Index: flang/lib/Optimizer/CodeGen/TypeConverter.h
===================================================================
--- flang/lib/Optimizer/CodeGen/TypeConverter.h
+++ flang/lib/Optimizer/CodeGen/TypeConverter.h
@@ -47,7 +47,13 @@
 class LLVMTypeConverter : public mlir::LLVMTypeConverter {
 public:
   LLVMTypeConverter(mlir::ModuleOp module, bool applyTBAA)
-      : mlir::LLVMTypeConverter(module.getContext()),
+      : mlir::LLVMTypeConverter(module.getContext(),
+                                [&] {
+                                  mlir::LowerToLLVMOptions options(
+                                      module.getContext());
+                                  options.useOpaquePointers = false;
+                                  return options;
+                                }()),
         kindMapping(getKindMapping(module)),
         specifics(CodeGenSpecifics::get(module.getContext(),
                                         getTargetTriple(module),
Index: mlir/include/mlir/Conversion/LLVMCommon/LoweringOptions.h
===================================================================
--- mlir/include/mlir/Conversion/LLVMCommon/LoweringOptions.h
+++ mlir/include/mlir/Conversion/LLVMCommon/LoweringOptions.h
@@ -33,7 +33,7 @@
   LowerToLLVMOptions(MLIRContext *ctx, const DataLayout &dl);
 
   bool useBarePtrCallConv = false;
-  bool useOpaquePointers = false;
+  bool useOpaquePointers = true;
 
   enum class AllocLowering {
     /// Use malloc for for heap allocations.
Index: mlir/include/mlir/Conversion/Passes.td
===================================================================
--- mlir/include/mlir/Conversion/Passes.td
+++ mlir/include/mlir/Conversion/Passes.td
@@ -158,7 +158,7 @@
   ];
   let options = [
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-           /*default=*/"false", "Generate LLVM IR using opaque pointers "
+           /*default=*/"true", "Generate LLVM IR using opaque pointers "
            "instead of typed pointers">,
   ];
 }
@@ -251,7 +251,7 @@
            /*default=kDeriveIndexBitwidthFromDataLayout*/"0",
            "Bitwidth of the index type, 0 to use size of machine word">,
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                   /*default=*/"false", "Generate LLVM IR using opaque pointers "
+                   /*default=*/"true", "Generate LLVM IR using opaque pointers "
                    "instead of typed pointers">,
   ];
 }
@@ -314,7 +314,7 @@
            "String description (LLVM format) of the data layout that is "
            "expected on the produced module">,
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                       /*default=*/"false", "Generate LLVM IR using opaque pointers "
+                       /*default=*/"true", "Generate LLVM IR using opaque pointers "
                        "instead of typed pointers">,
   ];
 }
@@ -362,7 +362,7 @@
                "Annotation attribute string for GPU binary"
                >,
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-               /*default=*/"false", "Generate LLVM IR using opaque pointers "
+               /*default=*/"true", "Generate LLVM IR using opaque pointers "
                "instead of typed pointers">,
   ];
 
@@ -388,7 +388,7 @@
 
   let options = [
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                 /*default=*/"false", "Generate LLVM IR using opaque pointers "
+                 /*default=*/"true", "Generate LLVM IR using opaque pointers "
                  "instead of typed pointers">
   ];
 
@@ -414,7 +414,7 @@
     Option<"hasRedux", "has-redux", "bool", /*default=*/"false",
            "Target gpu supports redux">,
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                   /*default=*/"false", "Generate LLVM IR using opaque pointers "
+                   /*default=*/"true", "Generate LLVM IR using opaque pointers "
                    "instead of typed pointers">,
   ];
 }
@@ -451,7 +451,7 @@
             clEnumValN(::mlir::gpu::amd::Runtime::OpenCL, "OpenCL", "OpenCL")
           )}]>,
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-               /*default=*/"false", "Generate LLVM IR using opaque pointers "
+               /*default=*/"true", "Generate LLVM IR using opaque pointers "
                "instead of typed pointers">,
   ];
 }
@@ -507,7 +507,7 @@
 
   let options = [
      Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-            /*default=*/"false", "Generate LLVM IR using opaque pointers "
+            /*default=*/"true", "Generate LLVM IR using opaque pointers "
             "instead of typed pointers">
   ];
 
@@ -545,11 +545,10 @@
   let summary = "Convert the operations from the linalg dialect into the LLVM "
                 "dialect";
   let dependentDialects = ["scf::SCFDialect", "LLVM::LLVMDialect"];
-
   let options = [
      Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-            /*default=*/"false", "Generate LLVM IR using opaque pointers "
-            "instead of typed pointers">
+                /*default=*/"true", "Generate LLVM IR using opaque pointers "
+                "instead of typed pointers">
   ];
 }
 
@@ -657,7 +656,7 @@
            "Use generic allocation and deallocation functions instead of the "
            "classic 'malloc', 'aligned_alloc' and 'free' functions">,
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-               /*default=*/"false", "Generate LLVM IR using opaque pointers "
+               /*default=*/"true", "Generate LLVM IR using opaque pointers "
                "instead of typed pointers">
   ];
 }
@@ -702,7 +701,7 @@
   ];
   let options = [
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-              /*default=*/"false", "Generate LLVM IR using opaque pointers "
+              /*default=*/"true", "Generate LLVM IR using opaque pointers "
               "instead of typed pointers">
   ];
 }
@@ -727,7 +726,7 @@
   let dependentDialects = ["LLVM::LLVMDialect"];
   let options = [
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-           /*default=*/"false", "Generate LLVM IR using opaque pointers "
+           /*default=*/"true", "Generate LLVM IR using opaque pointers "
            "instead of typed pointers">,
   ];
 }
@@ -798,7 +797,7 @@
 
   let options = [
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                 /*default=*/"false", "Generate LLVM IR using opaque pointers "
+                 /*default=*/"true", "Generate LLVM IR using opaque pointers "
                  "instead of typed pointers">
   ];
 
@@ -888,7 +887,7 @@
 
   let options = [
     Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                 /*default=*/"false", "Generate LLVM IR using opaque pointers "
+                 /*default=*/"true", "Generate LLVM IR using opaque pointers "
                  "instead of typed pointers">
   ];
 }
@@ -1098,7 +1097,7 @@
            "Enables the use of X86Vector dialect while lowering the vector "
 	   "dialect.">,
 	  Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-               /*default=*/"false", "Generate LLVM IR using opaque pointers "
+               /*default=*/"true", "Generate LLVM IR using opaque pointers "
                "instead of typed pointers">
   ];
 }
Index: mlir/test/mlir-cpu-runner/bare-ptr-call-conv.mlir
===================================================================
--- mlir/test/mlir-cpu-runner/bare-ptr-call-conv.mlir
+++ mlir/test/mlir-cpu-runner/bare-ptr-call-conv.mlir
@@ -26,8 +26,6 @@
 }
 
 // External declarations.
-llvm.func @malloc(i64) -> !llvm.ptr<i8>
-llvm.func @free(!llvm.ptr<i8>)
 func.func private @printF32(%arg0: f32)
 func.func private @printComma()
 func.func private @printNewline()