Re: [fpc-pascal] Floating point question
>> You cannot do this in Pascal. The evaluation of the expression on the >> right of := does not >> know (and should not know) what the type is of the expression on the left. > It's even theoretically impossible to do in case the result is passed to > a function or intrinsic that is overloaded with single/double/extended > parameters. In other cases, I got a "can't determine which overloaded function to call" error, so I think this should be handable; but I understand the first argument of course. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Floating point question
On 12/02/2024 10:55, Michael Van Canneyt via fpc-pascal wrote: On Mon, 12 Feb 2024, Thomas Kurz via fpc-pascal wrote: I wouldn't say so. Or at least, not generally. Why can't the compiler do what the programer intends to do: var s: single; d: double; e: extended; begin s := 8427.0 + 33.0 / 1440.0; // treat all constants all "single" d := 8427.0 + 33.0 / 1440.0; // treat all constants all "double" e := 8427.0 + 33.0 / 1440.0; // treat all constants all "extended" end. You cannot do this in Pascal. The evaluation of the expression on the right of := does not know (and should not know) what the type is of the expression on the left. It's even theoretically impossible to do in case the result is passed to a function or intrinsic that is overloaded with single/double/extended parameters. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Floating point question
On Mon, 12 Feb 2024, Thomas Kurz via fpc-pascal wrote: I wouldn't say so. Or at least, not generally. Why can't the compiler do what the programer intends to do: var s: single; d: double; e: extended; begin s := 8427.0 + 33.0 / 1440.0; // treat all constants all "single" d := 8427.0 + 33.0 / 1440.0; // treat all constants all "double" e := 8427.0 + 33.0 / 1440.0; // treat all constants all "extended" end. You cannot do this in Pascal. The evaluation of the expression on the right of := does not know (and should not know) what the type is of the expression on the left. Michael. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Floating point question
I wouldn't say so. Or at least, not generally. Why can't the compiler do what the programer intends to do: var s: single; d: double; e: extended; begin s := 8427.0 + 33.0 / 1440.0; // treat all constants all "single" d := 8427.0 + 33.0 / 1440.0; // treat all constants all "double" e := 8427.0 + 33.0 / 1440.0; // treat all constants all "extended" end. Shouldn't this satisfy all the needs? Those caring for precision will work with double precision and don't have to take care for a loss in precision. Those caring for speed can use the single precision type and be sure that no costly conversion to double or extended will take place. - Original Message - From: Jonas Maebe via fpc-pascal To: fpc-pascal@lists.freepascal.org Sent: Sunday, February 11, 2024, 23:29:42 Subject: [fpc-pascal] Floating point question On 11/02/2024 23:21, Bernd Oppolzer via fpc-pascal wrote: > and this would IMHO be the solution which is the easiest to document and > maybe to implement > and which would satisfy the users. And generate the slowest code possible on most platforms. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
