Craig Topper f1a870d05f [IR] Use a binary search in DataLayout::getAlignmentInfo ... Summary: We currently do a linear scan through all of the Alignments array entries anytime getAlignmentInfo is called. I noticed while profiling compile time on a -O2 opt run that this function can be called quite frequently and was showing about as about 1% of the time in callgrind. This patch puts the Alignments array into a sorted order by type and then by bitwidth. We can then do a binary search. And use the sorted nature to handle the special cases for INTEGER_ALIGN. Some of this is modeled after the sorting/searching we do for pointers already. This reduced the time spent in this routine by about 2/3 in the one compilation I was looking at. We could maybe improve this more by using a DenseMap to cache the results, but just sorting was easy and didn't require extra data structure. And I think it made the integer handling simpler. Reviewers: sanjoy, davide, majnemer, resistor, arsenm, mehdi_amini Reviewed By: arsenm Subscribers: arsenm, llvm-commits Differential Revision: https://reviews.llvm.org/D31232 llvm-svn: 298579		2017-03-23 06:15:56 +00:00
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llvm	[IR] Use a binary search in DataLayout::getAlignmentInfo	2017-03-23 06:15:56 +00:00
llvm-c	[GVN] Initial check-in of a new global value numbering algorithm.	2016-12-22 16:03:48 +00:00