https://gcc.gnu.org/g:53da069328ee9662518b100181dd5ac59a8f6fad
commit r15-10972-g53da069328ee9662518b100181dd5ac59a8f6fad Author: Richard Biener <[email protected]> Date: Thu Jan 29 10:41:16 2026 +0100 tree-optimization/123596 - fix partial virtual SSA update in eh_cleanup The following replaces the not quite correct use of mark_virtual_operand_for_renaming by an appropriate way of dealing with a possibly partially up-to-date virtual SSA form. Namely when we just move stmts and not remove a VDEF we should arrange for missing virtual PHIs to be created and just queue its arguments for possible renaming. For the testcase at hand there's no renaming necessary in the end when done this way. PR tree-optimization/123596 * tree-eh.cc (sink_clobbers): Create a virtual PHI when one is required but not present, queuing arguments for renaming. * g++.dg/torture/pr123596.C: New testcase. (cherry picked from commit 4c49f8e53698cce2fc93fb31cbd190c7ff3d04c4) Diff: --- gcc/testsuite/g++.dg/torture/pr123596.C | 18 ++++++++++++++++++ gcc/tree-eh.cc | 20 ++++++++++++-------- 2 files changed, 30 insertions(+), 8 deletions(-) diff --git a/gcc/testsuite/g++.dg/torture/pr123596.C b/gcc/testsuite/g++.dg/torture/pr123596.C new file mode 100644 index 000000000000..f146e41d5552 --- /dev/null +++ b/gcc/testsuite/g++.dg/torture/pr123596.C @@ -0,0 +1,18 @@ +// { dg-do compile } + +struct b { + ~b() {} +}; +struct c { + c(long, const int &, b = b()); +}; +int _setjmp(); +long d; +void e(int *); +int a; +int main() +{ + auto f = [](int *data) { e(data); }; + f(&a); + c(d, _setjmp()); +} diff --git a/gcc/tree-eh.cc b/gcc/tree-eh.cc index a4d59954c059..247dd58235d6 100644 --- a/gcc/tree-eh.cc +++ b/gcc/tree-eh.cc @@ -3770,6 +3770,18 @@ sink_clobbers (basic_block bb, } if (first_sunk) { + /* If there isn't a single predecessor but no virtual PHI node + create one and arrange for virtual operands to be renamed as + we cannot be sure all incoming edges will updated from sinking + something. */ + if (!vphi && !single_pred_p (succbb)) + { + vphi = create_phi_node (gimple_vop (cfun), succbb); + FOR_EACH_EDGE (e, ei, succbb->preds) + add_phi_arg (vphi, gimple_vop (cfun), e, UNKNOWN_LOCATION); + mark_virtual_operands_for_renaming (cfun); + todo |= TODO_update_ssa_only_virtuals; + } /* Adjust virtual operands if we sunk across a virtual PHI. */ if (vphi) { @@ -3789,14 +3801,6 @@ sink_clobbers (basic_block bb, gimple_vuse (last_sunk)); SET_USE (gimple_vuse_op (last_sunk), phi_def); } - /* If there isn't a single predecessor but no virtual PHI node - arrange for virtual operands to be renamed. */ - else if (!single_pred_p (succbb) - && TREE_CODE (gimple_vuse (last_sunk)) == SSA_NAME) - { - mark_virtual_operand_for_renaming (gimple_vuse (last_sunk)); - todo |= TODO_update_ssa_only_virtuals; - } } return todo;
