site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com On Nov 28, 2006, at 7:18 PM, Jay Reynolds Freeman wrote: My code establishes that a numeric string which manifestly is not a nan is interpreted as a nan by "strtold". I am running on a Macbook 1,1 with OS 10.4.8. The version of gcc is that which came with the download of XCode 2.4.1, which is gcc-4.0; however, I believe the problem is in a library which is not part of gcc per se. I think the library is provided by Apple. I have done a google search for information about this bug, and turned up some possible reports that the bug may be related to the fact that "long doubles" are in IEEE 80-bit format on the Macbook. Reports indicate that in architectures using IEEE 64-bit format for long double, the problem does not occur. Thus if you try to duplicate my bug, your mileage may vary depending on what processor you are using. In particular, if your compiler reports that sizeof( long double ) is 8 bytes, you may not see the bug. (IEEE 80-bits take at least 10 bytes, and maybe more if data must be word-aligned.) Non-zero bits in the output are common when the floating-point representation in use cannot represent the input string with perfect accuracy. That's not what is going on here. What I get is: (cut-and-paste of terminal output)

gcc -o bug2 bug2.c bug2 nan -- Jay Reynolds Freeman

Jay_Reynolds_Freeman@mac.com http://web.mac.com/jay_reynolds_freeman (personal web site) On Nov 28, 2006, at 5:31 PM, Justin C. Walker wrote: On Nov 28, 2006, at 14:37 , Jay Reynolds Freeman wrote: I have a one-line C program that breaks "strtold" (string to long double) when compiled with gcc and linked with the libraries that came with XCode 2.4, running on a Macbook with OS X 10.4.8. I would be curious myself to know whose problem this is, so that I can report it appropriately if it is not Apple's If this posting is inappropriate here, please forgive me, I just joined the group. Justin -- Justin C. Walker, Curmudgeon-at-Large () The ASCII Ribbon Campaign /\ Help Cure HTML Email _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/galimore%40mac.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... For what it's worth, I'm seeing this too with your code example on my MacBook Pro... SlackBookPro:~ terry$ uname -a Darwin SlackBookPro.local 8.8.1 Darwin Kernel Version 8.8.1: Mon Sep 25 19:42:00 PDT 2006; root:xnu-792.13.8.obj~1/RELEASE_I386 i386 i386 SlackBookPro:~ terry$ gcc --version i686-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build 5363) Copyright (C) 2005 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. SlackBookPro:~ terry$ uname -a Darwin SlackBookPro.local 8.8.1 Darwin Kernel Version 8.8.1: Mon Sep 25 19:42:00 PDT 2006; root:xnu-792.13.8.obj~1/RELEASE_I386 i386 i386 SlackBookPro:~ terry$ gcc -o bug2 bug2.c SlackBookPro:~ terry$ ./bug2 nan You don't say what "breaks" means. You also don't say what version of gcc you are using. This is a reasonable place to discuss this; so is the 'unix- porting' list. The Xcode list is more for issues dealing with the IDE itself. FWIW, I find that your code produces reasonable results with gcc 4.0.1. With 3.3 (on 10.4.8 and 10.3.9) and 3.1 (on 10.3.9), I get a bunch of non-zero bits in the output where there should presumably be 0's. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/ jay_reynolds_freeman%40mac.com This email sent to jay_reynolds_freeman@mac.com This email sent to galimore@mac.com This email sent to site_archiver@lists.apple.com