1; RUN: opt < %s -passes="function(instcombine),sample-profile" -sample-profile-file=%S/Inputs/calls.prof | opt -passes='print<branch-prob>' -disable-output 2>&1 | FileCheck %s 2 3; Original C++ test case 4; 5; #include <stdio.h> 6; 7; int sum(int x, int y) { 8; return x + y; 9; } 10; 11; int main() { 12; int s, i = 0; 13; while (i++ < 20000 * 20000) 14; if (i != 100) s = sum(i, s); else s = 30; 15; printf("sum is %d\n", s); 16; return 0; 17; } 18; 19@.str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align 1 20 21; Function Attrs: nounwind uwtable 22define i32 @_Z3sumii(i32 %x, i32 %y) #0 !dbg !4 { 23entry: 24 %x.addr = alloca i32, align 4 25 %y.addr = alloca i32, align 4 26 store i32 %x, ptr %x.addr, align 4 27 store i32 %y, ptr %y.addr, align 4 28 %0 = load i32, ptr %x.addr, align 4, !dbg !11 29 %1 = load i32, ptr %y.addr, align 4, !dbg !11 30 %add = add nsw i32 %0, %1, !dbg !11 31 ret i32 %add, !dbg !11 32} 33 34; Function Attrs: uwtable 35define i32 @main() #0 !dbg !7 { 36entry: 37 %retval = alloca i32, align 4 38 %s = alloca i32, align 4 39 %i = alloca i32, align 4 40 store i32 0, ptr %retval 41 store i32 0, ptr %i, align 4, !dbg !12 42 br label %while.cond, !dbg !13 43 44while.cond: ; preds = %if.end, %entry 45 %0 = load i32, ptr %i, align 4, !dbg !14 46 %inc = add nsw i32 %0, 1, !dbg !14 47 store i32 %inc, ptr %i, align 4, !dbg !14 48 %cmp = icmp slt i32 %0, 400000000, !dbg !14 49 br i1 %cmp, label %while.body, label %while.end, !dbg !14 50; CHECK: edge %while.cond -> %while.body probability is 0x77f2798d / 0x80000000 = 93.71% [HOT edge] 51; CHECK: edge %while.cond -> %while.end probability is 0x080d8673 / 0x80000000 = 6.29% 52 53while.body: ; preds = %while.cond 54 %1 = load i32, ptr %i, align 4, !dbg !16 55 %cmp1 = icmp ne i32 %1, 100, !dbg !16 56 br i1 %cmp1, label %if.then, label %if.else, !dbg !16 57; Without discriminator information, the profiler used to think that 58; both branches out of while.body had the same weight. In reality, 59; the edge while.body->if.then is taken most of the time. 60; 61; CHECK: edge %while.body -> %if.else probability is 0x0005b1e0 / 0x80000000 = 0.02% 62; CHECK: edge %while.body -> %if.then probability is 0x7ffa4e20 / 0x80000000 = 99.98% [HOT edge] 63 64 65if.then: ; preds = %while.body 66 %2 = load i32, ptr %i, align 4, !dbg !18 67 %3 = load i32, ptr %s, align 4, !dbg !18 68 %call = call i32 @_Z3sumii(i32 %2, i32 %3), !dbg !18 69 store i32 %call, ptr %s, align 4, !dbg !18 70 br label %if.end, !dbg !18 71 72if.else: ; preds = %while.body 73 store i32 30, ptr %s, align 4, !dbg !20 74 br label %if.end 75 76if.end: ; preds = %if.else, %if.then 77 br label %while.cond, !dbg !22 78 79while.end: ; preds = %while.cond 80 %4 = load i32, ptr %s, align 4, !dbg !24 81 %call2 = call i32 (ptr, ...) @printf(ptr @.str, i32 %4), !dbg !24 82 ret i32 0, !dbg !25 83} 84 85declare i32 @printf(ptr, ...) #2 86 87attributes #0 = {"use-sample-profile"} 88 89!llvm.dbg.cu = !{!0} 90!llvm.module.flags = !{!8, !9} 91!llvm.ident = !{!10} 92 93!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5 ", isOptimized: false, emissionKind: NoDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2) 94!1 = !DIFile(filename: "calls.cc", directory: ".") 95!2 = !{} 96!4 = distinct !DISubprogram(name: "sum", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 3, file: !1, scope: !5, type: !6, retainedNodes: !2) 97!5 = !DIFile(filename: "calls.cc", directory: ".") 98!6 = !DISubroutineType(types: !2) 99!7 = distinct !DISubprogram(name: "main", line: 7, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 7, file: !1, scope: !5, type: !6, retainedNodes: !2) 100!8 = !{i32 2, !"Dwarf Version", i32 4} 101!9 = !{i32 1, !"Debug Info Version", i32 3} 102!10 = !{!"clang version 3.5 "} 103!11 = !DILocation(line: 4, scope: !4) 104!12 = !DILocation(line: 8, scope: !7) 105!13 = !DILocation(line: 9, scope: !7) 106!14 = !DILocation(line: 9, scope: !15) 107!15 = !DILexicalBlockFile(discriminator: 2, file: !1, scope: !7) 108!16 = !DILocation(line: 10, scope: !17) 109!17 = distinct !DILexicalBlock(line: 10, column: 0, file: !1, scope: !7) 110!18 = !DILocation(line: 10, scope: !19) 111!19 = !DILexicalBlockFile(discriminator: 2, file: !1, scope: !17) 112!20 = !DILocation(line: 10, scope: !21) 113!21 = !DILexicalBlockFile(discriminator: 4, file: !1, scope: !17) 114!22 = !DILocation(line: 10, scope: !23) 115!23 = !DILexicalBlockFile(discriminator: 6, file: !1, scope: !17) 116!24 = !DILocation(line: 11, scope: !7) 117!25 = !DILocation(line: 12, scope: !7) 118