#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/GCOV.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
///
/// The reader supports two file formats: text and binary. The text format
/// is useful for debugging and testing, while the binary format is more
-/// compact. They can both be used interchangeably.
+/// compact and I/O efficient. They can both be used interchangeably.
class SampleProfileReader {
public:
SampleProfileReader(std::unique_ptr<MemoryBuffer> B, LLVMContext &C)
StringMap<FunctionSamples> &getProfiles() { return Profiles; }
/// \brief Report a parse error message.
- void reportParseError(int64_t LineNumber, Twine Msg) const {
+ void reportError(int64_t LineNumber, Twine Msg) const {
Ctx.diagnose(DiagnosticInfoSampleProfile(Buffer->getBufferIdentifier(),
LineNumber, Msg));
}
const uint8_t *End;
};
+// Represents the source position in GCC sample profiles.
+struct SourceInfo {
+ SourceInfo()
+ : FuncName(), DirName(), FileName(), StartLine(0), Line(0),
+ Discriminator(0) {}
+
+ SourceInfo(StringRef FuncName, StringRef DirName, StringRef FileName,
+ uint32_t StartLine, uint32_t Line, uint32_t Discriminator)
+ : FuncName(FuncName), DirName(DirName), FileName(FileName),
+ StartLine(StartLine), Line(Line), Discriminator(Discriminator) {}
+
+ bool operator<(const SourceInfo &p) const;
+
+ uint32_t Offset() const { return ((Line - StartLine) << 16) | Discriminator; }
+
+ bool Malformed() const { return Line < StartLine; }
+
+ StringRef FuncName;
+ StringRef DirName;
+ StringRef FileName;
+ uint32_t StartLine;
+ uint32_t Line;
+ uint32_t Discriminator;
+};
+
+typedef std::vector<SourceInfo> SourceStack;
+
+// Supported histogram types in GCC. Currently, we only need support for
+// call target histograms.
+enum HistType {
+ HIST_TYPE_INTERVAL,
+ HIST_TYPE_POW2,
+ HIST_TYPE_SINGLE_VALUE,
+ HIST_TYPE_CONST_DELTA,
+ HIST_TYPE_INDIR_CALL,
+ HIST_TYPE_AVERAGE,
+ HIST_TYPE_IOR,
+ HIST_TYPE_INDIR_CALL_TOPN
+};
+
+class SampleProfileReaderGCC : public SampleProfileReader {
+public:
+ SampleProfileReaderGCC(std::unique_ptr<MemoryBuffer> B, LLVMContext &C)
+ : SampleProfileReader(std::move(B), C), GcovBuffer(Buffer.get()) {}
+
+ /// \brief Read and validate the file header.
+ std::error_code readHeader() override;
+
+ /// \brief Read sample profiles from the associated file.
+ std::error_code read() override;
+
+ /// \brief Return true if \p Buffer is in the format supported by this class.
+ static bool hasFormat(const MemoryBuffer &Buffer);
+
+protected:
+ std::error_code readNameTable();
+ std::error_code addSourceCount(StringRef Name, const SourceStack &Src,
+ uint64_t Count);
+ std::error_code readOneFunctionProfile(const SourceStack &Stack, bool Update);
+ std::error_code readFunctionProfiles();
+ std::error_code readModuleGroup();
+ std::error_code readWorkingSet();
+ std::error_code skipNextWord();
+ template <typename T> ErrorOr<T> readNumber();
+ ErrorOr<StringRef> readString();
+
+ /// \brief Read the section tag and check that it's the same as \p Expected.
+ std::error_code readSectionTag(uint32_t Expected);
+
+ /// GCOV buffer containing the profile.
+ GCOVBuffer GcovBuffer;
+
+ /// Function names in this profile.
+ std::vector<std::string> Names;
+
+ /// GCOV tags used to separate sections in the profile file.
+ static const uint32_t GCOVTagAFDOFileNames = 0xaa000000;
+ static const uint32_t GCOVTagAFDOFunction = 0xac000000;
+};
+
} // End namespace sampleprof
} // End namespace llvm
// should not begin with a number.
