1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt -S -loop-unroll %s | FileCheck %s 3 4; In both cases, we have one unpredictable exit and one IV-based exit with 5; known trip count. We can fully unroll against the latter. In one of the 6; examples the IV-based exit is the latch exit, in the other the non-latch 7; exit. After full unrolling, the functions fold to ret i1 true. 8 9define i1 @test_latch() { 10; CHECK-LABEL: @test_latch( 11; CHECK-NEXT: start: 12; CHECK-NEXT: [[A1:%.*]] = alloca [2 x i64], align 8 13; CHECK-NEXT: [[A2:%.*]] = alloca [2 x i64], align 8 14; CHECK-NEXT: [[A1_0:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 0 15; CHECK-NEXT: store i64 -5015437470765251660, i64* [[A1_0]], align 8 16; CHECK-NEXT: [[A1_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 1 17; CHECK-NEXT: store i64 -8661621401413125213, i64* [[A1_1]], align 8 18; CHECK-NEXT: [[A2_0:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 0 19; CHECK-NEXT: store i64 -5015437470765251660, i64* [[A2_0]], align 8 20; CHECK-NEXT: [[A2_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 1 21; CHECK-NEXT: store i64 -8661621401413125213, i64* [[A2_1]], align 8 22; CHECK-NEXT: br label [[LOOP:%.*]] 23; CHECK: loop: 24; CHECK-NEXT: [[GEP1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 0 25; CHECK-NEXT: [[GEP2:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 0 26; CHECK-NEXT: [[LOAD1:%.*]] = load i64, i64* [[GEP1]], align 8 27; CHECK-NEXT: [[LOAD2:%.*]] = load i64, i64* [[GEP2]], align 8 28; CHECK-NEXT: [[EXITCOND2:%.*]] = icmp eq i64 [[LOAD1]], [[LOAD2]] 29; CHECK-NEXT: br i1 [[EXITCOND2]], label [[LATCH:%.*]], label [[EXIT:%.*]] 30; CHECK: latch: 31; CHECK-NEXT: [[GEP1_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 1 32; CHECK-NEXT: [[GEP2_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 1 33; CHECK-NEXT: [[LOAD1_1:%.*]] = load i64, i64* [[GEP1_1]], align 8 34; CHECK-NEXT: [[LOAD2_1:%.*]] = load i64, i64* [[GEP2_1]], align 8 35; CHECK-NEXT: [[EXITCOND2_1:%.*]] = icmp eq i64 [[LOAD1_1]], [[LOAD2_1]] 36; CHECK-NEXT: br i1 [[EXITCOND2_1]], label [[LATCH_1:%.*]], label [[EXIT]] 37; CHECK: exit: 38; CHECK-NEXT: [[EXIT_VAL:%.*]] = phi i1 [ false, [[LOOP]] ], [ false, [[LATCH]] ], [ true, [[LATCH_1]] ] 39; CHECK-NEXT: ret i1 [[EXIT_VAL]] 40; CHECK: latch.1: 41; CHECK-NEXT: br label [[EXIT]] 42; 43start: 44 %a1 = alloca [2 x i64], align 8 45 %a2 = alloca [2 x i64], align 8 46 %a1.0 = getelementptr inbounds [2 x i64], [2 x i64]* %a1, i64 0, i64 0 47 store i64 -5015437470765251660, i64* %a1.0, align 8 48 %a1.1 = getelementptr inbounds [2 x i64], [2 x i64]* %a1, i64 0, i64 1 49 store i64 -8661621401413125213, i64* %a1.1, align 8 50 %a2.0 = getelementptr inbounds [2 x i64], [2 x i64]* %a2, i64 0, i64 0 51 store i64 -5015437470765251660, i64* %a2.0, align 8 52 %a2.1 = getelementptr inbounds [2 x i64], [2 x i64]* %a2, i64 0, i64 1 53 store i64 -8661621401413125213, i64* %a2.1, align 8 54 br label %loop 55 56loop: 57 %iv = phi i64 [ 0, %start ], [ %iv.next, %latch ] 58 %gep1 = getelementptr inbounds [2 x i64], [2 x i64]* %a1, i64 0, i64 %iv 59 %gep2 = getelementptr inbounds [2 x i64], [2 x i64]* %a2, i64 0, i64 %iv 60 %load1 = load i64, i64* %gep1, align 8 61 %load2 = load i64, i64* %gep2, align 8 62 %exitcond2 = icmp eq i64 %load1, %load2 63 br i1 %exitcond2, label %latch, label %exit 64 65latch: 66 %iv.next = add nuw nsw i64 %iv, 1 67 %exitcond = icmp eq i64 %iv.next, 2 68 br i1 %exitcond, label %exit, label %loop 69 70exit: 71 %exit.val = phi i1 [ true, %latch ], [ false, %loop ] 72 ret i1 %exit.val 73} 74 75define i1 @test_non_latch() { 76; CHECK-LABEL: @test_non_latch( 77; CHECK-NEXT: start: 78; CHECK-NEXT: [[A1:%.