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Re: [RFA] mips-irix SEGV: long doubles are 128 bits long on IRIX


On Wed, Jul 21, 2004 at 06:19:34PM -0700, cgd@broadcom.com wrote:
> > According to GCC long double is 128-bit for all n64 and n32 targets.
> 
> Note that the actual 'long double' format is *different* between
> Linux and IRIX, AFAIK.
> 
> On Linux (w/ glibc), it's 128 bits in the typical IEEE format -- I
> don't recall what the exact terminology or specification for 128-bit
> IEEE-style value is, tho.  (like normal double, but wider mantissa and
> wider exponent.)
> 
> On IRIX, if i recall correctly, 'long double' is implemented as a
> *pair of doubles*, which allows one to get somewhat-extended
> precision, but doesn't allow the complete range of 128-bit IEEE-style.
> (I imagine the benefit is, you can do at least some of the 'long
> double' ops w/ 'double' FP ops in HW.  So, better speed... maybe.)

Oh, you're right.  We probably need to set the floatformat in one of
mips-linux or mips-irix, and the size in mips-tdep...

-- 
Daniel Jacobowitz


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