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llvm-mirror/test/Transforms/SampleProfile/inline-coverage.ll
Wei Mi 93d80a543f [SampleFDO] Add use-sample-profile function attribute.
When sampleFDO is enabled, people may expect they can use
-fno-profile-sample-use to opt-out using sample profile for a certain file.
That could be either for debugging purpose or for performance tuning purpose.
However, when thinlto is enabled, if a function in file A compiled with
-fno-profile-sample-use is imported to another file B compiled with
-fprofile-sample-use, the inlined copy of the function in file B may still
get its profile annotated.

The inconsistency may even introduce profile unused warning because if the
target is not compiled with explicit debug information flag, the function
in file A won't have its debug information enabled (debug information will
be enabled implicitly only when -fprofile-sample-use is used). After it is
imported into file B which is compiled with -fprofile-sample-use, profile
annotation for the outline copy of the function will fail because the
function has no debug information, and that will trigger  profile unused
warning.

We add a new attribute use-sample-profile to control whether a function
will use its sample profile no matter for its outline or inline copies.
That will make the behavior of -fno-profile-sample-use consistent.

Differential Revision: https://reviews.llvm.org/D79959
2020-06-02 17:23:17 -07:00

138 lines
6.6 KiB
LLVM

; RUN: opt < %s -instcombine -sample-profile -sample-profile-file=%S/Inputs/inline-coverage.prof -sample-profile-check-record-coverage=100 -sample-profile-check-sample-coverage=110 -pass-remarks=sample-profile -pass-remarks-analysis=sample-profile -o /dev/null 2>&1 | FileCheck %s
; RUN: opt < %s -passes="function(instcombine),sample-profile" -sample-profile-file=%S/Inputs/inline-coverage.prof -sample-profile-check-record-coverage=100 -sample-profile-check-sample-coverage=110 -pass-remarks=sample-profile -pass-remarks-analysis=sample-profile -o /dev/null 2>&1 | FileCheck %s
;
; Original code:
;
; 1 #include <stdlib.h>
; 2
; 3 long long int foo(long i) {
; 4 return rand() * i;
; 5 }
; 6
; 7 int main() {
; 8 long long int sum = 0;
; 9 for (int i = 0; i < 200000 * 3000; i++)
; 10 sum += foo(i);
; 11 return sum > 0 ? 0 : 1;
; 12 }
;
; CHECK: remark: coverage.cc:10:12: previous inlining reattempted for hotness: '_Z3fool' into 'main'
; CHECK: remark: coverage.cc:9:21: Applied 23478 samples from profile (offset: 2.1)
; CHECK: remark: coverage.cc:10:16: Applied 23478 samples from profile (offset: 3)
; CHECK: remark: coverage.cc:4:10: Applied 31878 samples from profile (offset: 1)
; CHECK: remark: coverage.cc:11:10: Applied 0 samples from profile (offset: 4)
; CHECK: remark: coverage.cc:10:16: most popular destination for conditional branches at coverage.cc:9:3
;
; There is one sample record with 0 samples at offset 4 in main() that we never
; use:
; CHECK: warning: coverage.cc:7: 4 of 5 available profile records (80%) were applied
;
; Since the unused sample record contributes no samples, sample coverage should
; be 100%. Note that we get this warning because we are requesting an impossible
; 110% coverage check.
; CHECK: warning: coverage.cc:7: 78834 of 78834 available profile samples (100%) were applied
define i64 @_Z3fool(i64 %i) #0 !dbg !4 {
entry:
%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(), !dbg !19
