Artur Pilipenko 1dd101bfef [Guards] Introduce loop-predication pass ... This patch introduces guard based loop predication optimization. The new LoopPredication pass tries to convert loop variant range checks to loop invariant by widening checks across loop iterations. For example, it will convert for (i = 0; i < n; i++) { guard(i < len); ... } to for (i = 0; i < n; i++) { guard(n - 1 < len); ... } After this transformation the condition of the guard is loop invariant, so loop-unswitch can later unswitch the loop by this condition which basically predicates the loop by the widened condition: if (n - 1 < len) for (i = 0; i < n; i++) { ... } else deoptimize This patch relies on an NFC change to make ScalarEvolution::isMonotonicPredicate public (revision 293062). Reviewed By: sanjoy Differential Revision: https://reviews.llvm.org/D29034 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293064 91177308-0d34-0410-b5e6-96231b3b80d8		2017-01-25 16:00:44 +00:00
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llvm	[Guards] Introduce loop-predication pass	2017-01-25 16:00:44 +00:00
llvm-c	[GVN] Initial check-in of a new global value numbering algorithm.	2016-12-22 16:03:48 +00:00