SmallVector<StringRef, 4> Matches;
if (!HeadRE.match(*LineIt, &Matches)) {
- reportParseError(LineIt.line_number(),
- "Expected 'mangled_name:NUM:NUM', found " + *LineIt);
+ reportError(LineIt.line_number(),
+ "Expected 'mangled_name:NUM:NUM', found " + *LineIt);
return sampleprof_error::malformed;
}
assert(Matches.size() == 4);
// EOF or when we see the start of the next function.
while (!LineIt.is_at_eof() && isdigit((*LineIt)[0])) {
if (!LineSampleRE.match(*LineIt, &Matches)) {
- reportParseError(
- LineIt.line_number(),
- "Expected 'NUM[.NUM]: NUM[ mangled_name:NUM]*', found " + *LineIt);
+ reportError(LineIt.line_number(),
+ "Expected 'NUM[.NUM]: NUM[ mangled_name:NUM]*', found " +
+ *LineIt);
return sampleprof_error::malformed;
}
assert(Matches.size() == 5);
while (CallsLine != "") {
SmallVector<StringRef, 3> CallSample;
if (!CallSampleRE.match(CallsLine, &CallSample)) {
- reportParseError(LineIt.line_number(),
- "Expected 'mangled_name:NUM', found " + CallsLine);
+ reportError(LineIt.line_number(),
+ "Expected 'mangled_name:NUM', found " + CallsLine);
return sampleprof_error::malformed;
}
StringRef CalledFunction = CallSample[1];
EC = sampleprof_error::success;
if (EC) {
- reportParseError(0, EC.message());
+ reportError(0, EC.message());
return EC;
}
StringRef Str(reinterpret_cast<const char *>(Data));
if (Data + Str.size() + 1 > End) {
EC = sampleprof_error::truncated;
- reportParseError(0, EC.message());
+ reportError(0, EC.message());
return EC;
}
return Magic == SPMagic();
}
+bool SourceInfo::operator<(const SourceInfo &P) const {
+ if (Line != P.Line)
+ return Line < P.Line;
+ if (StartLine != P.StartLine)
+ return StartLine < P.StartLine;
+ if (Discriminator != P.Discriminator)
+ return Discriminator < P.Discriminator;
+ return FuncName < P.FuncName;
+}
+
+std::error_code SampleProfileReaderGCC::skipNextWord() {
+ uint32_t dummy;
+ if (!GcovBuffer.readInt(dummy))
+ return sampleprof_error::truncated;
+ return sampleprof_error::success;
+}
+
+template <typename T> ErrorOr<T> SampleProfileReaderGCC::readNumber() {
+ if (sizeof(T) <= sizeof(uint32_t)) {
+ uint32_t Val;
+ if (GcovBuffer.readInt(Val) && Val <= std::numeric_limits<T>::max())
+ return static_cast<T>(Val);
+ } else if (sizeof(T) <= sizeof(uint64_t)) {
+ uint64_t Val;
+ if (GcovBuffer.readInt64(Val) && Val <= std::numeric_limits<T>::max())
+ return static_cast<T>(Val);
+ }
+
+ std::error_code EC = sampleprof_error::malformed;
+ reportError(0, EC.message());
+ return EC;
+}
+
+ErrorOr<StringRef> SampleProfileReaderGCC::readString() {
+ StringRef Str;
+ if (!GcovBuffer.readString(Str))
+ return sampleprof_error::truncated;
+ return Str;
+}
+
+std::error_code SampleProfileReaderGCC::readHeader() {
+ // Read the magic identifier.
+ if (!GcovBuffer.readGCDAFormat())
+ return sampleprof_error::unrecognized_format;
+
+ // Read the version number. Note - the GCC reader does not validate this
+ // version, but the profile creator generates v704.
+ GCOV::GCOVVersion version;
+ if (!GcovBuffer.readGCOVVersion(version))
+ return sampleprof_error::unrecognized_format;
+
+ if (version != GCOV::V704)
+ return sampleprof_error::unsupported_version;
+
+ // Skip the empty integer.
