[llvm] r253716 - SamplePGO - Do not count never-executed inlined functions when computing coverage.
Sean Silva via llvm-commits
llvm-commits at lists.llvm.org
Fri Nov 20 19:52:43 PST 2015
On Fri, Nov 20, 2015 at 1:46 PM, Diego Novillo via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Author: dnovillo
> Date: Fri Nov 20 15:46:38 2015
> New Revision: 253716
>
> URL: http://llvm.org/viewvc/llvm-project?rev=253716&view=rev
> Log:
> SamplePGO - Do not count never-executed inlined functions when computing
> coverage.
>
> If a function was originally inlined but not actually hot at runtime,
> its samples will not be counted inside the parent function. This throws
> off the coverage calculation because it expects to find more used
> records than it should.
>
> Fixed by ignoring functions that will not be inlined into the parent.
> Currently, this is inlined functions with 0 samples. In subsequent
> patches, I'll change this to mean "cold" functions.
>
> Added:
> llvm/trunk/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof
> llvm/trunk/test/Transforms/SampleProfile/cov-zero-samples.ll
> Modified:
> llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp
>
> Modified: llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp?rev=253716&r1=253715&r2=253716&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp (original)
> +++ llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp Fri Nov 20 15:46:38
> 2015
> @@ -225,20 +225,39 @@ bool SampleCoverageTracker::markSamplesU
> unsigned
> SampleCoverageTracker::countUsedSamples(const FunctionSamples *Samples)
> const {
> auto I = SampleCoverage.find(Samples);
> +
> + // The size of the coverage map for Samples represents the number of
> records
> + // that were marked used at least once.
> unsigned Count = (I != SampleCoverage.end()) ? I->second.size() : 0;
> - for (const auto &I : Samples->getCallsiteSamples())
> - Count += countUsedSamples(&I.second);
> +
> + // If there are inlined callsites in this function, count the samples
> found
> + // in the respective bodies. However, do not bother counting callees
> with 0
> + // total samples, these are callees that were never invoked at runtime.
> + for (const auto &I : Samples->getCallsiteSamples()) {
> + const FunctionSamples *CalleeSamples = &I.second;
> + if (CalleeSamples->getTotalSamples() > 0)
> + Count += countUsedSamples(&I.second);
>
I think you meant to replace the `&I.second` here with the variable you
defined.
Same in countBodySamples.
-- Sean Silva
> + }
> +
> return Count;
> }
>
> /// Return the number of sample records in the body of this profile.
> ///
> -/// The count includes all the samples in inlined callees.
> +/// The count includes all the samples in inlined callees. However,
> callsites
> +/// with 0 samples indicate inlined function calls that were never
> actually
> +/// invoked at runtime. Ignore these callsites for coverage purposes.
> unsigned
> SampleCoverageTracker::countBodySamples(const FunctionSamples *Samples)
> const {
> unsigned Count = Samples->getBodySamples().size();
> - for (const auto &I : Samples->getCallsiteSamples())
> - Count += countBodySamples(&I.second);
> +
> + // Count all the callsites with non-zero samples.
> + for (const auto &I : Samples->getCallsiteSamples()) {
> + const FunctionSamples *CalleeSamples = &I.second;
> + if (CalleeSamples->getTotalSamples() > 0)
> + Count += countBodySamples(&I.second);
> + }
> +
> return Count;
> }
>
>
> Added:
> llvm/trunk/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof?rev=253716&view=auto
>
> ==============================================================================
> --- llvm/trunk/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof
> (added)
> +++ llvm/trunk/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof
> Fri Nov 20 15:46:38 2015
> @@ -0,0 +1,10 @@
> +main:20111403:0
> + 2.1: 404065
> + 3: 443089
> + 3.1: 0
> + 4: 404066
> + 6: 0
> + 7: 0
> + 3.1: _Z12never_calledi:0
> + 0: 0
> + 1: 0
>
> Added: llvm/trunk/test/Transforms/SampleProfile/cov-zero-samples.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SampleProfile/cov-zero-samples.ll?rev=253716&view=auto
