[PATCH] Fix PR70333

[Richard Biener]

The following fixes another wide-int merge fallout by reverting back
to what the code did before it (doing a wide multiplication).

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2016-03-22  Richard Biener  <rguent...@suse.de>

        PR middle-end/70333
        * fold-const.c (extract_muldiv_1): Properly perform multiplication
        in the wide type.

        * gcc.dg/torture/pr70333.c: New testcase.

Index: gcc/fold-const.c
===================================================================
*** gcc/fold-const.c    (revision 234394)
--- gcc/fold-const.c    (working copy)
*************** extract_muldiv_1 (tree t, tree c, enum t
*** 6376,6393 ****
          bool overflow_p = false;
          bool overflow_mul_p;
          signop sign = TYPE_SIGN (ctype);
!         wide_int mul = wi::mul (op1, c, sign, &overflow_mul_p);
          overflow_p = TREE_OVERFLOW (c) | TREE_OVERFLOW (op1);
          if (overflow_mul_p
              && ((sign == UNSIGNED && tcode != MULT_EXPR) || sign == SIGNED))
            overflow_p = true;
          if (!overflow_p)
!           {
!             mul = wide_int::from (mul, TYPE_PRECISION (ctype),
!                                   TYPE_SIGN (TREE_TYPE (op1)));
!             return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
!                                 wide_int_to_tree (ctype, mul));
!           }
        }
  
        /* If these operations "cancel" each other, we have the main
--- 6376,6392 ----
          bool overflow_p = false;
          bool overflow_mul_p;
          signop sign = TYPE_SIGN (ctype);
!         unsigned prec = TYPE_PRECISION (ctype);
!         wide_int mul = wi::mul (wide_int::from (op1, prec, sign),
!                                 wide_int::from (c, prec, sign),
!                                 sign, &overflow_mul_p);
          overflow_p = TREE_OVERFLOW (c) | TREE_OVERFLOW (op1);
          if (overflow_mul_p
              && ((sign == UNSIGNED && tcode != MULT_EXPR) || sign == SIGNED))
            overflow_p = true;
          if (!overflow_p)
!           return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
!                               wide_int_to_tree (ctype, mul));
        }
  
        /* If these operations "cancel" each other, we have the main
Index: gcc/testsuite/gcc.dg/torture/pr70333.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr70333.c      (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr70333.c      (working copy)
***************
*** 0 ****
--- 1,19 ----
+ /* { dg-do run } */
+ /* { dg-require-effective-target lp64 } */
+ 
+ unsigned long int
+ foo (signed char b, signed char e)
+ {
+   return ((2ULL * b) * (e * 13)) * (32 << 24);
+ }
+ 
+ int
+ main ()
+ {
+   if (__CHAR_BIT__ == 8
+       && sizeof (int) == 4
+       && sizeof (long long) == 8
+       && foo (-60, 1) != 0xffffff3d00000000ULL)
+     __builtin_abort ();
+   return 0;
+ }