+ if (std::error_code EC = skipNextWord())
+ return EC;
+
+ return sampleprof_error::success;
+}
+
+std::error_code SampleProfileReaderGCC::readSectionTag(uint32_t Expected) {
+ uint32_t Tag;
+ if (!GcovBuffer.readInt(Tag))
+ return sampleprof_error::truncated;
+
+ if (Tag != Expected)
+ return sampleprof_error::malformed;
+
+ if (std::error_code EC = skipNextWord())
+ return EC;
+
+ return sampleprof_error::success;
+}
+
+std::error_code SampleProfileReaderGCC::readNameTable() {
+ if (std::error_code EC = readSectionTag(GCOVTagAFDOFileNames))
+ return EC;
+
+ uint32_t Size;
+ if (!GcovBuffer.readInt(Size))
+ return sampleprof_error::truncated;
+
+ for (uint32_t I = 0; I < Size; ++I) {
+ StringRef Str;
+ if (!GcovBuffer.readString(Str))
+ return sampleprof_error::truncated;
+ Names.push_back(Str);
+ }
+
+ return sampleprof_error::success;
+}
+
+std::error_code SampleProfileReaderGCC::readFunctionProfiles() {
+ if (std::error_code EC = readSectionTag(GCOVTagAFDOFunction))
+ return EC;
+
+ uint32_t NumFunctions;
+ if (!GcovBuffer.readInt(NumFunctions))
+ return sampleprof_error::truncated;
+
+ SourceStack Stack;
+ for (uint32_t I = 0; I < NumFunctions; ++I)
+ if (std::error_code EC = readOneFunctionProfile(Stack, true))
+ return EC;
+
+ return sampleprof_error::success;
+}
+
+std::error_code SampleProfileReaderGCC::addSourceCount(StringRef Name,
+ const SourceStack &Src,
+ uint64_t Count) {
+ if (Src.size() == 0 || Src[0].Malformed())
+ return sampleprof_error::malformed;
+ FunctionSamples &FProfile = Profiles[Name];
+ FProfile.addTotalSamples(Count);
+ // FIXME(dnovillo) - Properly update inline stack for FnName.
+ FProfile.addBodySamples(Src[0].Line, Src[0].Discriminator, Count);
+ return sampleprof_error::success;
+}
+
+
+std::error_code
+SampleProfileReaderGCC::readOneFunctionProfile(const SourceStack &Stack,
+ bool Update) {
+ uint64_t HeadCount = 0;
+ if (Stack.size() == 0)
+ if (!GcovBuffer.readInt64(HeadCount))
+ return sampleprof_error::truncated;
+
+ uint32_t NameIdx;
+ if (!GcovBuffer.readInt(NameIdx))
+ return sampleprof_error::truncated;
+
+ StringRef Name(Names[NameIdx]);
+
+ uint32_t NumPosCounts;
+ if (!GcovBuffer.readInt(NumPosCounts))
+ return sampleprof_error::truncated;
+
+ uint32_t NumCallSites;
+ if (!GcovBuffer.readInt(NumCallSites))
+ return sampleprof_error::truncated;
+
+ if (Stack.size() == 0) {
+ FunctionSamples &FProfile = Profiles[Name];
+ FProfile.addHeadSamples(HeadCount);
+ if (FProfile.getTotalSamples() > 0)
+ Update = false;
+ }
+
+ for (uint32_t I = 0; I < NumPosCounts; ++I) {
+ uint32_t Offset;
+ if (!GcovBuffer.readInt(Offset))
+ return sampleprof_error::truncated;
+
+ uint32_t NumTargets;
+ if (!GcovBuffer.readInt(NumTargets))
+ return sampleprof_error::truncated;
+
+ uint64_t Count;
+ if (!GcovBuffer.readInt64(Count))
+ return sampleprof_error::truncated;
+
