--- gcc/ada/exp_strm.adb
+++ gcc/ada/exp_strm.adb
@@ -569,6 +569,9 @@ package body Exp_Strm is
          elsif P_Size <= Standard_Short_Integer_Size then
             Lib_RE := RE_I_SI;
 
+         elsif P_Size = 24 then
+            Lib_RE := RE_I_I24;
+
          elsif P_Size <= Standard_Integer_Size then
             Lib_RE := RE_I_I;
 
@@ -597,6 +600,9 @@ package body Exp_Strm is
          elsif P_Size <= Standard_Short_Integer_Size then
             Lib_RE := RE_I_SU;
 
+         elsif P_Size = 24 then
+            Lib_RE := RE_I_U24;
+
          elsif P_Size <= Standard_Integer_Size then
             Lib_RE := RE_I_U;
 
@@ -798,6 +804,8 @@ package body Exp_Strm is
             Lib_RE := RE_W_SSI;
          elsif P_Size <= Standard_Short_Integer_Size then
             Lib_RE := RE_W_SI;
+         elsif P_Size = 24 then
+            Lib_RE := RE_W_I24;
          elsif P_Size <= Standard_Integer_Size then
             Lib_RE := RE_W_I;
          elsif P_Size <= Standard_Long_Integer_Size then
@@ -822,6 +830,8 @@ package body Exp_Strm is
             Lib_RE := RE_W_SSU;
          elsif P_Size <= Standard_Short_Integer_Size then
             Lib_RE := RE_W_SU;
+         elsif P_Size = 24 then
+            Lib_RE := RE_W_U24;
          elsif P_Size <= Standard_Integer_Size then
             Lib_RE := RE_W_U;
          elsif P_Size <= Standard_Long_Integer_Size then

--- gcc/ada/libgnat/s-stratt.adb
+++ gcc/ada/libgnat/s-stratt.adb
@@ -59,6 +59,7 @@ package body System.Stream_Attributes is
    subtype S_C   is SEA (1 .. (Character'Size                + SU - 1) / SU);
    subtype S_F   is SEA (1 .. (Float'Size                    + SU - 1) / SU);
    subtype S_I   is SEA (1 .. (Integer'Size                  + SU - 1) / SU);
+   subtype S_I24 is SEA (1 .. (Integer_24'Size               + SU - 1) / SU);
    subtype S_LF  is SEA (1 .. (Long_Float'Size               + SU - 1) / SU);
    subtype S_LI  is SEA (1 .. (Long_Integer'Size             + SU - 1) / SU);
    subtype S_LLF is SEA (1 .. (Long_Long_Float'Size          + SU - 1) / SU);
@@ -71,6 +72,7 @@ package body System.Stream_Attributes is
    subtype S_SSU is SEA (1 .. (UST.Short_Short_Unsigned'Size + SU - 1) / SU);
    subtype S_SU  is SEA (1 .. (UST.Short_Unsigned'Size       + SU - 1) / SU);
    subtype S_U   is SEA (1 .. (UST.Unsigned'Size             + SU - 1) / SU);
+   subtype S_U24 is SEA (1 .. (Unsigned_24'Size              + SU - 1) / SU);
    subtype S_WC  is SEA (1 .. (Wide_Character'Size           + SU - 1) / SU);
    subtype S_WWC is SEA (1 .. (Wide_Wide_Character'Size      + SU - 1) / SU);
 
@@ -80,6 +82,7 @@ package body System.Stream_Attributes is
    function From_AS  is new UC (Thin_Pointer,             S_AS);
    function From_F   is new UC (Float,                    S_F);
    function From_I   is new UC (Integer,                  S_I);
+   function From_I24 is new UC (Integer_24,               S_I24);
    function From_LF  is new UC (Long_Float,               S_LF);
    function From_LI  is new UC (Long_Integer,             S_LI);
    function From_LLF is new UC (Long_Long_Float,          S_LLF);
@@ -92,6 +95,7 @@ package body System.Stream_Attributes is
    function From_SSU is new UC (UST.Short_Short_Unsigned, S_SSU);
    function From_SU  is new UC (UST.Short_Unsigned,       S_SU);
    function From_U   is new UC (UST.Unsigned,             S_U);
+   function From_U24 is new UC (Unsigned_24,              S_U24);
    function From_WC  is new UC (Wide_Character,           S_WC);
    function From_WWC is new UC (Wide_Wide_Character,      S_WWC);
 
