Re: [Qemu-devel] [PATCH 06/11] target-i386: use floatx80 constants in helper_fld*_ST0()

["Andreas Färber" <andreas.faerber@web.de>]

Am 20.05.2011 um 12:32 schrieb Peter Maydell:

> On 15 May 2011 15:13, Aurelien Jarno <aurelien@aurel32.net> wrote:
>> Instead of using a table which doesn't correspond to anything from
>> physical in the CPU, use directly the constants in helper_fld*_ST0().
>
> Actually I rather suspect there is effectively a table in the CPU
> indexed by the last 3 bits of the FLD* opcode... It would be
> possible to implement this group of insns in QEMU with a single
> helper function that took the index into the array, but since the
> array seems to be causing weird compilation problems we might
> as well stick with the lots-of-helpers approach, at which point
> this is a sensible cleanup.

In OpenBIOS we once ran into a similar error on ppc64 where a cast  
would've resulted in the truncation of a static pointer ... could this  
be an alignment issue here, that it's being truncated by the floatx80  
cast? I tried using __attribute__((packed)) on the floatx80 type  
without luck.
Or maybe the constant width is being handled weird, with LL being 128  
bits rather than the expected 64 bits? ;)

I wasn't specifically asking for the table to be removed, just for  
some working solution.

Andreas