X-Spam-Check-By: sourceware.org X-YMail-OSG: eGDFCyQVM1nhJPcRp6V.fsGEcFX6ssp8gj7JvI1k3K05uc8TyMSBPc5Bh6bFdpSx2LKtW8GH49zLE7s8MHIZupbp_9uNb3Mr_WLunZDLLaYYVM2ppzCePELq7BZ_wHpM Date: Mon, 23 Apr 2007 16:52:43 -0700 (PDT) From: "Cary R." Subject: Re: newlib?: pow function can produce incorrect results. To: cygwin AT cygwin DOT com MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="0-1884113354-1177372363=:86623" Content-Transfer-Encoding: 8bit Message-ID: <17190.86623.qm@web59108.mail.re1.yahoo.com> Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com --0-1884113354-1177372363=:86623 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Content-Id: Content-Disposition: inline I had some more time to look into this and when the simple C program I mentioned earlier uses variables like the other program, incorrect results are produced. I have attached this C/C++ program. I certainly don't understand what is going on. I would have expected pow to be pass-by value which should make the two calls identical from a system standpoint, but the results imply something different. Any suggestions would be greatly appreciated. Cary __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com --0-1884113354-1177372363=:86623 Content-Type: application/octet-stream; name="pow-error.c" Content-Transfer-Encoding: base64 Content-Description: 3225223843-pow-error.c Content-Disposition: attachment; filename="pow-error.c" I2luY2x1ZGUgPG1hdGguaD4KI2luY2x1ZGUgPHN0ZGlvLmg+CgppbnQgbWFp bigpCnsKICBkb3VibGUgdmFyLCBuYW4sIGluZiwgbWluZiwgb25lLCB6ZXJv OwogIGluZiA9IDEuMC8wLjA7CiAgbWluZiA9IC0xLjAgKiBpbmY7CiAgbmFu ID0gc3FydCgtMS4wKTsKICBvbmUgPSAxLjA7CiAgemVybyA9IDAuMDsKCiAg cHJpbnRmKCJVc2luZyBuYW4gPSAlZiwgaW5mID0gJWYgYW5kIC1pbmYgPSAl Zi5cblxuIiwgbmFuLCBpbmYsIG1pbmYpOwoKICAvLyBDaGVjayB0aGUgMSAq KiBpbmYgY2FzZS4KICB2YXIgPSBwb3coMS4xLCBpbmYpOwogIHByaW50Zigi MS4xICoqIGluZiBpcyAlZi5cbiIsIHZhcik7CgogIHZhciA9IHBvdygxLjAs IGluZik7CiAgcHJpbnRmKCIxLjAgKiogaW5mIGlzICVmIiwgdmFyKTsKICB2 YXIgPSBwb3cob25lLCBpbmYpOyAvLyBUaGlzIHByb2R1Y2VzIGluY29ycmVj dCByZXN1bHRzIQogIHByaW50ZigiLCAlZi5cbiIsIHZhcik7CgogIHZhciA9 IHBvdygwLjksIGluZik7CiAgcHJpbnRmKCIwLjkgKiogaW5mIGlzICVmLlxu XG4iLCB2YXIpOwoKCiAgLy8gQ2hlY2sgdGhlIDEgKiogLWluZiBjYXNlLgog IHZhciA9IHBvdygxLjEsIG1pbmYpOwogIHByaW50ZigiMS4xICoqIC1pbmYg aXMgJWYuXG4iLCB2YXIpOwoKICB2YXIgPSBwb3coMS4wLCBtaW5mKTsKICBw cmludGYoIjEuMCAqKiAtaW5mIGlzICVmIiwgdmFyKTsKICB2YXIgPSBwb3co b25lLCBtaW5mKTsgLy8gVGhpcyBwcm9kdWNlcyBpbmNvcnJlY3QgcmVzdWx0 cyEKICBwcmludGYoIiwgJWYuXG4iLCB2YXIpOwoKICB2YXIgPSBwb3coMC45 LCBtaW5mKTsKICBwcmludGYoIjAuOSAqKiAtaW5mIGlzICVmLlxuXG4iLCB2 YXIpOwoKCiAgLy8gQ2hlY2sgdGhlIC0xICoqIGluZiBjYXNlLgogIC8vIHZh ciA9IHBvdygtMS4xLCBpbmYpOyAvLyBTaG91bGRuJ3QgdGhpcyBhbHNvIGJl IG5hbj8KICAvLyBwcmludGYoIi0xLjEgKiogaW5mIGlzICVmLlxuIiwgdmFy KTsKICAvLyB2YXIgPSBwb3coLTEuMCwgaW5mKTsKICAvLyBwcmludGYoIi0x LjAgKiogaW5mIGlzICVmLlxuIiwgdmFyKTsKICAvLyB2YXIgPSBwb3coLTAu OSwgaW5mKTsKICAvLyBwcmludGYoIi0wLjkgKiogaW5mIGlzICVmLlxuXG4i LCB2YXIpOwoKCiAgLy8gQ2hlY2sgdGhlIC0xICoqIC1pbmYgY2FzZS4KICAv LyB2YXIgPSBwb3coLTEuMSwgbWluZik7IC8vIFNob3VsZG4ndCB0aGlzIGFs c28gYmUgbmFuPwogIC8vIHByaW50ZigiLTEuMSAqKiAtaW5mIGlzICVmLlxu IiwgdmFyKTsKICAvLyB2YXIgPSBwb3coLTEuMCwgbWluZik7CiAgLy8gcHJp bnRmKCItMS4wICoqIC1pbmYgaXMgJWYuXG4iLCB2YXIpOwogIC8vIHZhciA9 IHBvdygtMC45LCBtaW5mKTsKICAvLyBwcmludGYoIi0wLjkgKiogLWluZiBp cyAlZi5cblxuIiwgdmFyKTsKCgogIC8vIENoZWNrIHRoZSBuYW4gY2FzZXMu CiAgdmFyID0gcG93KDEuMCwgbmFuKTsKICBwcmludGYoIjEuMCAqKiBuYW4g aXMgJWYiLCB2YXIpOwogIHZhciA9IHBvdyhvbmUsIG5hbik7IC8vIFRoaXMg cHJvZHVjZXMgaW5jb3JyZWN0IHJlc3VsdHMhCiAgcHJpbnRmKCIsICVmLlxu IiwgdmFyKTsKCiAgdmFyID0gcG93KG5hbiwgMC4wKTsKICBwcmludGYoIm5h biAqKiAwLjAgaXMgJWYiLCB2YXIpOwogIHZhciA9IHBvdyhuYW4sIHplcm8p OyAvLyBUaGlzIHByb2R1Y2VzIGluY29ycmVjdCByZXN1bHRzIQogIHByaW50 ZigiLCAlZi5cbiIsIHZhcik7CgogIHJldHVybiAwOwp9Cg== --0-1884113354-1177372363=:86623 Content-Type: text/plain; charset=us-ascii -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/ --0-1884113354-1177372363=:86623--