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Re: Selecting the correct default ABI for the iWMMXt processor


Hi Ian,

It seems very strange to me that a -mcpu option will change the ABI.


It won't, It will select an ABI to use if the user has not specified one. The code in arm_override_options() already makes a decision of which ABI to use when the user has not specified one. This patch simply extends the logic used so that the ABI selected will be compatible with the iWMMXt processor.

Also, it appears that your patch will force the use of ARM_ABI_AAPCS
(why not ARM_ABI_IWMMXT?)


Oops - that was a typo which I will fix once we have sorted out the rest of this patch.

Also, I think that changing

! MULTILIB_OPTIONS = mlittle-endian/mbig-endian

to

! MULTILIB_OPTIONS = mbig-endian

is definitely wrong. You should use MULTILIB_DEFAULTS for this kind
of thing. The same for your other MULTILIB_OPTIONS changes.


Why is it wrong ? It works. It eliminates a duplicate set of multlibs and it keeps the makefile fragment simple.

Cheers
 Nick


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