Index: llvm/lib/Passes/StandardInstrumentations.cpp
===================================================================
--- llvm/lib/Passes/StandardInstrumentations.cpp
+++ llvm/lib/Passes/StandardInstrumentations.cpp
@@ -68,7 +68,8 @@
 // or indicating that the IR has been filtered out.  The extra options
 // can be combined, allowing only changed IRs for certain passes on certain
 // functions to be reported in different formats, with the rest being
-// reported as filtered out.
+// reported as filtered out.  The -also-print-before option will print
+// the IR as it was before each pass that changed it.
 static cl::opt<bool> PrintChanged("print-changed",
                                   cl::desc("Print changed IRs"),
                                   cl::init(false), cl::Hidden);
@@ -80,6 +81,13 @@
                     cl::desc("Only consider IR changes for passes whose names "
                              "match for the print-changed option"),
                     cl::CommaSeparated, cl::Hidden);
+// An option that supports the -print-changed option.  See
+// the description for -print-changed for an explanation of the use
+// of this option.  Note that this option has no effect without -print-changed.
+static cl::opt<bool>
+    AlsoPrintBefore("also-print-before",
+                    cl::desc("Print before passes that change them"),
+                    cl::init(false), cl::Hidden);
 
 namespace {
 
@@ -394,6 +402,19 @@
   StringRef AfterRef = After;
   StringRef Banner =
       AfterRef.take_until([](char C) -> bool { return C == '\n'; });
+
+  // Report the IR before the changes when requested.
+  if (AlsoPrintBefore) {
+    Out << "*** IR Dump Before" << Banner.substr(17);
+    // LazyCallGraph::SCC already has "(scc:..." in banner so only add
+    // in the name if it isn't already there.
+    if (Name.substr(0, 6) != " (scc:" && !llvm::forcePrintModuleIR())
+      Out << Name;
+
+    StringRef BeforeRef = Before;
+    Out << BeforeRef.substr(Banner.size());
+  }
+
   Out << Banner;
 
   // LazyCallGraph::SCC already has "(scc:..." in banner so only add
Index: llvm/test/Other/change-printer.ll
===================================================================
--- llvm/test/Other/change-printer.ll
+++ llvm/test/Other/change-printer.ll
@@ -34,6 +34,15 @@
 ; others (including g) are filtered out.  Note that the second time
 ; instsimplify is run on f, it does not change the IR
 ; RUN: opt -S -print-changed -passes="instsimplify,instsimplify" -filter-print-funcs=f  2>&1 -o /dev/null < %s | FileCheck %s --check-prefix=CHECK-MULT-PASSES-FILTER-FUNC
+;
+; Simple -also-print-before functionality check.
+; RUN: opt -S -print-changed -also-print-before -passes=instsimplify 2>&1 -o /dev/null < %s | FileCheck %s --check-prefix=CHECK-SIMPLE-BEFORE
+;
+; Check that -also-print-before obeys the function filtering
+; RUN: opt -S -print-changed -also-print-before -passes=instsimplify -filter-print-funcs=f  2>&1 -o /dev/null < %s | FileCheck %s --check-prefix=CHECK-FUNC-FILTER-BEFORE
+;
+; Check that the reporting of IRs with -also-print-before respects -print-module-scope
+; RUN: opt -S -print-changed -also-print-before -passes=instsimplify -print-module-scope 2>&1 -o /dev/null < %s | FileCheck %s --check-prefix=CHECK-PRINT-MOD-SCOPE-BEFORE
 