@@ -101,6 +105,7 @@ package body System.Stream_Attributes is
    function To_AS  is new UC (S_AS,  Thin_Pointer);
    function To_F   is new UC (S_F,   Float);
    function To_I   is new UC (S_I,   Integer);
+   function To_I24 is new UC (S_I24, Integer_24);
    function To_LF  is new UC (S_LF,  Long_Float);
    function To_LI  is new UC (S_LI,  Long_Integer);
    function To_LLF is new UC (S_LLF, Long_Long_Float);
@@ -113,6 +118,7 @@ package body System.Stream_Attributes is
    function To_SSU is new UC (S_SSU, UST.Short_Short_Unsigned);
    function To_SU  is new UC (S_SU,  UST.Short_Unsigned);
    function To_U   is new UC (S_U,   UST.Unsigned);
+   function To_U24 is new UC (S_U24, Unsigned_24);
    function To_WC  is new UC (S_WC,  Wide_Character);
    function To_WWC is new UC (S_WWC, Wide_Wide_Character);
 
@@ -233,6 +239,24 @@ package body System.Stream_Attributes is
       end if;
    end I_I;
 
+   -----------
+   -- I_I24 --
+   -----------
+
+   function I_I24 (Stream : not null access RST) return Integer_24 is
+      T : S_I24;
+      L : SEO;
+
+   begin
+      Ada.Streams.Read (Stream.all, T, L);
+
+      if L < T'Last then
+         raise Err;
+      else
+         return To_I24 (T);
+      end if;
+   end I_I24;
+
    ----------
    -- I_LF --
    ----------
@@ -453,6 +477,24 @@ package body System.Stream_Attributes is
       end if;
    end I_U;
 
+   -----------
+   -- I_U24 --
+   -----------
+
+   function I_U24 (Stream : not null access RST) return Unsigned_24 is
+      T : S_U24;
+      L : SEO;
+
+   begin
+      Ada.Streams.Read (Stream.all, T, L);
+
+      if L < T'Last then
+         raise Err;
+      else
+         return To_U24 (T);
+      end if;
+   end I_U24;
+
    ----------
    -- I_WC --
    ----------
@@ -551,6 +593,16 @@ package body System.Stream_Attributes is
       Ada.Streams.Write (Stream.all, T);
    end W_I;
 
+   -----------
+   -- W_I24 --
+   -----------
+
+   procedure W_I24 (Stream : not null access RST; Item : Integer_24) is
+      T : constant S_I24 := From_I24 (Item);
+   begin
+      Ada.Streams.Write (Stream.all, T);
+   end W_I24;
+
    ----------
    -- W_LF --
    ----------
@@ -683,6 +735,16 @@ package body System.Stream_Attributes is
       Ada.Streams.Write (Stream.all, T);
    end W_U;
 
+   -----------
+   -- W_U24 --
+   -----------
+
+   procedure W_U24 (Stream : not null access RST; Item : Unsigned_24) is
+      T : constant S_U24 := From_U24 (Item);
+   begin
+      Ada.Streams.Write (Stream.all, T);
+   end W_U24;
+
    ----------
    -- W_WC --
    ----------

--- gcc/ada/libgnat/s-stratt.ads
+++ gcc/ada/libgnat/s-stratt.ads
@@ -53,6 +53,12 @@ package System.Stream_Attributes is
 
    subtype SEC is Ada.Streams.Stream_Element_Count;
 
+   type Integer_24 is range -2 ** 23 .. 2 ** 23 - 1;
+   for Integer_24'Size use 24;
+
+   type Unsigned_24 is mod 2 ** 24;
+   for Unsigned_24'Size use 24;
+
    --  Enumeration types are usually transferred using the routine for the
    --  corresponding integer. The exception is that special routines are
    --  provided for Boolean and the character types, in case the protocol
@@ -104,6 +110,7 @@ package System.Stream_Attributes is
    function I_C   (Stream : not null access RST) return Character;
    function I_F   (Stream : not null access RST) return Float;
    function I_I   (Stream : not null access RST) return Integer;
+   function I_I24 (Stream : not null access RST) return Integer_24;
    function I_LF  (Stream : not null access RST) return Long_Float;
    function I_LI  (Stream : not null access RST) return Long_Integer;
    function I_LLF (Stream : not null access RST) return Long_Long_Float;
@@ -117,6 +124,7 @@ package System.Stream_Attributes is
                                                    UST.Short_Short_Unsigned;
    function I_SU  (Stream : not null access RST) return UST.Short_Unsigned;
    function I_U   (Stream : not null access RST) return UST.Unsigned;
+   function I_U24 (Stream : not null access RST) return Unsigned_24;
    function I_WC  (Stream : not null access RST) return Wide_Character;
    function I_WWC (Stream : not null access RST) return Wide_Wide_Character;
 
