1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; Test CFG simplify removal of branch instructions. 3; 4; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s 5; RUN: opt < %s -passes=simplifycfg -S | FileCheck %s 6 7define void @test1() { 8; CHECK-LABEL: @test1( 9; CHECK-NEXT: ret void 10; 11 br label %1 12 ret void 13} 14 15define void @test2() { 16; CHECK-LABEL: @test2( 17; CHECK-NEXT: ret void 18; 19 ret void 20 ret void 21} 22 23define void @test3(i1 %T) { 24; CHECK-LABEL: @test3( 25; CHECK-NEXT: ret void 26; 27 br i1 %T, label %1, label %1 28 ret void 29} 30 31; Folding branch to a common destination. 32define void @test4_fold(i32 %a, i32 %b) { 33; CHECK-LABEL: @test4_fold( 34; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[A:%.*]], [[B:%.*]] 35; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i32 [[A]], 0 36; CHECK-NEXT: [[OR_COND:%.*]] = and i1 [[CMP1]], [[CMP2]] 37; CHECK-NEXT: br i1 [[OR_COND]], label [[ELSE:%.*]], label [[COMMON_RET:%.*]] 38; CHECK: common.ret: 39; CHECK-NEXT: ret void 40; CHECK: else: 41; CHECK-NEXT: call void @foo() 42; CHECK-NEXT: br label [[COMMON_RET]] 43; 44 %cmp1 = icmp eq i32 %a, %b 45 br i1 %cmp1, label %taken, label %untaken 46 47taken: 48 %cmp2 = icmp ugt i32 %a, 0 49 br i1 %cmp2, label %else, label %untaken 50 51else: 52 call void @foo() 53 ret void 54 55untaken: 56 ret void 57} 58 59; Prefer a simplification based on a dominating condition rather than folding a 60; branch to a common destination. 61define void @test4_no_fold(i32 %a, i32 %b) { 62; CHECK-LABEL: @test4_no_fold( 63; CHECK-NEXT: untaken: 64; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[A:%.*]], [[B:%.*]] 65; CHECK-NEXT: ret void 66; 67 %cmp1 = icmp eq i32 %a, %b 68 br i1 %cmp1, label %taken, label %untaken 69 70taken: 71 %cmp2 = icmp ugt i32 %a, %b 72 br i1 %cmp2, label %else, label %untaken 73 74else: 75 call void @foo() 76 ret void 77 78untaken: 79 ret void 80} 81 82declare void @foo() 83 84; PR5795 85define void @test5(i32 %A) { 86; CHECK-LABEL: @test5( 87; CHECK-NEXT: common.ret: 88; CHECK-NEXT: ret void 89; 90 switch i32 %A, label %return [ 91 i32 2, label %1 92 i32 10, label %2 93 ] 94 95 ret void 96 97 ret void 98 99return: ; preds = %entry 100 ret void 101} 102 103 104; PR14893 105define i8 @test6f() { 106; CHECK-LABEL: @test6f( 107; CHECK-NEXT: bb0: 108; CHECK-NEXT: [[R:%.*]] = alloca i8, align 1 109; CHECK-NEXT: [[TMP:%.*]] = call i8 @test6g(ptr [[R]]) 110; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 [[TMP]], 0 111; CHECK-NEXT: [[TMP3:%.*]] = load i8, ptr [[R]], align 1, !range [[RNG5:![0-9]+]] 112; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i8 [[TMP3]], 1 113; CHECK-NEXT: [[OR_COND:%.*]] = select i1 [[TMP1]], i1 true, i1 [[TMP4]] 114; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[OR_COND]], i8 0, i8 1 115; CHECK-NEXT: ret i8 [[TMP6]] 116; 117 118bb0: 119 %r = alloca i8, align 1 120 %tmp = call i8 @test6g(ptr %r) 121 %tmp1 = icmp eq i8 %tmp, 0 122 br i1 %tmp1, label %bb2, label %bb1 123bb1: 124 %tmp3 = load i8, ptr %r, align 1, !range !2, !tbaa !10, !dbg !5 125 %tmp4 = icmp eq i8 %tmp3, 1 126 br i1 %tmp4, label %bb2, label %bb3 127bb2: 128 br label %bb3 129bb3: 130 %tmp6 = phi i8 [ 0, %bb2 ], [ 1, %bb1 ] 131 ret i8 %tmp6 132} 133declare i8 @test6g(ptr) 134 135!llvm.dbg.cu = !{!3} 136!llvm.module.flags = !{!8, !9} 137 138!0 = !{!10, !10, i64 0} 139!1 = !{!"foo"} 140!2 = !{i8 0, i8 2} 141!3 = distinct !DICompileUnit(language: DW_LANG_C99, file: !7, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !4) 142!4 = !{} 143!5 = !DILocation(line: 23, scope: !6) 144!6 = distinct !DISubprogram(name: "foo", scope: !3, file: !7, line: 1, type: !DISubroutineType(types: !4), isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, unit: !3, retainedNodes: !4) 145!7 = !DIFile(filename: "foo.c", directory: "/") 146!8 = !{i32 2, !"Dwarf Version", i32 2} 147!9 = !{i32 2, !"Debug Info Version", i32 3} 148!10 = !{!"scalar type", !1} 149