Messages in this thread | | | Date | Tue, 30 Sep 2003 14:41:33 +0200 (CEST) | From | Artur Klauser <> | Subject | Re: div64.h:do_div() bug |
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On Tue, 30 Sep 2003, Andreas Schwab wrote: > Matti Aarnio <matti.aarnio@zmailer.org> writes: > > On Tue, Sep 30, 2003 at 01:14:38PM +0300, Matti Aarnio wrote: > >> On Tue, Sep 30, 2003 at 11:52:29AM +0200, Rogier Wolff wrote: > >> > On Mon, Sep 29, 2003 at 03:25:19PM +0200, Artur Klauser wrote: > >> > > I've found that a bug in asm-arm/div64.h:do_div() is preventing correct > >> > > conversion of timestamps in smbfs (and probably ntfs as well) from NT to > >> > > >> > Nope. > >> > >> Nope yourself. > >> > >> > > if (in.n64 != out.n64) { > >> > > printf("FAILURE: asm/div64.h:do_div() is broken for 64-bit dividends\n"); > >> > > >> > do_div should be/is documented as not doing 64 bit dividents. It does > >> > 64/32 -> 32 divides, IIRC... > >> > >> 64/32 -> 64,32 > >> > >> The REMAINDER is 32 bit value. > > > > Non-native english speaker makes the mistake.. MODULUS is 32 bits as is > > DIVISOR, REMAINDER is 64 bit, as is DIVIDEND. > > > > That is: > > DIVIDEND / DIVISOR -> REMAINDER , MODULUS > ^^^^^^^^^^^^^^^^^^^ > ??? > QUOTIENT, REMAINDER
Actually, I have to agree with Andreas here - and with Matti's 1st naming attempt :)
But whatever the naming is, the operation AFAICT should be, and is implemented that way in other asm-<arch>/div64.h:do_div() macros:
do_div(u64, u32) u64 / u32 -> u64 (modifies 1st argument) u64 % u32 -> u32 (return value)
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