diff --git a/rtl/x86_jit.pas b/rtl/x86_jit.pas
index 7be2dc12..a960cebf 100644
--- a/rtl/x86_jit.pas
+++ b/rtl/x86_jit.pas
@@ -22,7 +22,7 @@ type
   ALock    :Boolean;
  end;
 
- t_op_opt=Set of (not_impl,not_prefix,not_vex_len);
+ t_op_opt=Set of (not_impl,not_os8,not_prefix,not_vex_len);
 
  t_op_type=packed object
   op    :DWORD;
@@ -2153,7 +2153,7 @@ begin
  op:=desc.op;
  case mreg.AMemSize of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2234,7 +2234,7 @@ begin
  op:=desc.op;
  case mreg.AMemSize of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2323,7 +2323,7 @@ begin
  op:=desc.op;
  case mreg.AMemSize of
   os8:
-      if (not (not_prefix in desc.opt)) then
+      if (not (not_os8 in desc.opt)) then
       begin
        Dec(op);
       end;
@@ -2405,7 +2405,7 @@ begin
  op:=desc.op;
  case size of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2475,7 +2475,7 @@ begin
  op:=desc.op;
  case size of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2551,7 +2551,7 @@ begin
  op:=desc.op;
  case size of
   os8:
-      if (not (not_prefix in desc.opt)) then
+      if (not (not_os8 in desc.opt)) then
       begin
        Dec(op);
       end;
@@ -2609,7 +2609,7 @@ begin
  op:=desc.op;
  case reg.ASize of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2658,7 +2658,7 @@ begin
 
  case Size of
    os8:
-       if (not (not_prefix in opt)) then
+       if (not (not_os8 in opt)) then
        begin
         Dec(op);
        end;
@@ -2729,7 +2729,7 @@ begin
  op:=desc.op;
  case reg.ASize of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2829,7 +2829,7 @@ begin
  begin
   case mreg.AMemSize of
     os8:
-        if (not (not_prefix in desc.opt)) then
+        if (not (not_os8 in desc.opt)) then
         begin
          Dec(op);
         end;
@@ -2904,7 +2904,7 @@ begin
  op:=desc.op;
  case reg.ASize of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
@@ -2971,7 +2971,7 @@ begin
  op:=desc.op;
  case mreg.AMemSize of
    os8:
-       if (not (not_prefix in desc.opt)) then
+       if (not (not_os8 in desc.opt)) then
        begin
         Dec(op);
        end;
diff --git a/sys/jit/kern_jit_dynamic.pas b/sys/jit/kern_jit_dynamic.pas
index 4438c976..4a35b1c9 100644
--- a/sys/jit/kern_jit_dynamic.pas
+++ b/sys/jit/kern_jit_dynamic.pas
@@ -671,7 +671,7 @@ begin
 
  if (p_print_jit_preload<>0) then
  begin
-  Writeln('build_chunk:0x',HexStr(jcode^.dest,16),'..',HexStr(jcode^.d_end,16),':',i,':',count);
+  Writeln('build_chunk:0x',HexStr(jcode^.dest,16),'..',HexStr(jcode^.d_end,16),':',count);
  end;
 
  //writeln('[0x',HexStr(start,16),':0x',HexStr(__end,16),':',count);
diff --git a/sys/jit/kern_jit_ops.pas b/sys/jit/kern_jit_ops.pas
index f2f90cbf..215e9445 100644
--- a/sys/jit/kern_jit_ops.pas
+++ b/sys/jit/kern_jit_ops.pas
@@ -914,7 +914,26 @@ begin
 
   tmp.op   :=ctx.dis.opcode;
   tmp.index:=ctx.dis.ModRM.Index;
-  tmp.opt  :=[not_prefix];
+  tmp.opt  :=[not_os8];
+
+  op_emit1(ctx,tmp,[]);
+ end else
+ begin
+  add_orig(ctx);
+ end;
+end;
+
+procedure op_emit1_gn_np(var ctx:t_jit_context2);
+var
+ tmp:t_op_type;
+begin
+ if is_preserved(ctx.din) or is_memory(ctx.din) then
+ begin
+  tmp:=Default(t_op_type);
+
+  tmp.op   :=ctx.dis.opcode;
+  tmp.index:=ctx.dis.ModRM.Index;
+  tmp.opt  :=[not_os8,not_prefix];
 
