/// \returns True if there is any inline happened.
bool SampleProfileLoader::inlineHotFunctions(Function &F) {
bool Changed = false;
+ LLVMContext &Ctx = F.getContext();
while (true) {
bool LocalChanged = false;
SmallVector<CallInst *, 10> CIS;
}
for (auto CI : CIS) {
InlineFunctionInfo IFI;
- if (InlineFunction(CI, IFI))
+ Function *CalledFunction = CI->getCalledFunction();
+ DebugLoc DLoc = CI->getDebugLoc();
+ uint64_t NumSamples = findCalleeFunctionSamples(*CI)->getTotalSamples();
+ if (InlineFunction(CI, IFI)) {
LocalChanged = true;
+ emitOptimizationRemark(Ctx, DEBUG_TYPE, F, DLoc,
+ Twine("inlined hot callee '") +
+ CalledFunction->getName() + "' with " +
+ Twine(NumSamples) + " samples into '" +
+ F.getName() + "'");
+ }
}
if (LocalChanged) {
Changed = true;
// Generate MD_prof metadata for every branch instruction using the
// edge weights computed during propagation.
DEBUG(dbgs() << "\nPropagation complete. Setting branch weights\n");
- MDBuilder MDB(F.getContext());
+ LLVMContext &Ctx = F.getContext();
+ MDBuilder MDB(Ctx);
for (auto &BI : F) {
BasicBlock *BB = &BI;
TerminatorInst *TI = BB->getTerminator();
DEBUG(dbgs() << "\nGetting weights for branch at line "
<< TI->getDebugLoc().getLine() << ".\n");
SmallVector<uint32_t, 4> Weights;
- bool AllWeightsZero = true;
+ uint32_t MaxWeight = 0;
+ BasicBlock *MaxDestBB = nullptr;
+ DebugLoc MaxDestLoc;
for (unsigned I = 0; I < TI->getNumSuccessors(); ++I) {
BasicBlock *Succ = TI->getSuccessor(I);
Edge E = std::make_pair(BB, Succ);
Weight = std::numeric_limits<uint32_t>::max();
}
Weights.push_back(static_cast<uint32_t>(Weight));
- if (Weight != 0)
- AllWeightsZero = false;
+ if (Weight != 0) {
+ if (Weight > MaxWeight) {
+ MaxWeight = Weight;
+ MaxDestBB = Succ;
+ MaxDestLoc = Succ->getFirstNonPHIOrDbgOrLifetime()->getDebugLoc();
+ }
+ }
}
// Only set weights if there is at least one non-zero weight.
// In any other case, let the analyzer set weights.
- if (!AllWeightsZero) {
+ if (MaxWeight > 0) {
DEBUG(dbgs() << "SUCCESS. Found non-zero weights.\n");
TI->setMetadata(llvm::LLVMContext::MD_prof,
MDB.createBranchWeights(Weights));
+ DebugLoc BranchLoc = TI->getDebugLoc();
+ emitOptimizationRemark(
+ Ctx, DEBUG_TYPE, F, MaxDestLoc,
+ Twine("most popular destination for conditional branches at ") +
+ BranchLoc->getFilename() + ":" + Twine(BranchLoc.getLine()) +
+ ":" + Twine(BranchLoc.getCol()));
} else {
DEBUG(dbgs() << "SKIPPED. All branch weights are zero.\n");
}
--- /dev/null
+; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/remarks.prof -S -pass-remarks=sample-profile 2>&1 | FileCheck %s
+;
+; Original test case.
+;
+; 1 #include <stdlib.h>
+; 2
+; 3 long long foo() {
+; 4 long long int sum = 0;
+; 5 for (int i = 0; i < 500000000; i++)
+; 6 if (i < 1000)
+; 7 sum -= i;
+; 8 else
+; 9 sum += -i * rand();
+; 10 return sum;
+; 11 }
+; 12
+; 13 int main() { return foo() > 0; }
+
+; We are expecting foo() to be inlined in main() (almost all the cycles are
+; spent inside foo).
+; CHECK: remark: remarks.cc:13:21: inlined hot callee '_Z3foov' with 623868 samples into 'main'
+
+; The back edge for the loop is the hottest edge in the loop subgraph.
+; CHECK: remark: remarks.cc:6:9: most popular destination for conditional branches at remarks.cc:5:3
+
+; The predicate almost always chooses the 'else' branch.
