Re: [edk2-devel] [PATCH v2 6/6] UefiCpuPkg/MtrrLib: use new IS_POW2() macro.

["Michael D Kinney" <michael.d.kinney@intel.com>]

Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>

Mike

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Gerd Hoffmann
> Sent: Wednesday, March 22, 2023 12:03 AM
> To: devel@edk2.groups.io
> Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Aktas, Erdem <erdemaktas@google.com>; James Bottomley <jejb@linux.ibm.com>;
> Gao, Liming <gaoliming@byosoft.com.cn>; Marvin Häuser <mhaeuser@posteo.de>; Pawel Polawski <ppolawsk@redhat.com>; Michael Roth
> <michael.roth@amd.com>; Tom Lendacky <thomas.lendacky@amd.com>; Gerd Hoffmann <kraxel@redhat.com>; Yao, Jiewen
> <jiewen.yao@intel.com>; Wang, Jian J <jian.j.wang@intel.com>; Ard Biesheuvel <ardb+tianocore@kernel.org>; Justen, Jordan L
> <jordan.l.justen@intel.com>; Wu, Hao A <hao.a.wu@intel.com>; Liu, Zhiguang <zhiguang.liu@intel.com>; Ni, Ray <ray.ni@intel.com>;
> Xu, Min M <min.m.xu@intel.com>; Oliver Steffen <osteffen@redhat.com>
> Subject: [edk2-devel] [PATCH v2 6/6] UefiCpuPkg/MtrrLib: use new IS_POW2() macro.
> 
> Drop MtrrLibIsPowerOfTwo function, use the new IS_POW2() macro instead.
> 
> The ASSERT() removed (inside MtrrLibIsPowerOfTwo) is superfluous,
> another ASSERT() a few lines up in MtrrLibCalculateMtrrs() already
> guarantees that Length can not be zero at this point.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 17 +----------------
>  1 file changed, 1 insertion(+), 16 deletions(-)
> 
> diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
> index e5c862c83d61..dd0b668d7782 100644
> --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
> +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
> @@ -1253,21 +1253,6 @@ MtrrLibLowestType (
>    return (MTRR_MEMORY_CACHE_TYPE)Type;
>  }
> 
> -/**
> -  Return TRUE when the Operand is exactly power of 2.
> -
> -  @retval TRUE  Operand is exactly power of 2.
> -  @retval FALSE Operand is not power of 2.
> -**/
> -BOOLEAN
> -MtrrLibIsPowerOfTwo (
> -  IN     UINT64  Operand
> -  )
> -{
> -  ASSERT (Operand != 0);
> -  return (BOOLEAN)((Operand & (Operand - 1)) == 0);
> -}
> -
>  /**
>    Calculate the subtractive path from vertex Start to Stop.
> 
> @@ -1638,7 +1623,7 @@ MtrrLibCalculateMtrrs (
>            break;
>          }
> 
> -        if ((Weight[M (Start, Stop)] == MAX_WEIGHT) && MtrrLibIsPowerOfTwo (Length)) {
> +        if ((Weight[M (Start, Stop)] == MAX_WEIGHT) && IS_POW2 (Length)) {
>            if (MtrrLibGetNumberOfTypes (
>                  Ranges,
>                  RangeCount,
> --
> 2.39.2
> 
> 
> 
> 
>