Comments on: Efficient C Tips #4 – Use Speed Optimization http://embeddedgurus.com/stack-overflow/2008/09/efficient-c-tips-4-use-speed-optimization/ Thoughts on embedded systems by Nigel Jones Sun, 06 May 2012 10:34:02 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Eric Miller http://embeddedgurus.com/stack-overflow/2008/09/efficient-c-tips-4-use-speed-optimization/comment-page-1/#comment-14409 Eric Miller Tue, 14 Feb 2012 20:03:15 +0000 http://www.gfcdev.org/test-stack/2008/09/08/efficient-c-tips-4-use-speed-optimization/#comment-14409 I've gone in the opposite direction: using size optimization after getting burned by "speed optimization." One particular speed optimization in particular (loop unrolling) can cause code size to balloon, introducing i-cache misses into code that fits in cache when size optimized. I’ve gone in the opposite direction: using size optimization after getting burned by “speed optimization.”

One particular speed optimization in particular (loop unrolling) can cause code size to balloon, introducing i-cache misses into code that fits in cache when size optimized.

]]> By: Anonymous http://embeddedgurus.com/stack-overflow/2008/09/efficient-c-tips-4-use-speed-optimization/comment-page-1/#comment-55 Anonymous Tue, 23 Sep 2008 08:50:00 +0000 http://www.gfcdev.org/test-stack/2008/09/08/efficient-c-tips-4-use-speed-optimization/#comment-55 what are the different size optimization methods? what are the different size optimization methods?

]]> By: Nigel Jones http://embeddedgurus.com/stack-overflow/2008/09/efficient-c-tips-4-use-speed-optimization/comment-page-1/#comment-54 Nigel Jones Mon, 15 Sep 2008 11:57:00 +0000 http://www.gfcdev.org/test-stack/2008/09/08/efficient-c-tips-4-use-speed-optimization/#comment-54 I think the point of the post was that most of the time in an embedded system you <b>can</b> afford to use speed optimization. Unfortunately most compilers are set up to use size optimization and most of us are taught that small size code is good - without fully understanding what it can cost us. I think the point of the post was that most of the time in an embedded system you can afford to use speed optimization. Unfortunately most compilers are set up to use size optimization and most of us are taught that small size code is good – without fully understanding what it can cost us.

]]> By: Anonymous http://embeddedgurus.com/stack-overflow/2008/09/efficient-c-tips-4-use-speed-optimization/comment-page-1/#comment-53 Anonymous Mon, 15 Sep 2008 11:11:00 +0000 http://www.gfcdev.org/test-stack/2008/09/08/efficient-c-tips-4-use-speed-optimization/#comment-53 There ofcourse are more speed optimizations that are killing code size. Loop unrolling, automatic function inlining are just two examples. In general: use size optimizations where you need to, use speed optimizations if you can affortd to... There ofcourse are more speed optimizations that are killing code size. Loop unrolling, automatic function inlining are just two examples. In general: use size optimizations where you need to, use speed optimizations if you can affortd to…

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