diff --git a/spirv/emit_exp.pas b/spirv/emit_exp.pas
index 3fa116d3..9c59dbac 100644
--- a/spirv/emit_exp.pas
+++ b/spirv/emit_exp.pas
@@ -100,7 +100,7 @@ begin
     $4:src[0]:=fetch_vsrc8(FSPI.EXP.VSRC2,dtFloat32);
     $8:src[0]:=fetch_vsrc8(FSPI.EXP.VSRC3,dtFloat32);
     else
-     Assert(false);
+     Assert(false,'FSPI.EXP.COMPR='+HexStr(f,1));
    end;
    dout:=FetchOutput(TpsslExportType(FSPI.EXP.TGT),dtFloat32); //output in FSPI.EXP.TGT
    OpStore(line,dout,src[0]);
@@ -112,7 +112,7 @@ begin
     3:rtype:=dtVec3f;
     4:rtype:=dtVec4f;
     else
-      Assert(false,IntToStr(p));
+      Assert(false,'FSPI.EXP.COMPR='+HexStr(f,1));
    end;
 
    i:=0;
@@ -158,13 +158,11 @@ begin
        fetch_vsrc8_vec2h(FSPI.EXP.VSRC3,src[2],src[3]);
       end;
    else
-    Assert(false);
+    Assert(false,'FSPI.EXP.COMPR='+HexStr(f,1));
   end;
 
   if Config.UseOutput16 then
   begin
-   dst:=OpMakeVec(line,dtVec4h,@src);
-
    rtype:=dtVec4h;
   end else
   begin
diff --git a/spirv/emit_post_op.pas b/spirv/emit_post_op.pas
index c4d26709..bb99836d 100644
--- a/spirv/emit_post_op.pas
+++ b/spirv/emit_post_op.pas
@@ -819,6 +819,7 @@ end;
 
 Function ReverseBits(src:QWORD;count:Byte):QWORD;
 var
+ v:QWORD;
  i:Byte;
 begin
  Result:=0;
@@ -826,7 +827,8 @@ begin
  dec(count);
  For i:=0 to count do
  begin
-  Result.Bits[i]:=src.Bits[count-i];
+  v:=((src shr i) and 1); //get
+  Result:=Result or (v shl (count-i)); //set
  end;
 end;
 
@@ -1014,31 +1016,35 @@ end;
 function TEmitPostOp.OnCompositeExtract1(node:PSpirvOp):Integer;
 var
  pc:PsrConst;
- dst,src:PsrRegNode;
+ dst,org,src:PsrRegNode;
  pos:PtrUint;
 begin
  Result:=0;
  dst:=node^.pDst^.AsType(ntReg);
- src:=RegDown(node^.ParamNode(0)^.AsReg);
+ org:=node^.ParamNode(0)^.AsReg;
+ src:=RegDown(org);
 
  if (dst=nil) or (src=nil) then Exit;
 
  pos:=0;
  if not node^.ParamNode(1)^.TryGetValue(pos) then Exit;
 
- if src^.is_const then
- begin
-  pc:=src^.AsConst;
-  if (pos<pc^.ItemCount) then
-  begin
-   pc:=pc^.GetConst(pos);
-   dst^.pWriter:=pc;
+ if not src^.is_const then Exit;
 
-   node^.mark_not_used;
-   node^.pDst:=nil;
-   Inc(Result);
-  end;
- end;
+ pc:=src^.AsConst;
+
+ pc:=ConstList.Bitcast(org^.dtype,pc);
+
+ if (pos>=pc^.ItemCount) then Exit;
+
+ pc:=pc^.GetConst(pos);
+ if (pc=nil) then Exit;
+
+ dst^.pWriter:=pc;
+
+ node^.mark_not_used;
+ node^.pDst:=nil;
+ Inc(Result);
 end;
 
