1; RUN: opt < %s -analyze -basicaa -lda | FileCheck %s 2 3@x = common global [256 x i32] zeroinitializer, align 4 4@y = common global [256 x i32] zeroinitializer, align 4 5 6;; for (i = 0; i < 256; i++) 7;; x[i] = x[255 - i] + y[i] 8 9define void @f1(...) nounwind { 10entry: 11 br label %for.body 12 13for.body: 14 %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ] 15 %i.255 = sub i64 255, %i 16 %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i 17 %x.ld.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i.255 18 %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i 19 %x = load i32* %x.ld.addr ; 0 20 %y = load i32* %y.ld.addr ; 1 21 %r = add i32 %y, %x 22 store i32 %r, i32* %x.st.addr ; 2 23; CHECK: 0,2: dep 24; CHECK: 1,2: ind 25 %i.next = add i64 %i, 1 26 %exitcond = icmp eq i64 %i.next, 256 27 br i1 %exitcond, label %for.end, label %for.body 28 29for.end: 30 ret void 31} 32 33;; for (i = 0; i < 100; i++) 34;; x[i] = x[255 - i] + y[i] 35 36define void @f2(...) nounwind { 37entry: 38 br label %for.body 39 40for.body: 41 %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ] 42 %i.255 = sub i64 255, %i 43 %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i 44 %x.ld.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i.255 45 %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i 46 %x = load i32* %x.ld.addr ; 0 47 %y = load i32* %y.ld.addr ; 1 48 %r = add i32 %y, %x 49 store i32 %r, i32* %x.st.addr ; 2 50; CHECK: 0,2: dep 51; CHECK: 1,2: ind 52 %i.next = add i64 %i, 1 53 %exitcond = icmp eq i64 %i.next, 100 54 br i1 %exitcond, label %for.end, label %for.body 55 56for.end: 57 ret void 58} 59 60;; // the first iteration (i=0) leads to an out-of-bounds access of x. as the 61;; // result of this access is undefined, _any_ dependence result is safe. 62;; for (i = 0; i < 256; i++) 63;; x[i] = x[256 - i] + y[i] 64 65define void @f3(...) nounwind { 66entry: 67 br label %for.body 68 69for.body: 70 %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ] 71 %i.256 = sub i64 0, %i 72 %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i 73 %x.ld.addr = getelementptr [256 x i32]* @x, i64 1, i64 %i.256 74 %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i 75 %x = load i32* %x.ld.addr ; 0 76 %y = load i32* %y.ld.addr ; 1 77 %r = add i32 %y, %x 78 store i32 %r, i32* %x.st.addr ; 2 79; CHECK: 0,2: dep 80; CHECK: 1,2: 81 %i.next = add i64 %i, 1 82 %exitcond = icmp eq i64 %i.next, 256 83 br i1 %exitcond, label %for.end, label %for.body 84 85for.end: 86 ret void 87} 88 89;; // slightly contrived but valid IR for the following loop, where all 90;; // accesses in all iterations are within bounds. while this example's first 91;; // (ZIV-)subscript is (0, 1), accesses are dependent. 92;; for (i = 1; i < 256; i++) 93;; x[i] = x[256 - i] + y[i] 94 95define void @f4(...) nounwind { 96entry: 97 br label %for.body 98 99for.body: 100 %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ] 101 %i.1 = add i64 1, %i 102 %i.256 = sub i64 -1, %i 103 %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i.1 104 %x.ld.addr = getelementptr [256 x i32]* @x, i64 1, i64 %i.256 105 %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i.1 106 %x = load i32* %x.ld.addr ; 0 107 %y = load i32* %y.ld.addr ; 1 108 %r = add i32 %y, %x 109 store i32 %r, i32* %x.st.addr ; 2 110; CHECK: 0,2: dep 111; CHECK: 1,2: ind 112 %i.next = add i64 %i, 1 113 %exitcond = icmp eq i64 %i.next, 256 114 br i1 %exitcond, label %for.end, label %for.body 115 116for.end: 117 ret void 118} 119