ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) (10/12/90)
Just for a change I thought I'd post something that _wasn't_ a problem.
Lint just caught a mistake in some code of mine where I was shifting
by 32 instead of 5 ("shift greater than size of object").
Am I _glad_ that I ran lint after typing in every few functions!
No, I'm not a new convert to lint, it's just the first time I've made
this particular mistake in C. Lint saved me a great deal of embarrassment.
--
Fear most of all to be in error. -- Kierkegaard, quoting Socrates.meissner@osf.org (Michael Meissner) (10/12/90)
In article <3965@goanna.cs.rmit.oz.au> ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes: | Path: paperboy!snorkelwacker!usc!samsung!munnari.oz.au!goanna!ok | From: ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) | Newsgroups: comp.lang.c | Date: 12 Oct 90 09:35:56 GMT | Organization: Comp Sci, RMIT, Melbourne, Australia | Lines: 8 | | Just for a change I thought I'd post something that _wasn't_ a problem. | Lint just caught a mistake in some code of mine where I was shifting | by 32 instead of 5 ("shift greater than size of object"). | Am I _glad_ that I ran lint after typing in every few functions! | No, I'm not a new convert to lint, it's just the first time I've made | this particular mistake in C. Lint saved me a great deal of embarrassment. Especially since shift by 32 gives rather surprising results on MIPS and 88K based systems. MIPS chips just use the 5 bit shift amount, which would mean that you did a shift of 0. The 88k doesn't have a shift instruction, instead it has several extract bit instructions, and uses the next 5 bits for the number of bits, which means that a shift of 32 would extract the bottom bit. Tom Wood found a few bugs in the GCC compiler that depended on doing a shift by 32 returning 0 (these have since been fixed). -- Michael Meissner email: meissner@osf.org phone: 617-621-8861 Open Software Foundation, 11 Cambridge Center, Cambridge, MA, 02142 Do apple growers tell their kids money doesn't grow on bushes?