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RE: [Patch] Add MIPS flag to avoid use of ldc1/sdc1/ldxc1/sdxc1
- From: Steve Ellcey <sellcey at imgtec dot com>
- To: Matthew Fortune <Matthew dot Fortune at imgtec dot com>
- Cc: Andrew Pinski <pinskia at gmail dot com>, "Moore, Catherine" <Catherine_Moore at mentor dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, "Raghu Gandham" <Raghu dot Gandham at imgtec dot com>
- Date: Tue, 28 Oct 2014 14:57:51 -0700
- Subject: RE: [Patch] Add MIPS flag to avoid use of ldc1/sdc1/ldxc1/sdxc1
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- Reply-to: <sellcey at imgtec dot com>
On Tue, 2014-10-28 at 14:06 -0700, Matthew Fortune wrote:
> While the patch could be fixed to account for all of this we need to
> determine if the case which won't work is the exact one which is needed
> (and I believe it is). I.e. Android applications for MIPS are MIPS32r1
> O32 FP32 NAN1985 currently and will transition from FP32 to FPXX to
> enable the use of things like MSA. Since MIPS32r1 does not have
> MTHC1/MFHC1 then this solution will not work.
>
> We'll have to talk with the google engineers to explain the issues.
>
> Matthew
FYI: I have emailed my Google contact to see if they could change their
allocator and included a reference to section 7.20.3 of the C standard.
Section 7.20.3 of C99 states: The pointer returned if the allocation
succeeds is suitably aligned so that it may be assigned to a pointer to
any type of object.
Steve Ellcey