[LV][EVL] Address post-comments for disabling fixed-order recurrence with EVL tail folding. (NFC)

Author: Mel-Chen

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -1447,11 +1447,11 @@ class LoopVectorizationCostModel {
     // Override forced styles if needed.
     // FIXME: use actual opcode/data type for analysis here.
     // FIXME: Investigate opportunity for fixed vector factor.
+    // FIXME: support fixed-order recurrences by fixing splice of non VFxUF
+    // penultimate EVL.
     bool EVLIsLegal =
         UserIC <= 1 && TTI.hasActiveVectorLength(0, nullptr, Align()) &&
-        !EnableVPlanNativePath &&
-        // FIXME: remove this once fixed-ordered recurrence is supported.
-        Legal->getFixedOrderRecurrences().empty();
+        !EnableVPlanNativePath && Legal->getFixedOrderRecurrences().empty();
     if (!EVLIsLegal) {
       // If for some reason EVL mode is unsupported, fallback to
       // DataWithoutLaneMask to try to vectorize the loop with folded tail

llvm/test/Transforms/LoopVectorize/RISCV/vectorize-force-tail-with-evl-fixed-order-recurrence.ll

@@ -12,8 +12,8 @@
 ; RUN: -mtriple=riscv64 -mattr=+v,+f -S < %s| FileCheck %s --check-prefix=NO-VP
 
 ; FIXME: Fixed-order recurrence is not supported yet with EVL tail folding.
-; The llvm.splice may occurs unexpected behavior if the evl of the
-; second-to-last iteration is not VF*UF.
+; The llvm.splice may occur unexpected behavior if the evl of the second-to-last
+; iteration is not VF*UF.
 
 define void @first_order_recurrence(ptr noalias %A, ptr noalias %B, i64 %TC) {
 ; IF-EVL-LABEL: define void @first_order_recurrence(