diff --git a/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp b/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
--- a/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
+++ b/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
@@ -1391,7 +1391,8 @@
     // reloads necessary.
     unsigned Op0Regs = (R + VF - 1) / VF * M;
     unsigned Op1Regs = (M + VF - 1) / VF * C;
-    return Op0Regs + Op1Regs > TTI.getNumberOfRegisters(true);
+    return Op0Regs + Op1Regs >
+           TTI.getNumberOfRegisters(TTI.getRegisterClassForType(true));
   }
 
   MatrixTy getZeroMatrix(Type *EltType, unsigned R, unsigned C) {