   op_emit1(ctx,tmp,[]);
  end else
@@ -933,7 +952,26 @@ begin
 
   tmp.op   :=ctx.dis.opcode;
   tmp.index:=ctx.dis.ModRM.Index;
-  tmp.opt  :=[not_prefix];
+  tmp.opt  :=[not_os8];
+
+  op_emit1(ctx,tmp,[his_ro]);
+ end else
+ begin
+  add_orig(ctx);
+ end;
+end;
+
+procedure op_emit1_ro_np(var ctx:t_jit_context2);
+var
+ tmp:t_op_type;
+begin
+ if is_preserved(ctx.din) or is_memory(ctx.din) then
+ begin
+  tmp:=Default(t_op_type);
+
+  tmp.op   :=ctx.dis.opcode;
+  tmp.index:=ctx.dis.ModRM.Index;
+  tmp.opt  :=[not_os8,not_prefix];
 
   op_emit1(ctx,tmp,[his_ro]);
  end else
@@ -952,7 +990,26 @@ begin
 
   tmp.op   :=ctx.dis.opcode;
   tmp.index:=ctx.dis.ModRM.Index;
-  tmp.opt  :=[not_prefix];
+  tmp.opt  :=[not_os8];
+
+  op_emit1(ctx,tmp,[his_rw]);
+ end else
+ begin
+  add_orig(ctx);
+ end;
+end;
+
+procedure op_emit1_rw_np(var ctx:t_jit_context2);
+var
+ tmp:t_op_type;
+begin
+ if is_preserved(ctx.din) or is_memory(ctx.din) then
+ begin
+  tmp:=Default(t_op_type);
+
+  tmp.op   :=ctx.dis.opcode;
+  tmp.index:=ctx.dis.ModRM.Index;
+  tmp.opt  :=[not_os8,not_prefix];
 
   op_emit1(ctx,tmp,[his_rw]);
  end else
@@ -1199,7 +1256,7 @@ end;
 const
  movx_desc:t_op_desc=(
   mem_reg:(opt:[not_impl]);
-  reg_mem:(op:$00;opt:[not_prefix]);
+  reg_mem:(op:$00;opt:[not_os8]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -1253,8 +1310,8 @@ end;
 
 const
  movbe_desc:t_op_desc=(
-  mem_reg:(op:$0F38F1;opt:[not_prefix]);
-  reg_mem:(op:$0F38F0;opt:[not_prefix]);
+  mem_reg:(op:$0F38F1;opt:[not_os8]);
+  reg_mem:(op:$0F38F0;opt:[not_os8]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -1274,7 +1331,7 @@ end;
 const
  movsxd_desc:t_op_desc=(
   mem_reg:(opt:[not_impl]);
-  reg_mem:(op:$63;opt:[not_prefix]);
+  reg_mem:(op:$63;opt:[not_os8]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -1703,22 +1760,22 @@ begin
  jit_cbs[OPPnone,OPshl ,OPSx_d ]:=@op_shld;
  jit_cbs[OPPnone,OPshr ,OPSx_d ]:=@op_shrd;
 
- jit_cbs[OPPnone,OPset__,OPSc_o  ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_no ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_b  ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_nb ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_z  ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_nz ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_be ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_nbe]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_s  ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_ns ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_p  ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_np ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_l  ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_nl ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_le ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPset__,OPSc_nle]:=@op_emit1_gn;
+ jit_cbs[OPPnone,OPset__,OPSc_o  ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_no ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_b  ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_nb ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_z  ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_nz ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_be ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_nbe]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_s  ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_ns ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_p  ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_np ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_l  ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_nl ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_le ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPset__,OPSc_nle]:=@op_emit1_gn_np;
 
  jit_cbs[OPPnone,OPemms      ,OPSnone]:=@add_orig;
  jit_cbs[OPPnone,OPfemms     ,OPSnone]:=@add_orig;
@@ -1832,42 +1889,42 @@ begin
 
  //
 
- jit_cbs[OPPnone,OPfldcw  ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfld    ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfild   ,OPSnone]:=@op_emit1_ro;
+ jit_cbs[OPPnone,OPfldcw  ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfld    ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfild   ,OPSnone]:=@op_emit1_ro_np;
 
