Re: [committed] ppc64: Handle short vectors as function return types

[Simon Marchi <simon dot marchi at ericsson dot com>]

On 15-06-12 11:46 AM, Ulrich Weigand wrote:
> Hello,
> 
> Short synthetic vector types (i.e. those defined using GCC's
> attribute ((vector_size)) instead of AltiVec vector types)
> are returned in r3.  Fix ppc64_sysv_abi_return_value to
> correctly handle this.
> 
> Tested on powerpc64-linux and powerpc64le-linux.
> Pushed to mainline.
> 
> Bye,
> Ulrich
> 
> gdb/ChangeLog:
> 
> 	* ppc-sysv-tdep.c (ppc64_sysv_abi_return_value_base): Handle short
> 	synthetic (non-AltiVec) vector types.
> 	(ppc64_sysv_abi_return_value): Likewise.
> 
> diff --git a/gdb/ppc-sysv-tdep.c b/gdb/ppc-sysv-tdep.c
> index 6487bec..ea98c6e 100644
> --- a/gdb/ppc-sysv-tdep.c
> +++ b/gdb/ppc-sysv-tdep.c
> @@ -1892,7 +1892,8 @@ ppc64_sysv_abi_return_value_base (struct gdbarch *gdbarch, struct type *valtype,
>      }
>  
>    /* AltiVec vectors are returned in VRs starting at v2.  */
> -  if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY && TYPE_VECTOR (valtype)
> +  if (TYPE_LENGTH (valtype) == 16
> +      && TYPE_CODE (valtype) == TYPE_CODE_ARRAY && TYPE_VECTOR (valtype)
>        && tdep->vector_abi == POWERPC_VEC_ALTIVEC)
>      {
>        int regnum = tdep->ppc_vr0_regnum + 2 + index;
> @@ -1904,6 +1905,25 @@ ppc64_sysv_abi_return_value_base (struct gdbarch *gdbarch, struct type *valtype,
>        return 1;
>      }
>  
> +  /* Short vectors are returned in GPRs starting at r3.  */
> +  if (TYPE_LENGTH (valtype) <= 8
> +      && TYPE_CODE (valtype) == TYPE_CODE_ARRAY && TYPE_VECTOR (valtype))
> +    {
> +      int regnum = tdep->ppc_gp0_regnum + 3 + index;
> +      int offset = 0;
> +
> +      if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
> +	offset = 8 - TYPE_LENGTH (valtype);
> +
> +      if (writebuf != NULL)
> +	regcache_cooked_write_part (regcache, regnum,
> +				    offset, TYPE_LENGTH (valtype), writebuf);
> +      if (readbuf != NULL)
> +	regcache_cooked_read_part (regcache, regnum,
> +				   offset, TYPE_LENGTH (valtype), readbuf);
> +      return 1;
> +    }
> +
>    return 0;
>  }
>  
> @@ -1993,6 +2013,7 @@ ppc64_sysv_abi_return_value (struct gdbarch *gdbarch, struct value *function,
>  
>    /* Small character arrays are returned, right justified, in r3.  */
>    if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY
> +      && !TYPE_VECTOR (valtype)
>        && TYPE_LENGTH (valtype) <= 8
>        && TYPE_CODE (TYPE_TARGET_TYPE (valtype)) == TYPE_CODE_INT
>        && TYPE_LENGTH (TYPE_TARGET_TYPE (valtype)) == 1)
> @@ -2012,7 +2033,13 @@ ppc64_sysv_abi_return_value (struct gdbarch *gdbarch, struct value *function,
>    /* In the ELFv2 ABI, homogeneous floating-point or vector
>       aggregates are returned in registers.  */
>    if (tdep->elf_abi == POWERPC_ELF_V2
> -      && ppc64_elfv2_abi_homogeneous_aggregate (valtype, &eltype, &nelt))
> +      && ppc64_elfv2_abi_homogeneous_aggregate (valtype, &eltype, &nelt)
> +      && (TYPE_CODE (eltype) == TYPE_CODE_FLT
> +	  || TYPE_CODE (eltype) == TYPE_CODE_DECFLOAT
> +	  || (TYPE_CODE (eltype) == TYPE_CODE_ARRAY
> +	      && TYPE_VECTOR (eltype)
> +	      && tdep->vector_abi == POWERPC_VEC_ALTIVEC
> +	      && TYPE_LENGTH (eltype) == 16)))
>      {
>        for (i = 0; i < nelt; i++)
>  	{
> 

Hi Ulrich,

I think you made a typo in the date in the ChangeLog (05 instead of 06). While
we are at it, there is a missing space before your name. Do I let you change it
or do I do it myself?

Thanks,

Simon