Messages in this thread | | | Date | Sun, 17 Mar 2019 16:44:44 +0100 | From | Stefan Agner <> | Subject | Re: [PATCH 1/2] ARM: drop unnecessary WASM |
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On 06.03.2019 01:47, Nick Desaulniers wrote: > On Tue, Mar 5, 2019 at 3:39 PM Robin Murphy <robin.murphy@arm.com> wrote: >> >> Hi Stefan, >> >> On 2019-03-05 10:18 pm, Stefan Agner wrote: >> > The W macro for generating wide instructions when targeting Thumb-2 >> > is not required for the preload data instructions (pld, pldw) since >> > they are only available as wide instructions. The GNU assembler seems >> > to work with or without the .w appended when compiling an Thumb-2 >> > kernel. However, Clang's integrated assembler does not consider the >> > .w variants as valid instructions: >> > >> > ./arch/arm/include/asm/processor.h:133:5: error: invalid instruction >> > "pldw.w\t%a0 \n" >> > ^ >> > <inline asm>:2:1: note: instantiated into assembly here >> > pldw.w [r0] >> > ^ >> > 1 error generated. >> >> Have you filed a bug against Clang for that? Something like "pldwal.w" > > Yes; please. For each deficiency you find, please file a bug. We're > working on identifying what's missing from Clang's integrated > assembler support. Given the list of issues, it's easier to estimate > how much effort is needed, which helps us allocate resources towards > fixing those issues better. > > It would be good to know if pldw.w is valid under UAL or not.
As far as I understand the Arm ARM it is valid under UAL.
Reported a bug in LLVM's bug tracker: https://bugs.llvm.org/show_bug.cgi?id=40972
Will send a v2 patch mentioning this is really a work around for LLVM and link to the bug report.
> > Hopefully, the ARM kernel team can stress the importance of assembler > support for their ISA to their LLVM team.
-- Stefan
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