- jit_cbs[OPPnone,OPfldenv ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfnstenv,OPSnone]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfnstcw ,OPSnone]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfnstsw ,OPSnone]:=@op_emit1_gn;
+ jit_cbs[OPPnone,OPfldenv ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfnstenv,OPSnone]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfnstcw ,OPSnone]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfnstsw ,OPSnone]:=@op_emit1_gn_np;
 
- jit_cbs[OPPnone,OPfxsave ,OPSnone]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfxrstor,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfst    ,OPSnone]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfst    ,OPSx_p ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfist   ,OPSnone]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfist   ,OPSx_p ]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfisttp ,OPSnone]:=@op_emit1_gn;
- jit_cbs[OPPnone,OPfadd   ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfiadd  ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfmul   ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfimul  ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfsub   ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfsubr  ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfisub  ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfdiv   ,OPSnone]:=@op_emit1_ro;
- jit_cbs[OPPnone,OPfdivr  ,OPSnone]:=@op_emit1_ro;
+ jit_cbs[OPPnone,OPfxsave ,OPSnone]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfxrstor,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfst    ,OPSnone]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfst    ,OPSx_p ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfist   ,OPSnone]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfist   ,OPSx_p ]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfisttp ,OPSnone]:=@op_emit1_gn_np;
+ jit_cbs[OPPnone,OPfadd   ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfiadd  ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfmul   ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfimul  ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfsub   ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfsubr  ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfisub  ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfdiv   ,OPSnone]:=@op_emit1_ro_np;
+ jit_cbs[OPPnone,OPfdivr  ,OPSnone]:=@op_emit1_ro_np;
 
- jit_cbs[OPPnone,OPclflush,OPSnone]:=@op_emit1_rw;
+ jit_cbs[OPPnone,OPclflush,OPSnone]:=@op_emit1_rw_np;
 
  //fpu
 
- jit_cbs[OPPnone,OPprefetch,OPSnone ]:=@op_emit1_rw;
- jit_cbs[OPPnone,OPprefetch,OPSp_w  ]:=@op_emit1_rw;
- jit_cbs[OPPnone,OPprefetch,OPSp_nta]:=@op_emit1_rw;
- jit_cbs[OPPnone,OPprefetch,OPSp_t0 ]:=@op_emit1_rw;
- jit_cbs[OPPnone,OPprefetch,OPSp_t1 ]:=@op_emit1_rw;
- jit_cbs[OPPnone,OPprefetch,OPSp_t2 ]:=@op_emit1_rw;
+ jit_cbs[OPPnone,OPprefetch,OPSnone ]:=@op_emit1_rw_np;
+ jit_cbs[OPPnone,OPprefetch,OPSp_w  ]:=@op_emit1_rw_np;
+ jit_cbs[OPPnone,OPprefetch,OPSp_nta]:=@op_emit1_rw_np;
+ jit_cbs[OPPnone,OPprefetch,OPSp_t0 ]:=@op_emit1_rw_np;
+ jit_cbs[OPPnone,OPprefetch,OPSp_t1 ]:=@op_emit1_rw_np;
+ jit_cbs[OPPnone,OPprefetch,OPSp_t2 ]:=@op_emit1_rw_np;
 
 end;
 
diff --git a/sys/jit/kern_jit_ops_sse.pas b/sys/jit/kern_jit_ops_sse.pas
index 16bbaffe..e86519e6 100644
--- a/sys/jit/kern_jit_ops_sse.pas
+++ b/sys/jit/kern_jit_ops_sse.pas
@@ -61,7 +61,7 @@ end;
 procedure op_emit2_simd_mem_reg(var ctx:t_jit_context2;hint:t_op_hint);
 const
  desc:t_op_desc=(
-  mem_reg:(op:0;opt:[not_prefix]);
+  mem_reg:(op:0;opt:[not_os8,not_prefix]);
   reg_mem:(opt:[not_impl]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
@@ -81,7 +81,7 @@ procedure op_emit2_simd_reg_mem(var ctx:t_jit_context2;hint:t_op_hint);
 const
  desc:t_op_desc=(
   mem_reg:(opt:[not_impl]);
-  reg_mem:(op:0;opt:[not_prefix]);
+  reg_mem:(op:0;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[];
@@ -159,8 +159,8 @@ end;
 
 const
  movsd_desc:t_op_desc=(
-  mem_reg:(op:$F20F11;opt:[not_prefix]);
-  reg_mem:(op:$F20F10;opt:[not_prefix]);
+  mem_reg:(op:$F20F11;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$F20F10;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -179,8 +179,8 @@ end;
 
