simplify-rtx.c (SIGN_EXTEND): New macro.

	* simplify-rtx.c (SIGN_EXTEND): New macro.
	(simplify_unary_operation, simplify_binary_operation,
	simplify_relational_operation): Use SIGN_EXTEND.  Make low
	halves of (low, high) pairs unsigned if they weren't already.
	(simplify_ternary_operation): Cast INTVAL to unsigned before
	comparing to a MODE_BITSIZE.

From-SVN: r34109

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a38bfebb89e96c9695765c6845dbd7e3bcaba1f6..54b7927619e34099d1e7798df01f869700d411d9 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2000-05-23  Zack Weinberg  <zack@wolery.cumb.org>
+
+       * simplify-rtx.c (SIGN_EXTEND): New macro.
+       (simplify_unary_operation, simplify_binary_operation, 
+       simplify_relational_operation): Use SIGN_EXTEND.  Make low
+       halves of (low, high) pairs unsigned if they weren't already.       
+       (simplify_ternary_operation): Cast INTVAL to unsigned before
+       comparing to a MODE_BITSIZE.
+
 2000-05-23  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
        * aclocal.m4 (gcc_AC_CHECK_DECL, gcc_AC_CHECK_DECLS): New macros

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 270371c371dbea99f49f5d1713586ef769e8b069..88d02c1031ab6f4f7f3e688533c50796a45a43dd 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -92,6 +92,12 @@ Boston, MA 02111-1307, USA.  */
           || XEXP (X, 0) == virtual_outgoing_args_rtx))        \
    || GET_CODE (X) == ADDRESSOF)
 
+/* Much code operates on (low, high) pairs; the low value is an
+   unsigned wide int, the high value a signed wide int.  We
+   occasionally need to sign extend from low to high as if low were a
+   signed wide int.  */
+#define SIGN_EXTEND(low) \
+ ((((HOST_WIDE_INT) low) < 0) ? ((HOST_WIDE_INT) -1) : ((HOST_WIDE_INT) 0))
 
 static rtx simplify_plus_minus         PARAMS ((enum rtx_code,
                                                 enum machine_mode, rtx, rtx));
@@ -246,7 +252,7 @@ simplify_unary_operation (code, mode, op, op_mode)
       REAL_VALUE_TYPE d;
 
       if (GET_CODE (op) == CONST_INT)
-       lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0;
+       lv = INTVAL (op), hv = SIGN_EXTEND (lv);
       else
        lv = CONST_DOUBLE_LOW (op),  hv = CONST_DOUBLE_HIGH (op);
 
@@ -279,7 +285,7 @@ simplify_unary_operation (code, mode, op, op_mode)
       REAL_VALUE_TYPE d;
 
       if (GET_CODE (op) == CONST_INT)
-       lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0;
+       lv = INTVAL (op), hv = SIGN_EXTEND (lv);
       else
        lv = CONST_DOUBLE_LOW (op),  hv = CONST_DOUBLE_HIGH (op);
 
@@ -399,12 +405,13 @@ simplify_unary_operation (code, mode, op, op_mode)
   else if (GET_MODE (op) == VOIDmode && width <= HOST_BITS_PER_INT * 2
           && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT))
     {
-      HOST_WIDE_INT l1, h1, lv, hv;
+      unsigned HOST_WIDE_INT l1, lv;
+      HOST_WIDE_INT h1, hv;
 
       if (GET_CODE (op) == CONST_DOUBLE)
        l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op);
       else
-       l1 = INTVAL (op), h1 = l1 < 0 ? -1 : 0;
+       l1 = INTVAL (op), h1 = SIGN_EXTEND (l1);
 
       switch (code)
        {
@@ -458,7 +465,7 @@ simplify_unary_operation (code, mode, op, op_mode)
                            << (GET_MODE_BITSIZE (op_mode) - 1))) != 0)
                lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
 
-             hv = (lv < 0) ? ~ (HOST_WIDE_INT) 0 : 0;
+             hv = SIGN_EXTEND (lv);
            }
          break;
 
@@ -709,17 +716,18 @@ simplify_binary_operation (code, mode, op0, op1)
       && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT)
       && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT))
     {
-      HOST_WIDE_INT l1, l2, h1, h2, lv, hv;
+      unsigned HOST_WIDE_INT l1, l2, lv;
+      HOST_WIDE_INT h1, h2, hv;
 
       if (GET_CODE (op0) == CONST_DOUBLE)
        l1 = CONST_DOUBLE_LOW (op0), h1 = CONST_DOUBLE_HIGH (op0);
       else
-       l1 = INTVAL (op0), h1 = l1 < 0 ? -1 : 0;
+       l1 = INTVAL (op0), h1 = SIGN_EXTEND (l1);
 
       if (GET_CODE (op1) == CONST_DOUBLE)
        l2 = CONST_DOUBLE_LOW (op1), h2 = CONST_DOUBLE_HIGH (op1);
       else
-       l2 = INTVAL (op1), h2 = l2 < 0 ? -1 : 0;
+       l2 = INTVAL (op1), h2 = SIGN_EXTEND (l2);
 
       switch (code)
        {
@@ -803,7 +811,7 @@ simplify_binary_operation (code, mode, op0, op1)
            l2 &= (GET_MODE_BITSIZE (mode) - 1), h2 = 0;
 #endif
 
-         if (h2 != 0 || l2 < 0 || l2 >= GET_MODE_BITSIZE (mode))
+         if (h2 != 0 || l2 >= GET_MODE_BITSIZE (mode))
            return 0;
 
          if (code == LSHIFTRT || code == ASHIFTRT)
@@ -1752,7 +1760,7 @@ simplify_relational_operation (code, mode, op0, op1)
       else
        {
          l0u = l0s = INTVAL (op0);
-         h0u = h0s = l0s < 0 ? -1 : 0;
+         h0u = h0s = SIGN_EXTEND (l0s);
        }
          
       if (GET_CODE (op1) == CONST_DOUBLE)
@@ -1763,13 +1771,13 @@ simplify_relational_operation (code, mode, op0, op1)
       else
        {
          l1u = l1s = INTVAL (op1);
-         h1u = h1s = l1s < 0 ? -1 : 0;
+         h1u = h1s = SIGN_EXTEND (l1s);
        }
 
       /* If WIDTH is nonzero and smaller than HOST_BITS_PER_WIDE_INT,
         we have to sign or zero-extend the values.  */
       if (width != 0 && width <= HOST_BITS_PER_WIDE_INT)
-       h0u = h1u = 0, h0s = l0s < 0 ? -1 : 0, h1s = l1s < 0 ? -1 : 0;
+       h0u = h1u = 0, h0s = SIGN_EXTEND (l0s), h1s = SIGN_EXTEND (l1s);
 
       if (width != 0 && width < HOST_BITS_PER_WIDE_INT)
        {
@@ -1904,7 +1912,8 @@ 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
-         && INTVAL (op1) + INTVAL (op2) <= GET_MODE_BITSIZE (op0_mode)
+         && ((unsigned) INTVAL (op1) + (unsigned) INTVAL (op2)
+             <= GET_MODE_BITSIZE (op0_mode))
          && width <= (unsigned) HOST_BITS_PER_WIDE_INT)
        {
          /* Extracting a bit-field from a constant */