[PATCH] D61683: [LoopRotate] Use UnrolledInstAnalyzer to account for simplifications in hoisted header. (WIP)

Wed May 8 08:32:40 PDT 2019

fhahn created this revision.
Herald added subscribers: dkrupp, donat.nagy, Szelethus, dexonsmith, dmgreen, a.sidorin, baloghadamsoftware, hiraditya, mehdi_amini.
Herald added a project: LLVM.

This is still work in progress, as the interface for
UnrolledInstAnalyzer needs improving and also the code-size impact is
all over the place (see results for X86 -Oz -flto). Presumably the issue
is that rotating more loops exposes more loops to other loop
optimizations, which do not respect -Oz properly. For example, in the
attached test case, the loop in test2 will get fully unrolled.

Program                                        master  patch   diff
 test-suite...ing-flt/Equivalencing-flt.test    17144   21240  23.9%
 test-suite...ing-dbl/Equivalencing-dbl.test    21240   17144  -19.3%
 test-suite...pps-C/SimpleMOC/SimpleMOC.test    26256   22160  -15.6%
 test-suite...cations/hexxagon/hexxagon.test    29916   25772  -13.9%
 test-suite...langs-C/football/football.test    40320   44416  10.2%
 test-suite...abench/jpeg/jpeg-6a/cjpeg.test    69648   73784   5.9%
 test-suite...ce/Benchmarks/PAQ8p/paq8p.test    89404   93500   4.6%
 test-suite...INT95/132.ijpeg/132.ijpeg.test    96772   100972  4.3%
 test-suite...000/186.crafty/186.crafty.test    176188  180452  2.4%
 test-suite...nsumer-lame/consumer-lame.test    189016  185032 -2.1%
 test-suite...ications/JM/ldecod/ldecod.test    254648  249680 -2.0%
 test-suite...ProxyApps-C++/CLAMR/CLAMR.test    244976  240696 -1.7%
 test-suite...006/447.dealII/447.dealII.test    609760  603200 -1.1%
 test-suite...nch/pcompress2/pcompress2.test    14500   14652   1.0%
 test-suite...Rodinia/backprop/backprop.test    12828   12932   0.8%

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D61683

Files:
  llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
  llvm/test/Transforms/LoopRotate/oz-disable.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D61683.198667.patch
Type: text/x-patch
Size: 4045 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190508/eb76f481/attachment.bin>