newbery@vuwcomp.UUCP (02/09/87)
MPW Pascal can generate bad code when widening a signedByte to a char. Consider the following code fragment. ---------------------------------------------------------------------- VAR p : Ptr; PROCEDURE test(ch:CHAR); BEGIN {$R+ } ch := CHR(ORD(ch) MOD 128); {--- this statement will fail with a CHECK ERROR ---} . . END; BEGIN . . p^ := $FF; . . test(CHAR(p^)); ------------------------------------------------------------------------ MPW Pascal generates an EXT.W to widen the signedByte to a Word (CHAR is word aligned), thus $FF becomes $FFFF instead of $00FF and test falls over with a CHECK ERROR. This may or may not be of interest to someone :-) -- Michael Newbery ACSnet: newbery@vuwcomp.nz UUCP: {ubc-vision,alberta}!calgary!vuwcomp!newbery Une boule qui roule tue les poules. (Landslides kill chickens)