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Re: [RFA] Mips, return_value_location, small structs
- From: Michael Snyder <msnyder at redhat dot com>
- To: Andrew Cagney <ac131313 at ges dot redhat dot com>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Fri, 09 Aug 2002 17:18:15 -0700
- Subject: Re: [RFA] Mips, return_value_location, small structs
- Organization: Red Hat, Inc.
- References: <3D5438A9.5F0FA8A8@redhat.com> <3D545AB2.4030803@ges.redhat.com>
Andrew Cagney wrote:
>
> > Re-submitted as a separate patch.
> >
> > The problem: small structs returned in one (or two) registers
> > are aligned left in N32/N64 and aligned right in the others
> > (or vice versa, depending on how you cross your eyes).
>
> I _think_ you also need to add o32. Can you check that out? Just post
> the results, not the patch.
I know o32 needs work too, but the two can be treated separately.
I do guarantee that this patch does not make o32 any worse.
In fact, I have been testing to make sure that none of my patches
have made o32 any worse.
Can I check this one in for n32, if I promise to work on o32 next?
>
> Andrew
>
> > There are two code paths here, one for structs of length < MIPS_REGSIZE,
> > and one for MIPS_REGSIZE < struct len < 2 * MIPS_REGSIZE.
> >
> > The first case I've split into two paths: one for N32 &&
> > TYPE_CODE_STRUCT,
> > and a second for everything else (the later being identical to what was
> > there before).
> >
> > In the second case, I've simply let the N32/N64 path fall thru.
> > The next "if" catches it and handles it correctly.
> >
> >
> >
> > 2002-08-08 Michael Snyder <msnyder@redhat.com>
> >
> > * mips-tdep.c (return_value_location): Structs returned in
> > registers are aligned differently (n32/64 vs. o32/64).
> >
> > Index: mips-tdep.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/mips-tdep.c,v
> > retrieving revision 1.92
> > diff -c -3 -p -r1.92 mips-tdep.c
> > *** mips-tdep.c 8 Aug 2002 00:26:51 -0000 1.92
> > --- mips-tdep.c 8 Aug 2002 21:48:09 -0000
> > *************** return_value_location (struct type *valt
> > *** 3608,3622 ****
> > if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
> > && len < MIPS_SAVED_REGSIZE)
> > {
> > ! /* "un-left-justify" the value in the low register */
> > ! lo->reg_offset = MIPS_SAVED_REGSIZE - len;
> > ! lo->len = len;
> > hi->reg_offset = 0;
> > hi->len = 0;
> > }
> > else if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
> > && len > MIPS_SAVED_REGSIZE /* odd-size structs */
> > && len < MIPS_SAVED_REGSIZE * 2
> > && (TYPE_CODE (valtype) == TYPE_CODE_STRUCT ||
> > TYPE_CODE (valtype) == TYPE_CODE_UNION))
> > {
> > --- 3608,3635 ----
> > if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
> > && len < MIPS_SAVED_REGSIZE)
> > {
> > ! if ((gdbarch_tdep (current_gdbarch) -> mips_abi == MIPS_ABI_N32
> > ! || gdbarch_tdep (current_gdbarch) -> mips_abi == MIPS_ABI_N64)
> > ! && (TYPE_CODE (valtype) == TYPE_CODE_STRUCT
> > ! || TYPE_CODE (valtype) == TYPE_CODE_UNION))
> > ! {
> > ! /* Values are already aligned in the low register. */
> > ! lo->reg_offset = 0;
> > ! }
> > ! else
> > ! {
> > ! /* "un-left-justify" the value in the low register */
> > ! lo->reg_offset = MIPS_SAVED_REGSIZE - len;
> > ! }
> > hi->reg_offset = 0;
> > + lo->len = len;
> > hi->len = 0;
> > }
> > else if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
> > && len > MIPS_SAVED_REGSIZE /* odd-size structs */
> > && len < MIPS_SAVED_REGSIZE * 2
> > + && gdbarch_tdep (current_gdbarch) -> mips_abi != MIPS_ABI_N32
> > + && gdbarch_tdep (current_gdbarch) -> mips_abi != MIPS_ABI_N64
> > && (TYPE_CODE (valtype) == TYPE_CODE_STRUCT ||
> > TYPE_CODE (valtype) == TYPE_CODE_UNION))
> > {