2021-03-09 09:59:23

by Tony Lindgren

[permalink] [raw]
Subject: Re: [PATCH] ARM: omap1: fix building with clang IAS

* Arnd Bergmann <[email protected]> [210308 15:35]:
> From: Arnd Bergmann <[email protected]>
>
> The clang integrated assembler fails to build one file with
> a complex asm instruction:
>
> arch/arm/mach-omap1/ams-delta-fiq-handler.S:249:2: error: invalid instruction, any one of the following would fix this:
> mov r10, #(1 << (((NR_IRQS_LEGACY + 12) - NR_IRQS_LEGACY) % 32)) @ set deferred_fiq bit
> ^
> arch/arm/mach-omap1/ams-delta-fiq-handler.S:249:2: note: instruction requires: armv6t2
> mov r10, #(1 << (((NR_IRQS_LEGACY + 12) - NR_IRQS_LEGACY) % 32)) @ set deferred_fiq bit
> ^
> arch/arm/mach-omap1/ams-delta-fiq-handler.S:249:2: note: instruction requires: thumb2
> mov r10, #(1 << (((NR_IRQS_LEGACY + 12) - NR_IRQS_LEGACY) % 32)) @ set deferred_fiq bit
> ^
>
> The problem is that 'NR_IRQS_LEGACY' is not defined here. Apparently
> gas does not care because we first add and then subtract this number,
> leading to the immediate value to be the same regardless of the
> specific definition of NR_IRQS_LEGACY.
>
> Neither the way that 'gas' just silently builds this file, nor the
> way that clang IAS makes nonsensical suggestions for how to fix it
> is great. Fortunately there is an easy fix, which is to #include
> the header that contains the definition.

Acked-by: Tony Lindgren <[email protected]>