https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115785
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:e08ebd7d77a216ee2313b585c370333c66497b53 commit r15-1944-ge08ebd7d77a216ee2313b585c370333c66497b53 Author: Richard Sandiford <richard.sandif...@arm.com> Date: Wed Jul 10 17:01:29 2024 +0100 rtl-ssa: Add replace_nondebug_insn [PR115785] change_insns is used to change multiple instructions at once, so that the IR on return is valid & self-consistent. These changes can involve moving instructions, and the new position for one instruction might be expressed in terms of the old position of another instruction that is changing at the same time. change_insns therefore adds placeholder instructions to mark each new instruction position, then replaces each placeholder with the corresponding real instruction. This replacement was done in two steps: removing the old placeholder instruction and inserting the new real instruction. But it's more convenient for the upcoming fix for PR115785 if we do the operation as a single step. That should also be slightly more efficient, since e.g. no splay tree operations are needed. This operation happens purely on the rtl-ssa instruction chain. The placeholders are never represented in rtl. gcc/ PR rtl-optimization/115785 * rtl-ssa/functions.h (function_info::replace_nondebug_insn): Declare. * rtl-ssa/insns.h (insn_info::order_node::set_uid): New function. (insn_info::remove_note): Declare. * rtl-ssa/insns.cc (insn_info::remove_note): New function. (function_info::replace_nondebug_insn): Likewise. * rtl-ssa/changes.cc (function_info::change_insns): Use replace_nondebug_insn instead of remove_insn + add_insn.
