Re: rs6000 -fdata-sections

[Alan Modra <amodra at bigpond dot net dot au>]

On Tue, Dec 04, 2001 at 03:17:46PM -0800, Geoff Keating wrote:
> 
> I'd appreciate it if you could leave 'prefixes' as a two-dimensional
> array, and leave the definitions of 'readonly' and 'needs_sdata', as
> both of these provide important documentation; I'm really not a big
> fan of the huge 'if ((x && a) || (y && b) || (z && (d || e)))'
> conditions.  Rewriting the assignment to 'sec' as a sequence of
> if-then conditions is good.  Can you submit a revised patch along
> those lines?

I'll take the liberty of interpreting your request regarding "readonly"
loosely.  How's this?

	* config/rs6000/rs6000.c (rs6000_unique_section): Simplify and
	correct code selecting section.

Index: gcc/config/rs6000/rs6000.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
retrieving revision 1.251
diff -c -r1.251 rs6000.c
*** rs6000.c	2001/12/04 23:23:19	1.251
--- rs6000.c	2001/12/05 03:26:21
***************
*** 9451,9459 ****
       tree decl;
       int reloc;
  {
-   int size = int_size_in_bytes (TREE_TYPE (decl));
-   int needs_sdata;
-   int readonly;
    int len;
    int sec;
    const char *name;
--- 9451,9456 ----
***************
*** 9462,9501 ****
  
    static const char *const prefixes[7][2] =
    {
-     { ".text.",   ".gnu.linkonce.t." },
      { ".rodata.", ".gnu.linkonce.r." },
      { ".sdata2.", ".gnu.linkonce.s2." },
      { ".data.",   ".gnu.linkonce.d." },
      { ".sdata.",  ".gnu.linkonce.s." },
      { ".bss.",    ".gnu.linkonce.b." },
!     { ".sbss.",   ".gnu.linkonce.sb." }
    };
!   
!   needs_sdata = (TREE_CODE (decl) != FUNCTION_DECL
! 		 && size > 0 
! 		 && size <= g_switch_value
! 		 && rs6000_sdata != SDATA_NONE
! 		 && (rs6000_sdata != SDATA_DATA || TREE_PUBLIC (decl)));
! 
!   if (TREE_CODE (decl) == STRING_CST)
!     readonly = ! flag_writable_strings;
!   else if (TREE_CODE (decl) == VAR_DECL)
!     readonly = (! (flag_pic && reloc)
! 		&& TREE_READONLY (decl)
! 		&& ! TREE_SIDE_EFFECTS (decl)
! 		&& DECL_INITIAL (decl)
! 		&& DECL_INITIAL (decl) != error_mark_node
! 		&& TREE_CONSTANT (DECL_INITIAL (decl)));
    else
!     readonly = 1;
!   if (needs_sdata && rs6000_sdata != SDATA_EABI)
!     readonly = 0;
! 
!   sec = ((TREE_CODE (decl) == FUNCTION_DECL ? 0 : 1)
! 	 + (readonly ? 0 : 2) 
! 	 + (needs_sdata ? 1 : 0)
! 	 + (DECL_INITIAL (decl) == 0
! 	    || DECL_INITIAL (decl) == error_mark_node) ? 4 : 0);
  
    STRIP_NAME_ENCODING (name, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
    prefix = prefixes[sec][DECL_ONE_ONLY (decl)];
--- 9459,9512 ----
  
    static const char *const prefixes[7][2] =
    {
      { ".rodata.", ".gnu.linkonce.r." },
      { ".sdata2.", ".gnu.linkonce.s2." },
      { ".data.",   ".gnu.linkonce.d." },
      { ".sdata.",  ".gnu.linkonce.s." },
      { ".bss.",    ".gnu.linkonce.b." },
!     { ".sbss.",   ".gnu.linkonce.sb." },
!     { ".text.",   ".gnu.linkonce.t." }
    };
! 
!   if (TREE_CODE (decl) == FUNCTION_DECL)
!     sec = 6;
    else
!     {
!       int readwrite;
!       int needs_sdata;
!       int size;
! 
!       readwrite = 0;
!       if (TREE_CODE (decl) == STRING_CST)
! 	readwrite = flag_writable_strings;
!       else if (TREE_CODE (decl) == VAR_DECL)
! 	readwrite = ((flag_pic && reloc)
! 		     || ! TREE_READONLY (decl)
! 		     || TREE_SIDE_EFFECTS (decl)
! 		     || ! TREE_CONSTANT (DECL_INITIAL (decl)));
! 
!       size = int_size_in_bytes (TREE_TYPE (decl));
!       needs_sdata = (size > 0 
! 		     && size <= g_switch_value
! 		     && rs6000_sdata != SDATA_NONE
! 		     && (rs6000_sdata != SDATA_DATA || TREE_PUBLIC (decl)));
! 
!       if (DECL_INITIAL (decl) == 0
! 	  || DECL_INITIAL (decl) == error_mark_node)
! 	sec = 4;
!       else if (readwrite)
! 	sec = 2;
!       else
! 	sec = 0;
! 
!       if (needs_sdata)
! 	{
! 	  /* .sdata2 is only for EABI.  */
! 	  if (sec == 0 && rs6000_sdata != SDATA_EABI)
! 	    sec = 2;
! 	  sec += 1;
! 	}
!     }
  
    STRIP_NAME_ENCODING (name, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
    prefix = prefixes[sec][DECL_ONE_ONLY (decl)];