May 2015
Intermediate to advanced
296 pages
5h 10m
English
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Optimizing SelectionDAG
A SelectionDAG representation shows data and instructions in the form of nodes. Similar to the InstCombine pass in the LLVM IR, these nodes can be combined and optimized to form a minimized SelectionDAG. But, it's not just a DAGCombine operation that optimizes the SelectionDAG. A DAGLegalize phase may generate some unnecessary DAG nodes, which are cleaned up by subsequent runs of the DAG optimization pass. This finally represents the SelectionDAG in a more simple and elegant way.
How to do it…
There are lots and lots of function members (most of them are named like this: visit**()) provided in the DAGCombiner class to perform optimizations by folding, reordering, combining, and modifying SDNode nodes. Note that, from the ...
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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.