+ SourceInfo Info(Name, "", "", 0, Offset >> 16, Offset & 0xffff);
+ SourceStack NewStack;
+ NewStack.push_back(Info);
+ NewStack.insert(NewStack.end(), Stack.begin(), Stack.end());
+ if (Update)
+ addSourceCount(NewStack[NewStack.size() - 1].FuncName, NewStack, Count);
+
+ for (uint32_t J = 0; J < NumTargets; J++) {
+ uint32_t HistVal;
+ if (!GcovBuffer.readInt(HistVal))
+ return sampleprof_error::truncated;
+
+ if (HistVal != HIST_TYPE_INDIR_CALL_TOPN)
+ return sampleprof_error::malformed;
+
+ uint64_t TargetIdx;
+ if (!GcovBuffer.readInt64(TargetIdx))
+ return sampleprof_error::truncated;
+ StringRef TargetName(Names[TargetIdx]);
+
+ uint64_t TargetCount;
+ if (!GcovBuffer.readInt64(TargetCount))
+ return sampleprof_error::truncated;
+
+ if (Update) {
+ FunctionSamples &TargetProfile = Profiles[TargetName];
+ TargetProfile.addBodySamples(NewStack[0].Line,
+ NewStack[0].Discriminator, TargetCount);
+ }
+ }
+ }
+
+ for (uint32_t I = 0; I < NumCallSites; I++) {
+ // The offset is encoded as:
+ // high 16 bits: line offset to the start of the function.
+ // low 16 bits: discriminator.
+ uint32_t Offset;
+ if (!GcovBuffer.readInt(Offset))
+ return sampleprof_error::truncated;
+ SourceInfo Info(Name, "", "", 0, Offset >> 16, Offset & 0xffff);
+ SourceStack NewStack;
+ NewStack.push_back(Info);
+ NewStack.insert(NewStack.end(), Stack.begin(), Stack.end());
+ if (std::error_code EC = readOneFunctionProfile(NewStack, Update))
+ return EC;
+ }
+
+ return sampleprof_error::success;
+}
+
+std::error_code SampleProfileReaderGCC::readModuleGroup() {
+ // FIXME(dnovillo) - Module support still not implemented.
+ return sampleprof_error::not_implemented;
+}
+
+std::error_code SampleProfileReaderGCC::readWorkingSet() {
+ // FIXME(dnovillo) - Working sets still not implemented.
+ return sampleprof_error::not_implemented;
+}
+
+
+/// \brief Read a GCC AutoFDO profile.
+///
+/// This format is generated by the Linux Perf conversion tool at
+/// https://github.com/google/autofdo.
+std::error_code SampleProfileReaderGCC::read() {
+ // Read the string table.
+ if (std::error_code EC = readNameTable())
+ return EC;
+
+ // Read the source profile.
+ if (std::error_code EC = readFunctionProfiles())
+ return EC;
+
+ // FIXME(dnovillo) - Module groups and working set support are not
+ // yet implemented.
+#if 0
+ // Read the module group file.
+ if (std::error_code EC = readModuleGroup())
+ return EC;
+
+ // Read the working set.
+ if (std::error_code EC = readWorkingSet())
+ return EC;
+#endif
+
+ return sampleprof_error::success;
+}
+
+bool SampleProfileReaderGCC::hasFormat(const MemoryBuffer &Buffer) {
+ StringRef Magic(reinterpret_cast<const char *>(Buffer.getBufferStart()));
+ return Magic == "adcg*704";
+}
+
/// \brief Prepare a memory buffer for the contents of \p Filename.
///
/// \returns an error code indicating the status of the buffer.
