Leif,
I didn’t realized tool supports a global NULL library class usage. I now found this https://bugzilla.tianocore.org/show_bug.cgi?id=645.

Thanks for the education😊

Thanks,
Ray


From: Leif Lindholm <leif@nuviainc.com>
Sent: Thursday, March 12, 2020 9:54 PM
To: Ni, Ray <ray.ni@intel.com>
Cc: devel@edk2.groups.io; daniel.schaefer@hpe.com; Abner Chang <abner.chang@hpe.com>; Gilbert Chen <gilbert.chen@hpe.com>; Bi, Dandan <dandan.bi@intel.com>; Dong, Eric <eric.dong@intel.com>
Subject: Re: [EXTERNAL] RE: [edk2-devel] [PATCH v2 3/3] MdeModulePkg: Use CopyMem instead of GUID assignment

Hi Ray,

On Thu, Mar 12, 2020 at 12:21 PM Ni, Ray <ray.ni@intel.com<mailto:ray.ni@intel.com>> wrote:
> Does CompilerIntrinsicsLib exist because GCC doesn't support to disable intrinsic?

It is not possible to disable all intrinsics on 32-bit ARM, and it's not necessarily desirable to do so for AArch64 (so I don't think it's implemented).

Note that this is somewhat true for x86 too - leading to things like DivU64x32 in BaseLib.

> How does the linker find the CompilerInstrinsicsLib in linking phase?

For example:
https://github.com/tianocore/edk2/blob/master/MdeModulePkg/MdeModulePkg.dsc#L172

Regards,

Leif