[llvm] [AArch64][LV] Cost low-VF interleaved access (PR #205844)

[Graham Hunter via llvm-commits]

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@@ -1277,14 +1256,14 @@ define void @PR34743(ptr %a, ptr %b, i64 %n) #1 {
 ; CHECK:       vector.body:
 ; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[VECTOR_RECUR:%.*]] = phi <vscale x 4 x i16> [ [[VECTOR_RECUR_INIT]], [[VECTOR_PH]] ], [ [[WIDE_MASKED_GATHER4:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[VEC_IND:%.*]] = phi <vscale x 4 x i64> [ [[TMP15]], [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[TMP17:%.*]] = add nuw nsw <vscale x 4 x i64> [[VEC_IND]], splat (i64 1)
-; CHECK-NEXT:    [[TMP19:%.*]] = add nuw nsw <vscale x 4 x i64> [[VEC_IND]], splat (i64 2)
-; CHECK-NEXT:    [[TMP20:%.*]] = getelementptr inbounds i16, ptr [[A]], <vscale x 4 x i64> [[TMP17]]
-; CHECK-NEXT:    [[WIDE_MASKED_GATHER:%.*]] = call <vscale x 4 x i16> @llvm.masked.gather.nxv4i16.nxv4p0(<vscale x 4 x ptr> align 4 [[TMP20]], <vscale x 4 x i1> splat (i1 true), <vscale x 4 x i16> poison), !alias.scope [[META26:![0-9]+]]
+; CHECK-NEXT:    [[TMP13:%.*]] = shl i64 [[INDEX]], 1
+; CHECK-NEXT:    [[TMP14:%.*]] = add nuw nsw i64 [[TMP13]], 1
+; CHECK-NEXT:    [[TMP15:%.*]] = getelementptr inbounds i16, ptr [[A]], i64 [[TMP14]]
+; CHECK-NEXT:    [[WIDE_VEC:%.*]] = load <vscale x 8 x i16>, ptr [[TMP15]], align 4, !alias.scope [[META26:![0-9]+]]
+; CHECK-NEXT:    [[STRIDED_VEC:%.*]] = call { <vscale x 4 x i16>, <vscale x 4 x i16> } @llvm.vector.deinterleave2.nxv8i16(<vscale x 8 x i16> [[WIDE_VEC]])
+; CHECK-NEXT:    [[WIDE_MASKED_GATHER:%.*]] = extractvalue { <vscale x 4 x i16>, <vscale x 4 x i16> } [[STRIDED_VEC]], 0
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huntergr-arm wrote:

Might be good to use the `-reset_variable_names` option for update_test_checks.py.

https://github.com/llvm/llvm-project/pull/205844