 define i32 @g() {
 entry:
@@ -126,3 +135,40 @@
 ; CHECK-MULT-PASSES-FILTER-FUNC: *** IR Dump After InstSimplifyPass *** (function: f)
 ; CHECK-MULT-PASSES-FILTER-FUNC-NEXT: define i32 @f()
 ; CHECK-MULT-PASSES-FILTER-FUNC: *** IR Dump After InstSimplifyPass (function: f) omitted because no change ***
+
+; CHECK-SIMPLE-BEFORE: *** IR Dump At Start: ***
+; CHECK-SIMPLE-BEFORE-NEXT: ; ModuleID = {{.+}}
+; CHECK-SIMPLE-BEFORE: *** IR Dump After VerifierPass (module) omitted because no change ***
+; CHECK-SIMPLE-BEFORE: *** IR Dump Before InstSimplifyPass *** (function: g)
+; CHECK-SIMPLE-BEFORE-NEXT: define i32 @g()
+; CHECK-SIMPLE-BEFORE: *** IR Dump After InstSimplifyPass *** (function: g)
+; CHECK-SIMPLE-BEFORE-NEXT: define i32 @g()
+; CHECK-SIMPLE-BEFORE: *** IR Pass PassManager{{.*}} (function: g) ignored ***
+; CHECK-SIMPLE-BEFORE: *** IR Dump Before InstSimplifyPass *** (function: f)
+; CHECK-SIMPLE-BEFORE-NEXT: define i32 @f()
+; CHECK-SIMPLE-BEFORE: *** IR Dump After InstSimplifyPass *** (function: f)
+; CHECK-SIMPLE-BEFORE-NEXT: define i32 @f()
+; CHECK-SIMPLE-BEFORE: *** IR Pass PassManager{{.*}} (function: f) ignored ***
+; CHECK-SIMPLE-BEFORE: *** IR Pass ModuleToFunctionPassAdaptor<{{.*}}PassManager{{.*}}> (module) ignored ***
+; CHECK-SIMPLE-BEFORE: *** IR Dump After VerifierPass (module) omitted because no change ***
+; CHECK-SIMPLE-BEFORE: *** IR Dump After PrintModulePass (module) omitted because no change ***
+; CHECK-SIMPLE-BEFORE-NOT: *** IR
+
+; CHECK-FUNC-FILTER-BEFORE: *** IR Dump At Start: ***
+; CHECK-FUNC-FILTER-BEFORE-NEXT: ; ModuleID = {{.+}}
+; CHECK-FUNC-FILTER-BEFORE: *** IR Dump After InstSimplifyPass (function: g) filtered out ***
+; CHECK-FUNC-FILTER-BEFORE: *** IR Dump Before InstSimplifyPass *** (function: f)
+; CHECK-FUNC-FILTER-BEFORE-NEXT: define i32 @f()
+; CHECK-FUNC-FILTER-BEFORE: *** IR Dump After InstSimplifyPass *** (function: f)
+; CHECK-FUNC-FILTER-BEFORE-NEXT: define i32 @f()
+
+; CHECK-PRINT-MOD-SCOPE-BEFORE: *** IR Dump At Start: ***
+; CHECK-PRINT-MOD-SCOPE-BEFORE-NEXT: ModuleID = {{.+}}
+; CHECK-PRINT-MOD-SCOPE-BEFORE: *** IR Dump Before InstSimplifyPass *** (function: g)
+; CHECK-PRINT-MOD-SCOPE-BEFORE-NEXT: ModuleID = {{.+}}
+; CHECK-PRINT-MOD-SCOPE-BEFORE: *** IR Dump After InstSimplifyPass *** (function: g)
+; CHECK-PRINT-MOD-SCOPE-BEFORE-NEXT: ModuleID = {{.+}}
+; CHECK-PRINT-MOD-SCOPE-BEFORE: *** IR Dump Before InstSimplifyPass *** (function: f)
+; CHECK-PRINT-MOD-SCOPE-BEFORE-NEXT: ModuleID = {{.+}}
+; CHECK-PRINT-MOD-SCOPE-BEFORE: *** IR Dump After InstSimplifyPass *** (function: f)
+; CHECK-PRINT-MOD-SCOPE-BEFORE-NEXT: ModuleID = {{.+}}