[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Lightning] Code patching, context switching

From: Paolo Bonzini
Subject: Re: [Lightning] Code patching, context switching
Date: Wed, 20 Feb 2008 17:55:56 +0100
User-agent: Thunderbird (Macintosh/20071031)

 Yes.  On the PowerPC, the argument registers are *not* available to the
 user, because they are caller-save while GNU lightning always provides
 the illusion that they are callee-save.

I don't get it. Are you saying that the PPC's entire register file is
not accessible via JIT_R, JIT_V and JIT_FPR?

Yes. r3-r9, which the ABI uses for argument passing, are not accessible at all. In the prolog, they are moved to other, callee-save registers, which are also not accessible with JIT_{R,V} but only with jit_getarg.

I'm wary of setjmp though, because I've inspected the Windows setjmp.h
header, and it doesn't seem to save the floating point registers on
x86. Anyway, it sounds like you're implying this is a Lightning
limitation, so any clarification is much appreciated. :-)

Yes, it is.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]