https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96151
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:510125d2272175f47b26227fbe9b8c8c5abfd988 commit r11-2023-g510125d2272175f47b26227fbe9b8c8c5abfd988 Author: Richard Sandiford <richard.sandif...@arm.com> Date: Fri Jul 10 19:06:46 2020 +0100 expr: Move reduce_bit_field target mode check [PR96151] In some cases, expand_expr_real_2 prefers to use the mode of the caller-suggested target instead of the mode of the expression when passing values to reduce_to_bit_field_precision. E.g.: else if (target == 0) op0 = convert_to_mode (mode, op0, TYPE_UNSIGNED (TREE_TYPE (treeop0))); else { convert_move (target, op0, TYPE_UNSIGNED (TREE_TYPE (treeop0))); op0 = target; } where âop0â might not have âmodeâ for the âelseâ branch, but does for all the others. reduce_to_bit_field_precision discards the suggested target if it has the wrong mode. This patch moves that to expand_expr_real_2 instead (conditional on reduce_bit_field). gcc/ PR middle-end/96151 * expr.c (expand_expr_real_2): When reducing bit fields, clear the target if it has a different mode from the expression. (reduce_to_bit_field_precision): Don't do that here. Instead assert that the target already has the correct mode.
