[Bug c/114239] New: ice: error: definition in block does not dominate use in block

[Bug c/114239] New: ice: error: definition in block does not dominate use in block

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239

            Bug ID: 114239
           Summary: ice: error: definition in block does not dominate use
                    in block
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

For this C code:

int ip4_getbit_a, ip4_getbit_pos, ip4_clrbit_pos;
void ip4_clrbit(int *a) { *a &= ip4_clrbit_pos; }
typedef struct {
  char pxlen;
  int prefix
} net_addr_ip4;
void fib_get_chain();
int trie_match_longest_ip4();
int trie_match_next_longest_ip4(net_addr_ip4 *n) {
  int __trans_tmp_1;
  while (n->pxlen) {
    n->pxlen--;
    ip4_clrbit(&n->prefix);
    __trans_tmp_1 = ip4_getbit_a >> ip4_getbit_pos;
    if (__trans_tmp_1)
      return 1;
  }
  return 0;
}
void net_roa_check_ip4_trie_tab() {
  net_addr_ip4 px0;
  for (int _n = trie_match_longest_ip4(&px0); _n;
       _n = trie_match_next_longest_ip4(&px0))
    fib_get_chain();
}

on x86_64, does this:

$ ../results/bin/gcc -c -O3 -march=znver3 -w ~/cvise/bug1021.c
/home/dcb38/cvise/bug1021.c: In function ‘net_roa_check_ip4_trie_tab’:
/home/dcb38/cvise/bug1021.c:20:6: error: definition in block 19 does not
dominate use in block 14
   20 | void net_roa_check_ip4_trie_tab() {
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~
for SSA_NAME: _117 in statement:
px0__lsm.22_47 = PHI <_117(14), _117(19)>
PHI argument
_117
for PHI node
px0__lsm.22_47 = PHI <_117(14), _117(19)>
during GIMPLE pass: vect
/home/dcb38/cvise/bug1021.c:20:6: internal compiler error: verify_ssa failed

The bug first seems to occur sometime between g:1e74ce8983fd4926
and g:71244316cf714725, which is 42 commits.

[Bug tree-optimization/114239] ice: error: definition in block does not dominate use in block

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
The testcase is the same as in PR113555 - so should've added to test suite I
suppose. Indeed ICEs on trunk.

[Bug tree-optimization/114239] [14 regression] ice: error: definition in block does not dominate use in block

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Priority|P3                          |P1
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
   Target Milestone|---                         |14.0
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2024-03-05

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  This is the peeled early exit reduction epilog case.  I will have a
look tomorrow.

[Bug tree-optimization/114239] [14 regression] ice: error: definition in block does not dominate use in block

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:89c443a7e9a0780a52a698fb02d4f5173e025918

commit r14-9335-g89c443a7e9a0780a52a698fb02d4f5173e025918
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Mar 6 10:31:02 2024 +0100

    tree-optimization/114239 - rework reduction epilogue driving

    The following reworks vectorizable_live_operation to pass the
    live stmt to vect_create_epilog_for_reduction also for early breaks
    and a peeled main exit.  This is to be able to figure the scalar
    definition to replace.  This reverts the PR114192 fix as it is
    subsumed by this cleanup.

            PR tree-optimization/114239
            * tree-vect-loop.cc (vect_get_vect_def): Remove.
            (vect_create_epilog_for_reduction): The passed in stmt_info
            should now be the live stmt that produces the scalar reduction
            result.  Revert PR114192 fix.  Base reduction info off
            info_for_reduction.  Remove special handling of
            early-break/peeled, restore original vector def gathering.
            Make sure to pick the correct exit PHIs.
            (vectorizable_live_operation): Pass in the proper stmt_info
            for early break exits.

            * gcc.dg/vect/vect-early-break_122-pr114239.c: New testcase.

[Bug tree-optimization/114239] [14 regression] ice: error: definition in block does not dominate use in block

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.

[Bug tree-optimization/114239] [14 regression] ice: error: definition in block does not dominate use in block

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
*** Bug 114234 has been marked as a duplicate of this bug. ***