[llvm] 8d5b289 - [LoopDelete][Assume] Allow deleting loops with assumes
via llvm-commits
llvm-commits at lists.llvm.org
Sat Sep 26 03:34:06 PDT 2020
Author: Tyker
Date: 2020-09-26T12:32:44+02:00
New Revision: 8d5b289a4681d89f4dedcd8926225333e0772967
URL: https://github.com/llvm/llvm-project/commit/8d5b289a4681d89f4dedcd8926225333e0772967
DIFF: https://github.com/llvm/llvm-project/commit/8d5b289a4681d89f4dedcd8926225333e0772967.diff
LOG: [LoopDelete][Assume] Allow deleting loops with assumes
This pervent very poor optimization caused by a signle assume like https://godbolt.org/z/EK3oMh
baseline flags: -O3
patched flags: -O3 -mllvm --enable-knowledge-retention
Before the patch
```
Metric: compile_time
Program baseline patched diff
test-suite :: CTMark/tramp3d-v4/tramp3d-v4.test 20.72 29.74 43.5%
test-suite :: CTMark/Bullet/bullet.test 24.39 24.91 2.2%
test-suite :: CTMark/7zip/7zip-benchmark.test 37.39 38.06 1.8%
test-suite :: CTMark/kimwitu++/kc.test 11.76 11.94 1.5%
test-suite :: CTMark/sqlite3/sqlite3.test 12.94 12.91 -0.3%
test-suite :: CTMark/SPASS/SPASS.test 11.72 11.70 -0.2%
test-suite :: CTMark/lencod/lencod.test 16.12 16.10 -0.1%
test-suite :: CTMark/ClamAV/clamscan.test 13.31 13.30 -0.1%
test-suite :: CTMark/mafft/pairlocalalign.test 9.12 9.12 -0.1%
test-suite :: CTMark/consumer-typeset/consumer-typeset.test 9.34 9.34 -0.1%
Geomean difference 4.2%
Metric: compiler_Kinst_count
Program baseline patched diff
test-suite :: CTMark/tramp3d-v4/tramp3d-v4.test 107576069.87 172886418.90 60.7%
test-suite :: CTMark/Bullet/bullet.test 123291865.66 125457117.96 1.8%
test-suite :: CTMark/kimwitu++/kc.test 56347884.64 57298544.14 1.7%
test-suite :: CTMark/7zip/7zip-benchmark.test 180637699.58 183341656.57 1.5%
test-suite :: CTMark/sqlite3/sqlite3.test 66723788.85 66664692.80 -0.1%
test-suite :: CTMark/ClamAV/clamscan.test 69581500.56 69597863.92 0.0%
test-suite :: CTMark/lencod/lencod.test 94236501.48 94216545.32 -0.0%
test-suite :: CTMark/SPASS/SPASS.test 58516756.95 58505089.07 -0.0%
test-suite :: CTMark/consumer-typeset/consumer-typeset.test 48832815.53 48841989.39 0.0%
test-suite :: CTMark/mafft/pairlocalalign.test 49682720.53 49686324.34 0.0%
Geomean difference 5.4%
```
After the patch
```
Metric: compile_time
Program baseline patched diff
test-suite :: CTMark/tramp3d-v4/tramp3d-v4.test 20.70 22.40 8.2%
test-suite :: CTMark/7zip/7zip-benchmark.test 37.13 38.05 2.5%
test-suite :: CTMark/Bullet/bullet.test 24.25 24.83 2.4%
test-suite :: CTMark/kimwitu++/kc.test 11.69 11.94 2.2%
test-suite :: CTMark/ClamAV/clamscan.test 13.19 13.36 1.3%
test-suite :: CTMark/lencod/lencod.test 16.02 16.19 1.1%
test-suite :: CTMark/consumer-typeset/consumer-typeset.test 9.29 9.36 0.7%
test-suite :: CTMark/SPASS/SPASS.test 11.64 11.73 0.7%
test-suite :: CTMark/mafft/pairlocalalign.test 9.10 9.15 0.5%
test-suite :: CTMark/sqlite3/sqlite3.test 12.95 12.96 0.0%
Geomean difference 1.9%
Metric: compiler_Kinst_count
Program baseline patched diff
test-suite :: CTMark/tramp3d-v4/tramp3d-v4.test 107590933.61 114044834.72 6.0%
