[LowerMatrixIntrinsics] Call getRegisterClassForType before getNumberOfRegisters.

[craig.topper]

Summary

getNumberOfRegisters takes a ClassID as it's argument. It shouldn't be passed a bool. Assuming the bool meant vector or not, we should call getRegisterClassForType first.

[fhahn]

LGTM, thanks!

llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp

bool isFusionProfitable(CallInst *MatMul) {
     if (R <= VF && C == 1)
       return false;
     // Then we need enough elements to exceed the number of vector
     // registers we have.  Note that this is an oversimplification since
     // fusing also takes some extra loads which may exceed the number of
     // 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) {
     MatrixTy Res;
     auto *ColumType = FixedVectorType::get(EltType, R);
     for (unsigned I = 0; I < C; ++I)
       Res.addVector(ConstantAggregateZero::get(ColumType));
     return Res;