[LLE] New test to check that no versioning for symbolic strides occurs. NFC

This is currently only performed in the Vectorizer.  I will change this
as symbolic stride collection is moved to LAA.

This test will track when the actual functional change occurs.

llvm-svn: 272918

1 files changed, 35 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopLoadElim/symbolic-stride.ll b/llvm/test/Transforms/LoopLoadElim/symbolic-stride.ll
new file mode 100644
index 00000000000..a0fc7e6749e
--- /dev/null
+++ b/llvm/test/Transforms/LoopLoadElim/symbolic-stride.ll
@@ -0,0 +1,35 @@
+; RUN: opt -loop-load-elim -S < %s | FileCheck %s -check-prefix=CHECK
+
+; Forwarding in the presence of symbolic strides is currently not supported:
+;
+;   for (unsigned i = 0; i < 100; i++)
+;     A[i + 1] = A[Stride * i] + B[i];
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+; CHECK-LABEL: @f(
+define void @f(i32* noalias nocapture %A, i32* noalias nocapture readonly %B, i64 %N,
+               i64 %stride) {
+entry:
+; CHECK-NOT: %load_initial = load i32, i32* %A
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+; CHECK-NOT: %store_forwarded = phi i32 [ %load_initial, %entry ], [ %add, %for.body ]
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %mul = mul i64 %indvars.iv, %stride
+  %arrayidx = getelementptr inbounds i32, i32* %A, i64 %mul
+  %load = load i32, i32* %arrayidx, align 4
+  %arrayidx2 = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
+  %load_1 = load i32, i32* %arrayidx2, align 4
+; CHECK-NOT: %add = add i32 %load_1, %store_forwarded
+  %add = add i32 %load_1, %load
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %arrayidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
+  store i32 %add, i32* %arrayidx_next, 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
+}