> Correct, ARM's emulate hardware floating point using software. That doesn't really say anything about compliance with standards/
________________________________________ From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] On Behalf Of O'Neill, Owen [oone...@averyberkel.com] Sent: Wednesday, November 04, 2009 9:36 AM To: General Discussion of SQLite Database Cc: Alexander Drozd Subject: Re: [sqlite] SQLite on PocketBook Correct, ARM's emulate hardware floating point using software. And it's really slow too since it forces a context switch as the processor spots it's been given a FP operation to do and has to jump into the fp emulation. If you are lucky enough to have control over it & depending on the level of accuracy you need, I'd recommend storing everything as an integer with a separate scalar. Owen. -----Original Message----- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of D. Richard Hipp Sent: Wednesday, November 04, 2009 3:26 PM To: General Discussion of SQLite Database Cc: Alexander Drozd Subject: Re: [sqlite] SQLite on PocketBook On Nov 4, 2009, at 4:53 AM, Alexander Drozd wrote: > > My name is Alexander. I am working on an open-source spaced- > repetition software project (http://code.google.com/p/pbanki/). My > software relies on SQLite library. I came across some bug-like > problems with running SQLite on a low-memory e-ink reader device. I > am very sorry to bother you, but I tried to submit my problem to > the bugtracker at the SQLite site, and for some reason anonymous > login failed. > > The problem appears at the point of reading real values from an > SQLite database. I created a simple database > > CREATE TABLE cards ( > text TEXT NOT NULL, > value REAL NOT NULL > ); > > I also tried to use NUMERIC and FLOAT instead of REAL. Then I > inserted a few values: > > INSERT INTO cards VALUES('second',100.1); > INSERT INTO cards VALUES('first', 100.0); > > Then I execute "select * from cards order by due" query with sample > code from http://www.sqlite.org/quickstart.html It works perfectly > when compiled on desktop computer, but fails on target device. The > device is PocketBook301+ (http://pocketbook.com.ua/). Unfortunately > their site does not have an English version. This device is based on > Samsung S3C2440 AL-40 CPU. It runs under open-source firmware called > pocketbookfree, that is based on Linux 2.6.18.2 armv4tl. > > The above query run on pocketbook returns corrupted values for > floats if they have a non-zero fractional part: > > text = first > val = 100.0 > > text = second > val = 1.90359837350824e+185 > > Sorting by columns containing float numbers also fails when > specified with ORDER BY. I am not sure whether this is an issue with > SQLite or with cross-compiler for PocketBook, but I would greatly > appreciate any suggestions on how to treat this problem. I'm guessing that your hardward does not implement IEEE 754 floating point correctly. We've seen that sort of thing before, especially with GCC. There are some options to GCC (which escape my memory right now) that can force it to use strict IEEE 754 floating point rather than its preferred, speedier but non-standard alternative. D. Richard Hipp d...@hwaci.com _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users The information contained in this e-mail is privileged and confidential information intended only for the use of the individual or entity named. If you are not the intended recipient, or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any disclosure, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and delete any copies from your system. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
