Re: [ACPI] ACPI global lock macros

[Paul Menage]

Andi Kleen wrote:
> It has even more bugs, e.g. it doesn't tell gcc that GLptr is modified (this hurts with
> newer versions that optimize more aggressively) 

GLptr itself isn't modified - *GLptr is, but none of the actual C code 
accesses *GLptr, so how does this affect the compiler's optimization 
efforts? Is it because gcc treats the call as a pure function that maps 
a pointer to an acquired value, and hence believes that it can move it 
around? There aren't any instances of ACPI_ACQUIRE_GLOBAL_LOCK being 
called twice in the same function, so it wouldn't be able to cache a 
result. But I agree that it ought to declare that it clobbers memory.

Paul


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