Commit Graph

15 Commits

Author SHA1 Message Date
Wei Mi 1cf58f8996 [PM] Port NaryReassociate to the new PM
Differential Revision: https://reviews.llvm.org/D22648

llvm-svn: 276349
2016-07-21 22:28:52 +00:00
Jingyue Wu ba3ca76ed2 [NaryReassociate] allow candidate to have a different type
Summary:
If Candiadte may have a different type from GEP, we should bitcast or
pointer cast it to GEP's type so that the later RAUW doesn't complain.

Added a test in nary-gep.ll

Reviewers: tra, meheff

Subscribers: mcrosier, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D15618

llvm-svn: 256035
2015-12-18 21:36:30 +00:00
Jingyue Wu df1a1b113b [NaryReassociate] SeenExprs records WeakVH
Summary:
The instructions SeenExprs records may be deleted during rewriting.
FindClosestMatchingDominator should ignore these deleted instructions.

Fixes PR24301.

Reviewers: grosser

Subscribers: grosser, llvm-commits

Differential Revision: http://reviews.llvm.org/D13315

llvm-svn: 248983
2015-10-01 03:51:44 +00:00
Mehdi Amini 8e468d6388 [NaryReassociate] Improve test CHECK
Add `CHECK` directives for the function calls.

Differential Revision: http://reviews.llvm.org/D12885

Patch by: Volkan Keles <vkeles@apple.com>

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 247774
2015-09-16 05:27:46 +00:00
Marcello Maggioni 454faa84e2 [NaryReassociate] Add support for Mul instructions
This patch extends the current pass by handling
Mul instructions as well.

Patch by: Volkan Keles (vkeles@apple.com)

llvm-svn: 247705
2015-09-15 17:22:52 +00:00
Jingyue Wu cf02ef315f [NaryReassociate] enhances nsw by leveraging @llvm.assume
Summary:
nsw are flaky and can often be removed by optimizations. This patch enhances
nsw by leveraging @llvm.assume in the IR. Specifically, NaryReassociate now
understands that

    assume(a + b >= 0) && assume(a >= 0) ==> a +nsw b

As a result, it can split more sext(a + b) into sext(a) + sext(b) for CSE.

Test Plan: nary-gep.ll

Reviewers: broune, meheff

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D10822

llvm-svn: 241139
2015-07-01 03:38:49 +00:00
Jingyue Wu c2a014697a [NaryReassociate] Run EarlyCSE after NaryReassociate
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
2015-05-28 04:56:52 +00:00
Jingyue Wu 4fc97f6df8 [NaryReassoc] reassociate GEP for CSE
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
2015-05-21 23:17:30 +00:00
Jingyue Wu c74e33bffe [NaryReassociate] avoid running forever
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
2015-05-13 18:12:24 +00:00
Jingyue Wu 72fca6c89b Resurrect r235688
We should skip vector types which are not SCEVable.

test/CodeGen/NVPTX/sched2.ll passes

llvm-svn: 235695
2015-04-24 04:22:39 +00:00
Jingyue Wu 62af99b0db Revert r235688
Seems breaking builds

llvm-svn: 235690
2015-04-24 03:26:11 +00:00
Jingyue Wu 3daace5295 [NVPTX] enable NaryReassociate in NVPTX
Summary:
We run NaryReassociate right after SLSR because SLSR enables many
opportunities for NaryReassociate. For example, in nary-slsr.ll

  foo((a + b) + c);
  foo((a + b * 2) + c);
  foo((a + b * 3) + c);   // 2 muls and 6 adds

after SLSR:

  ab = a + b;
  foo(ab + c);
  ab2 = ab + b;
  foo(ab2 + c);
  ab3 = ab2 + b;
  foo(ab3 + c);           // 6 adds

after NaryReassociate:

  abc = (a + b) + c;
  foo(abc);
  ab2c = abc + b;
  foo(ab2c);
  ab3c = ab2c + b;
  foo(ab3c);              // 4 adds

Test Plan: nary-slsr.ll

Reviewers: jholewinski, eliben

Reviewed By: eliben

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9066

llvm-svn: 235688
2015-04-24 02:54:06 +00:00
Jingyue Wu 8579b81329 [NaryReassociate] run NaryReassociate iteratively
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
2015-04-17 00:25:10 +00:00
Jingyue Wu 771dfe91cf [NaryReassociate] speeds up candidate searching
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
2015-04-16 18:42:31 +00:00
Jingyue Wu 8cb6b2a292 Simplify n-ary adds by reassociation
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
2015-04-14 04:59:22 +00:00