Committed patch to move MIPS comment

[Richard Sandiford <rsandifo at redhat dot com>]

Minor patch to move&update the cannot-change-mode comment.
Committed as obvious.

Richard

	* config/mips/mips.h (CANNOT_CHANGE_MODE_CLASS): Move comment to...
	* config/mips/mips.c (mips_cannot_change_mode_class): ...here.

Index: config/mips/mips.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/mips.h,v
retrieving revision 1.226
diff -c -d -p -F^[(a-zA-Z0-9_^#] -r1.226 mips.h
*** config/mips/mips.h	4 Nov 2002 16:57:06 -0000	1.226
--- config/mips/mips.h	5 Nov 2002 12:37:36 -0000
*************** #define SECONDARY_OUTPUT_RELOAD_CLASS(CL
*** 2326,2348 ****
  
  #define CLASS_MAX_NREGS(CLASS, MODE) mips_class_max_nregs (CLASS, MODE)
  
- /* If defined, gives a class of registers that cannot be used as the
-    operand of a SUBREG that changes the mode of the object illegally.
- 
-    In little-endian mode, the hi-lo registers are numbered backwards,
-    so (subreg:SI (reg:DI hi) 0) gets the high word instead of the low
-    word as intended.
- 
-    Similarly, when using paired floating-point registers, the first
-    register holds the low word, regardless of endianness.  So in big
-    endian mode, (subreg:SI (reg:DF $f0) 0) does not get the high word
-    as intended.
- 
-    Also, loading a 32-bit value into a 64-bit floating-point register
-    will not sign-extend the value, despite what LOAD_EXTEND_OP says.
-    We can't allow 64-bit float registers to change from a 32-bit
-    mode to a 64-bit mode.  */
- 
  #define CANNOT_CHANGE_MODE_CLASS(FROM, TO) \
    mips_cannot_change_mode_class (FROM, TO)
  
--- 2326,2331 ----
Index: config/mips/mips.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/mips.c,v
retrieving revision 1.239
diff -c -d -p -F^[(a-zA-Z0-9_^#] -r1.239 mips.c
*** config/mips/mips.c	4 Nov 2002 16:57:06 -0000	1.239
--- config/mips/mips.c	5 Nov 2002 12:37:36 -0000
*************** function_arg_pass_by_reference (cum, mod
*** 8400,8406 ****
  }
  
  /* Return the class of registers for which a mode change from FROM to TO
!    is invalid.  */
  enum reg_class
  mips_cannot_change_mode_class (from, to)
       enum machine_mode from, to;
--- 8400,8421 ----
  }
  
  /* Return the class of registers for which a mode change from FROM to TO
!    is invalid.
! 
!    In little-endian mode, the hi-lo registers are numbered backwards,
!    so (subreg:SI (reg:DI hi) 0) gets the high word instead of the low
!    word as intended.
! 
!    Similarly, when using paired floating-point registers, the first
!    register holds the low word, regardless of endianness.  So in big
!    endian mode, (subreg:SI (reg:DF $f0) 0) does not get the high word
!    as intended.
! 
!    Also, loading a 32-bit value into a 64-bit floating-point register
!    will not sign-extend the value, despite what LOAD_EXTEND_OP says.
!    We can't allow 64-bit float registers to change from a 32-bit
!    mode to a 64-bit mode.  */
! 
  enum reg_class
  mips_cannot_change_mode_class (from, to)
       enum machine_mode from, to;