fixed NextPowerOf2

Author: sglienke

Source/Base/Spring.pas

@@ -3113,9 +3113,9 @@ procedure IncUnchecked(var i: Integer; const n: Integer = 1); inline;
 
 procedure SwapPtr(arr: PPointer; left, right: Integer); inline;
 
-function IsPowerOf2(value: Integer): Boolean;
+function IsPowerOf2(value: NativeInt): Boolean;
 
-function NextPowerOf2(value: Integer): Integer;
+function NextPowerOf2(value: NativeInt): NativeInt;
 
 // copy from System.pas to make it possible to inline
 function DynArrayLength(const A: Pointer): NativeInt; inline;
@@ -4138,25 +4138,37 @@ procedure IncUnchecked(var i: Integer; const n: Integer = 1); inline;
   {$IFDEF OVERFLOWCHECKS_ON}{$Q+}{$ENDIF}
 end;
 
-function IsPowerOf2(value: Integer): Boolean;
+function IsPowerOf2(value: NativeInt): Boolean;
 begin
   Result := (value > 0) and (value and (value - 1) = 0);
 end;
 
-function NextPowerOf2(value: Integer): Integer;
-{$IFDEF MSWINDOWS}
+function NextPowerOf2(value: NativeInt): NativeInt;
+{$IFDEF ASSEMBLER}
+{$IFDEF CPUX86}
 asm
-  cmp value, 0
+  test eax, eax
   jle @negative
-  bsr ecx, value
-  add ecx, 1
-  mov eax, 1
+  bsr ecx, eax
+  mov eax, 2
   shl eax, cl
   ret
 @negative:
   mov eax, 1
 end;
 {$ELSE}
+asm
+  test rcx, rcx
+  jle @negative
+  bsr rcx, rcx
+  mov eax, 2
+  shl rax, cl
+  ret
+@negative:
+  mov eax, 1
+end;
+{$ENDIF}
+{$ELSE}
 begin
   Result := 1;
   while (Result <= value) and (Result > 0) do

Tests/Source/Base/Spring.Tests.Base.pas

@@ -4235,9 +4235,9 @@ procedure TTestEnum.TestParseStringException;
 
 procedure TTestBaseRoutines.TestNextPowerOf2;
 
-  procedure TestRange(Low, High, Power: Integer);
+  procedure TestRange(Low, High, Power: NativeInt);
   var
-    i: Integer;
+    i: NativeInt;
   begin
     for i := Low to High do
       CheckEquals(Power, NextPowerOf2(i), Format('NextPowerOf2(%d) did not return %d', [i, Power]));
@@ -4254,8 +4254,8 @@ procedure TTestBaseRoutines.TestNextPowerOf2;
   TestRange( 16, 31, 32);
 
   TestRange(Pow_2_30 - 50, Pow_2_30 - 1, Pow_2_30);
-  TestRange(High(Integer) div 2 + 1, High(Integer) div 2 + 2, Integer($80000000));
-  TestRange(High(Integer) - 1, High(Integer), Integer($80000000));
+  TestRange(High(NativeInt) div 2 + 1, High(NativeInt) div 2 + 2, Low(NativeInt));
+  TestRange(High(NativeInt) - 1, High(NativeInt), Low(NativeInt));
 end;
 
 {$ENDREGION}