* 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 e407547..eafc3b8 100644 (file)
--- 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 7426949..67f7bab 100644 (file)
--- 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 */