[llvm] r252563 - [PGO] Make indexed value profile data more compact

[Vedant Kumar via llvm-commits]

I haven't seen a failure yet, this is a latent issue.

AFAICT mutable static variables are generally avoided in llvm. We use llvm::ManagedStatic with atomics or locking if absolutely necessary.

Could you move this field into InstrProfWriter and InstrProfRecordTraits?

vedant

> On Jan 21, 2016, at 9:58 AM, Xinliang David Li <davidxl at google.com> wrote:
> 
> The setter call is invoked only in a unittest. Can you send me the
> failure report? (currently InstrProfRecordTraits has no members and is
> stateless).
> 
> thanks,
> 
> David
> 
> On Thu, Jan 21, 2016 at 1:17 AM, Vedant Kumar <vsk at apple.com> wrote:
>> Hi David,
>> 
>>> namespace {
>>> +static support::endianness ValueProfDataEndianness = support::little;
>>> +// Internal interface for testing purpose only.
>>> +void InstrProfWriter::setValueProfDataEndianness(
>>> +    support::endianness Endianness) {
>>> +  ValueProfDataEndianness = Endianness;
>>> +}
>> 
>> 
>> Please remove this static variable. It breaks clients who use llvm in a multi-threaded environment.
>> 
>> thanks
>> vedant
>>