@@ -135,6 +143,7 @@ package System.Stream_Attributes is
    procedure W_C   (Stream : not null access RST; Item : Character);
    procedure W_F   (Stream : not null access RST; Item : Float);
    procedure W_I   (Stream : not null access RST; Item : Integer);
+   procedure W_I24 (Stream : not null access RST; Item : Integer_24);
    procedure W_LF  (Stream : not null access RST; Item : Long_Float);
    procedure W_LI  (Stream : not null access RST; Item : Long_Integer);
    procedure W_LLF (Stream : not null access RST; Item : Long_Long_Float);
@@ -149,6 +158,7 @@ package System.Stream_Attributes is
                                                     UST.Short_Short_Unsigned);
    procedure W_SU  (Stream : not null access RST; Item : UST.Short_Unsigned);
    procedure W_U   (Stream : not null access RST; Item : UST.Unsigned);
+   procedure W_U24 (Stream : not null access RST; Item : Unsigned_24);
    procedure W_WC  (Stream : not null access RST; Item : Wide_Character);
    procedure W_WWC (Stream : not null access RST; Item : Wide_Wide_Character);
 

--- gcc/ada/libgnat/s-stratt__xdr.adb
+++ gcc/ada/libgnat/s-stratt__xdr.adb
@@ -139,40 +139,47 @@ package body System.Stream_Attributes is
 
    SSI_L : constant := 1;
    SI_L  : constant := 2;
+   I24_L : constant := 3;
    I_L   : constant := 4;
    LI_L  : constant := 8;
    LLI_L : constant := 8;
 
    subtype XDR_S_SSI is SEA (1 .. SSI_L);
    subtype XDR_S_SI  is SEA (1 .. SI_L);
+   subtype XDR_S_I24 is SEA (1 .. I24_L);
    subtype XDR_S_I   is SEA (1 .. I_L);
    subtype XDR_S_LI  is SEA (1 .. LI_L);
    subtype XDR_S_LLI is SEA (1 .. LLI_L);
 
    function Short_Short_Integer_To_XDR_S_SSI is
-      new Ada.Unchecked_Conversion (Short_Short_Integer, XDR_S_SSI);
+     new Ada.Unchecked_Conversion (Short_Short_Integer, XDR_S_SSI);
    function XDR_S_SSI_To_Short_Short_Integer is
-      new Ada.Unchecked_Conversion (XDR_S_SSI, Short_Short_Integer);
+     new Ada.Unchecked_Conversion (XDR_S_SSI, Short_Short_Integer);
 
    function Short_Integer_To_XDR_S_SI is
-      new Ada.Unchecked_Conversion (Short_Integer, XDR_S_SI);
+     new Ada.Unchecked_Conversion (Short_Integer, XDR_S_SI);
    function XDR_S_SI_To_Short_Integer is
-      new Ada.Unchecked_Conversion (XDR_S_SI, Short_Integer);
+     new Ada.Unchecked_Conversion (XDR_S_SI, Short_Integer);
+
+   function Integer_To_XDR_S_I24 is
+     new Ada.Unchecked_Conversion (Integer_24, XDR_S_I24);
+   function XDR_S_I24_To_Integer is
+     new Ada.Unchecked_Conversion (XDR_S_I24, Integer_24);
 
    function Integer_To_XDR_S_I is
-      new Ada.Unchecked_Conversion (Integer, XDR_S_I);
+     new Ada.Unchecked_Conversion (Integer, XDR_S_I);
    function XDR_S_I_To_Integer is
      new Ada.Unchecked_Conversion (XDR_S_I, Integer);
 
    function Long_Long_Integer_To_XDR_S_LI is
-      new Ada.Unchecked_Conversion (Long_Long_Integer, XDR_S_LI);
+     new Ada.Unchecked_Conversion (Long_Long_Integer, XDR_S_LI);
    function XDR_S_LI_To_Long_Long_Integer is
-      new Ada.Unchecked_Conversion (XDR_S_LI, Long_Long_Integer);
+     new Ada.Unchecked_Conversion (XDR_S_LI, Long_Long_Integer);
 
