diff --git a/libunwind/src/Registers.hpp b/libunwind/src/Registers.hpp
--- a/libunwind/src/Registers.hpp
+++ b/libunwind/src/Registers.hpp
@@ -339,7 +339,7 @@
     return true;
   if (regNum < 0)
     return false;
-  if (regNum > 15)
+  if (regNum > 16)
     return false;
   return true;
 }
@@ -382,6 +382,8 @@
     return _registers.__r14;
   case UNW_X86_64_R15:
     return _registers.__r15;
+  case UNW_X86_64_RIP:
+    return _registers.__rip;
   }
   _LIBUNWIND_ABORT("unsupported x86_64 register");
 }
@@ -442,6 +444,9 @@
   case UNW_X86_64_R15:
     _registers.__r15 = value;
     return;
+  case UNW_X86_64_RIP:
+    _registers.__rip = value;
+    return;
   }
   _LIBUNWIND_ABORT("unsupported x86_64 register");
 }
@@ -484,6 +489,8 @@
     return "r14";
   case UNW_X86_64_R15:
     return "r15";
+  case UNW_X86_64_RIP:
+    return "rip";
   case UNW_X86_64_XMM0:
     return "xmm0";
   case UNW_X86_64_XMM1:
diff --git a/libunwind/test/libunwind_01.pass.cpp b/libunwind/test/libunwind_01.pass.cpp
--- a/libunwind/test/libunwind_01.pass.cpp
+++ b/libunwind/test/libunwind_01.pass.cpp
@@ -1,5 +1,7 @@
 #include <libunwind.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 void backtrace(int lower_bound) {
   unw_context_t context;
@@ -55,10 +57,80 @@
     abort();
 }
 
+#if defined(__x86_64__)
+void test_reg_names() {
+  unw_context_t context;
+  unw_getcontext(&context);
+
+  unw_cursor_t cursor;
+  unw_init_local(&cursor, &context);
+
+  for (int i = 0; i < 33; ++i) {
+    const char prefix[] = "unknown";
+    if (strncmp(prefix, unw_regname(&cursor, i), sizeof(prefix) - 1) == 0)
+      abort();
+  }
+}
+
+void test_reg_get_set() {
+  unw_context_t context;
+  unw_getcontext(&context);
+
+  unw_cursor_t cursor;
+  unw_init_local(&cursor, &context);
+
+  for (int i = 0; i < 17; ++i) {
+    const unw_word_t set_value = 7;
+    if (unw_set_reg(&cursor, i, set_value) != UNW_ESUCCESS) {
+      printf("1\n");
+      abort();
+    }
+
+    unw_word_t get_value = 0;
+    if (unw_get_reg(&cursor, i, &get_value) != UNW_ESUCCESS) {
+      printf("2\n");
+      abort();
+    }
+
+    if (set_value != get_value) {
+      printf("3\n");
+      abort();
+    }
+  }
+}
+
+void test_fpreg_get_set() {
+  unw_context_t context;
+  unw_getcontext(&context);
+
+  unw_cursor_t cursor;
+  unw_init_local(&cursor, &context);
+
+  // get/set is not implemented for x86_64 fpregs.
+  for (int i = 17; i < 33; ++i) {
+    const unw_fpreg_t set_value = 7;
+    if (unw_set_fpreg(&cursor, i, set_value) != UNW_EBADREG)
+      abort();
+
+    unw_fpreg_t get_value = 0;
+    if (unw_get_fpreg(&cursor, i, &get_value) != UNW_EBADREG)
+      abort();
+  }
+}
+
+#else
+void test_reg_names() {}
+void test_reg_get_set() {}
+void test_fpreg_get_set() {}
+#endif
+
 int main(int, char**) {
   test1(1);
   test2(1, 2);
   test3(1, 2, 3);
   test_no_info();
+  test_reg_names();
+  test_reg_get_set();
+  test_fpreg_get_set();
   return 0;
 }