Re: [PATCH 2/2] AArch64: add support for DFP (Decimal Floating point)

[Christophe Lyon <christophe.lyon@arm.com>]

On 5/20/22 11:06, Christophe Lyon wrote:
> This small patch adds support for TYPE_CODE_DECFLOAT in
> aapcs_is_vfp_call_or_return_candidate_1 and pass_in_v_vfp_candidate,
> so that GDB for AArch64 knows how to pass DFP parameters and how to
> read DFP results when calling a function.
> 
> Tested on aarch64-linux-gnu, with a GCC with DFP support in the PATH,
> all of GDB's DFP tests pass.

More precisely, patch 1/2 has a side-effect of enabling the GDB DFP 
tests, some of which fail without this patch 2/2:
gdb.base/dfp-test.exp: Call function with many _Decimal128 arguments.
gdb.base/dfp-test.exp: Call function with many _Decimal32 arguments.
gdb.base/dfp-test.exp: Call function with many _Decimal64 arguments.
gdb.base/dfp-test.exp: Call function with many mixed decimal float 
arguments.
gdb.base/dfp-test.exp: Call function with mixed decimal float arguments 
TEST.
gdb.base/dfp-test.exp: Call function with mixed decimal float arguments.
gdb.base/dfp-test.exp: backtrace function with correct _Decimal128 
arguments.
gdb.base/dfp-test.exp: backtrace function with correct _Decimal32 arguments.
gdb.base/dfp-test.exp: backtrace function with correct _Decimal64 arguments.

OK?

Christophe


> ---
>   gdb/aarch64-tdep.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
> index e35c083454d..67a3f96e1a7 100644
> --- a/gdb/aarch64-tdep.c
> +++ b/gdb/aarch64-tdep.c
> @@ -1470,6 +1470,7 @@ aapcs_is_vfp_call_or_return_candidate_1 (struct type *type,
>     switch (type->code ())
>       {
>       case TYPE_CODE_FLT:
> +    case TYPE_CODE_DECFLOAT:
>         if (TYPE_LENGTH (type) > 16)
>   	return -1;
>   
> @@ -1780,6 +1781,7 @@ pass_in_v_vfp_candidate (struct gdbarch *gdbarch, struct regcache *regcache,
>     switch (arg_type->code ())
>       {
>       case TYPE_CODE_FLT:
> +    case TYPE_CODE_DECFLOAT:
>         return pass_in_v (gdbarch, regcache, info, TYPE_LENGTH (arg_type),
>   			value_contents (arg).data ());
>         break;