Jingyue Wu 1d56cda023 Partially revert r210444 due to performance regression ... Summary: Converting outermost zext(a) to sext(a) causes worse code when the computation of zext(a) could be reused. For example, after converting ... = array[zext(a)] ... = array[zext(a) + 1] to ... = array[sext(a)] ... = array[zext(a) + 1], the program computes sext(a), which is actually unnecessary. I added one test in split-gep-and-gvn.ll to illustrate this scenario. Also, with r211281 and r211084, we annotate more "nuw" tags to computation involving CUDA intrinsics such as threadIdx.x. These annotations help with splitting GEP a lot, rendering the benefit we get from this reverted optimization only marginal. Test Plan: make check-all Reviewers: eliben, meheff Reviewed By: meheff Subscribers: jholewinski, llvm-commits Differential Revision: http://reviews.llvm.org/D4542 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213209 91177308-0d34-0410-b5e6-96231b3b80d8		2014-07-16 23:25:00 +00:00
..
NVPTX	Partially revert r210444 due to performance regression	2014-07-16 23:25:00 +00:00