From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Tue, 29 Oct 2013 08:23:07 -0400 Subject: [U-Boot] Illegal use of FP ops in clock_ti814x.c In-Reply-To: <20131029104807.738E338061F@gemini.denx.de> References: <20131027211157.1AF2E380495@gemini.denx.de> <20131028235619.2507C380425@gemini.denx.de> <20131029104807.738E338061F@gemini.denx.de> Message-ID: <526FA8AB.9050500@ti.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 10/29/2013 06:48 AM, Wolfgang Denk wrote: > Dear M?ns Rullg?rd, > > In message you wrote: >> >>>> Something like this should be equivalent. That said, it >>>> looks suspiciously like it's meant to simply do a division >>>> and round up. If that is the case, +225 should be +249. It >>>> probably makes no difference for the values actually >>>> encountered. >>> >>> Umm... this is the part which I do not understand. >>> >>> The original code adds 90%; you add 90%, too. However, to >>> round up, one usually adds only 50% ? >> >> Adding 50% would round to nearest. For integer division to round >> up, you must add one less than the divisor. > > Agreed. But do we want to round up? The original code used +90%, > which is something else, too... And I imagine it's unlikely the original author of the code is around anymore, or recalls exactly why. I'm pretty sure Matt just lifted the code from the vendor tree and since it wasn't throwing warnings didn't notice the floating point part. >>> Where are these 90% coming from? Are they in any way >>> meaningful, or even critical? >> >> My guess is that it was someone's approximation of 249 / 250. I >> don't know the hardware, so it's conceivable that it really >> should be this way, although it seems unlikely. > > Are you able to test such a modificationon actual hardware? I suspect Matt can, after Linaro Connect. I don't have one of these platforms handy but I think he still does. - -- Tom -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJSb6iqAAoJENk4IS6UOR1W+JkP/j7MJ2s9RxNCpRTi+nvXgSL1 A9SWL0rAbgl6ggiYU1tIE1NUxrNmlaLJxzP/VKciJ7wPeHkmiZN4gsL5JmsbIj9y eWh1eqyXPI8Tv69x0v8JsDBC8hHHBgnWqe8afsLN0ZspU77GGgFAx0Dq7lfaaGZt GopTHbBEf9pePbE8X3y11kxtjyF5SJfdfvPsEFbNeuR5fkfqcanvNPi6uhYDnwgz UwW0htFyAO3vmZHv7Yhh5XhF+sIgHzEsYzZBZ0KVf+pDpyMd2Ni8RG1RTt66UHqE kuPLIU9EwZYBUTh0DGtx/QFYOHCAUTpAYV5OhLL2ycIpzF3CRj/cBdnhiDk7LPPz 5G5heIJmRxyTkvjdm4Lh552NQBo6oWVJP+NFIejYG3aD632lH+cp1lDxjPzk3LGQ qVwyE+rRiY96VW6qMeBzFxBJ3J4k73zxdyY4eM9Ka2uzWqM3rykZ1EESaDTrDTQ9 DnI9E1QVuXQLjaTZ0RjKVw8XA/yPlBZ/LVIQDpEUr0WV9+Qgjs94B6H1flkygcqW DLyg+PpB5czNNtMdAbj55wzXNmAX39MIKHkR0OWm5HEGg26u/zjlYF1kk1YeuQNT mgWhNohtRARkJMfUXmSu5M9e2S3elNcv61GnOzRajgTzO8XjkXO4LYjyfarIzGdK FitrvVe8n00RGK3u6M9j =hWQX -----END PGP SIGNATURE-----