From d5e0321c3f423e307f063c51a6e0795d9daa9309 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Wed, 25 Oct 2023 10:39:50 +0100 Subject: rtl-ssa: Create REG_UNUSED notes after all pending changes Unlike REG_DEAD notes, REG_UNUSED notes need to be kept free of false positives by all passes. function_info::change_insns does this by removing all REG_UNUSED notes, and then using add_reg_unused_notes to add notes back (or create new ones) where appropriate. The problem was that it called add_reg_unused_notes on the fly while updating each instruction, which meant that the information for later instructions in the change set wasn't up to date. This patch does it in a separate loop instead. gcc/ * rtl-ssa/changes.cc (function_info::apply_changes_to_insn): Remove call to add_reg_unused_notes and instead... (function_info::change_insns): ...use a separate loop here. --- gcc/rtl-ssa/changes.cc | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/gcc/rtl-ssa/changes.cc b/gcc/rtl-ssa/changes.cc index de6222a..c73c23c 100644 --- a/gcc/rtl-ssa/changes.cc +++ b/gcc/rtl-ssa/changes.cc @@ -586,8 +586,6 @@ function_info::apply_changes_to_insn (insn_change &change) insn->set_accesses (builder.finish ().begin (), num_defs, num_uses); } - - add_reg_unused_notes (insn); } // Add a temporary placeholder instruction after AFTER. @@ -733,9 +731,14 @@ function_info::change_insns (array_slice changes) } } - // Finally apply the changes to the underlying insn_infos. + // Apply the changes to the underlying insn_infos. for (insn_change *change : changes) apply_changes_to_insn (*change); + + // Now that the insns and accesses are up to date, add any REG_UNUSED notes. + for (insn_change *change : changes) + if (!change->is_deletion ()) + add_reg_unused_notes (change->insn ()); } // See the comment above the declaration. -- cgit v1.1