    function Long_Long_Integer_To_XDR_S_LLI is
-      new Ada.Unchecked_Conversion (Long_Long_Integer, XDR_S_LLI);
+     new Ada.Unchecked_Conversion (Long_Long_Integer, XDR_S_LLI);
    function XDR_S_LLI_To_Long_Long_Integer is
-      new Ada.Unchecked_Conversion (XDR_S_LLI, Long_Long_Integer);
+     new Ada.Unchecked_Conversion (XDR_S_LLI, Long_Long_Integer);
 
    --  An XDR unsigned integer is a 32-bit datum that encodes a nonnegative
    --  integer in the range [0,4294967295]. It is represented by an unsigned
@@ -187,12 +194,14 @@ package body System.Stream_Attributes is
 
    SSU_L : constant := 1;
    SU_L  : constant := 2;
+   U24_L : constant := 3;
    U_L   : constant := 4;
    LU_L  : constant := 8;
    LLU_L : constant := 8;
 
    subtype XDR_S_SSU is SEA (1 .. SSU_L);
    subtype XDR_S_SU  is SEA (1 .. SU_L);
+   subtype XDR_S_U24 is SEA (1 .. U24_L);
    subtype XDR_S_U   is SEA (1 .. U_L);
    subtype XDR_S_LU  is SEA (1 .. LU_L);
    subtype XDR_S_LLU is SEA (1 .. LLU_L);
@@ -200,26 +209,32 @@ package body System.Stream_Attributes is
    type XDR_SSU is mod BB ** SSU_L;
    type XDR_SU  is mod BB ** SU_L;
    type XDR_U   is mod BB ** U_L;
+   type XDR_U24 is mod BB ** U24_L;
 
    function Short_Unsigned_To_XDR_S_SU is
-      new Ada.Unchecked_Conversion (Short_Unsigned, XDR_S_SU);
+     new Ada.Unchecked_Conversion (Short_Unsigned, XDR_S_SU);
    function XDR_S_SU_To_Short_Unsigned is
-      new Ada.Unchecked_Conversion (XDR_S_SU, Short_Unsigned);
+     new Ada.Unchecked_Conversion (XDR_S_SU, Short_Unsigned);
+
+   function Unsigned_To_XDR_S_U24 is
+     new Ada.Unchecked_Conversion (Unsigned_24, XDR_S_U24);
+   function XDR_S_U24_To_Unsigned is
+     new Ada.Unchecked_Conversion (XDR_S_U24, Unsigned_24);
 
    function Unsigned_To_XDR_S_U is
-      new Ada.Unchecked_Conversion (Unsigned, XDR_S_U);
+     new Ada.Unchecked_Conversion (Unsigned, XDR_S_U);
    function XDR_S_U_To_Unsigned is
-      new Ada.Unchecked_Conversion (XDR_S_U, Unsigned);
+     new Ada.Unchecked_Conversion (XDR_S_U, Unsigned);
 
    function Long_Long_Unsigned_To_XDR_S_LU is
-      new Ada.Unchecked_Conversion (Long_Long_Unsigned, XDR_S_LU);
+     new Ada.Unchecked_Conversion (Long_Long_Unsigned, XDR_S_LU);
    function XDR_S_LU_To_Long_Long_Unsigned is
-      new Ada.Unchecked_Conversion (XDR_S_LU, Long_Long_Unsigned);
+     new Ada.Unchecked_Conversion (XDR_S_LU, Long_Long_Unsigned);
 
    function Long_Long_Unsigned_To_XDR_S_LLU is
-      new Ada.Unchecked_Conversion (Long_Long_Unsigned, XDR_S_LLU);
+     new Ada.Unchecked_Conversion (Long_Long_Unsigned, XDR_S_LLU);
    function XDR_S_LLU_To_Long_Long_Unsigned is
-      new Ada.Unchecked_Conversion (XDR_S_LLU, Long_Long_Unsigned);
+     new Ada.Unchecked_Conversion (XDR_S_LLU, Long_Long_Unsigned);
 
