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Fixes UInt64 to Double conversion on ARM64 #865

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Fixes UInt64 to Double conversion on ARM64 #865

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17 changes: 15 additions & 2 deletions sources/JsonDataObjects.pas
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Original file line number Diff line number Diff line change
Expand Up @@ -7175,6 +7175,19 @@ function ParseAsDoubleUtf8(F, P: PByte): Double;
end;
end;

// 32-bit ARM64 emulation fix: Manual digit-by-digit conversion
// Both UInt64/Double division AND UInt64->Double implicit conversion fail
function U64ToDouble(u: UInt64): Double;
const
TWO32: Double = 4294967296.0;
var
hi, lo: Cardinal;
begin
hi := Cardinal(u shr 32);
lo := Cardinal(u);
Result := hi * TWO32 + lo;
end;

procedure TUtf8JsonReader.LexNumber(P: PByte{$IFDEF CPUARM}; EndP: PByte{$ENDIF});
var
F: PByte;
Expand Down Expand Up @@ -7297,7 +7310,7 @@ procedure TUtf8JsonReader.LexNumber(P: PByte{$IFDEF CPUARM}; EndP: PByte{$ENDIF}
EndInt64P := EndP;
while (P < EndInt64P) and (P^ in [Ord('0')..Ord('9')]) do
Inc(P);
Value := Value + ParseUInt64Utf8(F, P) / Power10[P - F];
Value := Value + U64ToDouble(ParseUInt64Utf8(F, P)) / Power10[P - F];

// "Double" can't handle that many digits
while (P < EndP) and (P^ in [Ord('0')..Ord('9')]) do
Expand Down Expand Up @@ -7828,7 +7841,7 @@ procedure TStringJsonReader.LexNumber(P: PChar{$IFDEF CPUARM}; EndP: PChar{$ENDI
EndInt64P := EndP;
while (P < EndInt64P) and (P^ in ['0'..'9']) do
Inc(P);
Value := Value + ParseUInt64(F, P) / Power10[P - F];
Value := Value + U64ToDouble(ParseUInt64(F, P)) / Power10[P - F];

// "Double" can't handle that many digits
while (P < EndP) and (P^ in ['0'..'9']) do
Expand Down