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27 March 2024, 02:37:15 UTC
Revision e0f6dec35f9286e78879fe1ac92803fd69fc4fdc authored by H. Peter Anvin on 04 December 2013, 22:31:28 UTC, committed by H. Peter Anvin on 04 December 2013, 22:31:28 UTC 
x86, bitops: Correct the assembly constraints to testing bitops
 
In checkin:

0c44c2d0f459 x86: Use asm goto to implement better modify_and_test() functions

the various functions which do modify and test were unified and
optimized using "asm goto".  However, this change missed the detail
that the bitops require an "Ir" constraint rather than an "er"
constraint ("I" = integer constant from 0-31, "e" = signed 32-bit
integer constant).  This would cause code to miscompile if these
functions were used on constant bit positions 32-255 and the build to
fail if used on constant bit positions above 255.

Add the constraints as a parameter to the GEN_BINARY_RMWcc() macro to
avoid this problem.

Reported-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/529E8719.4070202@zytor.com
1 parent 5551a34
History
Tip revision: e0f6dec35f9286e78879fe1ac92803fd69fc4fdc authored by H. Peter Anvin on 04 December 2013, 22:31:28 UTC
x86, bitops: Correct the assembly constraints to testing bitops
Tip revision: e0f6dec
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