Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -2134,7 +2134,7 @@
 def mno_fix_cortex_a53_835769 : Flag<["-"], "mno-fix-cortex-a53-835769">,
   Group<m_aarch64_Features_Group>,
   HelpText<"Don't workaround Cortex-A53 erratum 835769 (AArch64 only)">;
-foreach i = {1-7,18,20} in
+foreach i = {1-7,9-15,18,20-28} in
   def ffixed_x#i : Flag<["-"], "ffixed-x"#i>, Group<m_aarch64_Features_Group>,
     HelpText<"Reserve the "#i#" register (AArch64 only)">;
 
Index: lib/Driver/ToolChains/Arch/AArch64.cpp
===================================================================
--- lib/Driver/ToolChains/Arch/AArch64.cpp
+++ lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -334,12 +334,54 @@
   if (Args.hasArg(options::OPT_ffixed_x7))
     Features.push_back("+reserve-x7");
 
+  if (Args.hasArg(options::OPT_ffixed_x9))
+    Features.push_back("+reserve-x9");
+
+  if (Args.hasArg(options::OPT_ffixed_x10))
+    Features.push_back("+reserve-x10");
+
+  if (Args.hasArg(options::OPT_ffixed_x11))
+    Features.push_back("+reserve-x11");
+
+  if (Args.hasArg(options::OPT_ffixed_x12))
+    Features.push_back("+reserve-x12");
+
+  if (Args.hasArg(options::OPT_ffixed_x13))
+    Features.push_back("+reserve-x13");
+
+  if (Args.hasArg(options::OPT_ffixed_x14))
+    Features.push_back("+reserve-x14");
+
+  if (Args.hasArg(options::OPT_ffixed_x15))
+    Features.push_back("+reserve-x15");
+
   if (Args.hasArg(options::OPT_ffixed_x18))
     Features.push_back("+reserve-x18");
 
   if (Args.hasArg(options::OPT_ffixed_x20))
     Features.push_back("+reserve-x20");
 
+  if (Args.hasArg(options::OPT_ffixed_x21))
+    Features.push_back("+reserve-x21");
+
+  if (Args.hasArg(options::OPT_ffixed_x22))
+    Features.push_back("+reserve-x22");
+
+  if (Args.hasArg(options::OPT_ffixed_x23))
+    Features.push_back("+reserve-x23");
+
+  if (Args.hasArg(options::OPT_ffixed_x24))
+    Features.push_back("+reserve-x24");
+
+  if (Args.hasArg(options::OPT_ffixed_x26))
+    Features.push_back("+reserve-x26");
+
+  if (Args.hasArg(options::OPT_ffixed_x27))
+    Features.push_back("+reserve-x27");
+
+  if (Args.hasArg(options::OPT_ffixed_x28))
+    Features.push_back("+reserve-x28");
+
   if (Args.hasArg(options::OPT_fcall_saved_x8))
     Features.push_back("+call-saved-x8");
 
Index: test/Driver/aarch64-fixed-x-register.c
===================================================================
--- test/Driver/aarch64-fixed-x-register.c
+++ test/Driver/aarch64-fixed-x-register.c
@@ -26,6 +26,34 @@
 // RUN: FileCheck --check-prefix=CHECK-FIXED-X7 < %t %s
 // CHECK-FIXED-X7: "-target-feature" "+reserve-x7"
 
+// RUN: %clang -target aarch64-none-gnu -ffixed-x9 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X9 < %t %s
+// CHECK-FIXED-X9: "-target-feature" "+reserve-x9"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x10 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X10 < %t %s
+// CHECK-FIXED-X10: "-target-feature" "+reserve-x10"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x11 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X11 < %t %s
+// CHECK-FIXED-X11: "-target-feature" "+reserve-x11"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x12 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X12 < %t %s
+// CHECK-FIXED-X12: "-target-feature" "+reserve-x12"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x13 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X13 < %t %s
+// CHECK-FIXED-X13: "-target-feature" "+reserve-x13"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x14 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X14 < %t %s
+// CHECK-FIXED-X14: "-target-feature" "+reserve-x14"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x15 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X15 < %t %s
+// CHECK-FIXED-X15: "-target-feature" "+reserve-x15"
+
 // RUN: %clang -target aarch64-none-gnu -ffixed-x18 -### %s 2> %t
 // RUN: FileCheck --check-prefix=CHECK-FIXED-X18 < %t %s
 // CHECK-FIXED-X18: "-target-feature" "+reserve-x18"
@@ -34,6 +62,38 @@
 // RUN: FileCheck --check-prefix=CHECK-FIXED-X20 < %t %s
 // CHECK-FIXED-X20: "-target-feature" "+reserve-x20"
 
