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* fixed swapendian(smallint) (bug found by Joost van der Sluis)

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* based swap(smallint) and swap(word) on swapendian(smallint/word),
    since the same bug was already fixed in swap(smallint) in r6752
    (so these routines now share the same code)
  * fixed potential range error in swapendian(word)
  + added basic test for the above four routines

git-svn-id: trunk@10840 -
This commit is contained in:
Jonas Maebe 2008-04-29 22:14:43 +00:00
parent 08a7e289cf
commit 95637dea75
4 changed files with 41 additions and 10 deletions
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1
.gitattributes vendored
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@ -6834,6 +6834,7 @@ tests/tbs/tb0544.pp svneol=native#text/plain
tests/tbs/tb0545.pp svneol=native#text/plain
tests/tbs/tb0546.pp svneol=native#text/plain
tests/tbs/tb0547.pp svneol=native#text/plain
tests/tbs/tb0548.pp svneol=native#text/plain
tests/tbs/tb205.pp svneol=native#text/plain
tests/tbs/ub0060.pp svneol=native#text/plain
tests/tbs/ub0069.pp svneol=native#text/plain

8
rtl/inc/generic.inc
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@ -1707,13 +1707,17 @@ end;
{$ifndef FPC_SYSTEM_HAS_SWAPENDIAN}
function SwapEndian(const AValue: SmallInt): SmallInt;
begin
Result := (AValue shr 8) or (AValue shl 8);
{ the extra Word type cast is necessary because the "AValue shr 8" }
{ is turned into "longint(AValue) shr 8", so if AValue < 0 then }
{ the sign bits from the upper 16 bits are shifted in rather than }
{ zeroes. }
Result := SmallInt((Word(AValue) shr 8) or (AValue shl 8));
end;
function SwapEndian(const AValue: Word): Word;
begin
Result := (AValue shr 8) or (AValue shl 8);
Result := Word((AValue shr 8) or (AValue shl 8));
end;

12
rtl/inc/system.inc
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@ -245,21 +245,17 @@ begin
Lo := b and $0f
end;
Function swap (X : Word) : Word;{$ifdef SYSTEMINLINE}inline;{$endif}
Function Swap (X : Word) : Word;{$ifdef SYSTEMINLINE}inline;{$endif}
Begin
swap:=(X and $ff) shl 8 + (X shr 8)
Swap := SwapEndian(X);
End;
Function Swap (X : Integer) : Integer;{$ifdef SYSTEMINLINE}inline;{$endif}
Begin
{ the extra 'and $ff' in the right term is necessary because the }
{ 'X shr 8' is turned into "longint(X) shr 8", so if x < 0 then }
{ the sign bits from the upper 16 bits are shifted in rather than }
{ zeroes. Another bug for TP/Delphi compatibility... }
swap:=(X and $ff) shl 8 + ((X shr 8) and $ff)
Swap := SwapEndian(X);
End;
Function swap (X : Longint) : Longint;{$ifdef SYSTEMINLINE}inline;{$endif}
Function Swap (X : Longint) : Longint;{$ifdef SYSTEMINLINE}inline;{$endif}
Begin
Swap:=(X and $ffff) shl 16 + (X shr 16)
End;

30
tests/tbs/tb0548.pp Normal file
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@ -0,0 +1,30 @@
{$r+}
{$q+}
var
wo: word;
si: smallint;
begin
wo:=$9876;
if swap(wo)<>$7698 then
halt(1);
if swapendian(wo)<>$7698 then
halt(2);
wo:=$1290;
if swap(wo)<>$9012 then
halt(3);
if swapendian(wo)<>$9012 then
halt(4);
si:=smallint($9876);
if swap(si)<>$7698 then
halt(5);
if swapendian(si)<>$7698 then
halt(6);
si:=$1290;
if swap(si)<>smallint($9012) then
halt(7);
if swapendian(si)<>smallint($9012) then
halt(8);
end.