Messages in this thread | | | Date | Thu, 14 May 2009 16:27:49 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH] x86: Extend test_and_set_bit() test_and_clean_bit() to 64 bits in X86_64 |
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On Thu, May 14, 2009 at 07:16:10AM -0700, H. Peter Anvin wrote: > Andi Kleen wrote: > >>> > >> The right way to do it is to pass the proper type of register. > > > > For the input index register you don't actually need 64bit and for the > > value it's typically memory anyways. > > > > If you have a 64-bit operation you have a 64-bit index register. And > you need a 64-bit index for it to handle over 2^31 (since it is signed.)
Pretty much all the bit ops and a few other operations currently have 2/4GB limits on x86-64. I don't think that's going to change.
In the kernel nothing is ever that big continuously anyways.
-Andi -- ak@linux.intel.com -- Speaking for myself only.
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