I revisited some old code and noticed there was a BSR using piece of assembler there that used bsr as a cheap 2log for some buffer dimensioning.
When I tried to replace it with the intrinsic bsrdword, hoping making it both inlinable and more portablw I noted that the intrinsic was exactly the same as my code but returned 255 instead of -1 for "0". Since this is a higher number than other values, it required another test to avoid outrageous large buffers, resulting in asm code (-O4): bsrl %eax,%eax jne .Lj7 movl $255,%eax .Lj7: # Var $result located in register eax #  if result=255 then result:=-1; cmpl $255,%eax jne .Lj9 movl $-1,%eax .Lj9: and then leal 2(%eax),%ebx to add two. Pretty hideous. If the dword version returned $FFFFFFFF it could be at least typecasted to -1. So the questions are: 1. why do the primitives deliver a signed result ? 2. why do they not all deliver -1 for their with ($FFFF for 2-byte etc). 3. (for Michael: :-) why doesn't the documentation doesn't mention the behaviour for no bits set?). Since (3) the behaviour is not documented, we can still fix this ? :-) The current choices (0..31 and 255) seem pointless. _______________________________________________ fpc-devel maillist - email@example.com http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel