Gentoo Archives: gentoo-amd64

From: Marc Joliet <marcec@×××.de>
To: gentoo-amd64@l.g.o
Subject: Re: [gentoo-amd64] Possible Math Problem - Request For Verification
Date: Sat, 25 Jun 2011 23:57:03
Message-Id: 20110626015453.4a67fe37@marcec.huntemann.uni-oldenburg.de
In Reply to: [gentoo-amd64] Possible Math Problem - Request For Verification by Frank Peters
1 Am Sat, 25 Jun 2011 13:41:11 -0400
2 schrieb Frank Peters <frank.peters@×××××××.net>:
3
4 > Hello,
5 >
6 [background information]
7
8 Huh, I was unaware that GNU (since they're the authors of GCC/GLIBC) ever had
9 problems in this area. Since I use my machine for numerical tasks, too, I was
10 interested in seeing whether I would see the same problem.
11
12 > The code will take several minutes to compile, execute, and complete. While
13 > the test is running it will spit out its progress to stdout. Upon completion
14 > a brief summary is given:
15 >
16 > UCBFAIL indicates problems!
17 > /tmp/fp-test-results/ccos_DP.output: ucbtest UCBFAIL in COS(X) at line 444 for generic
18 > /tmp/fp-test-results/clib_DP.output: ucbtest UCBFAIL in cabsd at line 701 for double
19 > /tmp/fp-test-results/clib_DP.output: ucbtest UCBFAIL in powd at line 701 for double
20 > /tmp/fp-test-results/clib_DP.output:UCBFAIL clib_DP.output , 25 out of 25 tests completed
21 > /tmp/fp-test-results/csin_DP.output: ucbtest UCBFAIL in SIN(X) at line 444 for generic
22 >
23 > only 11 out of 14 show UCBPASS!
24
25 I ran the tests without any modifications to ucbREADME/linux.sh and don't get
26 the cabsd failure:
27
28 UCBFAIL indicates problems!
29 /tmp/fp-test-results/ccos_DP.output: ucbtest UCBFAIL in COS(X) at line 444 for generic
30 /tmp/fp-test-results/clib_DP.output: ucbtest UCBFAIL in powd at line 701 for double
31 /tmp/fp-test-results/clib_DP.output:UCBFAIL clib_DP.output , 25 out of 25 tests completed
32 /tmp/fp-test-results/csin_DP.output: ucbtest UCBFAIL in SIN(X) at line 444 for generic
33
34 only 11 out of 14 show UCBPASS!
35
36 Out of curiosity, I ran the test two more times and got the same results.
37
38 This machine runs on stable, with a slightly older Athlon64 X2.
39
40 > There are expected failures in the trigonometric tests since trigonometric
41 > performance is not specified in IEEE754/854. The failure in powd (double power
42 > function) is also expected. But everything else should have passed.
43
44 Then according to the results above my machine is apparently OK. (I guess I
45 really should finally read about IEEE floating point more thoroughly, I've been
46 planning to do that for a while now.)
47
48 [...]
49 > Frank Peters
50
51 HTH
52 --
53 Marc Joliet
54 --
55 "People who think they know everything really annoy those of us who know we
56 don't" - Bjarne Stroustrup

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Replies

Subject Author
Re: [gentoo-amd64] Possible Math Problem - Request For Verification Mark Knecht <markknecht@×××××.com>
Re: [gentoo-amd64] Possible Math Problem - Request For Verification Frank Peters <frank.peters@×××××××.net>