diff --git a/flang/include/flang/Optimizer/Transforms/Passes.td b/flang/include/flang/Optimizer/Transforms/Passes.td
--- a/flang/include/flang/Optimizer/Transforms/Passes.td
+++ b/flang/include/flang/Optimizer/Transforms/Passes.td
@@ -127,7 +127,16 @@
   let options = [
     Option<"forceLoopToExecuteOnce", "always-execute-loop-body", "bool",
            /*default=*/"false",
-           "force the body of a loop to execute at least once">
+           "force the body of a loop to execute at least once">,
+    Option<"transformDoLoop", "transform-do-loop", "bool",
+           /*default=*/"true",
+           "apply the transformation the do loops">,
+    Option<"transformIf", "transform-if", "bool",
+           /*default=*/"true",
+           "apply transformation on if statments">,
+    Option<"transformIterateWhile", "transform-iterate-while", "bool",
+           /*default=*/"true",
+           "apply transformation on iterate while">
   ];
 }
 
diff --git a/flang/lib/Optimizer/Transforms/RewriteLoop.cpp b/flang/lib/Optimizer/Transforms/RewriteLoop.cpp
--- a/flang/lib/Optimizer/Transforms/RewriteLoop.cpp
+++ b/flang/lib/Optimizer/Transforms/RewriteLoop.cpp
@@ -297,14 +297,27 @@
   void runOnOperation() override {
     auto *context = &getContext();
     mlir::RewritePatternSet patterns(context);
-    patterns.insert<CfgLoopConv, CfgIfConv, CfgIterWhileConv>(
-        context, forceLoopToExecuteOnce);
     mlir::ConversionTarget target(*context);
     target.addLegalDialect<mlir::AffineDialect, FIROpsDialect,
                            mlir::StandardOpsDialect>();
 
