1 ; RUN: opt -basicaa -loop-distribute -S < %s | FileCheck %s 2 3 ; When emitting the memchecks for: 4 ; 5 ; for (i = 0; i < n; i++) { 6 ; A[i + 1] = A[i] * B[i]; 7 ; ======================= 8 ; C[i] = D[i] * E[i]; 9 ; } 10 ; 11 ; we had a bug when expanding the bounds for A and C. These are expanded 12 ; multiple times and rely on the caching in SCEV expansion to avoid any 13 ; redundancy. However, due to logic in SCEVExpander::ReuseOrCreateCast, we 14 ; can get earlier expanded values invalidated when casts are used. This test 15 ; ensure that we are not using the invalidated values. 16 17 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" 18 19 define void @f(i32* %a1, i32* %a2, 20 i32* %b, 21 i32* %c1, i32* %c2, 22 i32* %d, 23 i32* %e) { 24 entry: 25 26 %cond = icmp eq i32* %e, null 27 br i1 %cond, label %one, label %two 28 one: 29 br label %join 30 two: 31 br label %join 32 join: 33 34 ; The pointers need to be defined by PHIs in order for the bug to trigger. 35 ; Because of the PHIs the existing casts won't be at the desired location so a 36 ; new cast will be emitted and the old cast will get invalidated. 37 ; 38 ; These are the steps: 39 ; 40 ; 1. After the bounds for A and C are first expanded: 41 ; 42 ; join: 43 ; %a = phi i32* [ %a1, %one ], [ %a2, %two ] 44 ; %c = phi i32* [ %c1, %one ], [ %c2, %two ] 45 ; %c5 = bitcast i32* %c to i8* 46 ; %a3 = bitcast i32* %a to i8* 47 ; 48 ; 2. After A is expanded again: 49 ; 50 ; join: ; preds = %two, %one 51 ; %a = phi i32* [ %a1, %one ], [ %a2, %two ] 52 ; %c = phi i32* [ %c1, %one ], [ %c2, %two ] 53 ; %a3 = bitcast i32* %a to i8* <--- new 54 ; %c5 = bitcast i32* %c to i8* 55 ; %0 = bitcast i32* undef to i8* <--- old, invalidated 56 ; 57 ; 3. Finally, when C is expanded again: 58 ; 59 ; join: ; preds = %two, %one 60 ; %a = phi i32* [ %a1, %one ], [ %a2, %two ] 61 ; %c = phi i32* [ %c1, %one ], [ %c2, %two ] 62 ; %c5 = bitcast i32* %c to i8* <--- new 63 ; %a3 = bitcast i32* %a to i8* 64 ; %0 = bitcast i32* undef to i8* <--- old, invalidated 65 ; %1 = bitcast i32* undef to i8* 66 67 %a = phi i32* [%a1, %one], [%a2, %two] 68 %c = phi i32* [%c1, %one], [%c2, %two] 69 br label %for.body 70 71 72 ; CHECK: [[VALUE:%[0-9a-z]+]] = bitcast i32* undef to i8* 73 ; CHECK-NOT: [[VALUE]] 74 75 for.body: ; preds = %for.body, %entry 76 %ind = phi i64 [ 0, %join ], [ %add, %for.body ] 77 78 %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind 79 %loadA = load i32, i32* %arrayidxA, align 4 80 81 %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind 82 %loadB = load i32, i32* %arrayidxB, align 4 83 84 %mulA = mul i32 %loadB, %loadA 85 86 %add = add nuw nsw i64 %ind, 1 87 %arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add 88 store i32 %mulA, i32* %arrayidxA_plus_4, align 4 89 90 %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind 91 %loadD = load i32, i32* %arrayidxD, align 4 92 93 %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind 94 %loadE = load i32, i32* %arrayidxE, align 4 95 96 %mulC = mul i32 %loadD, %loadE 97 98 %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind 99 store i32 %mulC, i32* %arrayidxC, align 4 100 101 %exitcond = icmp eq i64 %add, 20 102 br i1 %exitcond, label %for.end, label %for.body 103 104 for.end: ; preds = %for.body 105 ret void 106 } 107
