Re: [PATCH] Support _Complex in hard-VFP abi

Will Newton
2014-08-11T13:12:21Z

On 11 August 2014 13:51, Yao Qi <yao@codesourcery.com> wrote:
> Hi,
> When we pass "-mfloat-abi=hard" flag in the GDB testing, we see the
> following fails,
>
> FAIL: gdb.base/callfuncs.exp: p t_float_complex_values(fc1, fc2)
> FAIL: gdb.base/callfuncs.exp: p t_float_complex_many_args(fc1, fc2, fc3, fc4, fc1, fc2, fc3, fc4, fc1, fc2, fc3, fc4, fc1, fc2, fc3, fc4)
> FAIL: gdb.base/callfuncs.exp: p t_double_complex_values(dc1, dc2)
> FAIL: gdb.base/callfuncs.exp: p t_double_complex_many_args(dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4)
> FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_values(ldc1, ldc2)
> FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_many_args(ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4)
> FAIL: gdb.base/callfuncs.exp: call inferior func with struct - returns float _Complex
> FAIL: gdb.base/callfuncs.exp: call inferior func with struct - returns double _Complex
>
> The hard-VFP ABI was supported by GDB overal, done by this patch
> https://sourceware.org/ml/gdb-patches/2009-07/msg00686.html but
> "vectors and complex types are not currently supported", mentioned in
> the patch. As a result, these tests fail.
>
> This patch is to support _Complex types in hard-VFP abi. As specified
> in "7.1.1, Procedure Call Standard for the ARM Arch", the layout of
> _Complex types is a struct, which is identical to the layout on amd64,
> so I copy Mark's comments to amd64 support.
>
> Regression tested on arm-none-eabi target. OK to apply?
>
> gdb:
>
> 2014-08-11 Yao Qi <yao@codesourcery.com>
>
> * arm-tdep.c (arm_vfp_cprc_sub_candidate): Handle _Complex
> types.
> ---
> gdb/arm-tdep.c | 34 ++++++++++++++++++++++++++++++++--
> 1 file changed, 32 insertions(+), 2 deletions(-)

Apart from a couple of minor nits below this looks ok to me.

> diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
> index b6ec456..10e74cf 100644
> --- a/gdb/arm-tdep.c
> +++ b/gdb/arm-tdep.c
> @@ -3557,8 +3557,8 @@ arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b)
> classified from *BASE_TYPE, or two types differently classified
> from each other, return -1, otherwise return the total number of
> base-type elements found (possibly 0 in an empty structure or
> - array). Vectors and complex types are not currently supported,
> - matching the generic AAPCS support. */
> + array). Vectors types are not currently supported, matching the

This should be "Vector types".

> + generic AAPCS support. */
>
> static int
> arm_vfp_cprc_sub_candidate (struct type *t,
> @@ -3589,6 +3589,36 @@ arm_vfp_cprc_sub_candidate (struct type *t,
> }
> break;
>
> + case TYPE_CODE_COMPLEX:
> + /* Arguments of complex T where T is one of the types float or
> + double get treated as if they are implemented as:
> +
> + struct complexT
> + {
> + T real;
> + T imag;
> + };*/

A line break before closing the comment might look nicer here.

> + switch (TYPE_LENGTH (t))
> + {
> + case 8:
> + if (*base_type == VFP_CPRC_UNKNOWN)
> + *base_type = VFP_CPRC_SINGLE;
> + else if (*base_type != VFP_CPRC_SINGLE)
> + return -1;
> + return 2;
> +
> + case 16:
> + if (*base_type == VFP_CPRC_UNKNOWN)
> + *base_type = VFP_CPRC_DOUBLE;
> + else if (*base_type != VFP_CPRC_DOUBLE)
> + return -1;
> + return 2;
> +
> + default:
> + return -1;
> + }
> + break;
> +
> case TYPE_CODE_ARRAY:
> {
> int count;
> --
> 1.9.0
>

--
Will Newton
Toolchain Working Group, Linaro