Re: [patch] calls.c, optabs.c: Remove multiple references to thelibcall return reg.

[Kazu Hirata <kazu at cs dot umass dot edu>]

Hi Richard,

> This should be
> 
> 	result = emit_library_call_value (memcmp_libfunc, NULL_RTX, ...);
> 
> I.e. the return value of emit_library_call_value should always 
> be honored.  And if we don't have a specific place it should go
> already, you just use NULL_RTX and let the call generate the
> target register.
> 
> The patch is ok with that change.

Previously, I committed a patch that did not honor the return value of
emit_library_call, so I fixed that, too.  I attached the final patch
that I comitted.

Kazu Hirata

2002-09-17  Kazu Hirata  <kazu@cs.umass.edu>

	* optabs.c (prepare_cmp_insn): Let emit_library_call_value
	generate a pseudo reg that receives the result of a libcall.
	(prepare_float_lib_cmp): Likewise.

Index: optabs.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/optabs.c,v
retrieving revision 1.147
diff -c -p -r1.147 optabs.c
*** optabs.c	16 Sep 2002 18:47:59 -0000	1.147
--- optabs.c	17 Sep 2002 18:53:41 -0000
*************** prepare_cmp_insn (px, py, pcomparison, s
*** 3436,3464 ****
  #endif
  	{
  #ifdef TARGET_MEM_FUNCTIONS
! 	  emit_library_call (memcmp_libfunc, LCT_PURE_MAKE_BLOCK,
! 			     TYPE_MODE (integer_type_node), 3,
! 			     XEXP (x, 0), Pmode, XEXP (y, 0), Pmode,
! 			     convert_to_mode (TYPE_MODE (sizetype), size,
! 					      TREE_UNSIGNED (sizetype)),
! 			     TYPE_MODE (sizetype));
  #else
! 	  emit_library_call (bcmp_libfunc, LCT_PURE_MAKE_BLOCK,
! 			     TYPE_MODE (integer_type_node), 3,
! 			     XEXP (x, 0), Pmode, XEXP (y, 0), Pmode,
! 			     convert_to_mode (TYPE_MODE (integer_type_node),
! 					      size,
! 					      TREE_UNSIGNED (integer_type_node)),
! 			     TYPE_MODE (integer_type_node));
  #endif
  
- 	  /* Immediately move the result of the libcall into a pseudo
- 	     register so reload doesn't clobber the value if it needs
- 	     the return register for a spill reg.  */
- 	  result = gen_reg_rtx (TYPE_MODE (integer_type_node));
  	  result_mode = TYPE_MODE (integer_type_node);
- 	  emit_move_insn (result,
- 			  hard_libcall_value (result_mode));
  	}
        *px = result;
        *py = const0_rtx;
--- 3436,3458 ----
  #endif
  	{
  #ifdef TARGET_MEM_FUNCTIONS
! 	  result = emit_library_call_value (memcmp_libfunc, NULL_RTX, LCT_PURE_MAKE_BLOCK,
! 					    TYPE_MODE (integer_type_node), 3,
! 					    XEXP (x, 0), Pmode, XEXP (y, 0), Pmode,
! 					    convert_to_mode (TYPE_MODE (sizetype), size,
! 							     TREE_UNSIGNED (sizetype)),
! 					    TYPE_MODE (sizetype));
  #else
! 	  result = emit_library_call_value (bcmp_libfunc, NULL_RTX, LCT_PURE_MAKE_BLOCK,
! 					    TYPE_MODE (integer_type_node), 3,
! 					    XEXP (x, 0), Pmode, XEXP (y, 0), Pmode,
! 					    convert_to_mode (TYPE_MODE (integer_type_node),
! 							     size,
! 							     TREE_UNSIGNED (integer_type_node)),
! 					    TYPE_MODE (integer_type_node));
  #endif
  
  	  result_mode = TYPE_MODE (integer_type_node);
  	}
        *px = result;
        *py = const0_rtx;
*************** prepare_cmp_insn (px, py, pcomparison, s
*** 3483,3496 ****
        if (unsignedp && ucmp_optab->handlers[(int) mode].libfunc)
  	libfunc = ucmp_optab->handlers[(int) mode].libfunc;
  
!       emit_library_call (libfunc, LCT_CONST_MAKE_BLOCK, word_mode, 2, x, mode,
! 			 y, mode);
! 
!       /* Immediately move the result of the libcall into a pseudo
! 	 register so reload doesn't clobber the value if it needs
! 	 the return register for a spill reg.  */
!       result = gen_reg_rtx (word_mode);
!       emit_move_insn (result, hard_libcall_value (word_mode));
  
        /* Integer comparison returns a result that must be compared against 1,
  	 so that even if we do an unsigned compare afterward,
--- 3477,3484 ----
        if (unsignedp && ucmp_optab->handlers[(int) mode].libfunc)
  	libfunc = ucmp_optab->handlers[(int) mode].libfunc;
  
!       result = emit_library_call_value (libfunc, NULL_RTX, LCT_CONST_MAKE_BLOCK,
! 					word_mode, 2, x, mode, y, mode);
  
        /* Integer comparison returns a result that must be compared against 1,
  	 so that even if we do an unsigned compare afterward,
*************** prepare_float_lib_cmp (px, py, pcomparis
*** 4006,4014 ****
    if (libfunc == 0)
      abort ();
  
!   result = gen_reg_rtx (word_mode);
!   emit_library_call_value (libfunc, result, LCT_CONST_MAKE_BLOCK,
! 			   word_mode, 2, x, mode, y, mode);
    *px = result;
    *py = const0_rtx;
    *pmode = word_mode;
--- 3994,4001 ----
    if (libfunc == 0)
      abort ();
  
!   result = emit_library_call_value (libfunc, NULL_RTX, LCT_CONST_MAKE_BLOCK,
! 				    word_mode, 2, x, mode, y, mode);
    *px = result;
    *py = const0_rtx;
    *pmode = word_mode;