From gcc bugzilla https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60155 Upstream status: in trunk. Signed-off-by: Gustavo Zacarias --- gcc/gcse.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 64 insertions(+), 7 deletions(-) --- a/gcc/gcse.c +++ b/gcc/gcse.c @@ -2479,6 +2479,65 @@ } } +struct set_data +{ + rtx insn; + const_rtx set; + int nsets; +}; + +/* Increment number of sets and record set in DATA. */ + +static void +record_set_data (rtx dest, const_rtx set, void *data) +{ + struct set_data *s = (struct set_data *)data; + + if (GET_CODE (set) == SET) + { + /* We allow insns having multiple sets, where all but one are + dead as single set insns. In the common case only a single + set is present, so we want to avoid checking for REG_UNUSED + notes unless necessary. */ + if (s->nsets == 1 + && find_reg_note (s->insn, REG_UNUSED, SET_DEST (s->set)) + && !side_effects_p (s->set)) + s->nsets = 0; + + if (!s->nsets) + { + /* Record this set. */ + s->nsets += 1; + s->set = set; + } + else if (!find_reg_note (s->insn, REG_UNUSED, dest) + || side_effects_p (set)) + s->nsets += 1; + } +} + +static const_rtx +single_set_gcse (rtx insn) +{ + struct set_data s; + rtx pattern; + + gcc_assert (INSN_P (insn)); + + /* Optimize common case. */ + pattern = PATTERN (insn); + if (GET_CODE (pattern) == SET) + return pattern; + + s.insn = insn; + s.nsets = 0; + note_stores (pattern, record_set_data, &s); + + /* Considered invariant insns have exactly one set. */ + gcc_assert (s.nsets == 1); + return s.set; +} + /* Emit move from SRC to DEST noting the equivalence with expression computed in INSN. */ @@ -2486,7 +2545,8 @@ gcse_emit_move_after (rtx dest, rtx src, rtx insn) { rtx new_rtx; - rtx set = single_set (insn), set2; + const_rtx set = single_set_gcse (insn); + rtx set2; rtx note; rtx eqv = NULL_RTX; @@ -3345,13 +3405,12 @@ FOR_EACH_VEC_ELT (occrs_to_hoist, j, occr) { rtx insn; - rtx set; + const_rtx set; gcc_assert (!occr->deleted_p); insn = occr->insn; - set = single_set (insn); - gcc_assert (set); + set = single_set_gcse (insn); /* Create a pseudo-reg to store the result of reaching expressions into. Get the mode for the new pseudo @@ -3432,10 +3491,8 @@ { rtx reg; enum reg_class pressure_class; - rtx set = single_set (insn); + const_rtx set = single_set_gcse (insn); - /* Considered invariant insns have only one set. */ - gcc_assert (set != NULL_RTX); reg = SET_DEST (set); if (GET_CODE (reg) == SUBREG) reg = SUBREG_REG (reg);