[libav-devel] [GASPP PATCH] Comment out "it" instructions for armasm

Janne Grunau janne-libav at jannau.net
Thu Oct 3 11:45:25 CEST 2019


On 2019-10-02 11:53:28 +0300, Martin Storsjö wrote:
> Armasm implicitly adds it instructions as needed. In VS 2019 16.3,
> there's a bug [1] in armasm making it fail to parse these it instructions
> (but it can still add them implicitly just fine).
> 
> I'm not sure if it really is worth working around this issue, or just
> wait for it to hopefully be fixed by the next release again.
> 
> [1] https://developercommunity.visualstudio.com/content/problem/757709/armasm-fails-to-handle-it-instructions.html
> ---
>  gas-preprocessor.pl | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/gas-preprocessor.pl b/gas-preprocessor.pl
> index b6c2786..9d8fb5d 100755
> --- a/gas-preprocessor.pl
> +++ b/gas-preprocessor.pl
> @@ -1168,6 +1168,10 @@ sub handle_serialized_line {
>          $line =~ s/fmxr/vmsr/;
>          $line =~ s/fmrx/vmrs/;
>          $line =~ s/fadds/vadd.f32/;
> +        # Armasm in VS 2019 16.3 errors out on "it" instructions. But
> +        # armasm implicitly adds the necessary it instructions anyway, so we
> +        # can just filter it out.
> +        $line =~ s/^\s*it[te]*\s+/$comm$&/;
>      }
>      if ($as_type eq "armasm" and $arch eq "aarch64") {
>          # Convert "b.eq" into "beq"

I guess ok-ish since armasm can handle implicit it instructions. Do you 
have expectation when a fixed version might be released? If it's more 
than a couple of weeks I'd say the workaround is worth it.

Janne


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