    --  The standard defines the floating-point data type "float" (32 bits
    --  or 4 bytes). The encoding used is the IEEE standard for normalized
@@ -484,6 +499,40 @@ package body System.Stream_Attributes is
       end if;
    end I_I;
 
+   -----------
+   -- I_I24 --
+   -----------
+
+   function I_I24 (Stream : not null access RST) return Integer_24 is
+      S : XDR_S_I24;
+      L : SEO;
+      U : XDR_U24 := 0;
+
+   begin
+      Ada.Streams.Read (Stream.all, S, L);
+
+      if L /= S'Last then
+         raise Data_Error;
+
+      elsif Optimize_Integers then
+         return XDR_S_I24_To_Integer (S);
+
+      else
+         for N in S'Range loop
+            U := U * BB + XDR_U24 (S (N));
+         end loop;
+
+         --  Test sign and apply two complement notation
+
+         if S (1) < BL then
+            return Integer_24 (U);
+
+         else
+            return Integer_24 (-((XDR_U24'Last xor U) + 1));
+         end if;
+      end if;
+   end I_I24;
+
    ----------
    -- I_LF --
    ----------
@@ -1042,6 +1091,33 @@ package body System.Stream_Attributes is
       end if;
    end I_U;
 
+   -----------
+   -- I_U24 --
+   -----------
+
+   function I_U24 (Stream : not null access RST) return Unsigned_24 is
+      S : XDR_S_U24;
+      L : SEO;
+      U : XDR_U24 := 0;
+
+   begin
+      Ada.Streams.Read (Stream.all, S, L);
+
+      if L /= S'Last then
+         raise Data_Error;
+
+      elsif Optimize_Integers then
+         return XDR_S_U24_To_Unsigned (S);
+
+      else
+         for N in S'Range loop
+            U := U * BB + XDR_U24 (S (N));
+         end loop;
+
+         return Unsigned_24 (U);
+      end if;
+   end I_U24;
+
    ----------
    -- I_WC --
    ----------
@@ -1289,6 +1365,38 @@ package body System.Stream_Attributes is
       Ada.Streams.Write (Stream.all, S);
    end W_I;
 
+   -----------
+   -- W_I24 --
+   -----------
+
+   procedure W_I24 (Stream : not null access RST; Item : Integer_24) is
+      S : XDR_S_I24;
+      U : XDR_U24;
+
+   begin
+      if Optimize_Integers then
+         S := Integer_To_XDR_S_I24 (Item);
+
+      else
+         --  Test sign and apply two complement notation
+
+         U := (if Item < 0
+               then XDR_U24'Last xor XDR_U24 (-(Item + 1))
+               else XDR_U24 (Item));
+
+         for N in reverse S'Range loop
+            S (N) := SE (U mod BB);
+            U := U / BB;
+         end loop;
+
+         if U /= 0 then
+            raise Data_Error;
+         end if;
+      end if;
+
+      Ada.Streams.Write (Stream.all, S);
+   end W_I24;
+
    ----------
    -- W_LF --
    ----------
@@ -1846,6 +1954,32 @@ package body System.Stream_Attributes is
       Ada.Streams.Write (Stream.all, S);
    end W_U;
 
+   -----------
+   -- W_U24 --
+   -----------
+
+   procedure W_U24 (Stream : not null access RST; Item : Unsigned_24) is
+      S : XDR_S_U24;
+      U : XDR_U24 := XDR_U24 (Item);
+
+   begin
+      if Optimize_Integers then
+         S := Unsigned_To_XDR_S_U24 (Item);
+
+      else
+         for N in reverse S'Range loop
+            S (N) := SE (U mod BB);
+            U := U / BB;
+         end loop;
+
+         if U /= 0 then
+            raise Data_Error;
+         end if;
+      end if;
+
+      Ada.Streams.Write (Stream.all, S);
+   end W_U24;
+
    ----------
    -- W_WC --
    ----------

--- gcc/ada/rtsfind.ads
+++ gcc/ada/rtsfind.ads
@@ -1377,6 +1377,7 @@ package Rtsfind is
      RE_I_C,                             -- System.Stream_Attributes
      RE_I_F,                             -- System.Stream_Attributes
      RE_I_I,                             -- System.Stream_Attributes
+     RE_I_I24,                           -- System.Stream_Attributes
      RE_I_LF,                            -- System.Stream_Attributes
      RE_I_LI,                            -- System.Stream_Attributes
      RE_I_LLF,                           -- System.Stream_Attributes
@@ -1389,6 +1390,7 @@ package Rtsfind is
      RE_I_SSU,                           -- System.Stream_Attributes
      RE_I_SU,                            -- System.Stream_Attributes
      RE_I_U,                             -- System.Stream_Attributes
+     RE_I_U24,                           -- System.Stream_Attributes
      RE_I_WC,                            -- System.Stream_Attributes
      RE_I_WWC,                           -- System.Stream_Attributes
 