%conv = sext i32 %call to i64, !dbg !19
%0 = load i64, i64* %i.addr, align 8, !dbg !20
%mul = mul nsw i64 %conv, %0, !dbg !21
ret i64 %mul, !dbg !22
}
declare void @llvm.dbg.declare(metadata, metadata, metadata)
declare i32 @rand()
define i32 @main() #0 !dbg !9 {
entry:
%retval = alloca i32, align 4
%sum = alloca i64, align 8
%i = alloca i32, align 4
store i32 0, i32* %retval, align 4
call void @llvm.dbg.declare(metadata i64* %sum, metadata !23, metadata !17), !dbg !24
store i64 0, i64* %sum, align 8, !dbg !24
call void @llvm.dbg.declare(metadata i32* %i, metadata !25, metadata !17), !dbg !27
store i32 0, i32* %i, align 4, !dbg !27
br label %for.cond, !dbg !28
for.cond: ; preds = %for.inc, %entry
%0 = load i32, i32* %i, align 4, !dbg !29
%cmp = icmp slt i32 %0, 600000000, !dbg !32
br i1 %cmp, label %for.body, label %for.end, !dbg !33
for.body: ; preds = %for.cond
%1 = load i32, i32* %i, align 4, !dbg !34
%conv = sext i32 %1 to i64, !dbg !34
%call = call i64 @_Z3fool(i64 %conv), !dbg !35
%2 = load i64, i64* %sum, align 8, !dbg !36
%add = add nsw i64 %2, %call, !dbg !36
store i64 %add, i64* %sum, align 8, !dbg !36
br label %for.inc, !dbg !37
for.inc: ; preds = %for.body
%3 = load i32, i32* %i, align 4, !dbg !38
%inc = add nsw i32 %3, 1, !dbg !38
store i32 %inc, i32* %i, align 4, !dbg !38
br label %for.cond, !dbg !39
for.end: ; preds = %for.cond
%4 = load i64, i64* %sum, align 8, !dbg !40
%cmp1 = icmp sgt i64 %4, 0, !dbg !41
%cond = select i1 %cmp1, i32 0, i32 1, !dbg !40
ret i32 %cond, !dbg !42
}
attributes #0 = { "use-sample-profile" }
!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 251738) (llvm/trunk 251737)", isOptimized: false, runtimeVersion: 0, emissionKind: NoDebug, enums: !2)
!1 = !DIFile(filename: "coverage.cc", directory: ".")
!2 = !{}
!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, unit: !0, retainedNodes: !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, unit: !0, retainedNodes: !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 251738) (llvm/trunk 251737)"}
!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: 10, scope: !4)
!20 = !DILocation(line: 4, column: 19, scope: !4)
!21 = !DILocation(line: 4, column: 17, scope: !4)
!22 = !DILocation(line: 4, column: 3, scope: !4)
!23 = !DILocalVariable(name: "sum", scope: !9, file: !1, line: 8, type: !7)
!24 = !DILocation(line: 8, column: 17, scope: !9)
!25 = !DILocalVariable(name: "i", scope: !26, file: !1, line: 9, type: !12)
!26 = distinct !DILexicalBlock(scope: !9, file: !1, line: 9, column: 3)
!27 = !DILocation(line: 9, column: 12, scope: !26)
!28 = !DILocation(line: 9, column: 8, scope: !26)
!29 = !DILocation(line: 9, column: 19, scope: !30)
!30 = !DILexicalBlockFile(scope: !31, file: !1, discriminator: 2)
!31 = distinct !DILexicalBlock(scope: !26, file: !1, line: 9, column: 3)
!32 = !DILocation(line: 9, column: 21, scope: !30)
!33 = !DILocation(line: 9, column: 3, scope: !30)
!34 = !DILocation(line: 10, column: 16, scope: !31)
!35 = !DILocation(line: 10, column: 12, scope: !31)
!36 = !DILocation(line: 10, column: 9, scope: !31)
!37 = !DILocation(line: 10, column: 5, scope: !31)
!38 = !DILocation(line: 9, column: 39, scope: !31)
!39 = !DILocation(line: 9, column: 3, scope: !31)
!40 = !DILocation(line: 11, column: 10, scope: !9)
!41 = !DILocation(line: 11, column: 14, scope: !9)
!42 = !DILocation(line: 11, column: 3, scope: !9)