Message117675
I found out that $x2xx (test both $12xx and $02xx) gives identical results to python. Here is what it means.
The PC field (bits 9 and 8) or Precision Control determines to what precision the FPU rounds results after each arithmetic instruction in one of three ways:
00 = 24 bits (REAL4)
01 = Not used
10 = 53 bits (REAL8) <- This is required by _Py_dg_dtoa
11 = 64 bits (REAL10) (this is the initialized state)
So contrary to my expectation it is not the rounding control bits but the Precision control bits that matter. |
|
Date |
User |
Action |
Args |
2010-09-29 23:26:41 | Kiriakos.Vlahos | set | recipients:
+ Kiriakos.Vlahos, loewis, sjmachin, mark.dickinson, eric.smith, brian.curtin, skrah |
2010-09-29 23:26:41 | Kiriakos.Vlahos | set | messageid: <1285802801.3.0.974327957001.issue9980@psf.upfronthosting.co.za> |
2010-09-29 23:26:39 | Kiriakos.Vlahos | link | issue9980 messages |
2010-09-29 23:26:39 | Kiriakos.Vlahos | create | |
|