Update the new PM pipeline to make ICP aware if it is SamplePGO build.

Summary: In ThinLTO backend compile, OPTOptions are not set so that the ICP in ThinLTO backend does not know if it is a SamplePGO build, in which profile count needs to be annotated directly on call instructions. This patch cleaned up the PGOOptions handling logic and passes down PGOOptions to ThinLTO backend.

Reviewers: chandlerc, tejohnson, davidxl

Reviewed By: chandlerc

Subscribers: sanjoy, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D36052

llvm-svn: 309780

diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 3f72e44..6d1e37f 100644 (file)
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -131,9 +131,13 @@ createTargetMachine(Config &Conf, const Target *TheTarget, Module &M) {
       Conf.CodeModel, Conf.CGOptLevel));
 }
 
-static void runNewPMPasses(Module &Mod, TargetMachine *TM, unsigned OptLevel,
-                           bool IsThinLTO) {
-  PassBuilder PB(TM);
+static void runNewPMPasses(Config &Conf, Module &Mod, TargetMachine *TM,
+                           unsigned OptLevel, bool IsThinLTO) {
+  Optional<PGOOptions> PGOOpt;
+  if (!Conf.SampleProfile.empty())
+    PGOOpt = PGOOptions("", "", Conf.SampleProfile, false, true);
+
+  PassBuilder PB(TM, PGOOpt);
   AAManager AA;
 
   // Parse a custom AA pipeline if asked to.
@@ -262,7 +266,7 @@ bool opt(Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
     runNewPMCustomPasses(Mod, TM, Conf.OptPipeline, Conf.AAPipeline,
                          Conf.DisableVerify);
   else if (Conf.UseNewPM)
-    runNewPMPasses(Mod, TM, Conf.OptLevel, IsThinLTO);
+    runNewPMPasses(Conf, Mod, TM, Conf.OptLevel, IsThinLTO);
   else
     runOldPMPasses(Conf, Mod, TM, IsThinLTO, ExportSummary, ImportSummary);
   return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod);

diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index de9e2a9..f2dd950 100644 (file)
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -571,23 +571,12 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   GlobalCleanupPM.addPass(SimplifyCFGPass());
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM)));
 
-  // Add all the requested passes for PGO, if requested.
-  if (PGOOpt) {
-    if (!PGOOpt->ProfileGenFile.empty() || !PGOOpt->ProfileUseFile.empty())
-      // Instrumentation based PGO (gen and use)
-      addPGOInstrPasses(MPM, DebugLogging, Level, PGOOpt->RunProfileGen,
-                        PGOOpt->ProfileGenFile, PGOOpt->ProfileUseFile);
-    else if (!PGOOpt->SampleProfileFile.empty())
-      // SamplePGO use
-      MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile));
-
-    // Indirect call promotion that promotes intra-module targes only.
-    // Do not enable it in PreLinkThinLTO phase during sample PGO because
-    // it changes IR to makes profile annotation in back compile inaccurate.
-    if ((Phase != ThinLTOPhase::PreLink && !PGOOpt->SampleProfileFile.empty())
-        || !PGOOpt->ProfileUseFile.empty())
-      MPM.addPass(PGOIndirectCallPromotion(
-          false, PGOOpt && !PGOOpt->SampleProfileFile.empty()));
+  // Add all the requested passes for instrumentation PGO, if requested.
+  if (PGOOpt && Phase != ThinLTOPhase::PostLink &&
+      (!PGOOpt->ProfileGenFile.empty() || !PGOOpt->ProfileUseFile.empty())) {
+    addPGOInstrPasses(MPM, DebugLogging, Level, PGOOpt->RunProfileGen,
+                      PGOOpt->ProfileGenFile, PGOOpt->ProfileUseFile);
+    MPM.addPass(PGOIndirectCallPromotion(false, false));
   }
 
   // Require the GlobalsAA analysis for the module so we can query it within
@@ -779,8 +768,13 @@ PassBuilder::buildPerModuleDefaultPipeline(OptimizationLevel Level,
   // Force any function attributes we want the rest of the pipeline to observe.
   MPM.addPass(ForceFunctionAttrsPass());
 
-  if (PGOOpt && PGOOpt->SamplePGOSupport)
+  if (PGOOpt && PGOOpt->SamplePGOSupport) {
     MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
+    if (!PGOOpt->SampleProfileFile.empty()) {
+      MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile));
+      MPM.addPass(PGOIndirectCallPromotion(false, true));
+    }
+  }
 
