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* Improved sign(x) functions to be branchless in most cases. Resolves #14206.

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git-svn-id: trunk@33067 -
This commit is contained in:
sergei 2016-02-07 11:18:31 +00:00
parent 56b6cedcf4
commit a4ed9f3b54
1 changed files with 14 additions and 24 deletions
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38
rtl/objpas/math.pp
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@ -638,35 +638,35 @@ end;
function Sign(const AValue: Integer): TValueSign;inline;
begin
If Avalue<0 then
Result:=NegativeValue
else If Avalue>0 then
Result:=PositiveValue
else
Result:=ZeroValue;
result:=TValueSign(
SarLongint(AValue,sizeof(AValue)*8-1) or { gives -1 for negative values, 0 otherwise }
(-AValue shr (sizeof(AValue)*8-1)) { gives 1 for positive values, 0 otherwise }
);
end;
function Sign(const AValue: Int64): TValueSign;inline;
begin
{$ifdef cpu64}
result:=TValueSign(
SarInt64(AValue,sizeof(AValue)*8-1) or
(-AValue shr (sizeof(AValue)*8-1))
);
{$else cpu64}
If Avalue<0 then
Result:=NegativeValue
else If Avalue>0 then
Result:=PositiveValue
else
Result:=ZeroValue;
{$endif}
end;
{$ifdef FPC_HAS_TYPE_SINGLE}
function Sign(const AValue: Single): TValueSign;inline;
begin
If Avalue<0.0 then
Result:=NegativeValue
else If Avalue>0.0 then
Result:=PositiveValue
else
Result:=ZeroValue;
Result:=ord(AValue>0.0)-ord(AValue<0.0);
end;
{$endif}
@ -674,24 +674,14 @@ end;
function Sign(const AValue: Double): TValueSign;inline;
begin
If Avalue<0.0 then
Result:=NegativeValue
else If Avalue>0.0 then
Result:=PositiveValue
else
Result:=ZeroValue;
Result:=ord(AValue>0.0)-ord(AValue<0.0);
end;
{$ifdef FPC_HAS_TYPE_EXTENDED}
function Sign(const AValue: Extended): TValueSign;inline;
begin
If Avalue<0.0 then
Result:=NegativeValue
else If Avalue>0.0 then
Result:=PositiveValue
else
Result:=ZeroValue;
Result:=ord(AValue>0.0)-ord(AValue<0.0);
end;
{$endif}