@@ -1398,6 +1400,7 @@ package Rtsfind is
      RE_W_C,                             -- System.Stream_Attributes
      RE_W_F,                             -- System.Stream_Attributes
      RE_W_I,                             -- System.Stream_Attributes
+     RE_W_I24,                           -- System.Stream_Attributes
      RE_W_LF,                            -- System.Stream_Attributes
      RE_W_LI,                            -- System.Stream_Attributes
      RE_W_LLF,                           -- System.Stream_Attributes
@@ -1410,6 +1413,7 @@ package Rtsfind is
      RE_W_SSU,                           -- System.Stream_Attributes
      RE_W_SU,                            -- System.Stream_Attributes
      RE_W_U,                             -- System.Stream_Attributes
+     RE_W_U24,                           -- System.Stream_Attributes
      RE_W_WC,                            -- System.Stream_Attributes
      RE_W_WWC,                           -- System.Stream_Attributes
 
@@ -2654,6 +2658,7 @@ package Rtsfind is
      RE_I_C                              => System_Stream_Attributes,
      RE_I_F                              => System_Stream_Attributes,
      RE_I_I                              => System_Stream_Attributes,
+     RE_I_I24                            => System_Stream_Attributes,
      RE_I_LF                             => System_Stream_Attributes,
      RE_I_LI                             => System_Stream_Attributes,
      RE_I_LLF                            => System_Stream_Attributes,
@@ -2666,6 +2671,7 @@ package Rtsfind is
      RE_I_SSU                            => System_Stream_Attributes,
      RE_I_SU                             => System_Stream_Attributes,
      RE_I_U                              => System_Stream_Attributes,
+     RE_I_U24                            => System_Stream_Attributes,
      RE_I_WC                             => System_Stream_Attributes,
      RE_I_WWC                            => System_Stream_Attributes,
 
@@ -2675,6 +2681,7 @@ package Rtsfind is
      RE_W_C                              => System_Stream_Attributes,
      RE_W_F                              => System_Stream_Attributes,
      RE_W_I                              => System_Stream_Attributes,
+     RE_W_I24                            => System_Stream_Attributes,
      RE_W_LF                             => System_Stream_Attributes,
      RE_W_LI                             => System_Stream_Attributes,
      RE_W_LLF                            => System_Stream_Attributes,
@@ -2687,6 +2694,7 @@ package Rtsfind is
      RE_W_SSU                            => System_Stream_Attributes,
      RE_W_SU                             => System_Stream_Attributes,
      RE_W_U                              => System_Stream_Attributes,
+     RE_W_U24                            => System_Stream_Attributes,
      RE_W_WC                             => System_Stream_Attributes,
      RE_W_WWC                            => System_Stream_Attributes,
 

--- gcc/ada/sem_ch13.adb
+++ gcc/ada/sem_ch13.adb
@@ -6593,19 +6593,19 @@ package body Sem_Ch13 is
             elsif Is_Elementary_Type (U_Ent) then
                if Size /= System_Storage_Unit
                  and then Size /= System_Storage_Unit * 2
+                 and then Size /= System_Storage_Unit * 3
                  and then Size /= System_Storage_Unit * 4
                  and then Size /= System_Storage_Unit * 8
                then
-                  Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
                   Error_Msg_N
-                    ("stream size for elementary type must be a power of 2 "
-                     & "and at least ^", N);
+                    ("stream size for elementary type must be 8, 16, 24, " &
+                     "32 or 64", N);
 
                elsif RM_Size (U_Ent) > Size then
                   Error_Msg_Uint_1 := RM_Size (U_Ent);
                   Error_Msg_N
-                    ("stream size for elementary type must be a power of 2 "
-                     & "and at least ^", N);
+                    ("stream size for elementary type must be 8, 16, 24, " &
+                     "32 or 64 and at least ^", N);
                end if;
 
                Set_Has_Stream_Size_Clause (U_Ent);

