diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -208,35 +208,35 @@
 // and predicate the instructions accordingly. If tail-folding fails, there are
 // different fallback strategies depending on these values:
 namespace PreferPredicateTy {
-  enum Option {
-    ScalarEpilogue = 0,
-    PredicateElseScalarEpilogue,
-    VlenElseScalarEpilogue,
-    PredicateOrDontVectorize
-  };
+enum Option {
+  ScalarEpilogue = 0,
+  PredicateElseScalarEpilogue,
+  VlElseScalarEpilogue,
+  PredicateOrDontVectorize
+};
 } // namespace PreferPredicateTy
 
 static cl::opt<PreferPredicateTy::Option> PreferPredicateOverEpilogue(
     "prefer-predicate-over-epilogue",
-    cl::init(PreferPredicateTy::ScalarEpilogue),
-    cl::Hidden,
+    cl::init(PreferPredicateTy::ScalarEpilogue), cl::Hidden,
     cl::desc("Tail-folding and predication preferences over creating a scalar "
              "epilogue loop."),
-    cl::values(clEnumValN(PreferPredicateTy::ScalarEpilogue,
-                         "scalar-epilogue",
-                         "Don't tail-predicate loops, create scalar epilogue"),
-              clEnumValN(PreferPredicateTy::PredicateElseScalarEpilogue,
-                         "predicate-else-scalar-epilogue",
-                         "prefer tail-folding, create scalar epilogue if tail "
-                         "folding fails."),
-              clEnumValN(PreferPredicateTy::VlenElseScalarEpilogue,
-                         "vlen-else-scalar-epilogue",
-                         "prefer tail-folding, we use dynamic vlen to support it. Only works for rvv, create scalar epilogue if tail "
-                         "folding fails."),
-              clEnumValN(PreferPredicateTy::PredicateOrDontVectorize,
-                         "predicate-dont-vectorize",
-                         "prefers tail-folding, don't attempt vectorization if "
-                         "tail-folding fails.")));
+    cl::values(
+        clEnumValN(PreferPredicateTy::ScalarEpilogue, "scalar-epilogue",
+                   "Don't tail-predicate loops, create scalar epilogue"),
+        clEnumValN(PreferPredicateTy::PredicateElseScalarEpilogue,
+                   "predicate-else-scalar-epilogue",
+                   "prefer tail-folding, create scalar epilogue if tail "
+                   "folding fails."),
+        clEnumValN(PreferPredicateTy::VlElseScalarEpilogue,
+                   "vlen-else-scalar-epilogue",
+                   "prefer tail-folding, we use dynamic vlen to support it. "
+                   "Only works for rvv, create scalar epilogue if tail "
+                   "folding fails."),
+        clEnumValN(PreferPredicateTy::PredicateOrDontVectorize,
+                   "predicate-dont-vectorize",
+                   "prefers tail-folding, don't attempt vectorization if "
+                   "tail-folding fails.")));
 
 static cl::opt<bool> MaximizeBandwidth(
     "vectorizer-maximize-bandwidth", cl::init(false), cl::Hidden,
@@ -1115,7 +1115,7 @@
   // Loop hint predicate indicating an epilogue is undesired.
   CM_ScalarEpilogueNotNeededUsePredicate,
 
-  CM_ScalarEpilogueNotNeededUseVlen,
+  CM_ScalarEpilogueNotNeededUseVl,
 
   // Directive indicating we must either tail fold or not vectorize
   CM_ScalarEpilogueNotAllowedUsePredicate
@@ -5005,11 +5005,11 @@
     return computeFeasibleMaxVF(TC, UserVF, false);
   case CM_ScalarEpilogueNotAllowedUsePredicate:
     LLVM_FALLTHROUGH;
-  case CM_ScalarEpilogueNotNeededUseVlen:
-     LLVM_DEBUG(errs() << "LV: vector Vlen hint/switch found.\n"
-               << "LV: Not allowing scalar epilogue, creating vlenset "
-               << "vector loop.\n";);
-     break;
+  case CM_ScalarEpilogueNotNeededUseVl:
+    LLVM_DEBUG(errs() << "LV: vector Vlen hint/switch found.\n"
+                      << "LV: Not allowing scalar epilogue, creating vlenset "
+                      << "vector loop.\n";);
+    break;
   case CM_ScalarEpilogueNotNeededUsePredicate:
     LLVM_DEBUG(
         dbgs() << "LV: vector predicate hint/switch found.\n"
@@ -5041,7 +5041,8 @@
   if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) {
     // If there was a tail-folding hint/switch, but we can't fold the tail by
     // masking, fallback to a vectorization with a scalar epilogue.
-    if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate|| ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUseVlen) {
+    if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate ||
+        ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUseVl) {
       LLVM_DEBUG(dbgs() << "LV: Cannot fold tail by masking or vlen: vectorize with a "
                            "scalar epilogue instead.\n");
       ScalarEpilogueStatus = CM_ScalarEpilogueAllowed;
@@ -5093,14 +5094,14 @@
   // FIXME: look for a smaller MaxVF that does divide TC rather than masking.
   if (Legal->prepareToFoldTailByMasking()) {
     FoldTailByMasking = true;
-    if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUseVlen)
+    if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUseVl)
       FoldTailByImplictMasking = true;
     return MaxFactors;
   }
   // If there was a tail-folding hint/switch, but we can't fold the tail by
   // masking, fallback to a vectorization with a scalar epilogue.
-  if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate|| 
-      ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUseVlen) {
+  if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate ||
+      ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUseVl) {
     LLVM_DEBUG(dbgs() << "LV: Cannot fold tail by masking or vlen: vectorize with a "
                          "scalar epilogue instead.\n");
     ScalarEpilogueStatus = CM_ScalarEpilogueAllowed;
@@ -9779,8 +9780,8 @@
     switch (PreferPredicateOverEpilogue) {
     case PreferPredicateTy::ScalarEpilogue:
       return CM_ScalarEpilogueAllowed;
-    case PreferPredicateTy::VlenElseScalarEpilogue:
-      return  CM_ScalarEpilogueNotNeededUseVlen;
+    case PreferPredicateTy::VlElseScalarEpilogue:
+      return CM_ScalarEpilogueNotNeededUseVl;
     case PreferPredicateTy::PredicateElseScalarEpilogue:
       return CM_ScalarEpilogueNotNeededUsePredicate;
     case PreferPredicateTy::PredicateOrDontVectorize:
diff --git a/vectorizationREADME.md b/vectorizationREADME.md
--- a/vectorizationREADME.md
+++ b/vectorizationREADME.md
@@ -1,7 +1,9 @@
 # 向量化tail folding功能实现
 ## 注意事项
 添加新选项： 
-```--prefer-predicate-over-epilogue=vlen-else-scalar-epilogue ``` 
+```--prefer-predicate-over-epilogue=vlen-else-scalar-epilogue ``` ,可以在riscv 后端使用vsetvl指令进行tail folding
+在test/Transform/LoopVectorize/RISCV添加测试prefer_tail_folding_with_vsetvl.ll 测试，是由arm下的文件修改而来，满足了关于各种类型，各种类型混合，指定向量宽度后下tail_folding的正确性
+【WIP】：vector scatter gather 基于目前基础设施无法实现tail folding ,直接用assert表示
 ## 环境
 类似于如下构建
 ```