*]] = alloca [2 x i64], align 8 79; CHECK-NEXT: [[A2:%.*]] = alloca [2 x i64], align 8 80; CHECK-NEXT: [[A1_0:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 0 81; CHECK-NEXT: store i64 -5015437470765251660, i64* [[A1_0]], align 8 82; CHECK-NEXT: [[A1_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 1 83; CHECK-NEXT: store i64 -8661621401413125213, i64* [[A1_1]], align 8 84; CHECK-NEXT: [[A2_0:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 0 85; CHECK-NEXT: store i64 -5015437470765251660, i64* [[A2_0]], align 8 86; CHECK-NEXT: [[A2_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 1 87; CHECK-NEXT: store i64 -8661621401413125213, i64* [[A2_1]], align 8 88; CHECK-NEXT: br label [[LOOP:%.*]] 89; CHECK: loop: 90; CHECK-NEXT: br label [[LATCH:%.*]] 91; CHECK: latch: 92; CHECK-NEXT: [[GEP1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 0 93; CHECK-NEXT: [[GEP2:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 0 94; CHECK-NEXT: [[LOAD1:%.*]] = load i64, i64* [[GEP1]], align 8 95; CHECK-NEXT: [[LOAD2:%.*]] = load i64, i64* [[GEP2]], align 8 96; CHECK-NEXT: [[EXITCOND2:%.*]] = icmp eq i64 [[LOAD1]], [[LOAD2]] 97; CHECK-NEXT: br i1 [[EXITCOND2]], label [[LOOP_1:%.*]], label [[EXIT:%.*]] 98; CHECK: exit: 99; CHECK-NEXT: [[EXIT_VAL:%.*]] = phi i1 [ false, [[LATCH]] ], [ false, [[LATCH_1:%.*]] ], [ true, [[LOOP_2:%.*]] ], [ false, [[LATCH_2:%.*]] ] 100; CHECK-NEXT: ret i1 [[EXIT_VAL]] 101; CHECK: loop.1: 102; CHECK-NEXT: br label [[LATCH_1]] 103; CHECK: latch.1: 104; CHECK-NEXT: [[GEP1_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A1]], i64 0, i64 1 105; CHECK-NEXT: [[GEP2_1:%.*]] = getelementptr inbounds [2 x i64], [2 x i64]* [[A2]], i64 0, i64 1 106; CHECK-NEXT: [[LOAD1_1:%.*]] = load i64, i64* [[GEP1_1]], align 8 107; CHECK-NEXT: [[LOAD2_1:%.*]] = load i64, i64* [[GEP2_1]], align 8 108; CHECK-NEXT: [[EXITCOND2_1:%.*]] = icmp eq i64 [[LOAD1_1]], [[LOAD2_1]] 109; CHECK-NEXT: br i1 [[EXITCOND2_1]], label [[LOOP_2]], label [[EXIT]] 110; CHECK: loop.2: 111; CHECK-NEXT: br i1 true, label [[EXIT]], label [[LATCH_2]] 112; CHECK: latch.2: 113; CHECK-NEXT: br label [[EXIT]] 114; 115start: 116 %a1 = alloca [2 x i64], align 8 117 %a2 = alloca [2 x i64], align 8 118 %a1.0 = getelementptr inbounds [2 x i64], [2 x i64]* %a1, i64 0, i64 0 119 store i64 -5015437470765251660, i64* %a1.0, align 8 120 %a1.1 = getelementptr inbounds [2 x i64], [2 x i64]* %a1, i64 0, i64 1 121 store i64 -8661621401413125213, i64* %a1.1, align 8 122 %a2.0 = getelementptr inbounds [2 x i64], [2 x i64]* %a2, i64 0, i64 0 123 store i64 -5015437470765251660, i64* %a2.0, align 8 124 %a2.1 = getelementptr inbounds [2 x i64], [2 x i64]* %a2, i64 0, i64 1 125 store i64 -8661621401413125213, i64* %a2.1, align 8 126 br label %loop 127 128loop: 129 %iv = phi i64 [ 0, %start ], [ %iv.next, %latch ] 130 %exitcond = icmp eq i64 %iv, 2 131 br i1 %exitcond, label %exit, label %latch 132 133latch: 134 %iv.next = add nuw nsw i64 %iv, 1 135 %gep1 = getelementptr inbounds [2 x i64], [2 x i64]* %a1, i64 0, i64 %iv 136 %gep2 = getelementptr inbounds [2 x i64], [2 x i64]* %a2, i64 0, i64 %iv 137 %load1 = load i64, i64* %gep1, align 8 138 %load2 = load i64, i64* %gep2, align 8 139 %exitcond2 = icmp eq i64 %load1, %load2 140 br i1 %exitcond2, label %loop, label %exit 141 142exit: 143 %exit.val = phi i1 [ false, %latch ], [ true, %loop ] 144 ret i1 %exit.val 145} 146