2011-04-15 Tobias Burnus <burnus@net-b.de>

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

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 84f3863..847a4bb 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -34,7 +34,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "recog.h"
 #include "function.h"
 #include "expr.h"
-#include "toplev.h"
 #include "diagnostic-core.h"
 #include "output.h"
 #include "ggc.h"
@@ -1527,7 +1526,8 @@ simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
     }
 
   else if (GET_CODE (op) == CONST_DOUBLE
-          && SCALAR_FLOAT_MODE_P (mode))
+          && SCALAR_FLOAT_MODE_P (mode)
+          && SCALAR_FLOAT_MODE_P (GET_MODE (op)))
     {
       REAL_VALUE_TYPE d, t;
       REAL_VALUE_FROM_CONST_DOUBLE (d, op);
@@ -1550,7 +1550,10 @@ simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
          d = real_value_truncate (mode, d);
          break;
        case FLOAT_EXTEND:
-         /* All this does is change the mode.  */
+         /* All this does is change the mode, unless changing
+            mode class.  */
+         if (GET_MODE_CLASS (mode) != GET_MODE_CLASS (GET_MODE (op)))
+           real_convert (&d, mode, &d);
          break;
        case FIX:
          real_arithmetic (&d, FIX_TRUNC_EXPR, &d, NULL);
@@ -2481,6 +2484,46 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
                                                        XEXP (op0, 1), mode),
                                    op1);
 
+      /* Given (xor (and A B) C), using P^Q == (~P&Q) | (~Q&P),
+        we can transform like this:
+            (A&B)^C == ~(A&B)&C | ~C&(A&B)
+                    == (~A|~B)&C | ~C&(A&B)    * DeMorgan's Law
+                    == ~A&C | ~B&C | A&(~C&B)  * Distribute and re-order
+        Attempt a few simplifications when B and C are both constants.  */
+      if (GET_CODE (op0) == AND
+         && CONST_INT_P (op1)
+         && CONST_INT_P (XEXP (op0, 1)))
+       {
+         rtx a = XEXP (op0, 0);
+         rtx b = XEXP (op0, 1);
+         rtx c = op1;
+         HOST_WIDE_INT bval = INTVAL (b);
+         HOST_WIDE_INT cval = INTVAL (c);
+
+         rtx na_c
+           = simplify_binary_operation (AND, mode,
+                                        simplify_gen_unary (NOT, mode, a, mode),
+                                        c);
+         if ((~cval & bval) == 0)
+           {
+             /* Try to simplify ~A&C | ~B&C.  */
+             if (na_c != NULL_RTX)
+               return simplify_gen_binary (IOR, mode, na_c,
+                                           GEN_INT (~bval & cval));
+           }
+         else
+           {
+             /* If ~A&C is zero, simplify A&(~C&B) | ~B&C.  */
+             if (na_c == const0_rtx)
+               {
+                 rtx a_nc_b = simplify_gen_binary (AND, mode, a,
+                                                   GEN_INT (~cval & bval));
+                 return simplify_gen_binary (IOR, mode, a_nc_b,
+                                             GEN_INT (~bval & cval));
+               }
+           }
+       }
+
       /* (xor (comparison foo bar) (const_int 1)) can become the reversed
         comparison if STORE_FLAG_VALUE is 1.  */
       if (STORE_FLAG_VALUE == 1