# 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)''' | ||

+ | * Does it mean that <e>REAL_GENERAL</e> should inherit <e>PART_COMPARABLE</e> rather than <e>COMPARABLE</e>? | ||

+ | * 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`

?