+; CHECK: remark: remarks.cc:9:15: most popular destination for conditional branches at remarks.cc:6:9
+
+; Function Attrs: nounwind uwtable
+define i64 @_Z3foov() #0 {
+entry:
+ %sum = alloca i64, align 8
+ %i = alloca i32, align 4
+ %0 = bitcast i64* %sum to i8*, !dbg !19
+ call void @llvm.lifetime.start(i64 8, i8* %0) #4, !dbg !19
+ call void @llvm.dbg.declare(metadata i64* %sum, metadata !9, metadata !20), !dbg !21
+ store i64 0, i64* %sum, align 8, !dbg !21, !tbaa !22
+ %1 = bitcast i32* %i to i8*, !dbg !26
+ call void @llvm.lifetime.start(i64 4, i8* %1) #4, !dbg !26
+ call void @llvm.dbg.declare(metadata i32* %i, metadata !10, metadata !20), !dbg !27
+ store i32 0, i32* %i, align 4, !dbg !27, !tbaa !28
+ br label %for.cond, !dbg !26
+
+for.cond: ; preds = %for.inc, %entry
+ %2 = load i32, i32* %i, align 4, !dbg !30, !tbaa !28
+ %cmp = icmp slt i32 %2, 500000000, !dbg !34
+ br i1 %cmp, label %for.body, label %for.cond.cleanup, !dbg !35
+
+for.cond.cleanup: ; preds = %for.cond
+ %3 = bitcast i32* %i to i8*, !dbg !36
+ call void @llvm.lifetime.end(i64 4, i8* %3) #4, !dbg !36
+ br label %for.end
+
+for.body: ; preds = %for.cond
+ %4 = load i32, i32* %i, align 4, !dbg !38, !tbaa !28
+ %cmp1 = icmp slt i32 %4, 1000, !dbg !40
+ br i1 %cmp1, label %if.then, label %if.else, !dbg !41
+
+if.then: ; preds = %for.body
+ %5 = load i32, i32* %i, align 4, !dbg !42, !tbaa !28
+ %conv = sext i32 %5 to i64, !dbg !42
+ %6 = load i64, i64* %sum, align 8, !dbg !43, !tbaa !22
+ %sub = sub nsw i64 %6, %conv, !dbg !43
+ store i64 %sub, i64* %sum, align 8, !dbg !43, !tbaa !22
+ br label %if.end, !dbg !44
+
+if.else: ; preds = %for.body
+ %7 = load i32, i32* %i, align 4, !dbg !45, !tbaa !28
+ %sub2 = sub nsw i32 0, %7, !dbg !46
+ %call = call i32 @rand() #4, !dbg !47
+ %mul = mul nsw i32 %sub2, %call, !dbg !48
+ %conv3 = sext i32 %mul to i64, !dbg !46
+ %8 = load i64, i64* %sum, align 8, !dbg !49, !tbaa !22
+ %add = add nsw i64 %8, %conv3, !dbg !49
+ store i64 %add, i64* %sum, align 8, !dbg !49, !tbaa !22
+ br label %if.end
+
+if.end: ; preds = %if.else, %if.then
+ br label %for.inc, !dbg !50
+
+for.inc: ; preds = %if.end
+ %9 = load i32, i32* %i, align 4, !dbg !51, !tbaa !28
+ %inc = add nsw i32 %9, 1, !dbg !51
+ store i32 %inc, i32* %i, align 4, !dbg !51, !tbaa !28
+ br label %for.cond, !dbg !52
+
+for.end: ; preds = %for.cond.cleanup
+ %10 = load i64, i64* %sum, align 8, !dbg !53, !tbaa !22
+ %11 = bitcast i64* %sum to i8*, !dbg !54
+ call void @llvm.lifetime.end(i64 8, i8* %11) #4, !dbg !54
+ ret i64 %10, !dbg !55
+}
+
+; Function Attrs: nounwind argmemonly
+declare void @llvm.lifetime.start(i64, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #2
+
+; Function Attrs: nounwind
+declare i32 @rand() #3
+
+; Function Attrs: nounwind argmemonly
+declare void @llvm.lifetime.end(i64, i8* nocapture) #1
+
+; Function Attrs: nounwind uwtable
+define i32 @main() #0 {
+entry:
+ %retval = alloca i32, align 4
+ store i32 0, i32* %retval, align 4
+ %call = call i64 @_Z3foov(), !dbg !56
+ %cmp = icmp sgt i64 %call, 0, !dbg !57
+ %conv = zext i1 %cmp to i32, !dbg !56
+ ret i32 %conv, !dbg !58
+}
+
+attributes #0 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind argmemonly }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!16, !17}
+!llvm.ident = !{!18}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.8.0 (trunk 251041) (llvm/trunk 251053)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "remarks.cc", directory: ".")
