llvm-project/llvm/lib/Transforms/Scalar
Artur Pilipenko 8fb3d57e67 [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

llvm-svn: 293064
2017-01-25 16:00:44 +00:00
..
ADCE.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
AlignmentFromAssumptions.cpp [PH] Replace uses of AssertingVH from members of analysis results with 2017-01-24 12:55:57 +00:00
BDCE.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
CMakeLists.txt [Guards] Introduce loop-predication pass 2017-01-25 16:00:44 +00:00
ConstantHoisting.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
ConstantProp.cpp Don't remove side effecting instructions due to ConstantFoldInstruction 2016-07-22 04:54:44 +00:00
CorrelatedValuePropagation.cpp [PM] Teach LVI to correctly invalidate itself when its dependencies 2017-01-23 06:35:12 +00:00
DCE.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
DeadStoreElimination.cpp [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC) 2017-01-23 23:16:46 +00:00
EarlyCSE.cpp [EarlyCSE] Don't DSE across readnone functions that may throw 2017-01-17 20:15:47 +00:00
FlattenCFGPass.cpp Scalar: Remove some implicit ilist iterator conversions, NFC 2015-10-13 18:26:00 +00:00
Float2Int.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
GVN.cpp [DWARF] Null out the debug locs of load instructions that have been moved by GVN 2017-01-04 23:58:26 +00:00
GVNHoist.cpp [GVNHoist] Invalidate MemDep when an instruction is moved. 2016-12-07 19:55:59 +00:00
GuardWidening.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
IVUsersPrinter.cpp [PM] Separate the LoopAnalysisManager from the LoopPassManager and move 2017-01-11 09:43:56 +00:00
IndVarSimplify.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
InductiveRangeCheckElimination.cpp Revert @llvm.assume with operator bundles (r289755-r289757) 2016-12-19 08:22:17 +00:00
JumpThreading.cpp [PM] Replace the hard invalidate in JumpThreading for LVI with correct 2017-01-23 08:33:24 +00:00
LICM.cpp Improve what can be promoted in LICM. 2017-01-19 19:31:40 +00:00
LLVMBuild.txt
LoadCombine.cpp Use StringRef in Pass/PassManager APIs (NFC) 2016-10-01 02:56:57 +00:00
LoopAccessAnalysisPrinter.cpp [PM] Separate the LoopAnalysisManager from the LoopPassManager and move 2017-01-11 09:43:56 +00:00
LoopDataPrefetch.cpp Revert @llvm.assume with operator bundles (r289755-r289757) 2016-12-19 08:22:17 +00:00
LoopDeletion.cpp [LoopDeletion] (cleanup, NFC) Fix one more local variable that didn't 2017-01-18 02:43:01 +00:00
LoopDistribute.cpp [PM] Separate the LoopAnalysisManager from the LoopPassManager and move 2017-01-11 09:43:56 +00:00
LoopIdiomRecognize.cpp [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC) 2017-01-23 23:16:46 +00:00
LoopInstSimplify.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
LoopInterchange.cpp Revert @llvm.assume with operator bundles (r289755-r289757) 2016-12-19 08:22:17 +00:00
LoopLoadElimination.cpp Fix LoopLoadElimination to keep original alignment on the inital hoisted store 2017-01-06 21:06:51 +00:00
LoopPassManager.cpp [PM] Teach LoopUnroll to update the LPM infrastructure as it unrolls 2017-01-25 02:49:01 +00:00
LoopPredication.cpp [Guards] Introduce loop-predication pass 2017-01-25 16:00:44 +00:00
LoopRerollPass.cpp [LoopReroll] Make root-finding more aggressive. 2016-11-21 22:35:34 +00:00
LoopRotation.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
LoopSimplifyCFG.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
LoopSink.cpp [PM] Port LoopSink to the new pass manager. 2017-01-20 08:42:19 +00:00
LoopStrengthReduce.cpp [LoopStrengthReduce] Don't bother rewriting PHIs in catchswitch blocks 2017-01-13 22:24:27 +00:00
LoopUnrollPass.cpp [PM] Teach LoopUnroll to update the LPM infrastructure as it unrolls 2017-01-25 02:49:01 +00:00
LoopUnswitch.cpp Fix use after free 2017-01-06 21:49:08 +00:00
LoopVersioningLICM.cpp [LoopVersioning] Require loop-simplify form for loop versioning. 2016-12-19 17:13:37 +00:00
LowerAtomic.cpp [PM] Remove support for omitting the AnalysisManager argument to new 2016-06-17 00:11:01 +00:00
LowerExpectIntrinsic.cpp [Profile] handle select instruction in 'expect' lowering 2016-09-02 22:03:40 +00:00
LowerGuardIntrinsic.cpp [PM] Port LowerGuardIntrinsic to the new PM. 2016-07-28 22:08:41 +00:00
MemCpyOptimizer.cpp [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC) 2017-01-23 23:16:46 +00:00
MergedLoadStoreMotion.cpp Remove the load hoisting code of MLSM, it is completely subsumed by GVNHoist 2017-01-24 19:55:36 +00:00
NaryReassociate.cpp [PH] Replace uses of AssertingVH from members of analysis results with 2017-01-24 12:55:57 +00:00
NewGVN.cpp [NewGVN] Optimize processing for instructions found trivially dead. 2017-01-20 23:29:28 +00:00
PartiallyInlineLibCalls.cpp [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC) 2017-01-23 23:16:46 +00:00
PlaceSafepoints.cpp Apply clang-tidy's modernize-loop-convert to most of lib/Transforms. 2016-06-26 12:28:59 +00:00
Reassociate.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
Reg2Mem.cpp Apply clang-tidy's modernize-loop-convert to most of lib/Transforms. 2016-06-26 12:28:59 +00:00
RewriteStatepointsForGC.cpp Apply clang-tidy's performance-unnecessary-value-param to LLVM. 2017-01-13 14:39:03 +00:00
SCCP.cpp [SCCP] Teach the pass how to handle `div` with overdefined operands. 2017-01-19 23:07:51 +00:00
SROA.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
Scalar.cpp [Guards] Introduce loop-predication pass 2017-01-25 16:00:44 +00:00
Scalarizer.cpp Scalarizer: Support scalarizing intrinsics 2016-07-25 20:02:54 +00:00
SeparateConstOffsetFromGEP.cpp Revert @llvm.assume with operator bundles (r289755-r289757) 2016-12-19 08:22:17 +00:00
SimplifyCFGPass.cpp Revert @llvm.assume with operator bundles (r289755-r289757) 2016-12-19 08:22:17 +00:00
Sink.cpp [PM] Introduce an analysis set used to preserve all analyses over 2017-01-15 06:32:49 +00:00
SpeculativeExecution.cpp SpeculativeExecution: Allow speculating more inst types 2016-10-28 20:00:33 +00:00
StraightLineStrengthReduce.cpp IR: Change the gep_type_iterator API to avoid always exposing the "current" type. 2016-12-02 02:24:42 +00:00
StructurizeCFG.cpp [StructurizeCfg] Update dominator info. 2017-01-10 02:50:47 +00:00
TailRecursionElimination.cpp [TRE] Remove dead code 2016-11-07 22:17:37 +00:00