[X86] __tune_* defines don't follow -mtune

[topperc]

Bugzilla Link	50781
Version	trunk
OS	All
CC	@topperc,@RKSimon,@phoebewang,@rotateright

Extended Description

Note this is really a clang bug, but there's no good component for target specific clang code and this component has the right CC list.

When I implemented -mtune support, I failed to make the preprocessor defines follow the -mtune setting.

This probably means we need a setTuneCPU function like setCPU in TargetInfo. Then we need to split defineCPUMacros to remove the tuning define. I think other targets use defineCPUMacros, but set a bool to not define the tune defines so removing the code simplies the interface.

I probably won't have a chance to work on this for a while. Pengfei, can you or someone at Intel handle it?

[phoebewang]

Sure, I can do it.

[RKSimon]

@phoebewang Re: https://reviews.llvm.org/D118527 - are you intending to look at this issue as part of that work?

[phoebewang]

No, I intended to fix an downstream problem with it. But yes, this issue is in my todo list. I think it's a good chance to work for it too.

[MaskRay]

Defining __tune_* shall be nice. It does not block https://reviews.llvm.org/D118527 . I have checked various x86 __tune_*, they cannot be found in projects other than GCC :)

[phoebewang]

Great. Thanks @MaskRay !