r205023 - InstrProf: Emit runtime hook directly in IRGen
Duncan P. N. Exon Smith
dexonsmith at apple.com
Fri Mar 28 11:30:25 PDT 2014
On 2014 Mar 28, at 11:14, Richard Smith <richard at metafoo.co.uk> wrote:
> On Fri, Mar 28, 2014 at 10:53 AM, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote:
> Author: dexonsmith
> Date: Fri Mar 28 12:53:22 2014
> New Revision: 205023
>
> URL: http://llvm.org/viewvc/llvm-project?rev=205023&view=rev
> Log:
> InstrProf: Emit runtime hook directly in IRGen
>
> -u behaviour is apparently not portable between linkers (see cfe-commits
> discussions for r204379 and r205012). I've moved the logic to IRGen,
> where it should have been in the first place.
>
> I don't have a Linux system to test this on, so it's possible this logic
> *still* doesn't pull in the instrumented profiling runtime on Linux.
>
> I'm in the process of getting tests going on the compiler-rt side
> (llvm-commits "[PATCH] InstrProf: Add initial compiler-rt test"). Once
> we have tests for the full flow there, the runtime logic should get a
> whole lot less brittle.
>
> <rdar://problem/16458307>
>
> Modified:
> cfe/trunk/lib/CodeGen/CodeGenPGO.cpp
> cfe/trunk/lib/Driver/ToolChains.cpp
> cfe/trunk/lib/Driver/Tools.cpp
> cfe/trunk/test/Profile/c-linkage.c
> cfe/trunk/test/Profile/cxx-linkage.cpp
>
> Modified: cfe/trunk/lib/CodeGen/CodeGenPGO.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenPGO.cpp?rev=205023&r1=205022&r2=205023&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CodeGenPGO.cpp (original)
> +++ cfe/trunk/lib/CodeGen/CodeGenPGO.cpp Fri Mar 28 12:53:22 2014
> @@ -814,6 +814,35 @@ namespace {
> };
> }
>
> +static void emitRuntimeHook(CodeGenModule &CGM) {
> + constexpr const char *RuntimeVarName = "__llvm_profile_runtime";
> + constexpr const char *RuntimeUserName = "__llvm_profile_runtime_user";
>
> MSVC2012 doesn't support 'constexpr’.
Sorry, that was careless. Fixed in r205025.
> + if (CGM.getModule().getGlobalVariable(RuntimeVarName))
> + return;
> +
> + // Declare the runtime hook.
> + llvm::LLVMContext &Ctx = CGM.getLLVMContext();
> + auto *Int32Ty = llvm::Type::getInt32Ty(Ctx);
> + auto *Var = new llvm::GlobalVariable(CGM.getModule(), Int32Ty, false,
> + llvm::GlobalValue::ExternalLinkage,
> + nullptr, RuntimeVarName);
> +
> + // Make a function that uses it.
> + auto *User = llvm::Function::Create(llvm::FunctionType::get(Int32Ty, false),
> + llvm::GlobalValue::LinkOnceODRLinkage,
> + RuntimeUserName, &CGM.getModule());
> + User->addFnAttr(llvm::Attribute::NoInline);
> + if (CGM.getCodeGenOpts().DisableRedZone)
> + User->addFnAttr(llvm::Attribute::NoRedZone);
> + CGBuilderTy Builder(llvm::BasicBlock::Create(CGM.getLLVMContext(), "", User));
> + auto *Load = Builder.CreateLoad(Var);
> + Builder.CreateRet(Load);
> +
> + // Create a use of the function. Now the definition of the runtime variable
> + // should get pulled in, along with any static initializears.
