Another 20020412-1.c mips fix

[Richard Sandiford <rsandifo at redhat dot com>]

Although this:

   http://gcc.gnu.org/ml/gcc-patches/2003-09/msg01696.html

was enough to fix 20020412-1.c for n32 & n64, there's a further
problem for o32 & o64.  main() passes the first part of x[] in
the register save area, which foo() then clobbers when saving
the argument registers.

An obvious fix is to make FUNCTION_ARG{,_ADVANCE} skip all registers
if they see a MUST_PASS_IN_STACK argument.  This is an ABI change for
o32 & o64, so I don't think it's "obviously correct", just obvious.
OTOH, I doubt things could really work properly the way they were.

This also fixes the case where a constant-sized argument
is passed after a variable-sized one for n32 & n64.

Tested on mips-sgi-irix6.5, mips64-linux-gnu, mipsisa64-elf,
mips64{,el}-elf and mips64vrel-elf.  OK to install?

Richard


	* config/mips/mips.c (mips_arg_info): If MUST_PASS_IN_STACK,
	skip any remaining register arguments.

diff -cpdr config/mips.fix/mips.c config/mips/mips.c
*** config/mips.fix/mips.c	Sat Oct  4 13:00:07 2003
--- config/mips/mips.c	Sat Oct  4 14:04:39 2003
*************** mips_arg_info (const CUMULATIVE_ARGS *cu
*** 3661,3675 ****
  	even_reg_p = true;
      }
  
!   /* Set REG_OFFSET to the register count we're interested in.
!      The EABI allocates the floating-point registers separately,
!      but the other ABIs allocate them like integer registers.  */
!   info->reg_offset = (mips_abi == ABI_EABI && info->fpr_p
! 		      ? cum->num_fprs
! 		      : cum->num_gprs);
  
!   if (even_reg_p)
!     info->reg_offset += info->reg_offset & 1;
  
    /* The alignment applied to registers is also applied to stack arguments.  */
    info->stack_offset = cum->stack_words;
--- 3661,3682 ----
  	even_reg_p = true;
      }
  
!   if (mips_abi != ABI_EABI && MUST_PASS_IN_STACK (mode, type))
!     /* This argument must be passed on the stack.  Eat up all the
!        remaining registers.  */
!     info->reg_offset = MAX_ARGS_IN_REGISTERS;
!   else
!     {
!       /* Set REG_OFFSET to the register count we're interested in.
! 	 The EABI allocates the floating-point registers separately,
! 	 but the other ABIs allocate them like integer registers.  */
!       info->reg_offset = (mips_abi == ABI_EABI && info->fpr_p
! 			  ? cum->num_fprs
! 			  : cum->num_gprs);
  
!       if (even_reg_p)
! 	info->reg_offset += info->reg_offset & 1;
!     }
  
    /* The alignment applied to registers is also applied to stack arguments.  */
    info->stack_offset = cum->stack_words;