std::unique_ptr<SampleProfileReader> Reader;
if (SampleProfileReaderBinary::hasFormat(*Buffer))
Reader.reset(new SampleProfileReaderBinary(std::move(Buffer), C));
+ else if (SampleProfileReaderGCC::hasFormat(*Buffer))
+ Reader.reset(new SampleProfileReaderGCC(std::move(Buffer), C));
else
Reader.reset(new SampleProfileReaderText(std::move(Buffer), C));
--- /dev/null
+; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/gcc-simple.afdo -S | FileCheck %s
+;
+; Original code:
+;
+; #include <stdlib.h>
+;
+; long long int foo(long i) {
+; if (rand() < 500) return 2; else if (rand() > 5000) return 10; else return 90;
+; }
+;
+; int main() {
+; long long int sum = 0;
+; for (int k = 0; k < 3000; k++)
+; for (int i = 0; i < 200000; i++) sum += foo(i);
+; return sum > 0 ? 0 : 1;
+; }
+;
+; This test was compiled down to bytecode at -O0 to avoid inlining foo() into
+; main(). The profile was generated using a GCC-generated binary (also compiled
+; at -O0). The conversion from the Linux Perf profile to the GCC autofdo
+; profile used the converter at https://github.com/google/autofdo
+;
+; $ gcc -g -O0 gcc-simple.cc -o gcc-simple
+; $ perf record -b ./gcc-simple
+; $ create_gcov --binary=gcc-simple --gcov=gcc-simple.afdo
+
+define i64 @_Z3fool(i64 %i) #0 {
+; CHECK: !prof ![[EC1:[0-9]+]]
+entry:
+ %retval = alloca i64, align 8
+ %i.addr = alloca i64, align 8
+ store i64 %i, i64* %i.addr, align 8
+ call void @llvm.dbg.declare(metadata i64* %i.addr, metadata !16, metadata !17), !dbg !18
+ %call = call i32 @rand() #3, !dbg !19
+ %cmp = icmp slt i32 %call, 500, !dbg !21
+ br i1 %cmp, label %if.then, label %if.else, !dbg !22
+; CHECK: !prof ![[PROF1:[0-9]+]]
+
+if.then: ; preds = %entry
+ store i64 2, i64* %retval, align 8, !dbg !23
+ br label %return, !dbg !23
+
+if.else: ; preds = %entry
+ %call1 = call i32 @rand() #3, !dbg !25
+ %cmp2 = icmp sgt i32 %call1, 5000, !dbg !28
+ br i1 %cmp2, label %if.then.3, label %if.else.4, !dbg !29
+; CHECK: !prof ![[PROF2:[0-9]+]]
+
+if.then.3: ; preds = %if.else
+ store i64 10, i64* %retval, align 8, !dbg !30
+ br label %return, !dbg !30
+
+if.else.4: ; preds = %if.else
+ store i64 90, i64* %retval, align 8, !dbg !32
+ br label %return, !dbg !32
+
+return: ; preds = %if.else.4, %if.then.3, %if.then
+ %0 = load i64, i64* %retval, align 8, !dbg !34
+ ret i64 %0, !dbg !34
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: nounwind
+declare i32 @rand() #2
+
+; Function Attrs: nounwind uwtable
+define i32 @main() #0 {
+; CHECK: !prof ![[EC2:[0-9]+]]
+entry:
+ %retval = alloca i32, align 4
+ %sum = alloca i64, align 8
+ %k = alloca i32, align 4
+ %i = alloca i32, align 4
+ store i32 0, i32* %retval, align 4
+ call void @llvm.dbg.declare(metadata i64* %sum, metadata !35, metadata !17), !dbg !36
+ store i64 0, i64* %sum, align 8, !dbg !36
+ call void @llvm.dbg.declare(metadata i32* %k, metadata !37, metadata !17), !dbg !39
+ store i32 0, i32* %k, align 4, !dbg !39
+ br label %for.cond, !dbg !40
+
+for.cond: ; preds = %for.inc.4, %entry
+ %0 = load i32, i32* %k, align 4, !dbg !41
+ %cmp = icmp slt i32 %0, 3000, !dbg !45
+ br i1 %cmp, label %for.body, label %for.end.6, !dbg !46
+; CHECK: !prof ![[PROF3:[0-9]+]]
+
