diff --git a/compiler/cgobj.pas b/compiler/cgobj.pas
index 959c1b681e..6e80061501 100644
--- a/compiler/cgobj.pas
+++ b/compiler/cgobj.pas
@@ -260,6 +260,7 @@ unit cgobj;
           procedure a_loadfpu_reg_reg(list: TAsmList; fromsize, tosize:tcgsize; reg1, reg2: tregister); virtual; abstract;
           procedure a_loadfpu_ref_reg(list: TAsmList; fromsize, tosize: tcgsize; const ref: treference; reg: tregister); virtual; abstract;
           procedure a_loadfpu_reg_ref(list: TAsmList; fromsize, tosize: tcgsize; reg: tregister; const ref: treference); virtual; abstract;
+          procedure a_loadfpu_ref_ref(list: TAsmList; fromsize, tosize: tcgsize; const ref1,ref2: treference);
           procedure a_loadfpu_loc_reg(list: TAsmList; tosize: tcgsize; const loc: tlocation; const reg: tregister);
           procedure a_loadfpu_reg_loc(list: TAsmList; fromsize: tcgsize; const reg: tregister; const loc: tlocation);
           procedure a_paramfpu_reg(list : TAsmList;size : tcgsize;const r : tregister;const cgpara : TCGPara);virtual;
@@ -2469,6 +2470,21 @@ implementation
       end;
 
 
+    procedure tcg.a_loadfpu_ref_ref(list: TAsmList; fromsize, tosize: tcgsize; const ref1,ref2: treference);
+      var
+        reg: tregister;
+        regsize: tcgsize;
+      begin
+        if (fromsize>=tosize) then
+          regsize:=fromsize
+        else
+          regsize:=tosize;
+        reg:=getfpuregister(list,regsize);
+        a_loadfpu_ref_reg(list,fromsize,regsize,ref1,reg);
+        a_loadfpu_reg_ref(list,regsize,tosize,reg,ref2);
+      end;
+
+
     procedure tcg.a_paramfpu_reg(list : TAsmList;size : tcgsize;const r : tregister;const cgpara : TCGPara);
       var
          ref : treference;
diff --git a/compiler/ncgld.pas b/compiler/ncgld.pas
index 627d20c9c8..f89d4120b2 100644
--- a/compiler/ncgld.pas
+++ b/compiler/ncgld.pas
@@ -692,27 +692,57 @@ implementation
                     LOC_REFERENCE,
                     LOC_CREFERENCE :
                       begin
-{$warning HACK: unaligned test, maybe remove all unaligned locations (array of char) from the compiler}
-                        { Use unaligned copy when the offset is not aligned }
-                        len:=left.resultdef.size;
-                        if (right.location.reference.offset mod sizeof(aint)<>0) or
-                          (left.location.reference.offset mod sizeof(aint)<>0) or
-                          (right.resultdef.alignment<sizeof(aint)) or
-                          ((right.location.reference.alignment<>0) and
-                           (right.location.reference.alignment<sizeof(aint))) or
-                          ((left.location.reference.alignment<>0) and
-                           (left.location.reference.alignment<sizeof(aint))) then
-                          cg.g_concatcopy_unaligned(current_asmdata.CurrAsmList,right.location.reference,left.location.reference,len)
+                        if (left.resultdef.typ=floatdef) and
+                           (right.resultdef.typ=floatdef) and
+                           (left.location.size<>right.location.size) then
+                          begin
+                            cg.a_loadfpu_ref_ref(current_asmdata.CurrAsmList,
+                              right.location.size,left.location.size,
+                              right.location.reference,left.location.reference)
+                          end
                         else
-                          cg.g_concatcopy(current_asmdata.CurrAsmList,right.location.reference,left.location.reference,len);
+                          begin
+{$warning HACK: unaligned test, maybe remove all unaligned locations (array of char) from the compiler}
+                            { Use unaligned copy when the offset is not aligned }
+                            len:=left.resultdef.size;
+                            if (right.location.reference.offset mod sizeof(aint)<>0) or
+                              (left.location.reference.offset mod sizeof(aint)<>0) or
+                              (right.resultdef.alignment<sizeof(aint)) or
+                              ((right.location.reference.alignment<>0) and
+                               (right.location.reference.alignment<sizeof(aint))) or
+                              ((left.location.reference.alignment<>0) and
+                               (left.location.reference.alignment<sizeof(aint))) then
+                              cg.g_concatcopy_unaligned(current_asmdata.CurrAsmList,right.location.reference,left.location.reference,len)
+                            else
+                              cg.g_concatcopy(current_asmdata.CurrAsmList,right.location.reference,left.location.reference,len);
+                          end;
                       end;
                     LOC_MMREGISTER,
                     LOC_CMMREGISTER:
-                      cg.a_loadmm_ref_reg(current_asmdata.CurrAsmList,
-                        right.location.size,
-                        left.location.size,
-                        right.location.reference,
-                        left.location.register,mms_movescalar);
+                      begin
+{$ifdef x86}
