fix the comments

Author: LiqinWeng

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -18155,7 +18155,7 @@ bool RISCVTargetLowering::isDesirableToCommuteWithShift(
   // LD/ST will optimize constant Offset extraction, so when AddNode is used by
   // LD/ST, it can still complete the folding optimization operation performed
   // above.
-  auto isLDST = [&]() {
+  auto isUsedByLdSt = [&]() {
     bool CanOptAlways = false;
     if (N0->getOpcode() == ISD::ADD && !N0->hasOneUse()) {
       for (SDNode *Use : N0->uses()) {
@@ -18189,7 +18189,7 @@ bool RISCVTargetLowering::isDesirableToCommuteWithShift(
   if (Ty.isScalarInteger() &&
       (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::OR)) {
     if (N0.getOpcode() == ISD::ADD && !N0->hasOneUse())
-      return isLDST();
+      return isUsedByLdSt();
 
     auto *C1 = dyn_cast<ConstantSDNode>(N0->getOperand(1));
     auto *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1));
@@ -18232,7 +18232,7 @@ bool RISCVTargetLowering::isDesirableToCommuteWithShift(
   if (N0->getOpcode() == ISD::SIGN_EXTEND &&
       N0->getOperand(0)->getOpcode() == ISD::ADD &&
       !N0->getOperand(0)->hasOneUse())
-    return isLDST();
+    return isUsedByLdSt();
 
   return true;
 }