optabs.c (prepare_float_lib_cmp): Avoid searching for REG_RETVAL instruction by…

optabs.c (prepare_float_lib_cmp): Avoid searching for REG_RETVAL instruction by using LCT_CONST and then calling...


	* optabs.c (prepare_float_lib_cmp): Avoid searching for REG_RETVAL
	instruction by using LCT_CONST and then calling emit_libcall_block
	ourselves.

Co-Authored-By: Zack Weinberg <zack@codesourcery.com>

From-SVN: r72171

gcc/ChangeLog

+2003-10-06  Roger Sayle  <roger@eyesopen.com>
+	    Zack Weinberg  <zack@codesourcery.com>
+
+	* optabs.c (prepare_float_lib_cmp): Avoid searching for REG_RETVAL
+	instruction by using LCT_CONST and then calling emit_libcall_block
+	ourselves.
+
 2003-10-06  Falk Hueffner  <falk.hueffner@student.uni-tuebingen.de>
 
         PR optimization/11974

gcc/optabs.c

@@ -3878,9 +3878,8 @@ prepare_float_lib_cmp (rtx *px, rtx *py, enum rtx_code *pcomparison,
   rtx y = protect_from_queue (*py, 0);
   enum machine_mode orig_mode = GET_MODE (x);
   enum machine_mode mode;
-  rtx before_call;
+  rtx value, target, insns, equiv;
   rtx libfunc = 0;
-  rtx result;
 
   for (mode = orig_mode; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
     {
@@ -3905,11 +3904,6 @@ prepare_float_lib_cmp (rtx *px, rtx *py, enum rtx_code *pcomparison,
       y = convert_to_mode (mode, y, 0);
     }
 
-  before_call = get_last_insn ();
-
-  result = emit_library_call_value (libfunc, NULL_RTX, LCT_CONST_MAKE_BLOCK,
-				    word_mode, 2, x, mode, y, mode);
-
   /* If we're optimizing attach a REG_EQUAL note describing the semantics
      of the libcall to the RTL.  The allows the RTL optimizers to delete
      the libcall if the condition can be determined at compile-time.  */
@@ -3917,86 +3911,79 @@ prepare_float_lib_cmp (rtx *px, rtx *py, enum rtx_code *pcomparison,
       && ! side_effects_p (x)
       && ! side_effects_p (y))
     {
-      /* Search backwards through the insns emitted above looking for
-	 the instruction with the REG_RETVAL note.  */
-      rtx last = get_last_insn ();
-      while (last != before_call)
+      if (comparison == UNORDERED)
 	{
-	  if (find_reg_note (last, REG_RETVAL, NULL))
-	    break;
-	  last = PREV_INSN (last);
+	  rtx temp = simplify_gen_relational (NE, word_mode, mode, x, x);
+	  equiv = simplify_gen_relational (NE, word_mode, mode, y, y);
+	  equiv = simplify_gen_ternary (IF_THEN_ELSE, word_mode, word_mode,
+					temp, const_true_rtx, equiv);
 	}
-
-      if (last != before_call)
+      else
 	{
-	  rtx equiv;
-	  if (comparison == UNORDERED)
+	  equiv = simplify_gen_relational (comparison, word_mode, mode, x, y);
+	  if (! FLOAT_LIB_COMPARE_RETURNS_BOOL (mode, comparison))
 	    {
-	      rtx temp = simplify_gen_relational (NE, word_mode,
-						  mode, x, x);
-	      equiv = simplify_gen_relational (NE, word_mode,
-					       mode, y, y);
-	      equiv = simplify_gen_ternary (IF_THEN_ELSE, word_mode,
-					    word_mode, temp,
-					    const_true_rtx, equiv);
-	    }
-	  else
-	    {
-	      equiv = simplify_gen_relational (comparison, word_mode,
-					       mode, x, y);
-	      if (! FLOAT_LIB_COMPARE_RETURNS_BOOL (mode, comparison))
+	      rtx true_rtx, false_rtx;
+
+	      switch (comparison)
 		{
-		  rtx true_rtx, false_rtx;
+		case EQ:
+		  true_rtx = const0_rtx;
+		  false_rtx = const_true_rtx;
+		  break;
 
-		  switch (comparison)
-		    {
-		    case EQ:
-		      true_rtx = const0_rtx;
-		      false_rtx = const_true_rtx;
-		      break;
-
-		    case NE:
-		      true_rtx = const_true_rtx;
-		      false_rtx = const0_rtx;
-		      break;
-
-		    case GT:
-		      true_rtx = const1_rtx;
-		      false_rtx = const0_rtx;
-		      break;
-
-		    case GE:
-		      true_rtx = const0_rtx;
-		      false_rtx = constm1_rtx;
-		      break;
-
-		    case LT:
-		      true_rtx = constm1_rtx;
-		      false_rtx = const0_rtx;
-		      break;
-
-		    case LE:
-		      true_rtx = const0_rtx;
-		      false_rtx = const1_rtx;
-		      break;
-
-		    default:
-		      abort ();
-		    }
-		  equiv = simplify_gen_ternary (IF_THEN_ELSE, word_mode,
-						word_mode, equiv,
-						true_rtx, false_rtx);
+		case NE:
+		  true_rtx = const_true_rtx;
+		  false_rtx = const0_rtx;
+		  break;
+
+		case GT:
+		  true_rtx = const1_rtx;
+		  false_rtx = const0_rtx;
+		  break;
+
+		case GE:
+		  true_rtx = const0_rtx;
+		  false_rtx = constm1_rtx;
+		  break;
+
+		case LT:
+		  true_rtx = constm1_rtx;
+		  false_rtx = const0_rtx;
+		  break;
+
+		case LE:
+		  true_rtx = const0_rtx;
+		  false_rtx = const1_rtx;
+		  break;
+
+		default:
+		  abort ();
 		}
+	      equiv = simplify_gen_ternary (IF_THEN_ELSE, word_mode,
+					    word_mode, equiv,
+					    true_rtx, false_rtx);
 	    }
-	  set_unique_reg_note (last, REG_EQUAL, equiv);
 	}
     }
+  else
+    equiv = NULL_RTX;
+
+  start_sequence ();
+  value = emit_library_call_value (libfunc, NULL_RTX, LCT_CONST,
+				   word_mode, 2, x, mode, y, mode);
+  insns = get_insns ();
+  end_sequence ();
+
+  target = gen_reg_rtx (word_mode);
+  emit_libcall_block (insns, target, value, equiv);
+
 
   if (comparison == UNORDERED
       || FLOAT_LIB_COMPARE_RETURNS_BOOL (mode, comparison))
     comparison = NE;
 
-  *px = result;
+  *px = target;
   *py = const0_rtx;
   *pmode = word_mode;
   *pcomparison = comparison;