diff --git a/mlir/lib/Conversion/MathToLLVM/MathToLLVM.cpp b/mlir/lib/Conversion/MathToLLVM/MathToLLVM.cpp
--- a/mlir/lib/Conversion/MathToLLVM/MathToLLVM.cpp
+++ b/mlir/lib/Conversion/MathToLLVM/MathToLLVM.cpp
@@ -74,8 +74,8 @@
         [&](Type llvm1DVectorTy, ValueRange operands) {
           LLVM::ConstantOp zero =
               rewriter.create<LLVM::ConstantOp>(loc, boolType, boolZero);
-          return rewriter.replaceOpWithNewOp<LLVMOp>(op, llvm1DVectorTy,
-                                                     operands[0], zero);
+          return rewriter.create<LLVMOp>(loc, llvm1DVectorTy, operands[0],
+                                         zero);
         },
         rewriter);
   }
diff --git a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
--- a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
+++ b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
@@ -259,6 +259,8 @@
 
   // tosa::ClzOp
   if (isa<tosa::ClzOp>(op) && elementTy.isa<IntegerType>()) {
+    return rewriter.create<math::CountLeadingZerosOp>(loc, elementTy, args[0]);
+    /*
     int bitWidth = elementTy.getIntOrFloatBitWidth();
     auto zero =
         rewriter.create<arith::ConstantOp>(loc, IntegerAttr::get(elementTy, 0));
@@ -307,6 +309,7 @@
 
     rewriter.setInsertionPointAfter(whileOp);
     return whileOp->getResult(1);
+    */
   }
 
   // tosa::LogicalAnd
diff --git a/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir b/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir
--- a/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir
+++ b/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir
@@ -366,12 +366,7 @@
   // CHECK: arith.addi
   %12 = "tosa.arithmetic_right_shift"(%arg0, %arg0) {round = 1 : i1} : (tensor<1xi32>, tensor<1xi32>) -> tensor<1xi32>
 
-  // CHECK: scf.while
-  // CHECK: arith.cmpi ne
-  // CHECK: scf.condition
-  // CHECK: arith.shrui
-  // CHECK: arith.subi
-  // CHECK: scf.yield
+  // CHECK: math.ctlz
   %13 = "tosa.clz"(%arg0) : (tensor<1xi32>) -> tensor<1xi32>
 
   // CHECK: linalg.generic