diff --git a/llvm/test/tools/llvm-reduce/Inputs/llvm-dis-and-filecheck.py b/llvm/test/tools/llvm-reduce/Inputs/llvm-dis-and-filecheck.py
new file mode 100755
--- /dev/null
+++ b/llvm/test/tools/llvm-reduce/Inputs/llvm-dis-and-filecheck.py
@@ -0,0 +1,29 @@
+"""
+Script to disassembles a bitcode file and run FileCheck on the output with the
+provided arguments. The first 2 arguments are the paths to the llvm-dis and
+FileCheck binaries, followed by arguments to be passed to FileCheck. The last
+argument is the bitcode file to disassemble.
+
+Usage:
+    python llvm-dis-and-filecheck.py
+      <path to llvm-dis> <path to FileCheck>
+      [arguments passed to FileCheck] <path to bitcode file>
+
+"""
+
+
+import sys
+import subprocess
+
+llvm_dis = sys.argv[1]
+filecheck = sys.argv[2]
+filecheck_args = [filecheck, ]
+filecheck_args.extend(sys.argv[3:-1])
+bitcode_file = sys.argv[-1]
+
+disassemble = subprocess.Popen([llvm_dis, "-o", "-", bitcode_file],
+        stdout=subprocess.PIPE)
+check = subprocess.Popen(filecheck_args, stdin=disassemble.stdout)
+disassemble.stdout.close()
+check.communicate()
+sys.exit(check.returncode)
diff --git a/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll b/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-reduce -write-tmp-files-as-bitcode --delta-passes=basic-blocks %s -o %t \
+; RUN:     --test %python --test-arg %p/Inputs/llvm-dis-and-filecheck.py --test-arg llvm-dis --test-arg FileCheck --test-arg --check-prefixes=CHECK-ALL,CHECK-INTERESTINGNESS --test-arg %s
+; RUN: cat %t | FileCheck --check-prefixes=CHECK-ALL,CHECK-FINAL %s
+
+; CHECK-INTERESTINGNESS: @callee(
+; CHECK-FINAL: declare void @callee()
+define void @callee() {
+  ret void
+}
+
+; CHECK-ALL: define void @caller()
+define void @caller() {
+entry:
+; CHECK-ALL: call void @callee()
+; CHECK-ALL: ret void
+  call void @callee()
+  ret void
+}
diff --git a/llvm/tools/llvm-reduce/deltas/Delta.cpp b/llvm/tools/llvm-reduce/deltas/Delta.cpp
--- a/llvm/tools/llvm-reduce/deltas/Delta.cpp
+++ b/llvm/tools/llvm-reduce/deltas/Delta.cpp
@@ -15,6 +15,7 @@
 #include "Delta.h"
 #include "ReducerWorkItem.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ToolOutputFile.h"
@@ -31,6 +32,11 @@
     "starting-granularity-level",
     cl::desc("Number of times to divide chunks prior to first test"));
 
+static cl::opt<bool> TmpFilesAsBitcode(
+    "write-tmp-files-as-bitcode",
+    cl::desc("Write temporary files as bitcode, instead of textual IR"),
+    cl::init(false));
+
 void writeOutput(ReducerWorkItem &M, llvm::StringRef Message);
 
 bool isReduced(ReducerWorkItem &M, TestRunner &Test,
@@ -38,12 +44,26 @@
   // Write ReducerWorkItem to tmp file
   int FD;
   std::error_code EC = sys::fs::createTemporaryFile(
-      "llvm-reduce", M.isMIR() ? "mir" : "ll", FD, CurrentFilepath);
+      "llvm-reduce", M.isMIR() ? "mir" : (TmpFilesAsBitcode ? "bc" : "ll"), FD,
+      CurrentFilepath);
   if (EC) {
     errs() << "Error making unique filename: " << EC.message() << "!\n";
     exit(1);
   }
 
+  if (TmpFilesAsBitcode) {
+    llvm::raw_fd_ostream OutStream(FD, true);
+    WriteBitcodeToFile(M, OutStream);
+    OutStream.close();
+    if (OutStream.has_error()) {
+      errs() << "Error emitting bitcode to file '" << CurrentFilepath << "'!\n";
+      sys::fs::remove(CurrentFilepath);
+      exit(1);
+    }
+    bool Res = Test.run(CurrentFilepath);
+    sys::fs::remove(CurrentFilepath);
+    return Res;
+  }
   ToolOutputFile Out(CurrentFilepath, FD);
   M.print(Out.os(), /*AnnotationWriter=*/nullptr);
   Out.os().close();