 const
  movss_desc:t_op_desc=(
-  mem_reg:(op:$F30F11;opt:[not_prefix]);
-  reg_mem:(op:$F30F10;opt:[not_prefix]);
+  mem_reg:(op:$F30F11;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$F30F10;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -199,8 +199,8 @@ end;
 
 const
  mov_dq_desc:t_op_desc=(
-  mem_reg:(op:$0F7E;opt:[not_prefix]);
-  reg_mem:(op:$0F6E;opt:[not_prefix]);
+  mem_reg:(op:$0F7E;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$0F6E;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -219,8 +219,8 @@ end;
 
 const
  movdqa_desc:t_op_desc=(
-  mem_reg:(op:$660F7F;opt:[not_prefix]);
-  reg_mem:(op:$660F6F;opt:[not_prefix]);
+  mem_reg:(op:$660F7F;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$660F6F;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo,his_align];
@@ -239,8 +239,8 @@ end;
 
 const
  movdqu_desc:t_op_desc=(
-  mem_reg:(op:$F30F7F;opt:[not_prefix]);
-  reg_mem:(op:$F30F6F;opt:[not_prefix]);
+  mem_reg:(op:$F30F7F;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$F30F6F;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -261,8 +261,8 @@ end;
 
 const
  movu_ps_pd_desc:t_op_desc=(
-  mem_reg:(op:$0F11;opt:[not_prefix]);
-  reg_mem:(op:$0F10;opt:[not_prefix]);
+  mem_reg:(op:$0F11;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$0F10;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -283,8 +283,8 @@ end;
 
 const
  mova_ps_pd_desc:t_op_desc=(
-  mem_reg:(op:$0F29;opt:[not_prefix]);
-  reg_mem:(op:$0F28;opt:[not_prefix]);
+  mem_reg:(op:$0F29;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$0F28;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo,his_align];
@@ -306,7 +306,7 @@ end;
 const
  movntdqa_desc:t_op_desc=(
   mem_reg:(opt:[not_impl]);
-  reg_mem:(op:$660F382A;opt:[not_prefix]);
+  reg_mem:(op:$660F382A;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo,his_align];
@@ -334,8 +334,8 @@ end;
 
 const
  movl_ps_pd_desc:t_op_desc=(
-  mem_reg:(op:$0F13;opt:[not_prefix]);
-  reg_mem:(op:$0F12;opt:[not_prefix]);
+  mem_reg:(op:$0F13;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$0F12;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -356,8 +356,8 @@ end;
 
 const
  movh_ps_pd_desc:t_op_desc=(
-  mem_reg:(op:$0F17;opt:[not_prefix]);
-  reg_mem:(op:$0F16;opt:[not_prefix]);
+  mem_reg:(op:$0F17;opt:[not_os8,not_prefix]);
+  reg_mem:(op:$0F16;opt:[not_os8,not_prefix]);
   reg_imm:(opt:[not_impl]);
   reg_im8:(opt:[not_impl]);
   hint:[his_mov,his_wo];
@@ -379,7 +379,7 @@ end;
 
 const
  ldmxcsr_desc:t_op_type=(
-  op:$0FAE;index:2;opt:[not_prefix];
+  op:$0FAE;index:2;opt:[not_os8,not_prefix];
  );
 
 procedure op_ldmxcsr(var ctx:t_jit_context2);
@@ -389,7 +389,7 @@ end;
 
 const
  stmxcsr_desc:t_op_type=(
-  op:$0FAE;index:3;opt:[not_prefix];
+  op:$0FAE;index:3;opt:[not_os8,not_prefix];
  );
 
 procedure op_stmxcsr(var ctx:t_jit_context2);
diff --git a/sys/md/md_exception.pas b/sys/md/md_exception.pas
index 238393d2..799316f8 100644
--- a/sys/md/md_exception.pas
+++ b/sys/md/md_exception.pas
@@ -137,6 +137,9 @@ begin
   td^.td_frame.tf_rip:=tf_addr;
  end;
 
+ Writeln('tf_tsp:0x',HexStr(td^.td_frame.tf_rsp,16));
+ Writeln('tf_tbp:0x',HexStr(td^.td_frame.tf_rbp,16));
+
  print_backtrace_td(stderr);
 
  td^.td_frame.tf_trapno:=0;