From: Bruno H. <br...@cl...> - 2004-01-12 21:46:55
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Sam wrote: > Is it really worth it? > You are making life easier for a "clever user" ... I am eliminating a possible cause of "handler_fault...". The cost is 5 lines of code. > at the expense of making an additional system call for everyone else! alloca(1) is a single machine instruction, not a system call. And it occurs in an "if (never_never)" branch of code. > Moreover, __EVEN WITH__ this alloca() trick, clisp segfaults on the > first GC on mingw Is is related? > how is this better than just removing the alloca() trick and putting a > note in INSTALL that -fomit-frame-pointer is not supported? It reduces the number of things that an installer must be aware of, by 1. > Let us be consistent: if we want -fomit-frame-pointer to work - at > least sometimes - keep the trick and add -fomit-frame-pointer in > makemake.in (conditional on mingw where it does not work now). This is not about being consistent. It's about safety and speed. Since our measurements indicate the -fomit-frame-pointer brings absolutely no speed advantage, why should I add it back to makemake.in? > if we do not want it - remove all vestiges of it. No. We don't recommend -fomit-frame-pointer but we don't forbid it either. Similarly, we don't recommend gcc-2.7.2, but we don't forbid it either. Bruno |