Re: [RFA] mips eabi, passing corner-case structs

Mark Kettenis
2006-06-17T23:41:47Z

> Date: Wed, 31 May 2006 16:46:51 -0700
> From: Michael Snyder <msnyder@redhat.com>
>
> That odd little corner case in eabi, wherein structs whose
> single field is a float or double are passed like a float or double.

Is the MIPS eabi documented somewhere? Or are you just implementing
whatever the GCC du jour emits? Doesn't your fix also affect structs
that have a single "long long" field?

> 2006-05-31 Michael Snyder <msnyder@redhat.com>
>
> * mips-tdep.c (mips_eabi_push_dummy_call): Catch corner case,
> structs with a single field of floating point type.
>
> Index: mips-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/mips-tdep.c,v
> retrieving revision 1.393
> diff -p -r1.393 mips-tdep.c
> *** mips-tdep.c 31 May 2006 23:15:50 -0000 1.393
> --- mips-tdep.c 31 May 2006 23:44:31 -0000
> *************** mips_eabi_push_dummy_call (struct gdbarc
> *** 2453,2460 ****
>
> /* The EABI passes structures that do not fit in a register by
> reference. */
> ! if (len > mips_abi_regsize (gdbarch)
> ! && (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION))
> {
> store_unsigned_integer (valbuf, mips_abi_regsize (gdbarch),
> VALUE_ADDRESS (arg));
> --- 2453,2467 ----
>
> /* The EABI passes structures that do not fit in a register by
> reference. */
> ! /* MVS: unles the struct has only one field, and that field
> ! will fit into two registers. */
> ! if ((typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
> ! && TYPE_NFIELDS (arg_type) == 1
> ! && len == 2 * mips_abi_regsize (gdbarch))
> ! val = value_contents (arg);
> ! else if (len > mips_abi_regsize (gdbarch)
> ! && (typecode == TYPE_CODE_STRUCT
> ! || typecode == TYPE_CODE_UNION))
> {
> store_unsigned_integer (valbuf, mips_abi_regsize (gdbarch),
> VALUE_ADDRESS (arg));
>
> --------------090500030309010101070908--
>