[llvm] r353270 - [HotColdSplit] Move splitting after instrumented PGO use
Teresa Johnson via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 5 20:29:40 PST 2019
Author: tejohnson
Date: Tue Feb 5 20:29:39 2019
New Revision: 353270
URL: http://llvm.org/viewvc/llvm-project?rev=353270&view=rev
Log:
[HotColdSplit] Move splitting after instrumented PGO use
Summary:
Follow up to D57082 which moved splitting earlier in the pipeline, in
order to perform it before inlining. However, it was moved too early,
before the IR is annotated with instrumented PGO data. This caused the
splitting to incorrectly determine cold functions.
Move it to just after PGO annotation (still before inlining), in both
pass managers.
Reviewers: vsk, hiraditya, sebpop
Subscribers: mehdi_amini, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57805
Added:
llvm/trunk/test/Other/Inputs/pass-pipelines.proftext
Modified:
llvm/trunk/lib/Passes/PassBuilder.cpp
llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp
llvm/trunk/test/Other/new-pm-pgo.ll
llvm/trunk/test/Other/pass-pipelines.ll
Modified: llvm/trunk/lib/Passes/PassBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassBuilder.cpp?rev=353270&r1=353269&r2=353270&view=diff
==============================================================================
--- llvm/trunk/lib/Passes/PassBuilder.cpp (original)
+++ llvm/trunk/lib/Passes/PassBuilder.cpp Tue Feb 5 20:29:39 2019
@@ -680,14 +680,6 @@ PassBuilder::buildModuleSimplificationPi
// globals.
MPM.addPass(DeadArgumentEliminationPass());
- // Split out cold code. Splitting is done before inlining because 1) the most
- // common kinds of cold regions can (a) be found before inlining and (b) do
- // not grow after inlining, and 2) inhibiting inlining of cold code improves
- // code size & compile time. Split after Mem2Reg to make code model estimates
- // more accurate, but before InstCombine to allow it to clean things up.
- if (EnableHotColdSplit && Phase != ThinLTOPhase::PostLink)
- MPM.addPass(HotColdSplittingPass());
-
// Create a small function pass pipeline to cleanup after all the global
// optimizations.
FunctionPassManager GlobalCleanupPM(DebugLogging);
@@ -710,6 +702,14 @@ PassBuilder::buildModuleSimplificationPi
if (EnableSyntheticCounts && !PGOOpt)
MPM.addPass(SyntheticCountsPropagation());
+ // Split out cold code. Splitting is done before inlining because 1) the most
+ // common kinds of cold regions can (a) be found before inlining and (b) do
+ // not grow after inlining, and 2) inhibiting inlining of cold code improves
+ // code size & compile time. Split after Mem2Reg to make code model estimates
+ // more accurate, but before InstCombine to allow it to clean things up.
+ if (EnableHotColdSplit && Phase != ThinLTOPhase::PostLink)
+ MPM.addPass(HotColdSplittingPass());
+
// Require the GlobalsAA analysis for the module so we can query it within
// the CGSCC pipeline.
MPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
Modified: llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp?rev=353270&r1=353269&r2=353270&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp Tue Feb 5 20:29:39 2019
@@ -517,11 +517,6 @@ void PassManagerBuilder::populateModuleP
MPM.add(createDeadArgEliminationPass()); // Dead argument elimination
- // Split out cold code before inlining. See comment in the new PM
- // (\ref buildModuleSimplificationPipeline).
- if (EnableHotColdSplit && DefaultOrPreLinkPipeline)
- MPM.add(createHotColdSplittingPass());
-
addInstructionCombiningPass(MPM); // Clean up after IPCP & DAE
addExtensionsToPM(EP_Peephole, MPM);
MPM.add(createCFGSimplificationPass()); // Clean up after IPCP & DAE
@@ -534,6 +529,11 @@ void PassManagerBuilder::populateModuleP
if (DefaultOrPreLinkPipeline && !PrepareForThinLTOUsingPGOSampleProfile)
addPGOInstrPasses(MPM);
+ // Split out cold code before inlining. See comment in the new PM
+ // (\ref buildModuleSimplificationPipeline).
+ if (EnableHotColdSplit && DefaultOrPreLinkPipeline)
+ MPM.add(createHotColdSplittingPass());
+
// We add a module alias analysis pass here. In part due to bugs in the
// analysis infrastructure this "works" in that the analysis stays alive
// for the entire SCC pass run below.