>
> ==============================================================================
> --- llvm/trunk/test/Transforms/SampleProfile/cov-zero-samples.ll (added)
> +++ llvm/trunk/test/Transforms/SampleProfile/cov-zero-samples.ll Fri Nov
> 20 15:46:38 2015
> @@ -0,0 +1,142 @@
> +; RUN: opt < %s -sample-profile
> -sample-profile-file=%S/Inputs/cov-zero-samples.prof
> -sample-profile-check-coverage=100 -pass-remarks=sample-profile -o
> /dev/null 2>&1 | FileCheck %s
> +;
> +; CHECK: remark: cov-zero-samples.cc:9:25: Applied 404065 samples from
> profile (offset: 2.1)
> +; CHECK: remark: cov-zero-samples.cc:10:9: Applied 443089 samples from
> profile (offset: 3)
> +; CHECK: remark: cov-zero-samples.cc:10:36: Applied 0 samples from
> profile (offset: 3.1)
> +; CHECK: remark: cov-zero-samples.cc:11:12: Applied 404066 samples from
> profile (offset: 4)
> +; CHECK: remark: cov-zero-samples.cc:13:25: Applied 0 samples from
> profile (offset: 6)
> +; CHECK: remark: cov-zero-samples.cc:14:3: Applied 0 samples from profile
> (offset: 7)
> +; CHECK: remark: cov-zero-samples.cc:10:9: most popular destination for
> conditional branches at cov-zero-samples.cc:9:3
> +; CHECK: remark: cov-zero-samples.cc:11:12: most popular destination for
> conditional branches at cov-zero-samples.cc:10:9
> +;
> +; Coverage for this profile should be 100%
> +; CHECK-NOT: warning: cov-zero-samples.cc:1:
> +
> + at N = global i64 8000000000, align 8
> + at .str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align
> 1
> +
> +; Function Attrs: nounwind uwtable
> +define i32 @_Z12never_calledi(i32 %i) !dbg !4 {
> +entry:
> + ret i32 0, !dbg !32
> +}
> +
> +; Function Attrs: nounwind readnone
> +declare void @llvm.dbg.declare(metadata, metadata, metadata)
> +
> +; Function Attrs: norecurse uwtable
> +define i32 @main() !dbg !8 {
> +entry:
> + %retval = alloca i32, align 4
> + %sum = alloca i32, align 4
> + %i = alloca i64, align 8
> + store i32 0, i32* %retval, align 4
> + call void @llvm.dbg.declare(metadata i32* %sum, metadata !33, metadata
> !19), !dbg !34
> + store i32 0, i32* %sum, align 4, !dbg !34
> + call void @llvm.dbg.declare(metadata i64* %i, metadata !35, metadata
> !19), !dbg !37
> + store i64 0, i64* %i, align 8, !dbg !37
> + br label %for.cond, !dbg !38
> +
> +for.cond: ; preds = %for.inc,
> %entry
> + %0 = load i64, i64* %i, align 8, !dbg !39
> + %1 = load volatile i64, i64* @N, align 8, !dbg !42
> + %cmp = icmp slt i64 %0, %1, !dbg !43
> + br i1 %cmp, label %for.body, label %for.end, !dbg !44
> +
> +for.body: ; preds = %for.cond
> + %2 = load i64, i64* %i, align 8, !dbg !45
> + %3 = load volatile i64, i64* @N, align 8, !dbg !48
> + %cmp1 = icmp sgt i64 %2, %3, !dbg !49
> + br i1 %cmp1, label %if.then, label %if.end, !dbg !50
> +
> +if.then: ; preds = %for.body
> + %4 = load i64, i64* %i, align 8, !dbg !51
> + %conv = trunc i64 %4 to i32, !dbg !51
> + %call = call i32 @_Z12never_calledi(i32 %conv), !dbg !53
> + %5 = load i32, i32* %sum, align 4, !dbg !54
> + %add = add nsw i32 %5, %call, !dbg !54
> + store i32 %add, i32* %sum, align 4, !dbg !54
> + br label %if.end, !dbg !55
> +
> +if.end: ; preds = %if.then,
> %for.body
> + %6 = load i64, i64* %i, align 8, !dbg !56
> + %div = sdiv i64 %6, 239, !dbg !57
> + %7 = load i32, i32* %sum, align 4, !dbg !58
> + %conv2 = sext i32 %7 to i64, !dbg !58
> + %mul = mul nsw i64 %conv2, %div, !dbg !58
> + %conv3 = trunc i64 %mul to i32, !dbg !58
> + store i32 %conv3, i32* %sum, align 4, !dbg !58
> + br label %for.inc, !dbg !59
> +
> +for.inc: ; preds = %if.end
> + %8 = load i64, i64* %i, align 8, !dbg !60
> + %inc = add nsw i64 %8, 1, !dbg !60
> + store i64 %inc, i64* %i, align 8, !dbg !60
> + br label %for.cond, !dbg !62
> +
> +for.end: ; preds = %for.cond
> + %9 = load i32, i32* %sum, align 4, !dbg !63
> + %call4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([11 x
> i8], [11 x i8]* @.str, i32 0, i32 0), i32 %9), !dbg !64
> + ret i32 0, !dbg !65
> +}
> +
> +declare i32 @printf(i8*, ...)
