[Bug ipa/103818] [12 Regression] ICE: in insert, at ipa-modref-tree.c:591 since r12-3202-gf5ff3a8ed4ca9173

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103818

--- Comment #4 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
We have access list:

      Base 0: alias set 2
        Ref 0: alias set 1
          access: Parm 0 param offset:0 offset:-4611686018427387936 size:32
max_size:32
          access: Parm 0 param offset:0 offset:352 size:32 max_size:32
          access: Parm 0 param offset:0 offset:64 size:32 max_size:32
          access: Parm 0 param offset:0 offset:0 size:32 max_size:32
          access: Parm 0 param offset:0 offset:32800 size:32 max_size:32
          access: Parm 0 param offset:0 offset:160 size:32 max_size:32
          access: Parm 0 param offset:0 offset:4629700416936869888 size:32
max_size:32
          access: Parm 0 param offset:0 offset:-96 size:32 max_size:32
          access: Parm 0 param offset:0 offset:1376 size:32 max_size:32
          access: Parm 0 param offset:0 offset:224 size:32 max_size:32
          access: Parm 0 param offset:0 offset:-288 size:32 max_size:32
          access: Parm 0 param offset:0 offset:448 size:32 max_size:32
          access: Parm 0 param offset:0 offset:288 size:32 max_size:32
          access: Parm 0 param offset:0 offset:1568 size:32 max_size:32
          access: Parm 0 param offset:0 offset:640 size:32 max_size:32
          access: Parm 0 param offset:0 offset:2624 size:32 max_size:32

and we want to merge
         Parm 0 param offset:0 offset:-4611686018427387936 size:32 max_size:32
and
         Parm 0 param offset:0 offset:4629700416936869888 size:32 max_size:32
into one entry since we think they have small difference.  

So an overflow issue:
      new_max_size = max_size2 + offset2 - offset1;                             
      if (known_le (new_max_size, max_size1))                                   
        new_max_size = max_size1;                                               
So we need 128bit math here.
I need to look into proper way to get this right (and corresponding overflow
that makes the lgoic to choose these two entries as closest to each other.