Difference between revisions of "Talk:Ieee arithmetic"
m (Added open questions on equality and ordering)
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:'''--[[User:Manus|manus]] 17:57, 3 February 2010 (UTC)''' How do you solve the problem of assertions then in ARRAY.put for example?
 
:'''--[[User:Manus|manus]] 17:57, 3 February 2010 (UTC)''' How do you solve the problem of assertions then in ARRAY.put for example?
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'''--[[User:Alexander Kogtenkov|Alexander Kogtenkov]] 20:01, 3 February 2010 (UTC)'''
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* Does it mean that <e>REAL_GENERAL</e> should inherit <e>PART_COMPARABLE</e> rather than <e>COMPARABLE</e>?
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* Do we need 2 equality queries: one that tells two objects represent the same value (it is used to ensure <e>copy</e> does what is expected, and it is used to implement <e>~</e>) and the other one that tells that the numbers are equal in terms of ordering relation of <e>(PART_)COMPARABLE</e>?

Revision as of 12:01, 3 February 2010

Most probably C compilers inline functions, but just to be sure, I'd convert them into the macros: 

#define to_raw_bits(d) *((EIF_NATURAL_64*)&(d))
 
#define eif_is_nan_bits(value) ((value & ~RTU64C(0x8000000000000000)) > RTU64C(0x7ff0000000000000))
 
#define eif_is_nan(v) ((*((EIF_NATURAL_64 *)&(v)) & ~RTU64C(0x8000000000000000)) > RTU64C(0x7ff0000000000000))

Does it affect the benchmarks?

--manus 17:59, 3 February 2010 (UTC) Actually it does not on Windows for sure, I've verified that it was inlined. But you are right that those could be simply defined as macros.

--Colin-adams 14:48, 3 February 2010 (UTC) Not IEEE arithmetic, nor maths, NaN = NaN is never true. And placing NaNs in a sort order isn't write either - REAL_32/64 are not totally ordered types.

--manus 17:57, 3 February 2010 (UTC) How do you solve the problem of assertions then in ARRAY.put for example?

--Alexander Kogtenkov 20:01, 3 February 2010 (UTC)

  • Does it mean that REAL_GENERAL should inherit PART_COMPARABLE rather than COMPARABLE?
  • Do we need 2 equality queries: one that tells two objects represent the same value (it is used to ensure copy does what is expected, and it is used to implement ~) and the other one that tells that the numbers are equal in terms of ordering relation of (PART_)COMPARABLE?
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