On 17.05.2016 20:09, Max Samukha wrote:
On Monday, 16 May 2016 at 19:01:19 UTC, Timon Gehr wrote:
You are not even guaranteed to get the same result on two different x86
implementations.
Without reading the x86 specification, I think it is safe to claim
that you actually are guaranteed to get the same result.
Correct. Sorry for the noise.
Interestingly, I was actually wrong:
https://hal.archives-ouvertes.fr/hal-00128124v5/document
I think that document is worth a read in any case.
Page 18: "Note, also, that different processors within the same
architecture can implement the same transcendental functions with
different accuracies. We already noted the difference between the AMD-K5
and the K6 and following processors with respect to angular reduction.
Intel also notes that the algorithms’ precision was improved between the
80387 / i486DX processors and the Pentium processors. [Int, 1997,§7.5.10]"
The language should ideally not leak such differences to the user.
