diff --git a/target-i386/helper.h b/target-i386/helper.h
index e40216b..709b195 100644
--- a/target-i386/helper.h
+++ b/target-i386/helper.h
@@ -17,6 +17,10 @@ DEF_HELPER_2(idivq_EAX, void, env, tl)
 #endif
 
 DEF_HELPER_FLAGS_2(bndck, TCG_CALL_NO_WG, void, env, i32)
+DEF_HELPER_FLAGS_3(bndldx32, TCG_CALL_NO_WG, i64, env, tl, tl)
+DEF_HELPER_FLAGS_3(bndldx64, TCG_CALL_NO_WG, i64, env, tl, tl)
+DEF_HELPER_FLAGS_5(bndstx32, TCG_CALL_NO_WG, void, env, tl, tl, i64, i64)
+DEF_HELPER_FLAGS_5(bndstx64, TCG_CALL_NO_WG, void, env, tl, tl, i64, i64)
 
 DEF_HELPER_2(aam, void, env, int)
 DEF_HELPER_2(aad, void, env, int)
diff --git a/target-i386/mpx_helper.c b/target-i386/mpx_helper.c
index e4d5aba..53d9834 100644
--- a/target-i386/mpx_helper.c
+++ b/target-i386/mpx_helper.c
@@ -59,3 +59,100 @@ void helper_bndck(CPUX86State *env, uint32_t fail)
         raise_exception_ra(env, EXCP05_BOUND, GETPC());
     }
 }
+
+static uint64_t lookup_bte64(CPUX86State *env, uint64_t base, uintptr_t ra)
+{
+    uint64_t bndcsr, bde, bt;
+
+    if ((env->hflags & HF_CPL_MASK) == 3) {
+        bndcsr = env->bndcs_regs.cfgu;
+    } else {
+        bndcsr = env->msr_bndcfgs;
+    }
+
+    bde = (extract64(base, 20, 28) << 3) + (extract64(bndcsr, 20, 44) << 12);
+    bt = cpu_ldq_data_ra(env, bde, ra);
+    if ((bt & 1) == 0) {
+        env->bndcs_regs.sts = bde | 2;
+        raise_exception_ra(env, EXCP05_BOUND, ra);
+    }
+
+    return (extract64(base, 3, 17) << 5) + (bt & ~7);
+}
+
+static uint32_t lookup_bte32(CPUX86State *env, uint32_t base, uintptr_t ra)
+{
+    uint32_t bndcsr, bde, bt;
+
+    if ((env->hflags & HF_CPL_MASK) == 3) {
+        bndcsr = env->bndcs_regs.cfgu;
+    } else {
+        bndcsr = env->msr_bndcfgs;
+    }
+
+    bde = (extract32(base, 12, 20) << 2) + (bndcsr & TARGET_PAGE_MASK);
+    bt = cpu_ldl_data_ra(env, bde, ra);
+    if ((bt & 1) == 0) {
+        env->bndcs_regs.sts = bde | 2;
+        raise_exception_ra(env, EXCP05_BOUND, ra);
+    }
+
+    return (extract32(base, 2, 10) << 4) + (bt & ~3);
+}
+
+uint64_t helper_bndldx64(CPUX86State *env, target_ulong base, target_ulong ptr)
+{
+    uintptr_t ra = GETPC();
+    uint64_t bte, lb, ub, pt;
+
+    bte = lookup_bte64(env, base, ra);
+    lb = cpu_ldq_data_ra(env, bte, ra);
+    ub = cpu_ldq_data_ra(env, bte + 8, ra);
+    pt = cpu_ldq_data_ra(env, bte + 16, ra);
+
+    if (pt != ptr) {
+        lb = ub = 0;
+    }
+    env->mmx_t0.MMX_Q(0) = ub;
+    return lb;
+}
+
+uint64_t helper_bndldx32(CPUX86State *env, target_ulong base, target_ulong ptr)
+{
+    uintptr_t ra = GETPC();
+    uint32_t bte, lb, ub, pt;
+
+    bte = lookup_bte32(env, base, ra);
+    lb = cpu_ldl_data_ra(env, bte, ra);
+    ub = cpu_ldl_data_ra(env, bte + 4, ra);
+    pt = cpu_ldl_data_ra(env, bte + 8, ra);
+
+    if (pt != ptr) {
+        lb = ub = 0;
+    }
+    return ((uint64_t)ub << 32) | lb;
+}
+
+void helper_bndstx64(CPUX86State *env, target_ulong base, target_ulong ptr,
+                     uint64_t lb, uint64_t ub)
+{
+    uintptr_t ra = GETPC();
+    uint64_t bte;
+
+    bte = lookup_bte64(env, base, ra);
+    cpu_stq_data_ra(env, bte, lb, ra);
+    cpu_stq_data_ra(env, bte + 8, ub, ra);
+    cpu_stq_data_ra(env, bte + 16, ptr, ra);
+}
+
+void helper_bndstx32(CPUX86State *env, target_ulong base, target_ulong ptr,
+                     uint64_t lb, uint64_t ub)
+{
+    uintptr_t ra = GETPC();
+    uint32_t bte;
