llvm dev - Jun 2021 - Outreachy 2021 intern at LLVM

Hello everyone,

I am an Outreachy intern at LLVM and I will be working on implementing
GlobaliSel for M68k backend. I have wired up globalisel for M68k up to
the point where we can select return void. But M68k is big endian and
globalisel doesn't support big endian.

I have created a test case to test  my implementation:

; RUN: llc -mtriple=m68k -global-isel -stop-after=irtranslator < %s |
FileCheck %s

; CHECK: name: f
; CHECK: RTS
define void @f() {
  ret void
}


But I get an error:

LLVM ERROR: unable to translate in big endian mode (in function: f)


How do I convert this error into a warning?

Hi Sushma,

I think many people have provided really useful tips in
https://reviews.llvm.org/D101819.
If you still find difficulties fixing this issue, I'll suggest starting
from searching the error message string in the code base and trace the code
from there. It should tell you which line of code prevents GlobalISel from
supporting big endian.
After you (temporarily) lift the restriction (of big endian), you can run
the test program again to see if it crashes any part of GlobalISel due to
big endian.
In other words the whole process is try-and-error: Using the crash/error as
a hint for missing big endian features.

-Min

On Thu, Jun 3, 2021 at 1:15 AM Sushma Unnibhavi via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hello everyone,
>
> I am an Outreachy intern at LLVM and I will be working on implementing
> GlobaliSel for M68k backend. I have wired up globalisel for M68k up to
> the point where we can select return void. But M68k is big endian and
> globalisel doesn't support big endian.
>
> I have created a test case to test  my implementation:
>
> ; RUN: llc -mtriple=m68k -global-isel -stop-after=irtranslator < %s |
> FileCheck %s
>
> ; CHECK: name: f
> ; CHECK: RTS
> define void @f() {
>   ret void
> }
>
>
> But I get an error:
>
> LLVM ERROR: unable to translate in big endian mode (in function: f)
>
>
> How do I convert this error into a warning?
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>

-- 
Min-Yih Hsu
Ph.D Student in ICS Department, University of California, Irvine (UCI).
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