> From: "Jonas Paulsson" <d0...@student.lth.se> > Date: Mon, 26 Apr 2010 11:07:04 +0200
> I recently completed my degree project on LTH on retargeting GCC. See > http://sam.cs.lth.se/ExjobGetFile?id=224 for my report (it will be moved to > http://cs.lth.se/examensarbete/rapporter/rapporter_2010/ soon). Interesting observations there; I wish there was incentive for you to actually resolve them the right way in GCC, meaning this project. I've recently been bitten by the lost-widening-multiplication- when-in-loop issue myself, and noted it for revisit Some Day. Fixing that by other means made a whopping 27% improvement for the application where I saw it: a hot loop doing a MDCT using Q31 fixed-point, where a common operation is to widen-multiply two 32-bit numbers and pick the high 32 bits of the 64-bit result (being the result divided by 2; i.e. Q30-ish for that operation). brgds, H-P