+                        if not use_sse(right.resultdef) then
+                          begin
+                            { perform size conversion if needed (the mm-code cannot }
+                            { convert an extended into a double/single, since sse   }
+                            { doesn't support extended)                             }
+                            r:=cg.getfpuregister(current_asmdata.CurrAsmList,right.location.size);
+                            tg.gettemp(current_asmdata.CurrAsmList,left.resultdef.size,tt_normal,href);
+                            cg.a_loadfpu_ref_reg(current_asmdata.CurrAsmList,right.location.size,right.location.size,right.location.reference,r);
+                            cg.a_loadfpu_reg_ref(current_asmdata.CurrAsmList,right.location.size,left.location.size,r,href);
+                            if releaseright then
+                              location_freetemp(current_asmdata.CurrAsmList,right.location);
+                            releaseright:=true;
+                            location_reset(right.location,LOC_REFERENCE,left.location.size);
+                            right.location.reference:=href;
+                          end;
+{$endif}
+                        cg.a_loadmm_ref_reg(current_asmdata.CurrAsmList,
+                          right.location.size,
+                          left.location.size,
+                          right.location.reference,
+                          left.location.register,mms_movescalar);
+                      end;
                     LOC_SUBSETREG,
                     LOC_CSUBSETREG:
                       cg.a_load_ref_subsetreg(current_asmdata.CurrAsmList,right.location.size,left.location.size,right.location.reference,left.location.sreg);
@@ -769,6 +799,17 @@ implementation
                   { we can't do direct moves between fpu and mm registers }
                   if left.location.loc in [LOC_MMREGISTER,LOC_CMMREGISTER] then
                     begin
+{$ifdef x86}
+                      if not use_sse(right.resultdef) then
+                        begin
+                          { perform size conversion if needed (the mm-code cannot convert an   }
+                          { extended into a double/single, since sse doesn't support extended) }
+                          tg.gettemp(current_asmdata.CurrAsmList,left.resultdef.size,tt_normal,href);
+                          cg.a_loadfpu_reg_ref(current_asmdata.CurrAsmList,right.location.size,left.location.size,right.location.register,href);
+                          location_reset(right.location,LOC_REFERENCE,left.location.size);
+                          right.location.reference:=href;
+                        end;
+{$endif}
                       location_force_mmregscalar(current_asmdata.CurrAsmList,right.location,false);
                       cg.a_loadmm_reg_reg(current_asmdata.CurrAsmList,
                           right.location.size,left.location.size,
diff --git a/compiler/nld.pas b/compiler/nld.pas
index 847392eb0e..ec757daefc 100644
--- a/compiler/nld.pas
+++ b/compiler/nld.pas
@@ -72,6 +72,7 @@ interface
           function dogetcopy : tnode;override;
           function pass_1 : tnode;override;
           function pass_typecheck:tnode;override;
+          function simplify : tnode;override;
        {$ifdef state_tracking}
           function track_state_pass(exec_known:boolean):boolean;override;
        {$endif state_tracking}
@@ -472,6 +473,22 @@ implementation
       end;
 
 
+    function tassignmentnode.simplify : tnode;
+      begin
+        result:=nil;
+        { assignment nodes can perform several floating point }
+        { type conversions directly, so no typeconversions    }
+        { are inserted in those cases. When inlining, a       }
+        { variable may be replaced by a constant which can be }
+        { converted at compile time, so check for this case   }
+        if is_real(left.resultdef) and
+           is_real(right.resultdef) and
+           is_constrealnode(right) and
+           not equal_defs(right.resultdef,left.resultdef) then
+          inserttypeconv(right,left.resultdef);
+      end;
+
+
     function tassignmentnode.pass_typecheck:tnode;
       var
         hp : tnode;
@@ -553,6 +570,21 @@ implementation
                exit;
             end
          end
+        { floating point assignments can also perform the conversion directly }
+        else if is_real(left.resultdef) and is_real(right.resultdef) and
+                not is_constrealnode(right)
+         
+{$ifdef x86}
+                { the assignment node code can't convert a double in an }
+                { sse register to an extended value in memory more      }
+                { efficiently than a type conversion node, so don't     }
+                { bother implementing support for that                  }
+                and (use_sse(left.resultdef) or not(use_sse(right.resultdef)))
+{$endif}
+        then
+          begin
+            check_ranges(fileinfo,right,left.resultdef);
+          end
         else
           begin
             { check if the assignment may cause a range check error }