Messages in this thread | | | Date | Thu, 16 Oct 2003 07:55:31 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH][2.6] constant_test_bit doesn't like my gcc |
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Ingo Oeser <ioe-lkml@rameria.de> wrote: > > On Thursday 16 October 2003 06:22, Zwane Mwaikambo wrote: > > On Wed, 15 Oct 2003, Andrew Morton wrote: > > > > static __inline__ int constant_test_bit(int nr, const volatile > > > > unsigned long * addr) { > > > > - return ((1UL << (nr & 31)) & (((const volatile unsigned int *) > > > > addr)[nr >> 5])) != 0; + return ((1UL << (nr & 31)) & (addr[nr >> 5])) > > > > != 0; > > > > } > > > > > > Looks fine. Does your compiler get this right? > > > > Yep, thanks. > > Sorry, but I still don't get, what a "const volatile" is supposed to mean.
const: this function doesn't alter it
volatile: someone else does modify it, so the compiler needs to avoid caching it in a register.
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