[Bug tree-optimization/79777] New: [7 Regression] ICE on -Os and above in on aarch64-linux-gnu (internal compiler error: in VN_INFO_GET, at tree-ssa-sccvn.c:407 })

["arnd at linaro dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79777

            Bug ID: 79777
           Summary: [7 Regression] ICE on -Os and above in on
                    aarch64-linux-gnu (internal compiler error: in
                    VN_INFO_GET, at tree-ssa-sccvn.c:407 })
           Product: gcc
           Version: 7.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: arnd at linaro dot org
  Target Milestone: ---

Created attachment 40860
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40860&action=edit
preprocessed linux/fs/hpfs/anode.c, compressed, not reduced

I ran into a regression building the kernel with the latest gcc yesterday:

/git/arm-soc/fs/hpfs/anode.c: In function 'hpfs_truncate_btree':
/git/arm-soc/fs/hpfs/anode.c:399:6: internal compiler error: in VN_INFO_GET, at
tree-ssa-sccvn.c:407
 void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned
secs)
      ^~~~~~~~~~~~~~~~~~~
0xb47fe6 VN_INFO_GET(tree_node*)
        /home/arnd/git/gcc/gcc/tree-ssa-sccvn.c:406
0xb27fd3 eliminate_insert
        /home/arnd/git/gcc/gcc/tree-ssa-pre.c:4137
0xb27fd3 eliminate_dom_walker::before_dom_children(basic_block_def*)
        /home/arnd/git/gcc/gcc/tree-ssa-pre.c:4271
0xe72f62 dom_walker::walk(basic_block_def*)
        /home/arnd/git/gcc/gcc/domwalk.c:265
0xb26c5f eliminate
        /home/arnd/git/gcc/gcc/tree-ssa-pre.c:4732
0xb26fbf execute
        /home/arnd/git/gcc/gcc/tree-ssa-pre.c:5166

This seems very similar to pr79740, but is not fixed by r245780, which was done
to address that one. I build this with "aarch64-linux-gcc-7.0.1 -c anode.i -Os 
 -Wall -fno-strict-aliasing -Wno-pointer-sign".