+!2 = !{}
+!3 = !{!4, !13}
+!4 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: !1, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, function: i64 ()* @_Z3foov, variables: !8)
+!5 = !DISubroutineType(types: !6)
+!6 = !{!7}
+!7 = !DIBasicType(name: "long long int", size: 64, align: 64, encoding: DW_ATE_signed)
+!8 = !{!9, !10}
+!9 = !DILocalVariable(name: "sum", scope: !4, file: !1, line: 4, type: !7)
+!10 = !DILocalVariable(name: "i", scope: !11, file: !1, line: 5, type: !12)
+!11 = distinct !DILexicalBlock(scope: !4, file: !1, line: 5, column: 3)
+!12 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!13 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 13, type: !14, isLocal: false, isDefinition: true, scopeLine: 13, flags: DIFlagPrototyped, isOptimized: true, function: i32 ()* @main, variables: !2)
+!14 = !DISubroutineType(types: !15)
+!15 = !{!12}
+!16 = !{i32 2, !"Dwarf Version", i32 4}
+!17 = !{i32 2, !"Debug Info Version", i32 3}
+!18 = !{!"clang version 3.8.0 (trunk 251041) (llvm/trunk 251053)"}
+!19 = !DILocation(line: 4, column: 3, scope: !4)
+!20 = !DIExpression()
+!21 = !DILocation(line: 4, column: 17, scope: !4)
+!22 = !{!23, !23, i64 0}
+!23 = !{!"long long", !24, i64 0}
+!24 = !{!"omnipotent char", !25, i64 0}
+!25 = !{!"Simple C/C++ TBAA"}
+!26 = !DILocation(line: 5, column: 8, scope: !11)
+!27 = !DILocation(line: 5, column: 12, scope: !11)
+!28 = !{!29, !29, i64 0}
+!29 = !{!"int", !24, i64 0}
+!30 = !DILocation(line: 5, column: 19, scope: !31)
+!31 = !DILexicalBlockFile(scope: !32, file: !1, discriminator: 3)
+!32 = !DILexicalBlockFile(scope: !33, file: !1, discriminator: 1)
+!33 = distinct !DILexicalBlock(scope: !11, file: !1, line: 5, column: 3)
+!34 = !DILocation(line: 5, column: 21, scope: !33)
+!35 = !DILocation(line: 5, column: 3, scope: !11)
+!36 = !DILocation(line: 5, column: 3, scope: !37)
+!37 = !DILexicalBlockFile(scope: !33, file: !1, discriminator: 2)
+!38 = !DILocation(line: 6, column: 9, scope: !39)
+!39 = distinct !DILexicalBlock(scope: !33, file: !1, line: 6, column: 9)
+!40 = !DILocation(line: 6, column: 11, scope: !39)
+!41 = !DILocation(line: 6, column: 9, scope: !33)
+!42 = !DILocation(line: 7, column: 14, scope: !39)
+!43 = !DILocation(line: 7, column: 11, scope: !39)
+!44 = !DILocation(line: 7, column: 7, scope: !39)
+!45 = !DILocation(line: 9, column: 15, scope: !39)
+!46 = !DILocation(line: 9, column: 14, scope: !39)
+!47 = !DILocation(line: 9, column: 19, scope: !39)
+!48 = !DILocation(line: 9, column: 17, scope: !39)
+!49 = !DILocation(line: 9, column: 11, scope: !39)
+!50 = !DILocation(line: 6, column: 13, scope: !39)
+!51 = !DILocation(line: 5, column: 35, scope: !33)
+!52 = !DILocation(line: 5, column: 3, scope: !33)
+!53 = !DILocation(line: 10, column: 10, scope: !4)
+!54 = !DILocation(line: 11, column: 1, scope: !4)
+!55 = !DILocation(line: 10, column: 3, scope: !4)
+!56 = !DILocation(line: 13, column: 21, scope: !13)
+!57 = !DILocation(line: 13, column: 27, scope: !13)
+!58 = !DILocation(line: 13, column: 14, scope: !13)