1 files changed, 57 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopVectorize/interleaved-accesses-3.ll b/llvm/test/Transforms/LoopVectorize/interleaved-accesses-3.ll
new file mode 100644
index 00000000000..7f8babea86a
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/interleaved-accesses-3.ll
@@ -0,0 +1,57 @@
+; RUN: opt -S -loop-vectorize -instcombine -force-vector-width=4 -force-vector-interleave=1 -enable-interleaved-mem-accesses=true < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; Check that the interleaved-mem-access analysis currently does not create an 
+; interleave group for access 'a' due to the possible pointer wrap-around.
+;
+; To begin with, in this test the candidate interleave group can be created 
+; only when getPtrStride is called with Assume=true. Next, because
+; the interleave-group of the loads is not full (has gaps), we also need to check 
+; for possible pointer wrapping. Here we currently use Assume=false and as a 
+; result cannot prove the transformation is safe and therefore invalidate the
+; candidate interleave group.
+;
+; FIXME: This is a missed optimization. Once we use Assume=true here, we will
+; not have to invalidate the group.
+
+; void func(unsigned * __restrict a, unsigned * __restrict b, unsigned char x, unsigned char y) {
+;  int i = 0;
+;  for (unsigned char index = x; i < y; index +=2, ++i)
+;    b[i] = a[index] * 2;
+;
+; }
+
+; CHECK: vector.body:
+; CHECK-NOT: %wide.vec = load <8 x i32>, <8 x i32>* {{.*}}, align 4
+; CHECK-NOT: shufflevector <8 x i32> %wide.vec, <8 x i32> undef, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
+
+define void @_Z4funcPjS_hh(i32* noalias nocapture readonly %a, i32* noalias nocapture %b, i8 zeroext %x, i8 zeroext %y) local_unnamed_addr {
+entry:
+  %cmp9 = icmp eq i8 %y, 0
+  br i1 %cmp9, label %for.cond.cleanup, label %for.body.preheader
+
+for.body.preheader:
+  %wide.trip.count = zext i8 %y to i64
+  br label %for.body
+
+for.cond.cleanup.loopexit:
+  br label %for.cond.cleanup
+
+for.cond.cleanup:
+  ret void
+
+for.body:
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ]
+  %index.011 = phi i8 [ %add, %for.body ], [ %x, %for.body.preheader ]
+  %idxprom = zext i8 %index.011 to i64
+  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %idxprom
+  %0 = load i32, i32* %arrayidx, align 4
+  %mul = shl i32 %0, 1
+  %arrayidx2 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
+  store i32 %mul, i32* %arrayidx2, align 4
+  %add = add i8 %index.011, 2
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count
+  br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body
+}