> +
> +!llvm.dbg.cu = !{!0}
> +!llvm.module.flags = !{!15, !16}
> +!llvm.ident = !{!17}
> +
> +!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1,
> producer: "clang version 3.8.0 (trunk 253667) (llvm/trunk 253670)",
> isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2,
> subprograms: !3, globals: !11)
> +!1 = !DIFile(filename: "cov-zero-samples.cc", directory: ".")
> +!2 = !{}
> +!3 = !{!4, !8}
> +!4 = distinct !DISubprogram(name: "never_called", linkageName:
> "_Z12never_calledi", scope: !1, file: !1, line: 5, type: !5, isLocal:
> false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped,
> isOptimized: false, variables: !2)
> +!5 = !DISubroutineType(types: !6)
> +!6 = !{!7, !7}
> +!7 = !DIBasicType(name: "int", size: 32, align: 32, encoding:
> DW_ATE_signed)
> +!8 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 7,
> type: !9, isLocal: false, isDefinition: true, scopeLine: 7, flags:
> DIFlagPrototyped, isOptimized: false, variables: !2)
> +!9 = !DISubroutineType(types: !10)
> +!10 = !{!7}
> +!11 = !{!12}
> +!12 = !DIGlobalVariable(name: "N", scope: !0, file: !1, line: 3, type:
> !13, isLocal: false, isDefinition: true, variable: i64* @N)
> +!13 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !14)
> +!14 = !DIBasicType(name: "long long int", size: 64, align: 64, encoding:
> DW_ATE_signed)
> +!15 = !{i32 2, !"Dwarf Version", i32 4}
> +!16 = !{i32 2, !"Debug Info Version", i32 3}
> +!17 = !{!"clang version 3.8.0 (trunk 253667) (llvm/trunk 253670)"}
> +!19 = !DIExpression()
> +!31 = !DILexicalBlockFile(scope: !4, file: !1, discriminator: 3)
> +!32 = !DILocation(line: 5, column: 27, scope: !31)
> +!33 = !DILocalVariable(name: "sum", scope: !8, file: !1, line: 8, type:
> !7)
> +!34 = !DILocation(line: 8, column: 7, scope: !8)
> +!35 = !DILocalVariable(name: "i", scope: !36, file: !1, line: 9, type:
> !14)
> +!36 = distinct !DILexicalBlock(scope: !8, file: !1, line: 9, column: 3)
> +!37 = !DILocation(line: 9, column: 18, scope: !36)
> +!38 = !DILocation(line: 9, column: 8, scope: !36)
> +!39 = !DILocation(line: 9, column: 25, scope: !40)
> +!40 = !DILexicalBlockFile(scope: !41, file: !1, discriminator: 1)
> +!41 = distinct !DILexicalBlock(scope: !36, file: !1, line: 9, column: 3)
> +!42 = !DILocation(line: 9, column: 29, scope: !40)
> +!43 = !DILocation(line: 9, column: 27, scope: !40)
> +!44 = !DILocation(line: 9, column: 3, scope: !40)
> +!45 = !DILocation(line: 10, column: 9, scope: !46)
> +!46 = distinct !DILexicalBlock(scope: !47, file: !1, line: 10, column: 9)
> +!47 = distinct !DILexicalBlock(scope: !41, file: !1, line: 9, column: 37)
> +!48 = !DILocation(line: 10, column: 13, scope: !46)
> +!49 = !DILocation(line: 10, column: 11, scope: !46)
> +!50 = !DILocation(line: 10, column: 9, scope: !47)
> +!51 = !DILocation(line: 10, column: 36, scope: !52)
> +!52 = !DILexicalBlockFile(scope: !46, file: !1, discriminator: 1)
> +!53 = !DILocation(line: 10, column: 23, scope: !52)
> +!54 = !DILocation(line: 10, column: 20, scope: !52)
> +!55 = !DILocation(line: 10, column: 16, scope: !52)
> +!56 = !DILocation(line: 11, column: 12, scope: !47)
> +!57 = !DILocation(line: 11, column: 14, scope: !47)
> +!58 = !DILocation(line: 11, column: 9, scope: !47)
> +!59 = !DILocation(line: 12, column: 3, scope: !47)
> +!60 = !DILocation(line: 9, column: 33, scope: !61)
> +!61 = !DILexicalBlockFile(scope: !41, file: !1, discriminator: 2)
> +!62 = !DILocation(line: 9, column: 3, scope: !61)
> +!63 = !DILocation(line: 13, column: 25, scope: !8)
> +!64 = !DILocation(line: 13, column: 3, scope: !8)
> +!65 = !DILocation(line: 14, column: 3, scope: !8)
>
>
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