Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -1677,7 +1677,8 @@
 // aliases for options that are spelled using the more common Unix / GNU flag
 // style of double-dash and equals-joined flags.
 def gcc_toolchain_legacy_spelling : Separate<["-"], "gcc-toolchain">, Alias<gcc_toolchain>;
-def target_legacy_spelling : Separate<["-"], "target">, Alias<target>;
+def target_legacy_spelling : Separate<["-", "--"], "target">, Alias<target>;
+def target_legacy_spelling_EQ : Joined<["-"], "target=">, Alias<target>;
 
 // Special internal option to handle -Xlinker --no-demangle.
 def Z_Xlinker__no_demangle : Flag<["-"], "Z-Xlinker-no-demangle">,
Index: test/Driver/target.c
===================================================================
--- test/Driver/target.c
+++ test/Driver/target.c
@@ -7,3 +7,9 @@
 // Also check that the legacy spelling works.
 // RUN: %clang -no-canonical-prefixes -target unknown-unknown-unknown -c %s \
 // RUN:   -o %t.o -### 2>&1 | FileCheck %s
+//
+// RUN: %clang -no-canonical-prefixes -target=unknown-unknown-unknown -c %s \
+// RUN:   -o %t.o -### 2>&1 | FileCheck %s
+//
+// RUN: %clang -no-canonical-prefixes --target unknown-unknown-unknown -c %s \
+// RUN:   -o %t.o -### 2>&1 | FileCheck %s