+for.body: ; preds = %for.cond
+ call void @llvm.dbg.declare(metadata i32* %i, metadata !47, metadata !17), !dbg !49
+ store i32 0, i32* %i, align 4, !dbg !49
+ br label %for.cond.1, !dbg !50
+
+for.cond.1: ; preds = %for.inc, %for.body
+ %1 = load i32, i32* %i, align 4, !dbg !51
+ %cmp2 = icmp slt i32 %1, 200000, !dbg !55
+ br i1 %cmp2, label %for.body.3, label %for.end, !dbg !56
+; CHECK: !prof ![[PROF4:[0-9]+]]
+
+for.body.3: ; preds = %for.cond.1
+ %2 = load i32, i32* %i, align 4, !dbg !57
+ %conv = sext i32 %2 to i64, !dbg !57
+ %call = call i64 @_Z3fool(i64 %conv), !dbg !59
+ %3 = load i64, i64* %sum, align 8, !dbg !60
+ %add = add nsw i64 %3, %call, !dbg !60
+ store i64 %add, i64* %sum, align 8, !dbg !60
+ br label %for.inc, !dbg !61
+
+for.inc: ; preds = %for.body.3
+ %4 = load i32, i32* %i, align 4, !dbg !62
+ %inc = add nsw i32 %4, 1, !dbg !62
+ store i32 %inc, i32* %i, align 4, !dbg !62
+ br label %for.cond.1, !dbg !64
+
+for.end: ; preds = %for.cond.1
+ br label %for.inc.4, !dbg !65
+
+for.inc.4: ; preds = %for.end
+ %5 = load i32, i32* %k, align 4, !dbg !67
+ %inc5 = add nsw i32 %5, 1, !dbg !67
+ store i32 %inc5, i32* %k, align 4, !dbg !67
+ br label %for.cond, !dbg !68
+
+for.end.6: ; preds = %for.cond
+ %6 = load i64, i64* %sum, align 8, !dbg !69
+ %cmp7 = icmp sgt i64 %6, 0, !dbg !70
+ %cond = select i1 %cmp7, i32 0, i32 1, !dbg !69
+ ret i32 %cond, !dbg !71
+}
+
+; CHECK ![[EC1]] = !{!"function_entry_count", i64 24108}
+; CHECK ![[PROF1]] = !{!"branch_weights", i32 1, i32 30124}
+; CHECK ![[PROF2]] = !{!"branch_weights", i32 30177, i32 29579}
+; CHECK ![[EC2]] = !{!"function_entry_count", i64 0}
+; CHECK ![[PROF3]] = !{!"branch_weights", i32 1, i32 1}
+; CHECK ![[PROF4]] = !{!"branch_weights", i32 1, i32 20238}
+
+attributes #0 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+attributes #2 = { nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #3 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!13, !14}
+!llvm.ident = !{!15}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.8.0 (trunk 247554) (llvm/trunk 247557)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "discriminator.cc", directory: "/usr/local/google/home/dnovillo/llvm/test/autofdo")
+!2 = !{}
+!3 = !{!4, !9}
+!4 = distinct !DISubprogram(name: "foo", linkageName: "_Z3fool", scope: !1, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: false, function: i64 (i64)* @_Z3fool, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{!7, !8}
+!7 = !DIBasicType(name: "long long int", size: 64, align: 64, encoding: DW_ATE_signed)
+!8 = !DIBasicType(name: "long int", size: 64, align: 64, encoding: DW_ATE_signed)
+!9 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 7, type: !10, isLocal: false, isDefinition: true, scopeLine: 7, flags: DIFlagPrototyped, isOptimized: false, function: i32 ()* @main, variables: !2)
+!10 = !DISubroutineType(types: !11)
+!11 = !{!12}
+!12 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!13 = !{i32 2, !"Dwarf Version", i32 4}
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !{!"clang version 3.8.0 (trunk 247554) (llvm/trunk 247557)"}
+!16 = !DILocalVariable(name: "i", arg: 1, scope: !4, file: !1, line: 3, type: !8)