+
+    bte = lookup_bte32(env, base, ra);
+    cpu_stl_data_ra(env, bte, lb, ra);
+    cpu_stl_data_ra(env, bte + 4, ub, ra);
+    cpu_stl_data_ra(env, bte + 8, ptr, ra);
+}
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 7db662f..0dda4a8 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -7507,6 +7507,36 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
                     /* bnd registers are now in-use */
                     gen_set_hflag(s, HF_MPX_IU_MASK);
                 }
+            } else if (mod != 3) {
+                /* bndldx */
+                AddressParts a = gen_lea_modrm_0(env, s, modrm);
+                if (reg >= 4
+                    || (prefixes & PREFIX_LOCK)
+                    || s->aflag == MO_16
+                    || a.base < -1) {
+                    goto illegal_op;
+                }
+                if (a.base >= 0) {
+                    tcg_gen_addi_tl(cpu_A0, cpu_regs[a.base], a.disp);
+                } else {
+                    tcg_gen_movi_tl(cpu_A0, 0);
+                }
+                gen_lea_v_seg(s, s->aflag, cpu_A0, a.def_seg, s->override);
+                if (a.index >= 0) {
+                    tcg_gen_mov_tl(cpu_T0, cpu_regs[a.index]);
+                } else {
+                    tcg_gen_movi_tl(cpu_T0, 0);
+                }
+                if (CODE64(s)) {
+                    gen_helper_bndldx64(cpu_bndl[reg], cpu_env, cpu_A0, cpu_T0);
+                    tcg_gen_ld_i64(cpu_bndu[reg], cpu_env,
+                                   offsetof(CPUX86State, mmx_t0.MMX_Q(0)));
+                } else {
+                    gen_helper_bndldx32(cpu_bndu[reg], cpu_env, cpu_A0, cpu_T0);
+                    tcg_gen_ext32u_i64(cpu_bndl[reg], cpu_bndu[reg]);
+                    tcg_gen_shri_i64(cpu_bndu[reg], cpu_bndu[reg], 32);
+                }
+                gen_set_hflag(s, HF_MPX_IU_MASK);
             }
         }
         gen_nop_modrm(env, s, modrm);
@@ -7582,6 +7612,33 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
                                             s->mem_index, MO_LEUL);
                     }
                 }
+            } else if (mod != 3) {
+                /* bndstx */
+                AddressParts a = gen_lea_modrm_0(env, s, modrm);
+                if (reg >= 4
+                    || (prefixes & PREFIX_LOCK)
+                    || s->aflag == MO_16
+                    || a.base < -1) {
+                    goto illegal_op;
+                }
+                if (a.base >= 0) {
+                    tcg_gen_addi_tl(cpu_A0, cpu_regs[a.base], a.disp);
+                } else {
+                    tcg_gen_movi_tl(cpu_A0, 0);
+                }
+                gen_lea_v_seg(s, s->aflag, cpu_A0, a.def_seg, s->override);
+                if (a.index >= 0) {
+                    tcg_gen_mov_tl(cpu_T0, cpu_regs[a.index]);
+                } else {
+                    tcg_gen_movi_tl(cpu_T0, 0);
+                }
+                if (CODE64(s)) {
+                    gen_helper_bndstx64(cpu_env, cpu_A0, cpu_T0,
+                                        cpu_bndl[reg], cpu_bndu[reg]);
+                } else {
+                    gen_helper_bndstx32(cpu_env, cpu_A0, cpu_T0,
+                                        cpu_bndl[reg], cpu_bndu[reg]);
+                }
             }
         }
         gen_nop_modrm(env, s, modrm);
