Index: llvm/test/tools/llvm-objdump/X86/source-interleave-prefix-windows.test
===================================================================
--- llvm/test/tools/llvm-objdump/X86/source-interleave-prefix-windows.test
+++ llvm/test/tools/llvm-objdump/X86/source-interleave-prefix-windows.test
@@ -6,6 +6,6 @@
 
 ; RUN: sed -e "s,SRC_COMPDIR,/Inputs,g" %p/Inputs/source-interleave.ll > %t.ll
 ; RUN: llc -o %t.o -filetype=obj -mtriple=x86_64-pc-linux %t.ll
-; RUN: llvm-objdump --prefix 'myprefix/\' --source %t.o 2>&1 | FileCheck %s -DFILE=%t.o -DPREFIX='myprefix'
+; RUN: llvm-objdump --prefix='myprefix/\' --source %t.o 2>&1 | FileCheck %s -DFILE=%t.o -DPREFIX='myprefix'
 ; CHECK: warning: '[[FILE]]': failed to find source [[PREFIX]]/Inputs\source-interleave-x86_64.c
 
Index: llvm/test/tools/llvm-objdump/X86/source-interleave-prefix.test
===================================================================
--- llvm/test/tools/llvm-objdump/X86/source-interleave-prefix.test
+++ llvm/test/tools/llvm-objdump/X86/source-interleave-prefix.test
@@ -11,7 +11,7 @@
 
 ; RUN: sed -e "s,SRC_COMPDIR,./Inputs,g" %p/Inputs/source-interleave.ll > %t-relative-path.ll
 ; RUN: llc -o %t-relative-path.o -filetype=obj -mtriple=x86_64-pc-linux %t-relative-path.ll
-; RUN: llvm-objdump --prefix myprefix --source %t-relative-path.o 2>&1 | \
+; RUN: llvm-objdump --prefix=myprefix --source %t-relative-path.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-BROKEN-PREFIX -DFILE=%t-relative-path.o -DPREFIX=. -DCOMPDIR=/Inputs
 ; CHECK-BROKEN-PREFIX: warning: '[[FILE]]': failed to find source [[PREFIX]][[COMPDIR]]{{[/\\]}}source-interleave-x86_64.c
 
@@ -19,7 +19,7 @@
 
 ; RUN: sed -e "s,SRC_COMPDIR,/Inputs,g" %p/Inputs/source-interleave.ll > %t-missing-prefix.ll
 ; RUN: llc -o %t-missing-prefix.o -filetype=obj -mtriple=x86_64-pc-linux %t-missing-prefix.ll
-; RUN: llvm-objdump --prefix %p --source %t-missing-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=%p --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX
 ; CHECK-MISSING-PREFIX-FIX: ; int foo() {
 
@@ -27,18 +27,18 @@
 
 ; RUN: sed -e "s,SRC_COMPDIR,%/p/Inputs,g" %p/Inputs/source-interleave.ll > %t-correct-prefix.ll
 ; RUN: llc -o %t-correct-prefix.o -filetype=obj -mtriple=x86_64-pc-linux %t-correct-prefix.ll
-; RUN: llvm-objdump --prefix myprefix --source %t-correct-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=myprefix --source %t-correct-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-BROKEN-PREFIX -DFILE=%t-correct-prefix.o -DPREFIX=myprefix%/p -DCOMPDIR=/Inputs
 
 ;; Using only a prefix separator is the same as not using the `--prefix` option.
 
-; RUN: llvm-objdump --prefix / --source %t-missing-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=/ --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-BROKEN-PREFIX -DFILE=%t-missing-prefix.o -DPREFIX='' -DCOMPDIR=/Inputs
 
 ;; All trailing separators on the prefix are discarded.
 ;; The prefix 'myprefix//' is converted to 'myprefix'.
 
-; RUN: llvm-objdump --prefix myprefix// --source %t-missing-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=myprefix// --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-BROKEN-PREFIX -DFILE=%t-missing-prefix.o -DPREFIX=myprefix -DCOMPDIR=/Inputs
 
 ;; Test invalid source interleave fixed by adding the correct prefix and
@@ -46,7 +46,7 @@
 
 ; RUN: sed -e "s,SRC_COMPDIR,/extra/Inputs,g" %p/Inputs/source-interleave.ll > %t-extra-path-prefix.ll
 ; RUN: llc -o %t-extra-path-prefix.o -filetype=obj -mtriple=x86_64-pc-linux %t-extra-path-prefix.ll
-; RUN: llvm-objdump --prefix %p --prefix-strip 1 --source %t-extra-path-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=%p --prefix-strip=1 --source %t-extra-path-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX
 
 ;; Test do not skip extra separators. The --prefix-strip should take into
@@ -56,36 +56,36 @@
 
 ; RUN: sed -e "s,SRC_COMPDIR,//extra/Inputs,g" %p/Inputs/source-interleave.ll > %t-extra-sep-path-prefix.ll
 ; RUN: llc -o %t-extra-sep-path-prefix.o -filetype=obj -mtriple=x86_64-pc-linux %t-extra-sep-path-prefix.ll
-; RUN: llvm-objdump --prefix %p --prefix-strip 2 --source %t-extra-sep-path-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=%p --prefix-strip=2 --source %t-extra-sep-path-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX
 
 ;; Test --prefix-strip value of 0. No effect.
-;; SRC_COMPDIR is set to '/Inputs' before and after --prefix-strip 0.
+;; SRC_COMPDIR is set to '/Inputs' before and after --prefix-strip=0.
 
