From: zack <zack@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 17 Jul 2000 18:31:50 +0000 (+0000)
Subject: 	* simplify-rtx.c (simplify_binary_operation): Recognize
X-Git-Url: http://git.sourceforge.jp/view?a=commitdiff_plain;h=e2496245b8453f49bb4428f281af7686be09ddf8;p=pf3gnuchains%2Fgcc-fork.git

	* simplify-rtx.c (simplify_binary_operation): Recognize
	   (compare (gt[u] (cc) 0) (lt[u] (cc) 0)).
	(simplify_ternary_operation):  Do not examine MODE_BITSIZE of
	   a CONST_INT, it will always be zero.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@35098 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e407547c5ea..eafc3b8a3af 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2000-07-17  Zack Weinberg  <zack@wolery.cumb.org>
+
+	* simplify-rtx.c (simplify_binary_operation): Recognize
+	   (compare (gt[u] (cc) 0) (lt[u] (cc) 0)).
+	(simplify_ternary_operation):  Do not examine MODE_BITSIZE of
+	   a CONST_INT, it will always be zero.
+
 2000-07-17  Chandrakala Chavva   <cchavva@cygnus.com>
 
 	* loop.c (check_dbra_loop) : Return if more than one condition is 
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 7426949456d..67f7babfc1f 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -948,11 +948,29 @@ simplify_binary_operation (code, mode, op0, op1)
 	       || ! FLOAT_MODE_P (mode) || flag_fast_math)
 	      && op1 == CONST0_RTX (mode))
 	    return op0;
+#endif
+
+	  /* Convert (compare (gt (flags) 0) (lt (flags) 0)) to (flags).  */
+	  if (((GET_CODE (op0) == GT && GET_CODE (op1) == LT)
+	       || (GET_CODE (op0) == GTU && GET_CODE (op1) == LTU))
+	      && XEXP (op0, 1) == const0_rtx && XEXP (op1, 1) == const0_rtx)
+	    {
+	      rtx xop00 = XEXP (op0, 0);
+	      rtx xop10 = XEXP (op1, 0);
+
+#ifdef HAVE_cc0
+	      if (GET_CODE (xop00) == CC0 && GET_CODE (xop10) == CC0)
 #else
-	  /* Do nothing here.  */
+	      if (GET_CODE (xop00) == REG && GET_CODE (xop10) == REG
+		  && GET_MODE (xop00) == GET_MODE (xop10)
+		  && REGNO (xop00) == REGNO (xop10)
+		  && GET_MODE_CLASS (GET_MODE (xop00)) == MODE_CC
+		  && GET_MODE_CLASS (GET_MODE (xop10)) == MODE_CC)
 #endif
-	  break;
-	      
+		return xop00;
+	    }
+
+	  break;	      
 	case MINUS:
 	  /* None of these optimizations can be done for IEEE
 	     floating point.  */
@@ -1912,8 +1930,7 @@ simplify_ternary_operation (code, mode, op0_mode, op0, op1, op2)
       if (GET_CODE (op0) == CONST_INT
 	  && GET_CODE (op1) == CONST_INT
 	  && GET_CODE (op2) == CONST_INT
-	  && ((unsigned) INTVAL (op1) + (unsigned) INTVAL (op2)
-	      <= GET_MODE_BITSIZE (op0_mode))
+	  && ((unsigned) INTVAL (op1) + (unsigned) INTVAL (op2) <= width)
 	  && width <= (unsigned) HOST_BITS_PER_WIDE_INT)
 	{
 	  /* Extracting a bit-field from a constant */