Hi Ian; I don't see how I misread the output. The output shows that char <op> long promotes to LONG except for the shift operations. char <op> ulong promotes to ULONG except shift operations promote to INT.uchar <op> long promotes to LONG (I would have expected ULONG) except for shift operations which promote to INT. uchar <op> ulong promotes to ULONG except for shifts and long <op> ULONG promotes to ULONG except for shifts. Can you explain how I have misread the output and/or what the standard defines as the correct promotion? I am at this stage very confused as to what is correct and what is not. If the output defines the correct output (which it might) then it seems inconsistent as well as inconsiderate. thanks art ----- Original Message ---- From: Ian Lance Taylor <iant@xxxxxxxxxx> To: Arthur Schwarz <aschwarz1309@xxxxxxx> Cc: gcc@xxxxxxxxxxx Sent: Tue, December 18, 2012 4:56:11 PM Subject: Re: Possible issue with integer promotion for << and >> in gcc.4.5.3 On Tue, Dec 18, 2012 at 2:39 PM, Arthur Schwarz <aschwarz1309@xxxxxxx> wrote: > > I have run some tests to determine the gcc 4.5.3 integer promotion policies. This message is not appropriate for the mailing list gcc@xxxxxxxxxxx, which is for the development of GCC itself. It would be appropriate on the mailing list gcc-help@xxxxxxxxxxx. Please take any followups to gcc-help@xxxxxxxxxxx. Thanks. The integer promotion policies are the ones specified in the language standard. > The > tests show that for 'char' input, "char << long" and "char >> long" promote to > INT while other operations using a long promote to" long", and that "char << > ulong" and "char >> ulong" promote to INT while other operations using ulong > promote to "ulong". In similar fashion, "long << long" and "long >> long" > promote to INT while other promotions are to long, and that "long << ulong" and > "long >> ulong" promote to long while other operations promote to ulong. The > code used and the output are included below. The shift operators produce a value of the same type as the left operand, subject to the usual integer promotions. You say in the paragraph above that long << long promotes to INT, but that sounds unlikely, and I don't see any support for that in the program output that you showed. You suggest that there is a bug somewhere, but I don't see one. Ian
