dojump.c (do_jump): If the expression being compared against zero...

	* dojump.c (do_jump): If the expression being compared against
	zero, is the subreg of a promoted variable, perform the comparison
	in the promoted mode.
	* simplify-rtx.c (simplify_unary_operation): Optimize sign and
	zero-extensions of subregs of promoted variables where the
	extension is identical to that used to promote the variable.

From-SVN: r74332

gcc/ChangeLog

+2003-12-05  Roger Sayle  <roger@eyesopen.com>
+
+	* dojump.c (do_jump): If the expression being compared against
+	zero, is the subreg of a promoted variable, perform the comparison
+	in the promoted mode.
+	* simplify-rtx.c (simplify_unary_operation): Optimize sign and
+	zero-extensions of subregs of promoted variables where the
+	extension is identical to that used to promote the variable.
+
 2003-12-05  Hans-Peter Nilsson  <hp@axis.com>
 
 	PR target/13256

gcc/dojump.c

@@ -584,7 +584,14 @@ do_jump (tree exp, rtx if_false_label, rtx if_true_label)
 	{
 	  /* The RTL optimizers prefer comparisons against pseudos.  */
 	  if (GET_CODE (temp) == SUBREG)
-	    temp = copy_to_reg (temp);
+	    {
+	      /* Compare promoted variables in their promoted mode.  */
+	      if (SUBREG_PROMOTED_VAR_P (temp)
+		  && GET_CODE (XEXP (temp, 0)) == REG)
+		temp = XEXP (temp, 0);
+	      else
+		temp = copy_to_reg (temp);
+	    }
 	  do_compare_rtx_and_jump (temp, CONST0_RTX (GET_MODE (temp)),
 				   NE, TREE_UNSIGNED (TREE_TYPE (exp)),
 				   GET_MODE (temp), NULL_RTX,

gcc/simplify-rtx.c

@@ -1031,6 +1031,15 @@ simplify_unary_operation (enum rtx_code code, enum machine_mode mode,
 	      && GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF)
 	    return XEXP (op, 0);
 
+	  /* Check for a sign extension of a subreg of a promoted
+	     variable, where the promotion is sign-extended, and the
+	     target mode is the same as the variable's promotion.  */
+	  if (GET_CODE (op) == SUBREG
+	      && SUBREG_PROMOTED_VAR_P (op)
+	      && ! SUBREG_PROMOTED_UNSIGNED_P (op)
+	      && GET_MODE (XEXP (op, 0)) == mode)
+	    return XEXP (op, 0);
+
 #if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
 	  if (! POINTERS_EXTEND_UNSIGNED
 	      && mode == Pmode && GET_MODE (op) == ptr_mode
@@ -1043,8 +1052,17 @@ simplify_unary_operation (enum rtx_code code, enum machine_mode mode,
 #endif
 	  break;
 
-#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
 	case ZERO_EXTEND:
+	  /* Check for a zero extension of a subreg of a promoted
+	     variable, where the promotion is zero-extended, and the
+	     target mode is the same as the variable's promotion.  */
+	  if (GET_CODE (op) == SUBREG
+	      && SUBREG_PROMOTED_VAR_P (op)
+	      && SUBREG_PROMOTED_UNSIGNED_P (op)
+	      && GET_MODE (XEXP (op, 0)) == mode)
+	    return XEXP (op, 0);
+
+#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
 	  if (POINTERS_EXTEND_UNSIGNED > 0
 	      && mode == Pmode && GET_MODE (op) == ptr_mode
 	      && (CONSTANT_P (op)
@@ -1053,8 +1071,8 @@ simplify_unary_operation (enum rtx_code code, enum machine_mode mode,
 		      && REG_POINTER (SUBREG_REG (op))
 		      && GET_MODE (SUBREG_REG (op)) == Pmode)))
 	    return convert_memory_address (Pmode, op);
-	  break;
 #endif
+	  break;
 
 	default:
 	  break;