1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py 2; RUN: opt < %s -analyze -scalar-evolution -scalar-evolution-classify-expressions=0 | FileCheck %s 3 4; Trip counts with trivial exit conditions. 5 6define void @a(i64 %n) nounwind { 7; CHECK-LABEL: 'a' 8; CHECK-NEXT: Determining loop execution counts for: @a 9; CHECK-NEXT: Loop %loop: Unpredictable backedge-taken count. 10; CHECK-NEXT: Loop %loop: Unpredictable max backedge-taken count. 11; CHECK-NEXT: Loop %loop: Unpredictable predicated backedge-taken count. 12; 13entry: 14 %t0 = icmp sgt i64 %n, 0 15 br i1 %t0, label %loop, label %return 16 17loop: 18 %i = phi i64 [ %i.next, %loop ], [ 0, %entry ] 19 %i.next = add nsw i64 %i, 1 20 %exitcond = icmp eq i64 %i.next, %n 21 br i1 false, label %return, label %loop 22 23return: 24 ret void 25} 26define void @b(i64 %n) nounwind { 27; CHECK-LABEL: 'b' 28; CHECK-NEXT: Determining loop execution counts for: @b 29; CHECK-NEXT: Loop %loop: backedge-taken count is false 30; CHECK-NEXT: Loop %loop: max backedge-taken count is false 31; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is false 32; CHECK-NEXT: Predicates: 33; CHECK: Loop %loop: Trip multiple is 1 34; 35entry: 36 %t0 = icmp sgt i64 %n, 0 37 br i1 %t0, label %loop, label %return 38 39loop: 40 %i = phi i64 [ %i.next, %loop ], [ 0, %entry ] 41 %i.next = add nsw i64 %i, 1 42 %exitcond = icmp eq i64 %i.next, %n 43 br i1 true, label %return, label %loop 44 45return: 46 ret void 47} 48define void @c(i64 %n) nounwind { 49; CHECK-LABEL: 'c' 50; CHECK-NEXT: Determining loop execution counts for: @c 51; CHECK-NEXT: Loop %loop: backedge-taken count is false 52; CHECK-NEXT: Loop %loop: max backedge-taken count is false 53; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is false 54; CHECK-NEXT: Predicates: 55; CHECK: Loop %loop: Trip multiple is 1 56; 57entry: 58 %t0 = icmp sgt i64 %n, 0 59 br i1 %t0, label %loop, label %return 60 61loop: 62 %i = phi i64 [ %i.next, %loop ], [ 0, %entry ] 63 %i.next = add nsw i64 %i, 1 64 %exitcond = icmp eq i64 %i.next, %n 65 br i1 false, label %loop, label %return 66 67return: 68 ret void 69} 70define void @d(i64 %n) nounwind { 71; CHECK-LABEL: 'd' 72; CHECK-NEXT: Determining loop execution counts for: @d 73; CHECK-NEXT: Loop %loop: Unpredictable backedge-taken count. 74; CHECK-NEXT: Loop %loop: Unpredictable max backedge-taken count. 75; CHECK-NEXT: Loop %loop: Unpredictable predicated backedge-taken count. 76; 77entry: 78 %t0 = icmp sgt i64 %n, 0 79 br i1 %t0, label %loop, label %return 80 81loop: 82 %i = phi i64 [ %i.next, %loop ], [ 0, %entry ] 83 %i.next = add nsw i64 %i, 1 84 %exitcond = icmp eq i64 %i.next, %n 85 br i1 true, label %loop, label %return 86 87return: 88 ret void 89} 90 91; Trip counts for non-polynomial iterations. It's theoretically possible 92; to compute a maximum count for these, but short of that, ScalarEvolution 93; should return unknown. 94 95; PR7416 96declare i1 @g() nounwind 97 98define void @nonpolynomial() { 99; CHECK-LABEL: 'nonpolynomial' 100; CHECK-NEXT: Determining loop execution counts for: @nonpolynomial 101; CHECK-NEXT: Loop %loophead: Unpredictable backedge-taken count. 102; CHECK-NEXT: Loop %loophead: Unpredictable max backedge-taken count. 103; CHECK-NEXT: Loop %loophead: Unpredictable predicated backedge-taken count. 104; 105entry: 106 br label %loophead 107loophead: 108 %x = phi i32 [0, %entry], [%x.1, %bb1], [%x.2, %bb2] 109 %y = icmp slt i32 %x, 100 110 br i1 %y, label %loopbody, label %retbb 111loopbody: 112 %z = call i1 @g() 113 br i1 %z, label %bb1, label %bb2 114bb1: 115 %x.1 = add i32 %x, 2 116 br label %loophead 117bb2: 118 %x.2 = add i32 %x, 3 119 br label %loophead 120retbb: 121 ret void 122} 123 124; PHI nodes with all constant operands. 125 126define void @constant_phi_operands() nounwind { 127; CHECK-LABEL: 'constant_phi_operands' 128; CHECK-NEXT: Determining loop execution counts for: @constant_phi_operands 129; CHECK-NEXT: Loop %loop: backedge-taken count is 1 130; CHECK-NEXT: Loop %loop: max backedge-taken count is 1 131; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is 1 132; CHECK-NEXT: Predicates: 133; CHECK: Loop %loop: Trip multiple is 2 134; 135entry: 136 br label %loop 137 138loop: 139 %i = phi i64 [ 1, %loop ], [ 0, %entry ] 140 %exitcond = icmp eq i64 %i, 1 141 br i1 %exitcond, label %return, label %loop 142 143return: 144 ret void 145} 146 147; PR16130: Loop exit depends on an 'or' expression. 148; One side of the expression test against a value that will be skipped. 149; We can't assume undefined behavior just because we have an NSW flag. 150; 151define void @exit_orcond_nsw(i32 *%a) nounwind { 152; CHECK-LABEL: 'exit_orcond_nsw' 153; CHECK-NEXT: Determining loop execution counts for: @exit_orcond_nsw 154; CHECK-NEXT: Loop %for.body.i: Unpredictable backedge-taken count. 155; CHECK-NEXT: Loop %for.body.i: max backedge-taken count is 1 156; CHECK-NEXT: Loop %for.body.i: Unpredictable predicated backedge-taken count. 157; 158entry: 159 br label %for.body.i 160 161for.body.i: ; preds = %for.body.i, %entry 162 %b.01.i = phi i32 [ 0, %entry ], [ %add.i, %for.body.i ] 163 %tobool.i = icmp ne i32 %b.01.i, 0 164 %add.i = add nsw i32 %b.01.i, 8 165 %cmp.i = icmp eq i32 %add.i, 13 166 %or.cond = or i1 %tobool.i, %cmp.i 167 br i1 %or.cond, label %exit, label %for.body.i 168 169exit: ; preds = %for.body.i 170 %b.01.i.lcssa = phi i32 [ %b.01.i, %for.body.i ] 171 store i32 %b.01.i.lcssa, i32* %a, align 4 172 ret void 173} 174