comment #13 from dhekir at gmail dot com --- Thank you very much for the work. Running the attached file with `-O -finline-small-functions` does compile in under 30 seconds on my computer. However, when trying to compile the original program (which is about 1 million lines, and each call passes 2 structures as arguments, instead of just calling a function without any arguments), it's taking several dozen minutes. I tried preprocessing it (5s to obtain the .i) file, and then running it with `-O -finline-small-functions`, or `-O2`, or `-O3`, and without any options at all, and in all cases, I ended up terminating the program before it finished (after more than 10 minutes; in some cases I waited up to 30 minutes). I tried re-simplifying the program. After preprocessing, I tried the following variants, with options `-O -finline-small-functions`: - 1M calls, no arguments, function returning a (global) struct: compiles in 30s; - 1M calls, each with a single argument of type `struct s`, function returns that same argument (that is, `struct s f(struct s s1) {return s1;}`): compiles in <2 minutes; - 1M calls, each with 2 arguments of types `struct s1` and `struct s2`, returning the second argument (that is, `struct s2 f(struct s1 arg1, struct s2 arg2) {return arg2;}`): >50 minutes (I had to terminate it). The last version, with -O2, I left it compiling for almost 3h before having to stop it. In any case, this bug seems definitely solved for me, and I no longer have the original stack overflow. However, I am still unable to compile my original code, so I'll have to try something else. It's possibly not a regression, however. I'm attaching it in case you may want to try it, but feel free to ignore it.