Index: lldb/source/Plugins/ABI/AArch64/ABIAArch64.h
===================================================================
--- lldb/source/Plugins/ABI/AArch64/ABIAArch64.h
+++ lldb/source/Plugins/ABI/AArch64/ABIAArch64.h
@@ -31,6 +31,8 @@
 
   uint32_t GetGenericNum(llvm::StringRef name) override;
 
+  void AugmentRegisterInfo(lldb_private::RegisterInfo &info) override;
+
   using lldb_private::MCBasedABI::MCBasedABI;
 };
 #endif
Index: lldb/source/Plugins/ABI/AArch64/ABIAArch64.cpp
===================================================================
--- lldb/source/Plugins/ABI/AArch64/ABIAArch64.cpp
+++ lldb/source/Plugins/ABI/AArch64/ABIAArch64.cpp
@@ -52,6 +52,7 @@
   MapRegisterName(reg, "x30", "lr");
   return reg;
 }
+
 uint32_t ABIAArch64::GetGenericNum(llvm::StringRef name) {
   return llvm::StringSwitch<uint32_t>(name)
       .Case("pc", LLDB_REGNUM_GENERIC_PC)
@@ -69,3 +70,11 @@
       .Case("x7", LLDB_REGNUM_GENERIC_ARG8)
       .Default(LLDB_INVALID_REGNUM);
 }
+
+void ABIAArch64::AugmentRegisterInfo(lldb_private::RegisterInfo &info) {
+  lldb_private::MCBasedABI::AugmentRegisterInfo(info);
+
+  // GDB sends x31 as "sp".  Add the "x31" alt_name for convenience.
+  if (!strcmp(info.name, "sp") && !info.alt_name)
+    info.alt_name = "x31";
+}
Index: lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -581,8 +581,12 @@
         // We have to make a temporary ABI here, and not use the GetABI because
         // this code gets called in DidAttach, when the target architecture
         // (and consequently the ABI we'll get from the process) may be wrong.
-        if (ABISP abi_sp = ABI::FindPlugin(shared_from_this(), arch_to_use))
+        if (ABISP abi_sp = ABI::FindPlugin(shared_from_this(), arch_to_use)) {
           abi_sp->AugmentRegisterInfo(reg_info);
+          // AugmentRegisterInfo() can modify alt_name
+          if (reg_info.alt_name)
+            alt_name.SetCString(reg_info.alt_name);
+        }
 
         m_register_info_sp->AddRegister(reg_info, reg_name, alt_name, set_name);
       } else {
@@ -4554,8 +4558,12 @@
         reg_num_remote = reg_info.kinds[eRegisterKindProcessPlugin] + 1;
         ++reg_num_local;
         reg_info.name = reg_name.AsCString();
-        if (abi_sp)
+        if (abi_sp) {
           abi_sp->AugmentRegisterInfo(reg_info);
+          // AugmentRegisterInfo() can modify alt_name
+          if (reg_info.alt_name)
+            alt_name.SetCString(reg_info.alt_name);
+        }
         dyn_reg_info.AddRegister(reg_info, reg_name, alt_name, set_name);
 
         return true; // Keep iterating through all "reg" elements
Index: lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py
===================================================================
--- lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py
+++ lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py
@@ -397,6 +397,12 @@
                    ["x0 = 0x0807060504030201"])
         self.match("register read x1",
                    ["x1 = 0x1817161514131211"])
+        self.match("register read x29",
+                   ["x29 = 0x3837363534333231"])
+        self.match("register read x30",
+                   ["x30 = 0x4847464544434241"])
+        self.match("register read x31",
+                   ["sp = 0x5857565554535251"])
         self.match("register read sp",
                    ["sp = 0x5857565554535251"])
         self.match("register read pc",