-; RUN: llvm-objdump --prefix %p --prefix-strip 0 --source %t-missing-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=%p --prefix-strip=0 --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX
 
 ;; Test --prefix-strip value equal to the number of directory components.
-;; SRC_COMPDIR is set to '/Inputs' before --prefix-strip 1.
-;; SRC_COMPDIR becomes '' after --prefix-strip 1.
+;; SRC_COMPDIR is set to '/Inputs' before --prefix-strip=1.
+;; SRC_COMPDIR becomes '' after --prefix-strip=1.
 
-; RUN: llvm-objdump --prefix %p/Inputs --prefix-strip 1 --source %t-missing-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=%p/Inputs --prefix-strip=1 --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX
 
 ;; Test --prefix-strip value greater than the number of components.
-;; SRC_COMPDIR is set to '/Inputs' before --prefix-strip 2.
-;; SRC_COMPDIR becomes '' after --prefix-strip 2.
+;; SRC_COMPDIR is set to '/Inputs' before --prefix-strip=2.
+;; SRC_COMPDIR becomes '' after --prefix-strip=2.
 
-; RUN: llvm-objdump --prefix %p/Inputs --prefix-strip 2 --source %t-missing-prefix.o 2>&1 | \
+; RUN: llvm-objdump --prefix=%p/Inputs --prefix-strip=2 --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX
 
 ;; Test negative value --prefix-strip. Reports an error.
 
-; RUN: not llvm-objdump --prefix %p --prefix-strip '-1' --source %t-missing-prefix.o 2>&1 | \
+; RUN: not llvm-objdump --prefix=%p --prefix-strip='-1' --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-INVALID-PREFIX-STRIP -DOPTION='-1'
-; CHECK-INVALID-PREFIX-STRIP: {{.*}}llvm-objdump{{.*}}: error: --prefix-strip: expected a non-negative integer, but got '[[OPTION]]'
+; CHECK-INVALID-PREFIX-STRIP: {{.*}}llvm-objdump{{.*}}: error: --prefix-strip=: expected a non-negative integer, but got '[[OPTION]]'
 
 ;; Test text value --prefix-strip. Reports an error.
 
-; RUN: not llvm-objdump --prefix %p --prefix-strip foo --source %t-missing-prefix.o 2>&1 | \
+; RUN: not llvm-objdump --prefix=%p --prefix-strip=foo --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-INVALID-PREFIX-STRIP -DOPTION='foo'
Index: llvm/tools/llvm-objdump/ObjdumpOpts.td
===================================================================
--- llvm/tools/llvm-objdump/ObjdumpOpts.td
+++ llvm/tools/llvm-objdump/ObjdumpOpts.td
@@ -180,10 +180,10 @@
   HelpText<"Ignored for compatibility with GNU objdump">;
 def : Flag<["-"], "w">, Alias<wide>;
 
-def prefix : Separate<["--"], "prefix">,
+def prefix_EQ : Joined<["--"], "prefix=">,
   HelpText<"Add prefix to absolute paths">;
 
-def prefix_strip : Separate<["--"], "prefix-strip">,
+def prefix_strip_EQ : Joined<["--"], "prefix-strip=">,
   HelpText<"Strip out initial directories from absolute "
            "paths. No effect without --prefix">;
 
Index: llvm/tools/llvm-objdump/llvm-objdump.cpp
===================================================================
--- llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -2560,8 +2560,8 @@
   TripleName = InputArgs.getLastArgValue(OBJDUMP_triple_EQ).str();
   UnwindInfo = InputArgs.hasArg(OBJDUMP_unwind_info);
   Wide = InputArgs.hasArg(OBJDUMP_wide);
-  Prefix = InputArgs.getLastArgValue(OBJDUMP_prefix).str();
-  parseIntArg(InputArgs, OBJDUMP_prefix_strip, PrefixStrip);
+  Prefix = InputArgs.getLastArgValue(OBJDUMP_prefix_EQ).str();
+  parseIntArg(InputArgs, OBJDUMP_prefix_strip_EQ, PrefixStrip);
   if (const opt::Arg *A = InputArgs.getLastArg(OBJDUMP_debug_vars_EQ)) {
     DbgVariables = StringSwitch<DebugVarsFormat>(A->getValue())
                        .Case("ascii", DVASCII)