May 2015
Intermediate to advanced
296 pages
5h 10m
English
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Various levels of optimization
There are various levels of optimization, starting at 0 and going up to 3 (there is also s for space optimization). The code gets more and more optimized as the optimization level increases. Let's try to explore the various optimization levels.
Getting ready...
Various optimization levels can be understood by running the opt command-line interface on LLVM IR. For this, an example C program can first be converted to IR using the Clang frontend.
- Open an
example.cfile and write the following code in it:$ vi example.c int main(int argc, char **argv) { int i, j, k, t = 0; for(i = 0; i < 10; i++) { for(j = 0; j < 10; j++) { for(k = 0; k < 10; k++) { t++; } } for(j = 0; j < 10; j++) { t++; } } for(i = 0; i < 20; i++) { for(j ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.