diff --git a/flang/include/flang/Tools/CLOptions.inc b/flang/include/flang/Tools/CLOptions.inc
--- a/flang/include/flang/Tools/CLOptions.inc
+++ b/flang/include/flang/Tools/CLOptions.inc
@@ -176,6 +176,7 @@
   llvm::StringMap<mlir::OpPassManager> pipelines;
   pm.addPass(
       mlir::createInlinerPass(pipelines, defaultFlangInlinerOptPipeline));
+  pm.addPass(fir::createSimplifyRegionLitePass());
   pm.addPass(mlir::createCSEPass());
 
   // convert control flow to CFG form
diff --git a/flang/test/Driver/bbc-mlir-pass-pipeline.f90 b/flang/test/Driver/bbc-mlir-pass-pipeline.f90
--- a/flang/test/Driver/bbc-mlir-pass-pipeline.f90
+++ b/flang/test/Driver/bbc-mlir-pass-pipeline.f90
@@ -32,6 +32,7 @@
 ! CHECK-NEXT:   MemoryAllocationOpt
 
 ! CHECK-NEXT: Inliner
+! CHECK-NEXT: SimplifyRegionLite
 ! CHECK-NEXT: CSE
 ! CHECK-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! CHECK-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
diff --git a/flang/test/Driver/mlir-pass-pipeline.f90 b/flang/test/Driver/mlir-pass-pipeline.f90
--- a/flang/test/Driver/mlir-pass-pipeline.f90
+++ b/flang/test/Driver/mlir-pass-pipeline.f90
@@ -35,6 +35,7 @@
 ! ALL-NEXT:   MemoryAllocationOpt
 
 ! ALL-NEXT: Inliner
+! ALL-NEXT: SimplifyRegionLite
 ! ALL-NEXT: CSE
 ! ALL-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! ALL-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
diff --git a/flang/test/Fir/basic-program.fir b/flang/test/Fir/basic-program.fir
--- a/flang/test/Fir/basic-program.fir
+++ b/flang/test/Fir/basic-program.fir
@@ -35,6 +35,7 @@
 // PASSES-NEXT:   MemoryAllocationOpt
 
 // PASSES-NEXT: Inliner
+// PASSES-NEXT: SimplifyRegionLite
 // PASSES-NEXT: CSE
 // PASSES-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 // PASSES-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
diff --git a/flang/test/Fir/simplify-region-lite-after-inliner.fir b/flang/test/Fir/simplify-region-lite-after-inliner.fir
new file mode 100644
--- /dev/null
+++ b/flang/test/Fir/simplify-region-lite-after-inliner.fir
@@ -0,0 +1,36 @@
+// RUN: tco %s | FileCheck %s
+
+
+// In flang pipeline, the inliner calls createCanonicalizerPass with the region
+// simplification disabled. The inliner pass does canonicalization even if
+// no inlining happens. After canonicalization, FIR lite region simplification
+// must be called to get rid of unreachable regions.
+// This code exposes the need to run SimplifyRegionLitePass after the inliner is
+// called with FIR pipeline.
+
+
+func.func @repro(%arg0: i8, %arg1: i8) {
+  %c34_i8 = arith.constant 34 : i8
+  %c-1_i8 = arith.constant -1 : i8
+  %2 = arith.xori %c34_i8, %c-1_i8 : i8
+  %3 = arith.andi %arg0, %c34_i8 : i8
+  %4 = arith.andi %arg1, %2 : i8
+  %5 = arith.ori %3, %4 : i8
+  %c34_i8_0 = arith.constant 34 : i8
+  %7 = arith.andi %arg0, %c34_i8_0 : i8
+  %c-35_i8 = arith.constant -35 : i8
+  %9 = arith.andi %arg1, %c-35_i8 : i8
+  %10 = arith.ori %7, %9 : i8
+  %11 = arith.cmpi ne, %5, %10 : i8
+  cf.cond_br %11, ^bb1, ^bb2
+^bb1:  // pred: ^bb0
+  %13 = func.call @foo() : () -> none
+  cf.br ^bb2
+^bb2:  // pred: ^bb0, ^bb2
+  return
+}
+func.func private @foo() -> none
+
+
+// CHECK: define void @repro(i8 %0, i8 %1)
+//   CHECK-NEXT  ret void