[LV] strip TailFoldingStyle::DataWithoutLaneMask

There is just one usage of TailFoldingStyle::DataWithoutLaneMask in
LoopVectorize, introduced by 413a66f ([LV, VP]VP intrinsics support for
the Loop Vectorizer + adding new tail-folding mode using EVL.), but this
usage is completely unnecessary, as @llvm.get.active.lane.mask is
unrelated to EVL. Moreover, SelectionDAG automatically detects if a
target supports the @llvm.get.active.lane.mask intrinsic, and lowers it
to equivalent instructions on targets where it is not preferred, since
243a532 ([SelectionDAG] Lower @llvm.get.active.lane.mask to setcc).

Author: artagnon

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -244,9 +244,6 @@ static cl::opt<TailFoldingStyle> ForceTailFoldingStyle(
         clEnumValN(
             TailFoldingStyle::Data, "data",
             "Create lane mask for data only, using active.lane.mask intrinsic"),
-        clEnumValN(TailFoldingStyle::DataWithoutLaneMask,
-                   "data-without-lane-mask",
-                   "Create lane mask with compare/stepvector"),
         clEnumValN(TailFoldingStyle::DataAndControlFlow, "data-and-control",
                    "Create lane mask using active.lane.mask intrinsic, and use "
                    "it for both data and control flow"),
@@ -1538,12 +1535,10 @@ class LoopVectorizationCostModel {
         // FIXME: remove this once reductions are supported.
         Legal->getReductionVars().empty();
     if (!EVLIsLegal) {
-      // If for some reason EVL mode is unsupported, fallback to
-      // DataWithoutLaneMask to try to vectorize the loop with folded tail
-      // in a generic way.
+      // If for some reason EVL mode is unsupported, fallback to Data to try to
+      // vectorize the loop with folded tail in a generic way.
       ChosenTailFoldingStyle =
-          std::make_pair(TailFoldingStyle::DataWithoutLaneMask,
-                         TailFoldingStyle::DataWithoutLaneMask);
+          std::make_pair(TailFoldingStyle::Data, TailFoldingStyle::Data);
       LLVM_DEBUG(
           dbgs()
           << "LV: Preference for VP intrinsics indicated. Will "

llvm/test/Transforms/LoopVectorize/AArch64/tail-folding-styles.ll

@@ -1,7 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -S -passes=loop-vectorize -force-tail-folding-style=none < %s | FileCheck %s --check-prefix=NONE
 ; RUN: opt -S -passes=loop-vectorize -force-tail-folding-style=data < %s | FileCheck %s --check-prefix=DATA
-; RUN: opt -S -passes=loop-vectorize -force-tail-folding-style=data-without-lane-mask < %s | FileCheck %s --check-prefix=DATA_NO_LANEMASK
 ; RUN: opt -S -passes=loop-vectorize -force-tail-folding-style=data-and-control < %s | FileCheck %s --check-prefix=DATA_AND_CONTROL
 ; RUN: opt -S -passes=loop-vectorize -force-tail-folding-style=data-and-control-without-rt-check < %s | FileCheck %s --check-prefix=DATA_AND_CONTROL_NO_RT_CHECK
 