test-suite :: CTMark/kimwitu++/kc.test 56344526.77 57235806.29 1.6%
test-suite :: CTMark/Bullet/bullet.test 123291285.10 125128334.97 1.5%
test-suite :: CTMark/7zip/7zip-benchmark.test 180641540.10 183155706.39 1.4%
test-suite :: CTMark/sqlite3/sqlite3.test 66725619.22 66668713.92 -0.1%
test-suite :: CTMark/SPASS/SPASS.test 58509029.85 58478704.75 -0.1%
test-suite :: CTMark/consumer-typeset/consumer-typeset.test 48843711.23 48826894.68 -0.0%
test-suite :: CTMark/lencod/lencod.test 94233305.79 94207544.23 -0.0%
test-suite :: CTMark/ClamAV/clamscan.test 69587887.66 69603549.90 0.0%
test-suite :: CTMark/mafft/pairlocalalign.test 49686968.65 49689291.04 0.0%
Geomean difference 1.0%
```
Reviewed By: jdoerfert, efriedma
Differential Revision: https://reviews.llvm.org/D86816
Added:
llvm/test/Transforms/LoopDeletion/assume.ll
Modified:
llvm/lib/Transforms/Scalar/LoopDeletion.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index be209d34be42..d9cde031cc60 100644
--- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -85,7 +85,9 @@ static bool isLoopDead(Loop *L, ScalarEvolution &SE,
// This includes instructions that could write to memory, and loads that are
// marked volatile.
for (auto &I : L->blocks())
- if (any_of(*I, [](Instruction &I) { return I.mayHaveSideEffects(); }))
+ if (any_of(*I, [](Instruction &I) {
+ return I.mayHaveSideEffects() && !I.isDroppable();
+ }))
return false;
return true;
}
diff --git a/llvm/test/Transforms/LoopDeletion/assume.ll b/llvm/test/Transforms/LoopDeletion/assume.ll
new file mode 100644
index 000000000000..124188cd5b65
--- /dev/null
+++ b/llvm/test/Transforms/LoopDeletion/assume.ll
@@ -0,0 +1,40 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -passes=loop-deletion -S | FileCheck %s --check-prefixes=CHECK
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%class.Loc.95 = type { %class.Domain.96 }
+%class.Domain.96 = type { %class.DomainBase.97 }
+%class.DomainBase.97 = type { [3 x %struct.WrapNoInit] }
+%struct.WrapNoInit = type { %class.Loc }
+%class.Loc = type { %class.Domain.67 }
+%class.Domain.67 = type { %class.DomainBase.68 }
+%class.DomainBase.68 = type { i32 }
+
+define dso_local void @_ZSt8_DestroyIP3LocILi3EES1_EvT_S3_RSaIT0_E(%class.Loc.95* %0) #0 {
+; CHECK-LABEL: @_ZSt8_DestroyIP3LocILi3EES1_EvT_S3_RSaIT0_E(
+; CHECK-NEXT: br label [[_ZST8_DESTROYIP3LOCILI3EEEVT_S3__EXIT:%.*]]
+; CHECK: _ZSt8_DestroyIP3LocILi3EEEvT_S3_.exit:
+; CHECK-NEXT: ret void
+;
+ br label %2
+
+2: ; preds = %4, %1
+ %.0.i.i = phi %class.Loc.95* [ undef, %1 ], [ %5, %4 ]
+ %3 = icmp ne %class.Loc.95* %.0.i.i, %0
+ br i1 %3, label %4, label %_ZSt8_DestroyIP3LocILi3EEEvT_S3_.exit
+
+4: ; preds = %2
+ call void @llvm.assume(i1 true) [ "align"(%class.Loc.95* %.0.i.i, i64 4) ]
+ %5 = getelementptr inbounds %class.Loc.95, %class.Loc.95* %.0.i.i, i32 1
+ br label %2
+
+_ZSt8_DestroyIP3LocILi3EEEvT_S3_.exit: ; preds = %2
+ ret void
+}
+
+declare void @llvm.assume(i1) #1
+
+attributes #0 = { "target-cpu"="x86-64" }
+attributes #1 = { willreturn readnone norecurse nocapture nofree }
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