Re: [RFA] mips: Fix "info registers" output

[Andrew Cagney <ac131313@cygnus.com>]

> On Sun, Mar 10, 2002 at 11:30:09AM -0500, Andrew Cagney wrote:

>> Suggest a FIXME and bug report here.  It isn't safe to assume things 
>> like builtin_type_double is 64 bit.  The code should use the ABI 
>> independant builtin_type_ieee_BLAH.  But this is a separate bug and not 
>> your problem :-)
> 
> 
> builtin_type_double =
>     init_type (TYPE_CODE_FLT, TARGET_DOUBLE_BIT / TARGET_CHAR_BIT,
>                0,
>                "double", (struct objfile *) NULL);
> 
> 
>   set_gdbarch_double_bit (gdbarch, 64);
> 
> 
> Why isn't it safe to assume that a double is 64-bit when we explicitly
> set it that way?  I assume that the builtin types get swapped out when
> we change gdbarch... yes, they do.  Besides, is MIPS FP actually IEEE? 
> Oh, I suppose the values probably are and only some of the math isn't.

Have a look at GCC's -fshort-double option.  I'm not sure how MIPS would 
respond to it but I suspect it would make everyones head hurt. :-)

The ``info registers'' code is both ISA and ABI dependant.  ISA since 
that determines the raw format of registers (ieee_double_{big,little} 
not double) - the ABI shouldn't change a MIPS DOUBLE.  ABI since that 
determins where bits of registers end up being saved on the stack.

> Committed without that last FIXME; I'll add it if it's really
> necessary
Er, where's the fire?  With all respect, it is always better to give the 
other party the chance to respond.

Andrew