Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v5 1/5] x86/asm: Carve out a generic movdir64b() helper for general usage | Date | Thu, 24 Sep 2020 11:25:27 +0000 |
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> > No, that just says the asm uses the value of the pointer. > > Not what it points to. > > Err, no, it is *exactly* what it points to that is important here and > you're telling the compiler that the instruction will read that much > memory through the pointer.
You need to use an "m" constraint for that. A 'register' constraint just requires the value of the address to be valid.
Look at the asm output from the example code I posted.
David
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