[llvm] [RISCV][LoopVectorize] Use DataWithEVL as the preferred tail folding style (PR #148686)

[Florian Hahn via llvm-commits]

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@@ -71,31 +71,33 @@ define void @masked_strided_factor2(ptr noalias nocapture readonly %p, ptr noali
 ; PREDICATED_TAIL_FOLDING-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <vscale x 16 x i32> poison, i32 [[CONV]], i64 0
 ; PREDICATED_TAIL_FOLDING-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <vscale x 16 x i32> [[BROADCAST_SPLATINSERT]], <vscale x 16 x i32> poison, <vscale x 16 x i32> zeroinitializer
 ; PREDICATED_TAIL_FOLDING-NEXT:    [[TMP4:%.*]] = call <vscale x 16 x i32> @llvm.stepvector.nxv16i32()
-; PREDICATED_TAIL_FOLDING-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <vscale x 16 x i32> poison, i32 [[TMP3]], i64 0
-; PREDICATED_TAIL_FOLDING-NEXT:    [[BROADCAST_SPLAT2:%.*]] = shufflevector <vscale x 16 x i32> [[BROADCAST_SPLATINSERT1]], <vscale x 16 x i32> poison, <vscale x 16 x i32> zeroinitializer
 ; PREDICATED_TAIL_FOLDING-NEXT:    br label [[VECTOR_BODY:%.*]]
 ; PREDICATED_TAIL_FOLDING:       vector.body:
 ; PREDICATED_TAIL_FOLDING-NEXT:    [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
+; PREDICATED_TAIL_FOLDING-NEXT:    [[EVL_BASED_IV:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_EVL_NEXT:%.*]], [[VECTOR_BODY]] ]
 ; PREDICATED_TAIL_FOLDING-NEXT:    [[VEC_IND:%.*]] = phi <vscale x 16 x i32> [ [[TMP4]], [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ]
-; PREDICATED_TAIL_FOLDING-NEXT:    [[ACTIVE_LANE_MASK:%.*]] = call <vscale x 16 x i1> @llvm.get.active.lane.mask.nxv16i1.i32(i32 [[INDEX]], i32 1024)
-; PREDICATED_TAIL_FOLDING-NEXT:    [[TMP5:%.*]] = icmp ugt <vscale x 16 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
-; PREDICATED_TAIL_FOLDING-NEXT:    [[TMP6:%.*]] = select <vscale x 16 x i1> [[ACTIVE_LANE_MASK]], <vscale x 16 x i1> [[TMP5]], <vscale x 16 x i1> zeroinitializer
+; PREDICATED_TAIL_FOLDING-NEXT:    [[AVL:%.*]] = sub i32 1024, [[EVL_BASED_IV]]
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fhahn wrote:

Is this now the same as `PREDICATED_EVL`? Can we combine the check lines? Should we still test tail-folding w/o EVL for RISCV?

https://github.com/llvm/llvm-project/pull/148686