+// RUN: %clang -target aarch64-none-gnu -ffixed-x21 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X21 < %t %s
+// CHECK-FIXED-X21: "-target-feature" "+reserve-x21"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x22 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X22 < %t %s
+// CHECK-FIXED-X22: "-target-feature" "+reserve-x22"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x23 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X23 < %t %s
+// CHECK-FIXED-X23: "-target-feature" "+reserve-x23"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x24 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X24 < %t %s
+// CHECK-FIXED-X24: "-target-feature" "+reserve-x24"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x25 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X25 < %t %s
+// CHECK-FIXED-X25: "-target-feature" "+reserve-x25"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x26 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X26 < %t %s
+// CHECK-FIXED-X26: "-target-feature" "+reserve-x26"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x27 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X27 < %t %s
+// CHECK-FIXED-X27: "-target-feature" "+reserve-x27"
+
+// RUN: %clang -target aarch64-none-gnu -ffixed-x28 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X28 < %t %s
+// CHECK-FIXED-X28: "-target-feature" "+reserve-x28"
+
 // Test multiple of reserve-x# options together.
 // RUN: %clang -target aarch64-none-gnu \
 // RUN: -ffixed-x1 \
@@ -55,8 +115,23 @@
 // RUN: -ffixed-x5 \
 // RUN: -ffixed-x6 \
 // RUN: -ffixed-x7 \
+// RUN: -ffixed-x9 \
+// RUN: -ffixed-x10 \
+// RUN: -ffixed-x11 \
+// RUN: -ffixed-x12 \
+// RUN: -ffixed-x13 \
+// RUN: -ffixed-x14 \
+// RUN: -ffixed-x15 \
 // RUN: -ffixed-x18 \
 // RUN: -ffixed-x20 \
+// RUN: -ffixed-x21 \
+// RUN: -ffixed-x22 \
+// RUN: -ffixed-x23 \
+// RUN: -ffixed-x24 \
+// RUN: -ffixed-x25 \
+// RUN: -ffixed-x26 \
+// RUN: -ffixed-x27 \
+// RUN: -ffixed-x28 \
 // RUN: -### %s 2> %t
 // RUN: FileCheck \
 // RUN: --check-prefix=CHECK-FIXED-X1 \
@@ -66,6 +141,21 @@
 // RUN: --check-prefix=CHECK-FIXED-X5 \
 // RUN: --check-prefix=CHECK-FIXED-X6 \
 // RUN: --check-prefix=CHECK-FIXED-X7 \
+// RUN: --check-prefix=CHECK-FIXED-X9 \
+// RUN: --check-prefix=CHECK-FIXED-X10 \
+// RUN: --check-prefix=CHECK-FIXED-X11 \
+// RUN: --check-prefix=CHECK-FIXED-X12 \
+// RUN: --check-prefix=CHECK-FIXED-X13 \
+// RUN: --check-prefix=CHECK-FIXED-X14 \
+// RUN: --check-prefix=CHECK-FIXED-X15 \
 // RUN: --check-prefix=CHECK-FIXED-X18 \
 // RUN: --check-prefix=CHECK-FIXED-X20 \
+// RUN: --check-prefix=CHECK-FIXED-X21 \
+// RUN: --check-prefix=CHECK-FIXED-X22 \
+// RUN: --check-prefix=CHECK-FIXED-X23 \
+// RUN: --check-prefix=CHECK-FIXED-X24 \
+// RUN: --check-prefix=CHECK-FIXED-X25 \
+// RUN: --check-prefix=CHECK-FIXED-X26 \
+// RUN: --check-prefix=CHECK-FIXED-X27 \
+// RUN: --check-prefix=CHECK-FIXED-X28 \
 // RUN: < %t %s