1 ; RUN: opt < %s -lcssa -loop-simplify -indvars -S | FileCheck %s 2 target triple = "x86_64-unknown-linux-gnu" 3 4 ; PR28272, PR28825 5 ; When LoopSimplify separates nested loops, it might break LCSSA form: values 6 ; from the original loop might be used in the outer loop. This test invokes 7 ; loop-unroll, which calls loop-simplify before itself. If LCSSA is broken 8 ; after loop-simplify, we crash on assertion. 9 10 ; CHECK-LABEL: @foo 11 define void @foo() { 12 entry: 13 br label %header 14 15 header: 16 br label %loop1 17 18 loop1: 19 br i1 true, label %loop1, label %bb43 20 21 bb43: 22 %a = phi i32 [ undef, %loop1 ], [ 0, %bb45 ], [ %a, %bb54 ] 23 %b = phi i32 [ 0, %loop1 ], [ 1, %bb54 ], [ %c, %bb45 ] 24 br i1 true, label %bb114, label %header 25 26 bb114: 27 %c = add i32 0, 1 28 %d = add i32 0, 1 29 br i1 true, label %bb45, label %bb54 30 31 bb45: 32 %x = add i32 %d, 0 33 br label %bb43 34 35 bb54: 36 br label %bb43 37 } 38 39 ; CHECK-LABEL: @foo2 40 define void @foo2() { 41 entry: 42 br label %outer 43 44 outer.loopexit: 45 br label %outer 46 47 outer: 48 br label %loop1 49 50 loop1: 51 br i1 true, label %loop1, label %loop2.preheader 52 53 loop2.preheader: 54 %a.ph = phi i32 [ undef, %loop1 ] 55 %b.ph = phi i32 [ 0, %loop1 ] 56 br label %loop2 57 58 loop2: 59 %a = phi i32 [ 0, %loop2.if.true ], [ %a, %loop2.if.false ], [ %a.ph, %loop2.preheader ], [0, %bb] 60 %b = phi i32 [ 1, %loop2.if.false ], [ %c, %loop2.if.true ], [ %b.ph, %loop2.preheader ], [%c, %bb] 61 br i1 true, label %loop2.if, label %outer.loopexit 62 63 loop2.if: 64 %c = add i32 0, 1 65 switch i32 undef, label %loop2.if.false [i32 0, label %loop2.if.true 66 i32 1, label %bb] 67 68 loop2.if.true: 69 br i1 undef, label %loop2, label %bb 70 71 loop2.if.false: 72 br label %loop2 73 74 bb: 75 br label %loop2 76 } 77 78 ; When LoopSimplify separates nested loops, it might break LCSSA form: values 79 ; from the original loop might be used in exit blocks of the outer loop. 80 ; CHECK-LABEL: @foo3 81 define void @foo3() { 82 entry: 83 br label %bb1 84 85 bb1: 86 br i1 undef, label %bb2, label %bb1 87 88 bb2: 89 %a = phi i32 [ undef, %bb1 ], [ %a, %bb3 ], [ undef, %bb5 ] 90 br i1 undef, label %bb3, label %bb1 91 92 bb3: 93 %b = load i32*, i32** undef 94 br i1 undef, label %bb2, label %bb4 95 96 bb4: 97 br i1 undef, label %bb5, label %bb6 98 99 bb5: 100 br i1 undef, label %bb2, label %bb4 101 102 bb6: 103 br i1 undef, label %bb_end, label %bb1 104 105 bb_end: 106 %x = getelementptr i32, i32* %b 107 br label %bb_end 108 } 109 110 ; When LoopSimplify separates nested loops, it might break LCSSA form: values 111 ; from the original loop might occur in a loop, which is now a sibling of the 112 ; original loop (before separating it was a subloop of the original loop, and 113 ; thus didn't require an lcssa phi nodes). 114 ; CHECK-LABEL: @foo4 115 define void @foo4() { 116 bb1: 117 br label %bb2 118 119 ; CHECK: bb2.loopexit: 120 bb2.loopexit: ; preds = %bb3 121 %i.ph = phi i32 [ 0, %bb3 ] 122 br label %bb2 123 124 ; CHECK: bb2.outer: 125 ; CHECK: bb2: 126 bb2: ; preds = %bb2.loopexit, %bb2, %bb1 127 %i = phi i32 [ 0, %bb1 ], [ %i, %bb2 ], [ %i.ph, %bb2.loopexit ] 128 %x = load i32, i32* undef, align 8 129 br i1 undef, label %bb2, label %bb3.preheader 130 131 ; CHECK: bb3.preheader: 132 bb3.preheader: ; preds = %bb2 133 ; CHECK: %x.lcssa = phi i32 [ %x, %bb2 ] 134 br label %bb3 135 136 bb3: ; preds = %bb3.preheader, %bb3 137 %y = add i32 2, %x 138 br i1 true, label %bb2.loopexit, label %bb3 139 } 140
