Re: [PATCH v2] Make iwmmxt.S support Clang's integrated assembler

From: Nick Desaulniers
Date: Tue Nov 10 2020 - 14:26:48 EST


On Mon, Nov 9, 2020 at 11:36 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>
> BE32 != BE8

Oh? Sorry, what does BE8 stand for? arch/arm/mm/Kconfig says:

CONFIG_CPU_ENDIAN_BE8
Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.

vs:
CPU_ENDIAN_BE32
Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.

So BE8 seems newer? It looks like in my tests, enabling
CPU_BIG_ENDIAN via menuconfig enabled CPU_ENDIAN_BE8.

>
> Please use, e.g., ixp4xx_defconfig with IWMMXT and BE enabled. It
> seems like .inst does the right thing here, i.e., the assembler knows
> that it should emit BE for BE32 and LE for BE8, but it needs to be
> confirmed.

Ah and ixp4xx_defconfig selects CPU_ENDIAN_BE32. Yep, and the
disassemblies of those match, too.
--
Thanks,
~Nick Desaulniers