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path: root/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
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* Make NaryReassociate pass the address space to isLegalAddressingModeMatt Arsenault2015-06-071-1/+3
| | | | | | | No test since the kinds of transforms this prevents seem to not really be relevant for SI's different addressing modes. llvm-svn: 239261
* [NaryReassociate] Run EarlyCSE after NaryReassociateJingyue Wu2015-05-281-1/+23
| | | | | | | | | | | | | | | | | | | | | | | Summary: This patch made two improvements to NaryReassociate and the NVPTX pipeline 1. Run EarlyCSE/GVN after NaryReassociate to get rid of redundant common expressions. 2. When adding an instruction to SeenExprs, maps both the SCEV before and after reassociation to that instruction. Test Plan: updated @reassociate_gep_nsw in nary-gep.ll Reviewers: meheff, broune Reviewed By: broune Subscribers: dberlin, jholewinski, llvm-commits Differential Revision: http://reviews.llvm.org/D9947 llvm-svn: 238396
* [NaryReassoc] reassociate GEP for CSEJingyue Wu2015-05-211-21/+245
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: x = &a[i]; y = &a[i + j]; => y = x + j; along with some refactoring work such as extracting method findClosestMatchingDominator. Depends on D9786 which provides the ScalarEvolution::getGEPExpr interface. Test Plan: nary-gep.ll Reviewers: meheff, broune Reviewed By: broune Subscribers: jholewinski, llvm-commits Differential Revision: http://reviews.llvm.org/D9802 llvm-svn: 237971
* [NaryReassociate] avoid running foreverJingyue Wu2015-05-131-4/+8
| | | | | | | | | Avoid running forever by checking we are not reassociating an expression into the same form. Tested with @avoid_infinite_loops in nary-add.ll llvm-svn: 237269
* Resurrect r235688Jingyue Wu2015-04-241-1/+2
| | | | | | | | We should skip vector types which are not SCEVable. test/CodeGen/NVPTX/sched2.ll passes llvm-svn: 235695
* [NaryReassociate] run NaryReassociate iterativelyJingyue Wu2015-04-171-7/+47
| | | | | | | | | | | | | | | | | | | | | | | Summary: An alternative is to use a worklist approach. However, that approach would break the traversing order so that we couldn't lookup SeenExprs efficiently. I don't see a clear winner here, so I picked the easier approach. Along with two minor improvements: 1. preserves ScalarEvolution by forgetting instructions replaced 2. removes dead code locally avoiding the need of running DCE afterwards Test Plan: add to slsr-add.ll a test that requires multiple iterations Reviewers: broune, dberlin, atrick, meheff Reviewed By: atrick Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D9058 llvm-svn: 235151
* [NaryReassociate] speeds up candidate searchingJingyue Wu2015-04-161-9/+15
| | | | | | | | | | | | | | | | | | | | | Summary: This fixes a left-over efficiency issue in D8950. As Andrew and Daniel suggested, we can store the candidates in a stack and pop the top element when it does not dominate the current instruction. This reduces the worst-case time complexity to O(n). Test Plan: a new test in nary-add.ll that exercises this optimization. Reviewers: broune, dberlin, meheff, atrick Reviewed By: atrick Subscribers: llvm-commits, sanjoy Differential Revision: http://reviews.llvm.org/D9055 llvm-svn: 235129
* Simplify n-ary adds by reassociationJingyue Wu2015-04-141-0/+206
Summary: This transformation reassociates a n-ary add so that the add can partially reuse existing instructions. For example, this pass can simplify void foo(int a, int b) { bar(a + b); bar((a + 2) + b); } to void foo(int a, int b) { int t = a + b; bar(t); bar(t + 2); } saving one add instruction. Fixes PR22357 (https://llvm.org/bugs/show_bug.cgi?id=22357). Test Plan: nary-add.ll Reviewers: broune, dberlin, hfinkel, meheff, sanjoy, atrick Reviewed By: sanjoy, atrick Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D8950 llvm-svn: 234855
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