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.

llvm-svn: 253716

2 files changed, 152 insertions, 0 deletions

diff --git a/llvm/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof b/llvm/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof
new file mode 100644
index 00000000000..528e42ca388
--- /dev/null
+++ b/llvm/test/Transforms/SampleProfile/Inputs/cov-zero-samples.prof
@@ -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
diff --git a/llvm/test/Transforms/SampleProfile/cov-zero-samples.ll b/llvm/test/Transforms/SampleProfile/cov-zero-samples.ll
new file mode 100644
index 00000000000..f7c5f82bb3e
--- /dev/null
+++ b/llvm/test/Transforms/SampleProfile/cov-zero-samples.ll
@@ -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:
+
+@N = global i64 8000000000, align 8
+@.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)