Index: lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.h
===================================================================
--- lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.h
+++ lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.h
@@ -112,6 +112,24 @@
   static uint32_t g_invalidate_fip[];
   static uint32_t g_invalidate_fdp[];
 
+  static uint32_t g_contained_st0_64[];
+  static uint32_t g_contained_st1_64[];
+  static uint32_t g_contained_st2_64[];
+  static uint32_t g_contained_st3_64[];
+  static uint32_t g_contained_st4_64[];
+  static uint32_t g_contained_st5_64[];
+  static uint32_t g_contained_st6_64[];
+  static uint32_t g_contained_st7_64[];
+
+  static uint32_t g_invalidate_st0_64[];
+  static uint32_t g_invalidate_st1_64[];
+  static uint32_t g_invalidate_st2_64[];
+  static uint32_t g_invalidate_st3_64[];
+  static uint32_t g_invalidate_st4_64[];
+  static uint32_t g_invalidate_st5_64[];
+  static uint32_t g_invalidate_st6_64[];
+  static uint32_t g_invalidate_st7_64[];
+
 protected:
   struct RegInfo {
     uint32_t num_registers;
Index: lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.cpp
===================================================================
--- lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.cpp
+++ lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.cpp
@@ -286,6 +286,40 @@
 uint32_t RegisterContextPOSIX_x86::g_invalidate_fdp[] = {
     lldb_fdp_x86_64, lldb_fooff_x86_64, lldb_foseg_x86_64, LLDB_INVALID_REGNUM};
 
+uint32_t RegisterContextPOSIX_x86::g_contained_st0_64[] = {lldb_st0_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st1_64[] = {lldb_st1_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st2_64[] = {lldb_st2_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st3_64[] = {lldb_st3_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st4_64[] = {lldb_st4_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st5_64[] = {lldb_st5_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st6_64[] = {lldb_st6_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_contained_st7_64[] = {lldb_st7_x86_64,
+                                                           LLDB_INVALID_REGNUM};
+
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st0_64[] = {
+    lldb_st0_x86_64, lldb_mm0_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st1_64[] = {
+    lldb_st1_x86_64, lldb_mm1_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st2_64[] = {
+    lldb_st2_x86_64, lldb_mm2_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st3_64[] = {
+    lldb_st3_x86_64, lldb_mm3_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st4_64[] = {
+    lldb_st4_x86_64, lldb_mm4_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st5_64[] = {
+    lldb_st5_x86_64, lldb_mm5_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st6_64[] = {
+    lldb_st6_x86_64, lldb_mm6_x86_64, LLDB_INVALID_REGNUM};
+uint32_t RegisterContextPOSIX_x86::g_invalidate_st7_64[] = {
+    lldb_st7_x86_64, lldb_mm7_x86_64, LLDB_INVALID_REGNUM};
+
 // Number of register sets provided by this context.
 enum { k_num_extended_register_sets = 1, k_num_register_sets = 3 };
 
Index: lldb/source/Plugins/Process/Utility/RegisterInfos_x86_64.h
===================================================================
--- lldb/source/Plugins/Process/Utility/RegisterInfos_x86_64.h
+++ lldb/source/Plugins/Process/Utility/RegisterInfos_x86_64.h
@@ -88,7 +88,7 @@
              nullptr, nullptr, nullptr, 0                                      \
   }
 
-#define DEFINE_FP_MM(reg, i)                                                   \
+#define DEFINE_FP_MM(reg, i, streg)                                            \
   {                                                                            \
     #reg #i, nullptr, sizeof(uint64_t),                                        \
                           LLVM_EXTENSION FPR_OFFSET(                           \
@@ -96,7 +96,9 @@
                               {dwarf_mm##i##_x86_64, dwarf_mm##i##_x86_64,     \
                                LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM,       \
                                lldb_mm##i##_x86_64 },                          \
-                               nullptr, nullptr, nullptr, 0                    \
+                               RegisterContextPOSIX_x86::g_contained_##streg,  \
+                               RegisterContextPOSIX_x86::g_invalidate_##streg, \
+                               nullptr, 0                                      \
   }
 
 #define DEFINE_XMM(reg, i)                                                     \
@@ -277,10 +279,12 @@
     // FP registers.
     DEFINE_FP_ST(st, 0), DEFINE_FP_ST(st, 1), DEFINE_FP_ST(st, 2),
     DEFINE_FP_ST(st, 3), DEFINE_FP_ST(st, 4), DEFINE_FP_ST(st, 5),
-    DEFINE_FP_ST(st, 6), DEFINE_FP_ST(st, 7), DEFINE_FP_MM(mm, 0),
-    DEFINE_FP_MM(mm, 1), DEFINE_FP_MM(mm, 2), DEFINE_FP_MM(mm, 3),
-    DEFINE_FP_MM(mm, 4), DEFINE_FP_MM(mm, 5), DEFINE_FP_MM(mm, 6),
-    DEFINE_FP_MM(mm, 7),
+    DEFINE_FP_ST(st, 6), DEFINE_FP_ST(st, 7),
+
+    DEFINE_FP_MM(mm, 0, st0_64), DEFINE_FP_MM(mm, 1, st1_64),
+    DEFINE_FP_MM(mm, 2, st2_64), DEFINE_FP_MM(mm, 3, st3_64),
+    DEFINE_FP_MM(mm, 4, st4_64), DEFINE_FP_MM(mm, 5, st5_64),
+    DEFINE_FP_MM(mm, 6, st6_64), DEFINE_FP_MM(mm, 7, st7_64),
 
     // XMM registers
     DEFINE_XMM(xmm, 0), DEFINE_XMM(xmm, 1), DEFINE_XMM(xmm, 2),