Re: [trunk]: Round 2 of libcall removal

[Kenneth Zadeck <zadeck at naturalbridge dot com>]

Eric,

there is another patch that i have in the queue where i clean up the 
handling of pure and const functions.  In that patch, i get rid of all 
of this, and the only thing that is left is the code that follows this 
stanza that looks like:

     /* If this was a CONST function, it is now PURE since
        it now reads memory.  */
     if (flags & ECF_CONST)
       {
         flags &= ~ECF_CONST;
         flags |= ECF_PURE;
       }

Note that the above code is actually dead on the trunk even though it is 
actually correct.    I went back and looked at the history, and the all 
of the code below was added to fix some place where flow was not 
properly keeping track of things.   Since things are being properly 
tracked now by df, and the other patch will hopefully go in first, your 
comment should be moot. 

Kenny

> @@ -3464,15 +3373,7 @@ emit_library_call_value_1 (int retval, r
>  	  int must_copy
>  	    = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
>  
> -	  /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
> -	     functions, so we have to pretend this isn't such a function.  */
> -	  if (flags & ECF_LIBCALL_BLOCK)
> -	    {
> -	      rtx insns = get_insns ();
> -	      end_sequence ();
> -	      emit_insn (insns);
> -	    }
> -	  flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
> +	  flags &= ~(ECF_CONST | ECF_PURE);
>  
>  	  /* If this was a CONST function, it is now PURE since
>  	     it now reads memory.  */
>
> Here we still need the comment (probably with a ???) until after we are sure 
> that loop.c was the only problematic pass.
>
>