Re: union type is evil, redux

On Tue, 24 Dec 2002 13:07:21 +0900, "Stephen J. Turnbull" said: And given that they apparently cited chapter-and-verse to justify their refusal, I have to consider the GCC people totally in the right on this one. This leaves us with two basic options: 1) Somebody wraps their brain around the problem code in XEmacs (which may be quite evil, as you note: Amen. ;) Note that I've pondered this for a bit, and haven't convinced myself that a sufficiently aggressive compiler may not *still* present us with great screwage - remember that if the compiler can screw us by reordering code, it can screw us by reordering the explicit temporaries unless you flag them as 'volatile' (otherwise it can screw up by optimizing them into total non-existence). However, 'volatile' has some performance issues that we'd *NOT* want having inside a LISP_ASSIGN macro.... To be honest, my confidence is more shaken by the out-and-out compiler ICE's that I've managed to get. There's a routine in XFree86 called 'mipmap2.c' which will crap the compiler out totally if compiled with '-O3 -march=pentium4 -mfpmath=sse' (though weirdly enough, using -Os rather than -O3 works). That bug started somewhere back whenever they added fpmath support, and is still in 3.2.1. And quite frankly, I'd much rather know the gcc people are devoting their limited resources to fixing out-and-out *bugs* than trying to "fix" something with unspecified semantics.. There's always option 2: Heave it over the side. ;) /Valdis