     // apply the patterns
-    target.addIllegalOp<ResultOp, DoLoopOp, IfOp, IterWhileOp>();
+    if (transformIterateWhile) {
+      patterns.insert<CfgIterWhileConv>(context, forceLoopToExecuteOnce);
+      target.addIllegalOp<IterWhileOp>();
+    }
+    if (transformDoLoop) {
+      patterns.insert<CfgLoopConv>(context, forceLoopToExecuteOnce);
+      target.addIllegalOp<DoLoopOp>();
+    }
+    if (transformIf) {
+      patterns.insert<CfgIfConv>(context, forceLoopToExecuteOnce);
+      target.addIllegalOp<IfOp>();
+    }
+    bool transformAll = transformIterateWhile && transformDoLoop && transformIf;
+    if (transformAll) {
+      target.addIllegalOp<ResultOp>();
+    }
     target.markUnknownOpDynamicallyLegal([](Operation *) { return true; });
     if (mlir::failed(mlir::applyPartialConversion(getOperation(), target,
                                                   std::move(patterns)))) {
diff --git a/flang/test/Fir/cfg-options.fir b/flang/test/Fir/cfg-options.fir
new file mode 100644
--- /dev/null
+++ b/flang/test/Fir/cfg-options.fir
@@ -0,0 +1,114 @@
+// RUN: rm -rf %t && mkdir %t
+// RUN: %split-file %s %t
+// RUN: fir-opt %t/all.fir --cfg-conversion | FileCheck %t/all.fir
+// RUN: fir-opt %t/loop.fir --cfg-conversion="transform-if=0 transform-iterate-while=0" | FileCheck %t/loop.fir
+// RUN: fir-opt %t/if.fir --cfg-conversion="transform-iterate-while=0" | FileCheck %t/if.fir
+// RUN: fir-opt %t/while.fir --cfg-conversion="transform-do-loop=0 transform-if=0" | FileCheck %t/while.fir
+
+//--- all.fir
+// CHECK-LABEL: @x
+// CHECK-NOT: fir.if
+// CHECK-NOT: fir.do_loop
+// CHECK-NOT: fir.iterate_while
+func @x(%lb : index, %ub : index, %step : index, %b : i1, %addr : !fir.ref<index>) {
+  fir.do_loop %iv = %lb to %ub step %step unordered {
+    fir.if %b {
+      fir.store %iv to %addr : !fir.ref<index>
+    } else {
+      %zero = arith.constant 0 : index
+      fir.store %zero to %addr : !fir.ref<index>
+    }
+  }
+  return
+}
+
+// CHECK-LABEL: @x2
+func @x2(%lo : index, %up : index, %ok : i1) {
+  %c1 = arith.constant 1 : index
+  %unused = fir.iterate_while (%i = %lo to %up step %c1) and (%ok1 = %ok) {
+    %ok2 = fir.call @f2() : () -> i1
+    fir.result %ok2 : i1
+  }
+  return
+}
+
+//--- loop.fir
+// CHECK-LABEL: @x
+// CHECK: fir.if
+// CHECK-NOT: fir.do_loop
+func @x(%lb : index, %ub : index, %step : index, %b : i1, %addr : !fir.ref<index>) {
+  fir.do_loop %iv = %lb to %ub step %step unordered {
+    fir.if %b {
+      fir.store %iv to %addr : !fir.ref<index>
+    } else {
+      %zero = arith.constant 0 : index
+      fir.store %zero to %addr : !fir.ref<index>
+    }
+  }
+  return
+}
+
+// CHECK-LABEL: @x2
+// CHECK: fir.iterate_while
+func @x2(%lo : index, %up : index, %ok : i1) {
+  %c1 = arith.constant 1 : index
+  %unused = fir.iterate_while (%i = %lo to %up step %c1) and (%ok1 = %ok) {
+    %ok2 = fir.call @f2() : () -> i1
+    fir.result %ok2 : i1
+  }
+  return
+}
+
+//--- if.fir
+// CHECK-LABEL: @x
+// CHECK-NOT: fir.if
+// CHECK-NOT: fir.do_loop
+func @x(%lb : index, %ub : index, %step : index, %b : i1, %addr : !fir.ref<index>) {
+  fir.do_loop %iv = %lb to %ub step %step unordered {
+    fir.if %b {
+      fir.store %iv to %addr : !fir.ref<index>
+    } else {
+      %zero = arith.constant 0 : index
+      fir.store %zero to %addr : !fir.ref<index>
+    }
+  }
+  return
+}
+
+// CHECK-LABEL: @x2
+// CHECK: fir.iterate_while
+func @x2(%lo : index, %up : index, %ok : i1) {
+  %c1 = arith.constant 1 : index
+  %unused = fir.iterate_while (%i = %lo to %up step %c1) and (%ok1 = %ok) {
+    %ok2 = fir.call @f2() : () -> i1
+    fir.result %ok2 : i1
+  }
+  return
+}
+
+//--- while.fir
+// CHECK-LABEL: @x
+// CHECK: fir.do_loop
+// CHECK: fir.if
+func @x(%lb : index, %ub : index, %step : index, %b : i1, %addr : !fir.ref<index>) {
+  fir.do_loop %iv = %lb to %ub step %step unordered {
+    fir.if %b {
+      fir.store %iv to %addr : !fir.ref<index>
+    } else {
+      %zero = arith.constant 0 : index
+      fir.store %zero to %addr : !fir.ref<index>
+    }
+  }
+  return
+}
+
+// CHECK-LABEL: @x2
+// CHECK-NOT: fir.iterate_while
+func @x2(%lo : index, %up : index, %ok : i1) {
+  %c1 = arith.constant 1 : index
+  %unused = fir.iterate_while (%i = %lo to %up step %c1) and (%ok1 = %ok) {
+    %ok2 = fir.call @f2() : () -> i1
+    fir.result %ok2 : i1
+  }
+  return
+}
diff --git a/flang/test/lit.cfg.py b/flang/test/lit.cfg.py
--- a/flang/test/lit.cfg.py
+++ b/flang/test/lit.cfg.py
@@ -74,7 +74,9 @@
 tools = [
         ToolSubst('%flang', command=FindTool('flang-new'), unresolved='fatal'),
     ToolSubst('%flang_fc1', command=FindTool('flang-new'), extra_args=['-fc1'],
-        unresolved='fatal')]
+        unresolved='fatal'),
+    ToolSubst('%split-file', FindTool('split-file'))
+]
 
 # Flang has several unimplemented features. TODO messages are used to mark and fail if these
 # features are exercised. TODOs exit with an error in non-assert builds but in assert builds