; RUN: opt < %s -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 { ; 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 100 / 101 = 99.0099% [HOT edge] ; CHECK: edge while.cond -> while.end probability is 1 / 101 = 0.990099% 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 5 / 100 = 5% ; CHECK: edge while.body -> if.end probability is 95 / 100 = 95% [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 = !{!"0x11\0012\00clang version 3.5 \000\00\000\00\000", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [discriminator.c] [DW_LANG_C99] !1 = !{!"discriminator.c", !"."} !2 = !{} !3 = !{!4} !4 = !{!"0x2e\00foo\00foo\00\001\000\001\000\006\00256\000\001", !1, !5, !6, null, i32 (i32)* @foo, null, null, !2} ; [ DW_TAG_subprogram ] [line 1] [def] [foo] !5 = !{!"0x29", !1} ; [ DW_TAG_file_type ] [discriminator.c] !6 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, !2, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ] !7 = !{i32 2, !"Dwarf Version", i32 4} !8 = !{i32 1, !"Debug Info Version", i32 2} !9 = !{!"clang version 3.5 "} !10 = !MDLocation(line: 2, scope: !4) !11 = !MDLocation(line: 3, scope: !4) !12 = !MDLocation(line: 3, scope: !13) !13 = !{!"0xb\001", !1, !4} ; [ DW_TAG_lexical_block ] [discriminator.c] !14 = !MDLocation(line: 4, scope: !15) !15 = !{!"0xb\004\000\001", !1, !16} ; [ DW_TAG_lexical_block ] [discriminator.c] !16 = !{!"0xb\003\000\000", !1, !4} ; [ DW_TAG_lexical_block ] [discriminator.c] !17 = !MDLocation(line: 4, scope: !18) !18 = !{!"0xb\001", !1, !15} ; [ DW_TAG_lexical_block ] [discriminator.c] !19 = !MDLocation(line: 5, scope: !16) !20 = !MDLocation(line: 6, scope: !16) !21 = !MDLocation(line: 7, scope: !4)