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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 %s2 3; Original C++ test case4;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 120 21; Function Attrs: nounwind uwtable22define i32 @_Z3sumii(i32 %x, i32 %y) #0 !dbg !4 {23entry:24 %x.addr = alloca i32, align 425 %y.addr = alloca i32, align 426 store i32 %x, ptr %x.addr, align 427 store i32 %y, ptr %y.addr, align 428 %0 = load i32, ptr %x.addr, align 4, !dbg !1129 %1 = load i32, ptr %y.addr, align 4, !dbg !1130 %add = add nsw i32 %0, %1, !dbg !1131 ret i32 %add, !dbg !1132}33 34; Function Attrs: uwtable35define i32 @main() #0 !dbg !7 {36entry:37 %retval = alloca i32, align 438 %s = alloca i32, align 439 %i = alloca i32, align 440 store i32 0, ptr %retval41 store i32 0, ptr %i, align 4, !dbg !1242 br label %while.cond, !dbg !1343 44while.cond: ; preds = %if.end, %entry45 %0 = load i32, ptr %i, align 4, !dbg !1446 %inc = add nsw i32 %0, 1, !dbg !1447 store i32 %inc, ptr %i, align 4, !dbg !1448 %cmp = icmp slt i32 %0, 400000000, !dbg !1449 br i1 %cmp, label %while.body, label %while.end, !dbg !1450; 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.cond54 %1 = load i32, ptr %i, align 4, !dbg !1655 %cmp1 = icmp ne i32 %1, 100, !dbg !1656 br i1 %cmp1, label %if.then, label %if.else, !dbg !1657; Without discriminator information, the profiler used to think that58; 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.body66 %2 = load i32, ptr %i, align 4, !dbg !1867 %3 = load i32, ptr %s, align 4, !dbg !1868 %call = call i32 @_Z3sumii(i32 %2, i32 %3), !dbg !1869 store i32 %call, ptr %s, align 4, !dbg !1870 br label %if.end, !dbg !1871 72if.else: ; preds = %while.body73 store i32 30, ptr %s, align 4, !dbg !2074 br label %if.end75 76if.end: ; preds = %if.else, %if.then77 br label %while.cond, !dbg !2278 79while.end: ; preds = %while.cond80 %4 = load i32, ptr %s, align 4, !dbg !2481 %call2 = call i32 (ptr, ...) @printf(ptr @.str, i32 %4), !dbg !2482 ret i32 0, !dbg !2583}84 85declare i32 @printf(ptr, ...) #286 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