| 298473 |
22-Apr-2016 |
avg |
lahf/sahf are supported on some amd64 processors
While the instructions were not included into the original instruction
set, their support can be indicated by a special feature bit.
For example:
CPU: AMD Phenom(tm) II X4 955 Processor (3214.71-MHz K8-class CPU)
...
AMD Features2=0x37ff<LAHF, ...>
Clang 3.8 uses lahf/sahf as a faster alternative to pushf/popf where
possible.
MFC after: 2 weeks
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