Messages in this thread | | | Date | Wed, 4 Dec 2013 09:59:53 +0100 | From | Ingo Molnar <> | Subject | Re: Regression due to 0c44c2d0f459 x86: Use asm goto to implement better modify_and_test() functions |
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* H. Peter Anvin <hpa@zytor.com> wrote:
> Hi guys, > > 0c44c2d0f459 x86: Use asm goto to implement better modify_and_test() > functions > > causes a regression, because it incorrectly changed the constraints of > bitops. > > Specifically, the GEN_BINARY_RMWcc() hardcodes a constraint as "er", but > it needs to be "Ir" for the bitops themselves. "I" is correct (as > opposed to "J" even on 64 bits, because we only generate the 64-bit > version when we have a register operand. > > Unfortunately there isn't a way we can get gcc+gas to generate a version > with an offset pointer.
Does the regression manifest itself in any actual breakage - if yes, how does it look like? (People experiencing similar symptoms will be helped by seeing a fix matching their problems.)
Thanks,
ngo
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