Re: AIX bootstrap failure (was Re: Hot/cold partitioning fixes)

[Caroline Tice <ctice at apple dot com>]

On Apr 1, 2005, at 8:43 AM, David Edelsohn wrote:

> 	The hot/cold partitioning patch is emitting hot and cold section
> labels unconditionally, regardless whether 
> reorder_blocks_and_partition is
> enabled.  The appended patch addresses that problem.  I am attempting
> another bootstrap now.
>
> 	Also, the implementation assumes that it can manipulate section
> names by appending strings, which is fundamentally not portable.  This
> functionality was not implemented portably for inclusion in GCC.
>
> David
>
>
> 	* varasm.c (assemble_start_function): Only emit hot_section_label
> 	if reorder_blocks_and_partition is enabled.
> 	(assemble_end_function): Only emit cold_section_end_label and
> 	hot_section_end_label if reorder_blocks_and_partition is enabled.
>
> Index: varasm.c
> ===================================================================
> RCS file: /cvs/gcc/gcc/gcc/varasm.c,v
> retrieving revision 1.492
> diff -c -p -r1.492 varasm.c
> *** varasm.c	1 Apr 2005 03:42:45 -0000	1.492
> --- varasm.c	1 Apr 2005 16:37:59 -0000
> *************** assemble_start_function (tree decl, cons
> *** 1303,1309 ****
>     /* Switch to the correct text section for the start of the 
> function.  */
>
>     function_section (decl);
> !   if (!hot_label_written)
>       ASM_OUTPUT_LABEL (asm_out_file, hot_section_label);
>
>     /* Tell assembler to move to target machine's alignment for 
> functions.  */
> --- 1303,1309 ----
>     /* Switch to the correct text section for the start of the 
> function.  */
>
>     function_section (decl);
> !   if (flag_reorder_blocks_and_partition && !hot_label_written)
>       ASM_OUTPUT_LABEL (asm_out_file, hot_section_label);
>
>     /* Tell assembler to move to target machine's alignment for 
> functions.  */
> *************** assemble_end_function (tree decl, const
> *** 1379,1387 ****
>        debug info.)  */
>     save_text_section = in_section;
>     unlikely_text_section ();
> !   ASM_OUTPUT_LABEL (asm_out_file, cold_section_end_label);
>     text_section ();
> !   ASM_OUTPUT_LABEL (asm_out_file, hot_section_end_label);
>     if (save_text_section == in_unlikely_executed_text)
>       unlikely_text_section ();
>   }
> --- 1379,1389 ----
>        debug info.)  */
>     save_text_section = in_section;
>     unlikely_text_section ();
> !   if (flag_reorder_blocks_and_partition)
> !     ASM_OUTPUT_LABEL (asm_out_file, cold_section_end_label);
>     text_section ();
> !   if (flag_reorder_blocks_and_partition)
> !     ASM_OUTPUT_LABEL (asm_out_file, hot_section_end_label);
>     if (save_text_section == in_unlikely_executed_text)
>       unlikely_text_section ();
>   }

It would make more sense to put all the code that puts out labels and 
changes back and forth
between sections in assemble_end_function into a single condition block 
as shown below:

l*************** assemble_end_function (tree decl, const
*** 1377,1389 ****
      }
    /* Output labels for end of hot/cold text sections (to be used by
       debug info.)  */
!   save_text_section = in_section;
!   unlikely_text_section ();
!   ASM_OUTPUT_LABEL (asm_out_file, cold_section_end_label);
!   text_section ();
!   ASM_OUTPUT_LABEL (asm_out_file, hot_section_end_label);
!   if (save_text_section == in_unlikely_executed_text)
!     unlikely_text_section ();
  }


  /* Assemble code to leave SIZE bytes of zeros.  */
--- 1379,1394 ----
      }
    /* Output labels for end of hot/cold text sections (to be used by
       debug info.)  */
!   if (flag_reorder_blocks_and_partition)
!     {
!       save_text_section = in_section;
!       unlikely_text_section ();
!       ASM_OUTPUT_LABEL (asm_out_file, cold_section_end_label);
!       text_section ();
!       ASM_OUTPUT_LABEL (asm_out_file, hot_section_end_label);
!       if (save_text_section == in_unlikely_executed_text)
!       unlikely_text_section ();
!     }
  }