#9667 closed enhancement (duplicate)
Use PARI's hash_GEN() for gen.__hash__
Reported by: | jdemeyer | Owned by: | was |
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Priority: | minor | Milestone: | sage-duplicate/invalid/wontfix |
Component: | interfaces | Keywords: | |
Cc: | Merged in: | ||
Authors: | Jeroen Demeyer | Reviewers: | |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
The latest version of PARI has a function hash_GEN
which hashes a PARI GEN
. Since this is very likely faster than hashing the string representation of a GEN
, we should use this for the gen
class in sage/libs/pari/gen.pyx
This patch has been included in #9764.
Attachments (1)
Change History (8)
comment:1 Changed 13 years ago by
Description: | modified (diff) |
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Changed 13 years ago by
Attachment: | 9667.patch added |
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comment:2 Changed 12 years ago by
Description: | modified (diff) |
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Milestone: | sage-4.6 → sage-duplicate/invalid/wontfix |
Status: | new → needs_review |
comment:3 Changed 12 years ago by
Status: | needs_review → positive_review |
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Ignore this ticket, see #9764 instead.
comment:4 Changed 12 years ago by
Resolution: | → duplicate |
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Status: | positive_review → closed |
comment:5 follow-ups: 6 7 Changed 12 years ago by
Hi,
For the record, this change introduced a major bug into Sage, because PARI's hash_GEN is itself buggy. For example, by playing with ideals in Sage (code is complicated though...), I quickly got into this situation:
sage: n0 [11, 3; 0, 1] sage: n1 [11, 3; 0, 1] sage: hash(n0) -7493989779944505307 sage: hash(n1) -6341068275337658331
comment:6 Changed 12 years ago by
comment:7 Changed 12 years ago by
Replying to was:
Hi,
For the record, this change introduced a major bug into Sage, because PARI's hash_GEN is itself buggy.
Don't blaim PARI when the fault is the Sage->PARI interface. The issue is not hash_GEN()
, it is a problem with how integers are converted from Sage to PARI. I have a patch for this issue at #11611.
Patch to be applied on top of #9343