Fix -ftime-report with -x ir

[arsenm]

Summary

This was only printing the clang frontend timer, and none of the
backend timers. Set the llvm global for enabling the backend time
report when creating the frontend timers, rather than in the
BackendConsumer constructor.

There's still something wrong with how the timers are managed though,
since the report seems to be printed twice for each one.

[arsenm]

I partially solved the problem with double printing the reports. It's from this in cc1_main:

// If any timers were active but haven't been destroyed yet, print theirp
// results now.  This happens in -disable-free mode.
llvm::TimerGroup::printAll(llvm::errs());

On a source file, -ftime-report -disable-free prints one report. -ftime-report without disable-free prints 2. For the IR file, both happen either way and it double prints. The printing destructor can still be called from the ManagedStatic in PassTimingInfo

[arsenm]

ping

[fedor.sergeev]

In D57835#1387622, @arsenm wrote:

I partially solved the problem with double printing the reports. It's from this in cc1_main:

// If any timers were active but haven't been destroyed yet, print theirp
// results now.  This happens in -disable-free mode.
llvm::TimerGroup::printAll(llvm::errs());

On a source file, -ftime-report -disable-free prints one report. -ftime-report without disable-free prints 2. For the IR file, both happen either way and it double prints. The printing destructor can still be called from the ManagedStatic in PassTimingInfo

I dont quite understand what clang is doing in terms of timers (and what -disable-free is/how does it interact with -ftime-report).
However if after doing printAll() you expect that there wont be any other reports then you should call clearAll() immediately after.

[fedor.sergeev]

test/Frontend/ftime-report-bitcode.ll

1

Can you, please, test -fexperimental-new-pass-manager mode as well?
Implementation of time-passes is different between legacy and newpm.

[fedor.sergeev]

just to make the comments visible :)

[arsenm]

Rebase, add new PM run line

[arsenm]

ping

lib/CodeGen/CodeGenAction.cpp

BackendConsumer(BackendAction Action, DiagnosticsEngine &Diags,
           CodeGenOpts(CodeGenOpts), TargetOpts(TargetOpts), LangOpts(LangOpts),
           AsmOutStream(std::move(OS)), Context(nullptr),
           LLVMIRGeneration("irgen", "LLVM IR Generation Time"),
           LLVMIRGenerationRefCount(0),
           Gen(CreateLLVMCodeGen(Diags, InFile, HeaderSearchOpts, PPOpts,
                                 CodeGenOpts, C, CoverageInfo)),
           LinkModules(std::move(LinkModules)) {
       FrontendTimesIsEnabled = TimePasses;
-      llvm::TimePassesIsEnabled = TimePasses;
     }
     llvm::Module *getModule() const { return Gen->GetModule(); }
     std::unique_ptr<llvm::Module> takeModule() {
       return std::unique_ptr<llvm::Module>(Gen->ReleaseModule());
     }
 
     CodeGenerator *getCodeGenerator() { return Gen.get(); }
 

lib/Frontend/CompilerInstance.cpp

if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
     getTarget().noSignedCharForObjCBool();
 
   // Validate/process some options.
   if (getHeaderSearchOpts().Verbose)
     OS << "clang -cc1 version " CLANG_VERSION_STRING
        << " based upon " << BACKEND_PACKAGE_STRING
        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
 
-  if (getFrontendOpts().ShowTimers)
+  if (getFrontendOpts().ShowTimers) {
+    llvm::TimePassesIsEnabled = true;
     createFrontendTimer();
+  }
 
   if (getFrontendOpts().ShowStats || !getFrontendOpts().StatsFile.empty())
     llvm::EnableStatistics(false);
 
   for (const FrontendInputFile &FIF : getFrontendOpts().Inputs) {
     // Reset the ID tables if we are reusing the SourceManager and parsing
     // regular files.
     if (hasSourceManager() && !Act.isModelParsingAction())

test/Frontend/ftime-report-bitcode.ll

+; RUN: %clang_cc1 -triple x86_64-apple-darwin10 -ftime-report -emit-obj -o /dev/null %s 2>&1 | FileCheck %s
+
+target triple ="x86_64-apple-darwin10"
+
+; Make sure the backend time reports are produced when compiling an IR
+; input
+
+; CHECK: Pass execution timing report
+; CHECK: LLVM IR Parsing
+; CHECK: Clang front-end time report
+
+define i32 @foo() {
+  ret i32 0
+}