> + CGM.addUsedGlobal(User);
> +}
> +
> void CodeGenPGO::assignRegionCounters(const Decl *D, llvm::Function *Fn) {
> bool InstrumentRegions = CGM.getCodeGenOpts().ProfileInstrGenerate;
> PGOProfileData *PGOData = CGM.getPGOData();
> @@ -839,8 +868,10 @@ void CodeGenPGO::assignRegionCounters(co
> }
>
> mapRegionCounters(D);
> - if (InstrumentRegions)
> + if (InstrumentRegions) {
> + emitRuntimeHook(CGM);
> emitCounterVariables();
> + }
> if (PGOData) {
> loadRegionCounts(PGOData);
> computeRegionCounts(D);
>
> Modified: cfe/trunk/lib/Driver/ToolChains.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains.cpp?rev=205023&r1=205022&r2=205023&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Driver/ToolChains.cpp (original)
> +++ cfe/trunk/lib/Driver/ToolChains.cpp Fri Mar 28 12:53:22 2014
> @@ -325,13 +325,6 @@ void DarwinClang::AddLinkRuntimeLibArgs(
> Args.hasArg(options::OPT_fprofile_instr_generate) ||
> Args.hasArg(options::OPT_fcreate_profile) ||
> Args.hasArg(options::OPT_coverage)) {
> - // Pull in runtime for -fprofile-inst-generate. This is required since
> - // there are no calls to the runtime in the code.
> - if (Args.hasArg(options::OPT_fprofile_instr_generate)) {
> - CmdArgs.push_back("-u");
> - CmdArgs.push_back("___llvm_profile_runtime");
> - }
> -
> // Select the appropriate runtime library for the target.
> if (isTargetIOSBased())
> AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.profile_ios.a");
>
> Modified: cfe/trunk/lib/Driver/Tools.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=205023&r1=205022&r2=205023&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Driver/Tools.cpp (original)
> +++ cfe/trunk/lib/Driver/Tools.cpp Fri Mar 28 12:53:22 2014
> @@ -1817,13 +1817,6 @@ static void addProfileRT(
> Args.hasArg(options::OPT_coverage)))
> return;
>
> - // Pull in runtime for -fprofile-inst-generate. This is required since there
> - // are no calls to the runtime in the code.
> - if (Args.hasArg(options::OPT_fprofile_instr_generate)) {
> - CmdArgs.push_back("-u");
> - CmdArgs.push_back("___llvm_profile_runtime");
> - }
> -
> SmallString<128> LibProfile = getCompilerRTLibDir(TC);
> llvm::sys::path::append(LibProfile,
> Twine("libclang_rt.profile-") + getArchNameForCompilerRTLib(TC) + ".a");
>
> Modified: cfe/trunk/test/Profile/c-linkage.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Profile/c-linkage.c?rev=205023&r1=205022&r2=205023&view=diff
> ==============================================================================
> --- cfe/trunk/test/Profile/c-linkage.c (original)
> +++ cfe/trunk/test/Profile/c-linkage.c Fri Mar 28 12:53:22 2014
> @@ -1,6 +1,7 @@
> // Check the data structures emitted by instrumentation.
> // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-linkage.c %s -o - -emit-llvm -fprofile-instr-generate | FileCheck %s
>
> +// CHECK: @__llvm_profile_runtime = external global i32
> // CHECK: @__llvm_profile_counters_foo = global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
> // CHECK: @__llvm_profile_name_foo = constant [3 x i8] c"foo", section "__DATA,__llvm_prf_names", align 1
> // CHECK: @__llvm_profile_data_foo = constant { i32, i32, i64, i8*, i64* } { i32 3, i32 1, i64 1, i8* getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i64* getelementptr inbounds ([1 x i64]* @__llvm_profile_counters_foo, i32 0, i32 0) }, section "__DATA,__llvm_prf_data", align 8
> @@ -28,4 +29,9 @@ int main(void) {
> // CHECK: @__llvm_profile_data_foo_internal = internal constant { i32, i32, i64, i8*, i64* } { i32 24, i32 3, i64 3, i8* getelementptr inbounds ([24 x i8]* @__llvm_profile_name_foo_internal, i32 0, i32 0), i64* getelementptr inbounds ([3 x i64]* @__llvm_profile_counters_foo_internal, i32 0, i32 0) }, section "__DATA,__llvm_prf_data", align 8
> static void foo_internal(void) { if (0){} if (0){} }
>
> -// CHECK: @llvm.used = appending global [4 x i8*] [i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_foo to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_foo_weak to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_main to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_foo_internal to i8*)], section "llvm.metadata"
> +// CHECK: @llvm.used = appending global [5 x i8*] [i8* bitcast (i32 ()* @__llvm_profile_runtime_user to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_foo to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_foo_weak to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_main to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_foo_internal to i8*)], section "llvm.metadata"
> +
> +// CHECK: define linkonce_odr i32 @__llvm_profile_runtime_user() {{.*}} {
> +// CHECK: %[[REG:.*]] = load i32* @__llvm_profile_runtime
> +// CHECK: ret i32 %[[REG]]
> +// CHECK: }
>
> Modified: cfe/trunk/test/Profile/cxx-linkage.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Profile/cxx-linkage.cpp?rev=205023&r1=205022&r2=205023&view=diff
> ==============================================================================
> --- cfe/trunk/test/Profile/cxx-linkage.cpp (original)
> +++ cfe/trunk/test/Profile/cxx-linkage.cpp Fri Mar 28 12:53:22 2014
> @@ -1,5 +1,6 @@
> // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9.0 -emit-llvm -main-file-name cxx-linkage.cpp %s -o - -fprofile-instr-generate | FileCheck %s
>
> +// CHECK: @__llvm_profile_runtime = external global i32
> // CHECK: @__llvm_profile_counters__Z3foov = global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
> // CHECK: @__llvm_profile_name__Z3foov = constant [7 x i8] c"_Z3foov", section "__DATA,__llvm_prf_names", align 1
> // CHECK: @__llvm_profile_data__Z3foov = constant { i32, i32, i64, i8*, i64* } { i32 7, i32 1, i64 1, i8* getelementptr inbounds ([7 x i8]* @__llvm_profile_name__Z3foov, i32 0, i32 0), i64* getelementptr inbounds ([1 x i64]* @__llvm_profile_counters__Z3foov, i32 0, i32 0) }, section "__DATA,__llvm_prf_data", align 8
> @@ -27,4 +28,9 @@ int main(void) {
> // CHECK: @__llvm_profile_data__Z10foo_inlinev = linkonce_odr constant { i32, i32, i64, i8*, i64* } { i32 15, i32 7, i64 7, i8* getelementptr inbounds ([15 x i8]* @__llvm_profile_name__Z10foo_inlinev, i32 0, i32 0), i64* getelementptr inbounds ([7 x i64]* @__llvm_profile_counters__Z10foo_inlinev, i32 0, i32 0) }, section "__DATA,__llvm_prf_data", align 8
> inline void foo_inline(void) { if (0){} if (0){} if (0){} if (0){} if (0){} if (0){}}
>
> -// CHECK: @llvm.used = appending global [4 x i8*] [i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data__Z3foov to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data__Z8foo_weakv to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_main to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data__Z10foo_inlinev to i8*)], section "llvm.metadata"
> +// CHECK: @llvm.used = appending global [5 x i8*] [i8* bitcast (i32 ()* @__llvm_profile_runtime_user to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data__Z3foov to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data__Z8foo_weakv to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data_main to i8*), i8* bitcast ({ i32, i32, i64, i8*, i64* }* @__llvm_profile_data__Z10foo_inlinev to i8*)], section "llvm.metadata"
> +
> +// CHECK: define linkonce_odr i32 @__llvm_profile_runtime_user() {{.*}} {
> +// CHECK: %[[REG:.*]] = load i32* @__llvm_profile_runtime
> +// CHECK: ret i32 %[[REG]]
> +// CHECK: }
>
>
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