+!17 = !DIExpression()
+!18 = !DILocation(line: 3, column: 24, scope: !4)
+!19 = !DILocation(line: 4, column: 7, scope: !20)
+!20 = distinct !DILexicalBlock(scope: !4, file: !1, line: 4, column: 7)
+!21 = !DILocation(line: 4, column: 14, scope: !20)
+!22 = !DILocation(line: 4, column: 7, scope: !4)
+!23 = !DILocation(line: 4, column: 21, scope: !24)
+!24 = !DILexicalBlockFile(scope: !20, file: !1, discriminator: 1)
+!25 = !DILocation(line: 4, column: 40, scope: !26)
+!26 = !DILexicalBlockFile(scope: !27, file: !1, discriminator: 2)
+!27 = distinct !DILexicalBlock(scope: !20, file: !1, line: 4, column: 40)
+!28 = !DILocation(line: 4, column: 47, scope: !27)
+!29 = !DILocation(line: 4, column: 40, scope: !20)
+!30 = !DILocation(line: 4, column: 55, scope: !31)
+!31 = !DILexicalBlockFile(scope: !27, file: !1, discriminator: 3)
+!32 = !DILocation(line: 4, column: 71, scope: !33)
+!33 = !DILexicalBlockFile(scope: !27, file: !1, discriminator: 4)
+!34 = !DILocation(line: 5, column: 1, scope: !4)
+!35 = !DILocalVariable(name: "sum", scope: !9, file: !1, line: 8, type: !7)
+!36 = !DILocation(line: 8, column: 17, scope: !9)
+!37 = !DILocalVariable(name: "k", scope: !38, file: !1, line: 9, type: !12)
+!38 = distinct !DILexicalBlock(scope: !9, file: !1, line: 9, column: 3)
+!39 = !DILocation(line: 9, column: 12, scope: !38)
+!40 = !DILocation(line: 9, column: 8, scope: !38)
+!41 = !DILocation(line: 9, column: 19, scope: !42)
+!42 = !DILexicalBlockFile(scope: !43, file: !1, discriminator: 2)
+!43 = !DILexicalBlockFile(scope: !44, file: !1, discriminator: 1)
+!44 = distinct !DILexicalBlock(scope: !38, file: !1, line: 9, column: 3)
+!45 = !DILocation(line: 9, column: 21, scope: !44)
+!46 = !DILocation(line: 9, column: 3, scope: !38)
+!47 = !DILocalVariable(name: "i", scope: !48, file: !1, line: 10, type: !12)
+!48 = distinct !DILexicalBlock(scope: !44, file: !1, line: 10, column: 5)
+!49 = !DILocation(line: 10, column: 14, scope: !48)
+!50 = !DILocation(line: 10, column: 10, scope: !48)
+!51 = !DILocation(line: 10, column: 21, scope: !52)
+!52 = !DILexicalBlockFile(scope: !53, file: !1, discriminator: 5)
+!53 = !DILexicalBlockFile(scope: !54, file: !1, discriminator: 1)
+!54 = distinct !DILexicalBlock(scope: !48, file: !1, line: 10, column: 5)
+!55 = !DILocation(line: 10, column: 23, scope: !54)
+!56 = !DILocation(line: 10, column: 5, scope: !48)
+!57 = !DILocation(line: 10, column: 49, scope: !58)
+!58 = !DILexicalBlockFile(scope: !54, file: !1, discriminator: 2)
+!59 = !DILocation(line: 10, column: 45, scope: !54)
+!60 = !DILocation(line: 10, column: 42, scope: !54)
+!61 = !DILocation(line: 10, column: 38, scope: !54)
+!62 = !DILocation(line: 10, column: 34, scope: !63)
+!63 = !DILexicalBlockFile(scope: !54, file: !1, discriminator: 4)
+!64 = !DILocation(line: 10, column: 5, scope: !54)
+!65 = !DILocation(line: 10, column: 50, scope: !66)
+!66 = !DILexicalBlockFile(scope: !48, file: !1, discriminator: 3)
+!67 = !DILocation(line: 9, column: 30, scope: !44)
+!68 = !DILocation(line: 9, column: 3, scope: !44)
+!69 = !DILocation(line: 11, column: 10, scope: !9)
+!70 = !DILocation(line: 11, column: 14, scope: !9)
+!71 = !DILocation(line: 11, column: 3, scope: !9)