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Date: Thu, 10 Nov 2022 17:21:01 +0000
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Subject: Re: [Patch Arm] Fix PR 92999
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To: Ramana Radhakrishnan <ramana.gcc@googlemail.com>,
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Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>
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On 08/11/2022 18:20, Ramana Radhakrishnan via Gcc-patches wrote:
> PR92999 is a case where the VFP calling convention does not allocate
> enough FP registers for a homogenous aggregate containing FP16 values.
> I believe this is the complete fix but would appreciate another set of
> eyes on this.
> 
> Could I get a hand with a regression test run on an armhf environment
> while I fix my environment ?
> 
> gcc/ChangeLog:
> 
> PR target/92999
> *  config/arm/arm.c (aapcs_vfp_allocate_return_reg): Adjust to handle
> aggregates with elements smaller than SFmode.
> 
> gcc/testsuite/ChangeLog:
> 
> * gcc.target/arm/pr92999.c: New test.
> 
> 
> Thanks,
> Ramana
> 
> Signed-off-by: Ramana Radhakrishnan <ramana.gcc@gmail.com>

I'm not sure about this.  The AAPCS does not mention a base type of a 
half-precision FP type as an appropriate homogeneous aggregate for using 
VFP registers for either calling or returning.

So perhaps the bug is that we try to treat this as a homogeneous 
aggregate at all.

R.