[Bug tree-optimization/120074] [15/16 regression] ICE on valid code at -O1 with "-fno-tree-copy-prop -fno-tree-forwprop -fno-tree-ccp" on x86_64-linux-gnu: in decompose, at wide-int.h:1049 since r15-6866

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120074

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I wonder about:
--- gcc/gimple-fold.cc.jj       2025-04-21 17:04:48.000000000 +0200
+++ gcc/gimple-fold.cc  2025-05-03 12:43:29.643908582 +0200
@@ -8337,7 +8337,8 @@ fold_truth_andor_for_ifcombine (enum tre
          if (!lr_and_mask.get_precision ())
            lr_and_mask = sign;
          else
-           lr_and_mask &= sign;
+           lr_and_mask &= wide_int::from (sign, lr_and_mask.get_precision (),
+                                          UNSIGNED);
          if (l_const.get_precision ())
            l_const &= wide_int::from (lr_and_mask,
                                       l_const.get_precision (), UNSIGNED);
@@ -8358,7 +8359,8 @@ fold_truth_andor_for_ifcombine (enum tre
          if (!rr_and_mask.get_precision ())
            rr_and_mask = sign;
          else
-           rr_and_mask &= sign;
+           rr_and_mask &= wide_int::from (sign, rr_and_mask.get_precision (),
+                                          UNSIGNED);
          if (r_const.get_precision ())
            r_const &= wide_int::from (rr_and_mask,
                                       r_const.get_precision (), UNSIGNED);
@@ -8762,7 +8764,7 @@ fold_truth_andor_for_ifcombine (enum tre
       wide_int lr_mask, rr_mask;
       if (lr_and_mask.get_precision ())
        lr_mask = wi::lshift (wide_int::from (lr_and_mask, rnprec, UNSIGNED),
-                         xlr_bitpos);
+                             xlr_bitpos);
       else
        lr_mask = wi::shifted_mask (xlr_bitpos, lr_bitsize, false, rnprec);
       if (rr_and_mask.get_precision ())

which fixes the ICE (and we punt later on on the 
      if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
test because ll_bitsize and rl_bitsize are 16 while lr_bitsize and rr_bitsize
are 32.
The &= sign works only if they have the same bitsize.