@@ -97,59 +96,6 @@ define void @simple_memset_tailfold(i32 %val, ptr %ptr, i64 %n) "target-features
 ; DATA:       while.end.loopexit:
 ; DATA-NEXT:    ret void
 ;
-; DATA_NO_LANEMASK-LABEL: @simple_memset_tailfold(
-; DATA_NO_LANEMASK-NEXT:  entry:
-; DATA_NO_LANEMASK-NEXT:    [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[N:%.*]], i64 1)
-; DATA_NO_LANEMASK-NEXT:    [[TMP0:%.*]] = sub i64 -1, [[UMAX]]
-; DATA_NO_LANEMASK-NEXT:    [[TMP1:%.*]] = call i64 @llvm.vscale.i64()
-; DATA_NO_LANEMASK-NEXT:    [[TMP2:%.*]] = mul i64 [[TMP1]], 4
-; DATA_NO_LANEMASK-NEXT:    [[TMP3:%.*]] = icmp ult i64 [[TMP0]], [[TMP2]]
-; DATA_NO_LANEMASK-NEXT:    br i1 [[TMP3]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
-; DATA_NO_LANEMASK:       vector.ph:
-; DATA_NO_LANEMASK-NEXT:    [[TMP4:%.*]] = call i64 @llvm.vscale.i64()
-; DATA_NO_LANEMASK-NEXT:    [[TMP5:%.*]] = mul i64 [[TMP4]], 4
-; DATA_NO_LANEMASK-NEXT:    [[TMP8:%.*]] = sub i64 [[TMP5]], 1
-; DATA_NO_LANEMASK-NEXT:    [[N_RND_UP:%.*]] = add i64 [[UMAX]], [[TMP8]]
-; DATA_NO_LANEMASK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[N_RND_UP]], [[TMP5]]
-; DATA_NO_LANEMASK-NEXT:    [[N_VEC:%.*]] = sub i64 [[N_RND_UP]], [[N_MOD_VF]]
-; DATA_NO_LANEMASK-NEXT:    [[TRIP_COUNT_MINUS_1:%.*]] = sub i64 [[UMAX]], 1
-; DATA_NO_LANEMASK-NEXT:    [[TMP15:%.*]] = call i64 @llvm.vscale.i64()
-; DATA_NO_LANEMASK-NEXT:    [[TMP16:%.*]] = mul i64 [[TMP15]], 4
-; DATA_NO_LANEMASK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <vscale x 4 x i64> poison, i64 [[TRIP_COUNT_MINUS_1]], i64 0
-; DATA_NO_LANEMASK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <vscale x 4 x i64> [[BROADCAST_SPLATINSERT]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
-; DATA_NO_LANEMASK-NEXT:    [[BROADCAST_SPLATINSERT4:%.*]] = insertelement <vscale x 4 x i32> poison, i32 [[VAL:%.*]], i64 0
-; DATA_NO_LANEMASK-NEXT:    [[BROADCAST_SPLAT5:%.*]] = shufflevector <vscale x 4 x i32> [[BROADCAST_SPLATINSERT4]], <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
-; DATA_NO_LANEMASK-NEXT:    br label [[VECTOR_BODY:%.*]]
-; DATA_NO_LANEMASK:       vector.body:
-; DATA_NO_LANEMASK-NEXT:    [[INDEX1:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT6:%.*]], [[VECTOR_BODY]] ]
-; DATA_NO_LANEMASK-NEXT:    [[TMP9:%.*]] = add i64 [[INDEX1]], 0
-; DATA_NO_LANEMASK-NEXT:    [[BROADCAST_SPLATINSERT2:%.*]] = insertelement <vscale x 4 x i64> poison, i64 [[INDEX1]], i64 0
-; DATA_NO_LANEMASK-NEXT:    [[BROADCAST_SPLAT3:%.*]] = shufflevector <vscale x 4 x i64> [[BROADCAST_SPLATINSERT2]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
-; DATA_NO_LANEMASK-NEXT:    [[TMP10:%.*]] = call <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
-; DATA_NO_LANEMASK-NEXT:    [[TMP11:%.*]] = add <vscale x 4 x i64> zeroinitializer, [[TMP10]]
-; DATA_NO_LANEMASK-NEXT:    [[VEC_IV:%.*]] = add <vscale x 4 x i64> [[BROADCAST_SPLAT3]], [[TMP11]]
-; DATA_NO_LANEMASK-NEXT:    [[TMP12:%.*]] = icmp ule <vscale x 4 x i64> [[VEC_IV]], [[BROADCAST_SPLAT]]
-; DATA_NO_LANEMASK-NEXT:    [[TMP13:%.*]] = getelementptr i32, ptr [[PTR:%.*]], i64 [[TMP9]]
-; DATA_NO_LANEMASK-NEXT:    [[TMP14:%.*]] = getelementptr i32, ptr [[TMP13]], i32 0
-; DATA_NO_LANEMASK-NEXT:    call void @llvm.masked.store.nxv4i32.p0(<vscale x 4 x i32> [[BROADCAST_SPLAT5]], ptr [[TMP14]], i32 4, <vscale x 4 x i1> [[TMP12]])
-; DATA_NO_LANEMASK-NEXT:    [[INDEX_NEXT6]] = add i64 [[INDEX1]], [[TMP16]]
-; DATA_NO_LANEMASK-NEXT:    [[TMP17:%.*]] = icmp eq i64 [[INDEX_NEXT6]], [[N_VEC]]
-; DATA_NO_LANEMASK-NEXT:    br i1 [[TMP17]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
-; DATA_NO_LANEMASK:       middle.block:
-; DATA_NO_LANEMASK-NEXT:    br i1 true, label [[WHILE_END_LOOPEXIT:%.*]], label [[SCALAR_PH]]
-; DATA_NO_LANEMASK:       scalar.ph:
-; DATA_NO_LANEMASK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
-; DATA_NO_LANEMASK-NEXT:    br label [[WHILE_BODY:%.*]]
-; DATA_NO_LANEMASK:       while.body:
-; DATA_NO_LANEMASK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[WHILE_BODY]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
-; DATA_NO_LANEMASK-NEXT:    [[GEP:%.*]] = getelementptr i32, ptr [[PTR]], i64 [[INDEX]]
-; DATA_NO_LANEMASK-NEXT:    store i32 [[VAL]], ptr [[GEP]], align 4
-; DATA_NO_LANEMASK-NEXT:    [[INDEX_NEXT]] = add nsw i64 [[INDEX]], 1
-; DATA_NO_LANEMASK-NEXT:    [[CMP10:%.*]] = icmp ult i64 [[INDEX_NEXT]], [[N]]
-; DATA_NO_LANEMASK-NEXT:    br i1 [[CMP10]], label [[WHILE_BODY]], label [[WHILE_END_LOOPEXIT]], !llvm.loop [[LOOP3:![0-9]+]]
-; DATA_NO_LANEMASK:       while.end.loopexit:
-; DATA_NO_LANEMASK-NEXT:    ret void
-;
 ; DATA_AND_CONTROL-LABEL: @simple_memset_tailfold(
 ; DATA_AND_CONTROL-NEXT:  entry:
 ; DATA_AND_CONTROL-NEXT:    [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[N:%.*]], i64 1)