Added: llvm/trunk/test/Other/Inputs/pass-pipelines.proftext
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Other/Inputs/pass-pipelines.proftext?rev=353270&view=auto
==============================================================================
--- llvm/trunk/test/Other/Inputs/pass-pipelines.proftext (added)
+++ llvm/trunk/test/Other/Inputs/pass-pipelines.proftext Tue Feb 5 20:29:39 2019
@@ -0,0 +1 @@
+:ir
Modified: llvm/trunk/test/Other/new-pm-pgo.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Other/new-pm-pgo.ll?rev=353270&r1=353269&r2=353270&view=diff
==============================================================================
--- llvm/trunk/test/Other/new-pm-pgo.ll (original)
+++ llvm/trunk/test/Other/new-pm-pgo.ll Tue Feb 5 20:29:39 2019
@@ -1,6 +1,7 @@
; RUN: opt -debug-pass-manager -passes='default<O2>' -pgo-kind=pgo-instr-gen-pipeline -profile-file='temp' %s 2>&1 |FileCheck %s --check-prefixes=GEN
; RUN: llvm-profdata merge %S/Inputs/new-pm-pgo.proftext -o %t.profdata
; RUN: opt -debug-pass-manager -passes='default<O2>' -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 |FileCheck %s --check-prefixes=USE
+; RUN: opt -debug-pass-manager -passes='default<O2>' -hot-cold-split -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 |FileCheck %s --check-prefixes=USE --check-prefixes=SPLIT
; RUN: opt -debug-pass-manager -passes='default<O2>' -pgo-kind=pgo-sample-use-pipeline -profile-file='%S/Inputs/new-pm-pgo.prof' %s 2>&1 \
; RUN: |FileCheck %s --check-prefixes=SAMPLE_USE,SAMPLE_USE_O
; RUN: opt -debug-pass-manager -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -profile-file='%S/Inputs/new-pm-pgo.prof' %s 2>&1 \
@@ -12,6 +13,7 @@
; GEN: Running pass: PGOInstrumentationGen
; USE: Running pass: PGOInstrumentationUse
; USE: Running pass: PGOIndirectCallPromotion
+; SPLIT: Running pass: HotColdSplittingPass
; USE: Running pass: PGOMemOPSizeOpt
; SAMPLE_USE_O: Running pass: ModuleToFunctionPassAdaptor<{{.*}}AddDiscriminatorsPass{{.*}}>
; SAMPLE_USE_PRE_LINK: Running pass: ModuleToFunctionPassAdaptor<{{.*}}AddDiscriminatorsPass{{.*}}>
Modified: llvm/trunk/test/Other/pass-pipelines.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Other/pass-pipelines.ll?rev=353270&r1=353269&r2=353270&view=diff
==============================================================================
--- llvm/trunk/test/Other/pass-pipelines.ll (original)
+++ llvm/trunk/test/Other/pass-pipelines.ll Tue Feb 5 20:29:39 2019
@@ -6,6 +6,16 @@
; RUN: opt -disable-output -disable-verify -debug-pass=Structure \
; RUN: -O2 %s 2>&1 \
; RUN: | FileCheck %s --check-prefix=CHECK-O2
+; RUN: llvm-profdata merge %S/Inputs/pass-pipelines.proftext -o %t.profdata
+; RUN: opt -disable-output -disable-verify -debug-pass=Structure \
+; RUN: -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' \
+; RUN: -O2 %s 2>&1 \
+; RUN: | FileCheck %s --check-prefix=CHECK-O2 --check-prefix=PGOUSE
+; RUN: opt -disable-output -disable-verify -debug-pass=Structure \
+; RUN: -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' \
+; RUN: -hot-cold-split \
+; RUN: -O2 %s 2>&1 \
+; RUN: | FileCheck %s --check-prefix=CHECK-O2 --check-prefix=PGOUSE --check-prefix=SPLIT
;
; In the first pipeline there should just be a function pass manager, no other
; pass managers.
@@ -27,6 +37,12 @@
; Very carefully assert the CGSCC pass pipeline as it is fragile and unusually
; susceptible to phase ordering issues.
; CHECK-O2: CallGraph Construction
+; PGOUSE: Call Graph SCC Pass Manager
+; PGOUSE: Function Integration/Inlining
+; PGOUSE: PGOInstrumentationUsePass
+; PGOUSE: PGOIndirectCallPromotion
+; SPLIT: Hot Cold Splitting
+; PGOUSE: CallGraph Construction
; CHECK-O2-NEXT: Globals Alias Analysis
; CHECK-O2-NEXT: Call Graph SCC Pass Manager
; CHECK-O2-NEXT: Remove unused exception handling info
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