* doc/install.texi (xtensa-*-elf): New target.

[pf3gnuchains/gcc-fork.git] / gcc / simplify-rtx.c

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 122768e..2db3ec0 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -109,7 +109,7 @@ static void simplify_binary_is2orm1 PARAMS ((PTR));
 
 \f
 /* Negate a CONST_INT rtx, truncating (because a conversion from a
-   maximally negative number can overflow). */
+   maximally negative number can overflow).  */
 static rtx
 neg_const_int (mode, i)
      enum machine_mode mode;
@@ -572,6 +572,8 @@ simplify_unary_operation (code, mode, op, op_mode)
        case SQRT:
        case FLOAT_EXTEND:
        case FLOAT_TRUNCATE:
+       case SS_TRUNCATE:
+       case US_TRUNCATE:
          return 0;
 
        default:
@@ -1412,7 +1414,17 @@ simplify_binary_operation (code, mode, op0, op1)
 
        case DIV:
          if (trueop1 == CONST1_RTX (mode))
-           return op0;
+           {
+             /* On some platforms DIV uses narrower mode than its
+                operands.  */
+             rtx x = gen_lowpart_common (mode, op0);
+             if (x)
+               return x;
+             else if (mode != GET_MODE (op0) && GET_MODE (op0) != VOIDmode)
+               return gen_lowpart_SUBREG (mode, op0);
+             else
+               return op0;
+           }
 
          /* In IEEE floating point, 0/x is not always 0.  */
          if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
@@ -1514,6 +1526,13 @@ simplify_binary_operation (code, mode, op0, op1)
            return op0;
          break;
 
+       case SS_PLUS:
+       case US_PLUS:
+       case SS_MINUS:
+       case US_MINUS:
+         /* ??? There are simplifications that can be done.  */
+         return 0;
+
        default:
          abort ();
        }
@@ -1790,7 +1809,7 @@ simplify_plus_minus (code, mode, op0, op1)
              if (n_ops != 7)
                {
                  ops[n_ops].op = constm1_rtx;
-                 ops[n_ops].neg = this_neg;
+                 ops[n_ops++].neg = this_neg;
                  ops[i].op = XEXP (this_op, 0);
                  ops[i].neg = !this_neg;
                  changed = 1;
@@ -1855,7 +1874,13 @@ simplify_plus_minus (code, mode, op0, op1)
                    && ! (GET_CODE (tem) == CONST
                          && GET_CODE (XEXP (tem, 0)) == ncode
                          && XEXP (XEXP (tem, 0), 0) == lhs
-                         && XEXP (XEXP (tem, 0), 1) == rhs))
+                         && XEXP (XEXP (tem, 0), 1) == rhs)
+                   /* Don't allow -x + -1 -> ~x simplifications in the
+                      first pass.  This allows us the chance to combine
+                      the -1 with other constants.  */
+                   && ! (first
+                         && GET_CODE (tem) == NOT
+                         && XEXP (tem, 0) == rhs))
                  {
                    lneg &= rneg;
                    if (GET_CODE (tem) == NEG)