; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/discriminator.prof | opt -analyze -branch-prob | FileCheck %s ; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/discriminator.prof | opt -analyze -branch-prob | FileCheck %s ; Original code ; ; 1 int foo(int i) { ; 2 int x = 0; ; 3 while (i < 100) { ; 4 if (i < 5) x--; ; 5 i++; ; 6 } ; 7 return x; ; 8 } ; ; In this test, if the loop is executed 100 times, the decrement operation ; at line 4 should only execute 5 times. This is reflected in the profile ; data for line offset 3. In Inputs/discriminator.prof, we have: ; ; 3: 100 ; 3.1: 5 ; ; This means that the predicate 'i < 5' (line 3) is executed 100 times, ; but the then branch (line 3.1) is only executed 5 times. define i32 @foo(i32 %i) #0 !dbg !4 { ; CHECK: Printing analysis 'Branch Probability Analysis' for function 'foo': entry: %i.addr = alloca i32, align 4 %x = alloca i32, align 4 store i32 %i, i32* %i.addr, align 4 store i32 0, i32* %x, align 4, !dbg !10 br label %while.cond, !dbg !11 while.cond: ; preds = %if.end, %entry %0 = load i32, i32* %i.addr, align 4, !dbg !12 %cmp = icmp slt i32 %0, 100, !dbg !12 br i1 %cmp, label %while.body, label %while.end, !dbg !12 ; CHECK: edge while.cond -> while.body probability is 0x7ebb907a / 0x80000000 = 99.01% [HOT edge] ; CHECK: edge while.cond -> while.end probability is 0x01446f86 / 0x80000000 = 0.99% while.body: ; preds = %while.cond %1 = load i32, i32* %i.addr, align 4, !dbg !14 %cmp1 = icmp slt i32 %1, 50, !dbg !14 br i1 %cmp1, label %if.then, label %if.end, !dbg !14 ; CHECK: edge while.body -> if.then probability is 0x06666666 / 0x80000000 = 5.00% ; CHECK: edge while.body -> if.end probability is 0x7999999a / 0x80000000 = 95.00% [HOT edge] if.then: ; preds = %while.body %2 = load i32, i32* %x, align 4, !dbg !17 %dec = add nsw i32 %2, -1, !dbg !17 store i32 %dec, i32* %x, align 4, !dbg !17 br label %if.end, !dbg !17 if.end: ; preds = %if.then, %while.body %3 = load i32, i32* %i.addr, align 4, !dbg !19 %inc = add nsw i32 %3, 1, !dbg !19 store i32 %inc, i32* %i.addr, align 4, !dbg !19 br label %while.cond, !dbg !20 while.end: ; preds = %while.cond %4 = load i32, i32* %x, align 4, !dbg !21 ret i32 %4, !dbg !21 } !llvm.dbg.cu = !{!0} !llvm.module.flags = !{!7, !8} !llvm.ident = !{!9} !0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.5 ", isOptimized: false, emissionKind: NoDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2) !1 = !DIFile(filename: "discriminator.c", directory: ".") !2 = !{} !4 = distinct !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2) !5 = !DIFile(filename: "discriminator.c", directory: ".") !6 = !DISubroutineType(types: !2) !7 = !{i32 2, !"Dwarf Version", i32 4} !8 = !{i32 1, !"Debug Info Version", i32 3} !9 = !{!"clang version 3.5 "} !10 = !DILocation(line: 2, scope: !4) !11 = !DILocation(line: 3, scope: !4) !12 = !DILocation(line: 3, scope: !13) !13 = !DILexicalBlockFile(discriminator: 1, file: !1, scope: !4) !14 = !DILocation(line: 4, scope: !15) !15 = distinct !DILexicalBlock(line: 4, column: 0, file: !1, scope: !16) !16 = distinct !DILexicalBlock(line: 3, column: 0, file: !1, scope: !4) !17 = !DILocation(line: 4, scope: !18) !18 = !DILexicalBlockFile(discriminator: 1, file: !1, scope: !15) !19 = !DILocation(line: 5, scope: !16) !20 = !DILocation(line: 6, scope: !16) !21 = !DILocation(line: 7, scope: !4)