   // Add the core simplification pipeline.
   MPM.addPass(buildModuleSimplificationPipeline(Level, ThinLTOPhase::None,
@@ -802,8 +796,14 @@ PassBuilder::buildThinLTOPreLinkDefaultPipeline(OptimizationLevel Level,
   // Force any function attributes we want the rest of the pipeline to observe.
   MPM.addPass(ForceFunctionAttrsPass());
 
-  if (PGOOpt && PGOOpt->SamplePGOSupport)
+  // Invoke the SamplePGO annotation pass for the first time to annotate
+  // profile for functions in the current module to give ThinLink info
+  // about module grouping.
+  if (PGOOpt && PGOOpt->SamplePGOSupport) {
     MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
+    if (!PGOOpt->SampleProfileFile.empty())
+      MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile));
+  }
 
   // If we are planning to perform ThinLTO later, we don't bloat the code with
   // unrolling/vectorization/... now. Just simplify the module as much as we
@@ -839,12 +839,16 @@ PassBuilder::buildThinLTODefaultPipeline(OptimizationLevel Level,
   // Force any function attributes we want the rest of the pipeline to observe.
   MPM.addPass(ForceFunctionAttrsPass());
 
+  // Invoke the SamplePGO annotation pass for the second time to annotate on
+  // functions imported from other modules.
+  if (PGOOpt && !PGOOpt->SampleProfileFile.empty())
+    MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile));
+
   // During the ThinLTO backend phase we perform early indirect call promotion
   // here, before globalopt. Otherwise imported available_externally functions
   // look unreferenced and are removed.
   MPM.addPass(PGOIndirectCallPromotion(
-      true /* InLTO */, PGOOpt && !PGOOpt->SampleProfileFile.empty() &&
-                            !PGOOpt->ProfileUseFile.empty()));
+      true /* InLTO */, PGOOpt && !PGOOpt->SampleProfileFile.empty()));
 
   // Add the core simplification pipeline.
   MPM.addPass(buildModuleSimplificationPipeline(Level, ThinLTOPhase::PostLink,

diff --git a/llvm/test/LTO/Resolution/X86/Inputs/load-sample-prof-icp.prof b/llvm/test/LTO/Resolution/X86/Inputs/load-sample-prof-icp.prof
new file mode 100644 (file)
index 0000000..ac9000c
--- /dev/null
+++ b/llvm/test/LTO/Resolution/X86/Inputs/load-sample-prof-icp.prof
@@ -0,0 +1,2 @@
+test:1000:0
+ 1: 1000 bar:1000

diff --git a/llvm/test/LTO/Resolution/X86/load-sample-prof-icp.ll b/llvm/test/LTO/Resolution/X86/load-sample-prof-icp.ll
new file mode 100644 (file)
index 0000000..57c870c
--- /dev/null
+++ b/llvm/test/LTO/Resolution/X86/load-sample-prof-icp.ll
@@ -0,0 +1,46 @@
+; Test that llvm-lto2 handles the -lto-sample-profile-file option and pass
+; down to the ICP correctly.
+;
+; RUN: opt -module-summary < %s -o %t.bc
+; RUN: llvm-lto2 run -o %t.out %t.bc -save-temps \
+; RUN:   -r %t.bc,test,px -r %t.bc,bar,x \
+; RUN:   -lto-sample-profile-file=%S/Inputs/load-sample-prof-icp.prof
+; RUN: llvm-dis %t.out.0.4.opt.bc -o - | FileCheck %s
+; RUN: llvm-lto2 run -o %t.out %t.bc -save-temps \
+; RUN:   -r %t.bc,test,px -r %t.bc,bar,x -use-new-pm \
+; RUN:   -lto-sample-profile-file=%S/Inputs/load-sample-prof-icp.prof
+; RUN: llvm-dis %t.out.0.4.opt.bc -o - | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK-LABEL: @test
+; Checks that the call instruction is promoted to direct call and has
+; profile count annotated on the direct call.
+define void @test(void ()*) !dbg !7 {
+  %2 = alloca void ()*
+  store void ()* %0, void ()** %2
+  %3 = load void ()*, void ()** %2
+  ; CHECK: call void @bar(),{{.*}}!prof
+  call void %3(), !dbg !10
+  ret void
+}
+
+declare void @bar() local_unnamed_addr
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "test.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 6.0.0 "}
+!7 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: true, unit: !0, variables: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !DILocation(line: 4, column: 5, scope: !7)
+!11 = !DILocation(line: 5, column: 1, scope: !7)