diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 140 |
1 files changed, 15 insertions, 125 deletions
@@ -255,18 +255,6 @@ struct qty_table_elem /* The table of all qtys, indexed by qty number. */ static struct qty_table_elem *qty_table; -/* For machines that have a CC0, we do not record its value in the hash - table since its use is guaranteed to be the insn immediately following - its definition and any other insn is presumed to invalidate it. - - Instead, we store below the current and last value assigned to CC0. - If it should happen to be a constant, it is stored in preference - to the actual assigned value. In case it is a constant, we store - the mode in which the constant should be interpreted. */ - -static rtx this_insn_cc0, prev_insn_cc0; -static machine_mode this_insn_cc0_mode, prev_insn_cc0_mode; - /* Insn being scanned. */ static rtx_insn *this_insn; @@ -348,9 +336,8 @@ static bool cse_jumps_altered; to put in the note. */ static bool recorded_label_ref; -/* canon_hash stores 1 in do_not_record - if it notices a reference to CC0, PC, or some other volatile - subexpression. */ +/* canon_hash stores 1 in do_not_record if it notices a reference to PC or + some other volatile subexpression. */ static int do_not_record; @@ -592,7 +579,7 @@ static struct cse_reg_info * get_cse_reg_info (unsigned int regno); static void flush_hash_table (void); static bool insn_live_p (rtx_insn *, int *); -static bool set_live_p (rtx, rtx_insn *, int *); +static bool set_live_p (rtx, int *); static void cse_change_cc_mode_insn (rtx_insn *, rtx); static void cse_change_cc_mode_insns (rtx_insn *, rtx_insn *, rtx); static machine_mode cse_cc_succs (basic_block, basic_block, rtx, rtx, @@ -854,8 +841,6 @@ new_basic_block (void) free_element_chain = first; } } - - prev_insn_cc0 = 0; } /* Say that register REG contains a quantity in mode MODE not in any @@ -2448,7 +2433,6 @@ hash_rtx_cb (const_rtx x, machine_mode mode, case PRE_MODIFY: case POST_MODIFY: case PC: - case CC0: case CALL: case UNSPEC_VOLATILE: if (do_not_record_p) { @@ -2633,7 +2617,6 @@ exp_equiv_p (const_rtx x, const_rtx y, int validate, bool for_gcse) switch (code) { case PC: - case CC0: CASE_CONST_UNIQUE: return x == y; @@ -2853,7 +2836,6 @@ canon_reg (rtx x, rtx_insn *insn) switch (code) { case PC: - case CC0: case CONST: CASE_CONST_ANY: case SYMBOL_REF: @@ -2909,9 +2891,9 @@ canon_reg (rtx x, rtx_insn *insn) what values are being compared. *PARG1 and *PARG2 are updated to contain the rtx representing the values - actually being compared. For example, if *PARG1 was (cc0) and *PARG2 - was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were - compared to produce cc0. + actually being compared. For example, if *PARG1 was (reg:CC CC_REG) and + *PARG2 was (const_int 0), *PARG1 and *PARG2 will be set to the objects that + were compared to produce (reg:CC CC_REG). The return value is the comparison operator and is either the code of A or the code corresponding to the inverse of the comparison. */ @@ -2943,10 +2925,7 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, x = 0; } - /* If arg1 is a COMPARE, extract the comparison arguments from it. - On machines with CC0, this is the only case that can occur, since - fold_rtx will return the COMPARE or item being compared with zero - when given CC0. */ + /* If arg1 is a COMPARE, extract the comparison arguments from it. */ if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx) x = arg1; @@ -3179,9 +3158,6 @@ fold_rtx (rtx x, rtx_insn *insn) case EXPR_LIST: return x; - case CC0: - return prev_insn_cc0; - case ASM_OPERANDS: if (insn) { @@ -3232,30 +3208,6 @@ fold_rtx (rtx x, rtx_insn *insn) const_arg = folded_arg; break; - case CC0: - /* The cc0-user and cc0-setter may be in different blocks if - the cc0-setter potentially traps. In that case PREV_INSN_CC0 - will have been cleared as we exited the block with the - setter. - - While we could potentially track cc0 in this case, it just - doesn't seem to be worth it given that cc0 targets are not - terribly common or important these days and trapping math - is rarely used. The combination of those two conditions - necessary to trip this situation is exceedingly rare in the - real world. */ - if (!prev_insn_cc0) - { - const_arg = NULL_RTX; - } - else - { - folded_arg = prev_insn_cc0; - mode_arg = prev_insn_cc0_mode; - const_arg = equiv_constant (folded_arg); - } - break; - default: folded_arg = fold_rtx (folded_arg, insn); const_arg = equiv_constant (folded_arg); @@ -3910,10 +3862,7 @@ record_jump_equiv (rtx_insn *insn, bool taken) op0 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 0), insn); op1 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 1), insn); - /* On a cc0 target the cc0-setter and cc0-user may end up in different - blocks. When that happens the tracking of the cc0-setter via - PREV_INSN_CC0 is spoiled. That means that fold_rtx may return - NULL_RTX. In those cases, there's nothing to record. */ + /* If fold_rtx returns NULL_RTX, there's nothing to record. */ if (op0 == NULL_RTX || op1 == NULL_RTX) return; @@ -4555,9 +4504,6 @@ cse_insn (rtx_insn *insn) sets = XALLOCAVEC (struct set, XVECLEN (x, 0)); this_insn = insn; - /* Records what this insn does to set CC0. */ - this_insn_cc0 = 0; - this_insn_cc0_mode = VOIDmode; /* Find all regs explicitly clobbered in this insn, to ensure they are not replaced with any other regs @@ -5658,21 +5604,6 @@ cse_insn (rtx_insn *insn) sets[i].rtl = 0; } } - - /* If setting CC0, record what it was set to, or a constant, if it - is equivalent to a constant. If it is being set to a floating-point - value, make a COMPARE with the appropriate constant of 0. If we - don't do this, later code can interpret this as a test against - const0_rtx, which can cause problems if we try to put it into an - insn as a floating-point operand. */ - if (dest == cc0_rtx) - { - this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src; - this_insn_cc0_mode = mode; - if (FLOAT_MODE_P (mode)) - this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0, - CONST0_RTX (mode)); - } } /* Now enter all non-volatile source expressions in the hash table @@ -6594,34 +6525,6 @@ cse_extended_basic_block (struct cse_basic_block_data *ebb_data) if (INSN_P (insn) && !recorded_label_ref && check_for_label_ref (insn)) recorded_label_ref = true; - - if (HAVE_cc0 && NONDEBUG_INSN_P (insn)) - { - /* If the previous insn sets CC0 and this insn no - longer references CC0, delete the previous insn. - Here we use fact that nothing expects CC0 to be - valid over an insn, which is true until the final - pass. */ - rtx_insn *prev_insn; - rtx tem; - - prev_insn = prev_nonnote_nondebug_insn (insn); - if (prev_insn && NONJUMP_INSN_P (prev_insn) - && (tem = single_set (prev_insn)) != NULL_RTX - && SET_DEST (tem) == cc0_rtx - && ! reg_mentioned_p (cc0_rtx, PATTERN (insn))) - delete_insn (prev_insn); - - /* If this insn is not the last insn in the basic - block, it will be PREV_INSN(insn) in the next - iteration. If we recorded any CC0-related - information for this insn, remember it. */ - if (insn != BB_END (bb)) - { - prev_insn_cc0 = this_insn_cc0; - prev_insn_cc0_mode = this_insn_cc0_mode; - } - } } } @@ -6670,10 +6573,6 @@ cse_extended_basic_block (struct cse_basic_block_data *ebb_data) bool taken = (next_bb == BRANCH_EDGE (bb)->dest); record_jump_equiv (insn, taken); } - - /* Clear the CC0-tracking related insns, they can't provide - useful information across basic block boundaries. */ - prev_insn_cc0 = 0; } gcc_assert (next_qty <= max_qty); @@ -6816,7 +6715,6 @@ count_reg_usage (rtx x, int *counts, rtx dest, int incr) return; case PC: - case CC0: case CONST: CASE_CONST_ANY: case SYMBOL_REF: @@ -6925,23 +6823,15 @@ is_dead_reg (const_rtx x, int *counts) /* Return true if set is live. */ static bool -set_live_p (rtx set, rtx_insn *insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0. */ - int *counts) +set_live_p (rtx set, int *counts) { - rtx_insn *tem; - if (set_noop_p (set)) - ; - - else if (GET_CODE (SET_DEST (set)) == CC0 - && !side_effects_p (SET_SRC (set)) - && ((tem = next_nonnote_nondebug_insn (insn)) == NULL_RTX - || !INSN_P (tem) - || !reg_referenced_p (cc0_rtx, PATTERN (tem)))) return false; - else if (!is_dead_reg (SET_DEST (set), counts) - || side_effects_p (SET_SRC (set))) + + if (!is_dead_reg (SET_DEST (set), counts) + || side_effects_p (SET_SRC (set))) return true; + return false; } @@ -6954,7 +6844,7 @@ insn_live_p (rtx_insn *insn, int *counts) if (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) return true; else if (GET_CODE (PATTERN (insn)) == SET) - return set_live_p (PATTERN (insn), insn, counts); + return set_live_p (PATTERN (insn), counts); else if (GET_CODE (PATTERN (insn)) == PARALLEL) { for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) @@ -6963,7 +6853,7 @@ insn_live_p (rtx_insn *insn, int *counts) if (GET_CODE (elt) == SET) { - if (set_live_p (elt, insn, counts)) + if (set_live_p (elt, counts)) return true; } else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE) |