 {
diff --git a/spirv/srBitcast.pas b/spirv/srBitcast.pas
index f01589b3..2baab4e7 100644
--- a/spirv/srBitcast.pas
+++ b/spirv/srBitcast.pas
@@ -32,7 +32,9 @@ type
    FNTree:TNodeFetch;
    rSlot:TsrRegSlot;
   procedure Init(Emit:TCustomEmit); inline;
-  function  Find(dtype:TsrDataType;src:PsrRegNode):PsrBitcast;
+  function  _Find(dtype:TsrDataType;src:PsrRegNode):PsrBitcast;
+  function  Find(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
+  Procedure Save(dtype:TsrDataType;src,dst:PsrRegNode);
   function  FetchRead(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
   function  FetchDstr(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
   function  FetchCast(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
@@ -54,7 +56,7 @@ begin
  rSlot.Init(Emit,'BCAST');
 end;
 
-function TsrBitcastList.Find(dtype:TsrDataType;src:PsrRegNode):PsrBitcast;
+function TsrBitcastList._Find(dtype:TsrDataType;src:PsrRegNode):PsrBitcast;
 var
  node:TsrBitcast;
 begin
@@ -64,16 +66,62 @@ begin
  Result:=FNTree.Find(@node);
 end;
 
+function TsrBitcastList.Find(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
+var
+ node:PsrBitcast;
+begin
+ Result:=nil;
+ node:=_Find(dtype,src);
+ if (node<>nil) then
+ begin
+  Result:=node^.dst;
+ end;
+end;
+
+Procedure TsrBitcastList.Save(dtype:TsrDataType;src,dst:PsrRegNode);
+var
+ node:PsrBitcast;
+begin
+ node:=rSlot.Emit.Alloc(SizeOf(TsrBitcast));
+ node^:=Default(TsrBitcast);
+ node^.key.dtype:=dtype;
+ node^.key.src:=src;
+ node^.dst:=dst;
+ FNTree.Insert(node);
+end;
+
 function TsrBitcastList.FetchRead(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
 var
+ pConstList:PsrConstList;
  dst:PsrRegNode;
+ pConst:PsrConst;
+
 begin
  Result:=src;
  if (src=nil) then Exit;
  if (dtype=dtUnknow) or (dtype=src^.dtype) then Exit;
 
- dst:=rSlot.New(src^.pLine,dtype);
- dst^.pWriter:=src;
+ if src^.is_const then
+ begin
+  //only from consts, first
+  dst:=Find(dtype,src);
+  if (dst<>nil) then Exit(dst);
+
+  pConst:=src^.AsConst;
+
+  pConstList:=rSlot.Emit.GetConstList;
+  pConst:=pConstList^.Bitcast(dtype,pConst);
+
+  dst:=rSlot.New(src^.pLine,dtype);
+  dst^.pWriter:=pConst;
+
+  //
+  Save(dtype,src,dst);
+ end else
+ begin
+  dst:=rSlot.New(src^.pLine,dtype);
+  dst^.pWriter:=src;
+ end;
 
  Result:=dst;
 end;
@@ -97,7 +145,6 @@ end;
 function TsrBitcastList.FetchCast(dtype:TsrDataType;src:PsrRegNode):PsrRegNode;
 var
  pConstList:PsrConstList;
- node:PsrBitcast;
  dst:PsrRegNode;
  pConst:PsrConst;
 
@@ -108,12 +155,9 @@ begin
 
  dst:=nil;
 
- node:=Find(dtype,src);
- if (node<>nil) then
- begin
-  Result:=node^.dst;
-  Exit;
- end;
+ //
+ dst:=Find(dtype,src);
+ if (dst<>nil) then Exit(dst);
 
  if src^.is_const then
  begin
@@ -137,12 +181,8 @@ begin
   end;
  end;
 
- node:=rSlot.Emit.Alloc(SizeOf(TsrBitcast));
- node^:=Default(TsrBitcast);
- node^.key.dtype:=dtype;
- node^.key.src:=src;
- node^.dst:=dst;
- FNTree.Insert(node);
+ //
+ Save(dtype,src,dst);
 
  Result:=dst;
 end;