Re: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy Bridge.

2023-08-09 Thread Uros Bizjak via Gcc-patches
Hongtao > > > Cc: gcc-patches@gcc.gnu.org > > > Subject: Re: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy > > > Bridge. > > > > > > On Wed, Aug 9, 2023 at 3:48 AM liuhongt wrote: > > > > > > >

Re: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy Bridge.

2023-08-09 Thread Uros Bizjak via Gcc-patches
On Wed, Aug 9, 2023 at 8:37 AM Liu, Hongtao wrote: > > > > > -Original Message- > > From: Uros Bizjak > > Sent: Wednesday, August 9, 2023 2:33 PM > > To: Liu, Hongtao > > Cc: gcc-patches@gcc.gnu.org > > Subject: Re: [PATCH V2] [X86] Work

RE: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy Bridge.

2023-08-09 Thread Liu, Hongtao via Gcc-patches
> -Original Message- > From: Uros Bizjak > Sent: Wednesday, August 9, 2023 2:33 PM > To: Liu, Hongtao > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy > Bridge. > > On Wed, Aug 9, 2023 at 3:48 AM liuhon

Re: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy Bridge.

2023-08-09 Thread Uros Bizjak via Gcc-patches
On Wed, Aug 9, 2023 at 3:48 AM liuhongt wrote: > > > Please rather do it in a more self-descriptive way, as proposed in the > > attached patch. You won't need a comment then. > > > > Adjusted in V2 patch. > > Don't access leaf 7 subleaf 1 unless subleaf 0 says it is > supported via EAX. > > Intel

Re: [PATCH V2] [X86] Workaround possible CPUID bug in Sandy Bridge.

2023-08-08 Thread Uros Bizjak via Gcc-patches
On Wed, Aug 9, 2023 at 3:48 AM liuhongt wrote: > > > Please rather do it in a more self-descriptive way, as proposed in the > > attached patch. You won't need a comment then. > > > > Adjusted in V2 patch. > > Don't access leaf 7 subleaf 1 unless subleaf 0 says it is > supported via EAX. > > Intel

[PATCH V2] [X86] Workaround possible CPUID bug in Sandy Bridge.

2023-08-08 Thread liuhongt via Gcc-patches
> Please rather do it in a more self-descriptive way, as proposed in the > attached patch. You won't need a comment then. > Adjusted in V2 patch. Don't access leaf 7 subleaf 1 unless subleaf 0 says it is supported via EAX. Intel documentation says invalid subleaves return 0. We had been relying