1 files changed, 54 insertions, 0 deletions
diff --git a/test/Transforms/LoopLoadElim/unknown-dep.ll b/test/Transforms/LoopLoadElim/unknown-dep.ll
new file mode 100644
index 000000000000..d2df718ca4c3
--- /dev/null
+++ b/test/Transforms/LoopLoadElim/unknown-dep.ll
@@ -0,0 +1,54 @@
+; RUN: opt -basicaa -loop-load-elim -S < %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+; Give up in the presence of unknown deps. Here, the different strides result
+; in unknown dependence:
+;
+;   for (unsigned i = 0; i < 100; i++) {
+;     A[i+1] = B[i] + 2;
+;     A[2*i] = C[i] + 2;
+;     D[i] = A[i] + 2;
+;   }
+
+define void @f(i32* noalias %A, i32* noalias %B, i32* noalias %C,
+               i32* noalias %D, i64 %N) {
+
+entry:
+; for.body.ph:
+; CHECK-NOT: %load_initial =
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+; CHECK-NOT: %store_forwarded =
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+
+  %Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
+  %Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
+  %Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
+  %Didx = getelementptr inbounds i32, i32* %D, i64 %indvars.iv
+  %Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
+  %indvars.m2 = mul nuw nsw i64 %indvars.iv, 2
+  %A2idx = getelementptr inbounds i32, i32* %A, i64 %indvars.m2
+
+  %b = load i32, i32* %Bidx, align 4
+  %a_p1 = add i32 %b, 2
+  store i32 %a_p1, i32* %Aidx_next, align 4
+
+  %c = load i32, i32* %Cidx, align 4
+  %a_m2 = add i32 %c, 2
+  store i32 %a_m2, i32* %A2idx, align 4
+
+  %a = load i32, i32* %Aidx, align 4
+; CHECK-NOT: %d = add i32 %store_forwarded, 2
+; CHECK: %d = add i32 %a, 2
+  %d = add i32 %a, 2
+  store i32 %d, i32* %Didx, align 4
+
+  %exitcond = icmp eq i64 %indvars.iv.next, %N
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret void
+}