Index: llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
+++ llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -132,16 +132,8 @@
 }
 
 Optional<unsigned> RISCVTTIImpl::getMaxVScale() const {
-  // There is no assumption of the maximum vector length in V specification.
-  // We use the value specified by users as the maximum vector length.
-  // This function will use the assumed maximum vector length to get the
-  // maximum vscale for LoopVectorizer.
-  // If users do not specify the maximum vector length, we have no way to
-  // know whether the LoopVectorizer is safe to do or not.
-  // We only consider to use single vector register (LMUL = 1) to vectorize.
-  unsigned MaxVectorSizeInBits = ST->getMaxRVVVectorSizeInBits();
-  if (ST->hasVInstructions() && MaxVectorSizeInBits != 0)
-    return MaxVectorSizeInBits / RISCV::RVVBitsPerBlock;
+  if (ST->hasVInstructions())
+    return ST->getRealMaxVLen() / RISCV::RVVBitsPerBlock;
   return BaseT::getMaxVScale();
 }