diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 186 |
1 files changed, 18 insertions, 168 deletions
diff --git a/gcc/cse.c b/gcc/cse.c index 73eb1c6805b..02420f1a076 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -584,7 +584,7 @@ static rtx equiv_constant (rtx); static void record_jump_equiv (rtx, bool); static void record_jump_cond (enum rtx_code, enum machine_mode, rtx, rtx, int); -static void cse_insn (rtx, rtx); +static void cse_insn (rtx); static void cse_prescan_path (struct cse_basic_block_data *); static void invalidate_from_clobbers (rtx); static rtx cse_process_notes (rtx, rtx, bool *); @@ -599,7 +599,6 @@ static int check_dependence (rtx *, void *); static void flush_hash_table (void); static bool insn_live_p (rtx, int *); static bool set_live_p (rtx, rtx, int *); -static bool dead_libcall_p (rtx, int *); static int cse_change_cc_mode (rtx *, void *); static void cse_change_cc_mode_insn (rtx, rtx); static void cse_change_cc_mode_insns (rtx, rtx, rtx); @@ -3929,11 +3928,7 @@ record_jump_cond (enum rtx_code code, enum machine_mode mode, rtx op0, First simplify sources and addresses of all assignments in the instruction, using previously-computed equivalents values. Then install the new sources and destinations in the table - of available values. - - If LIBCALL_INSN is nonzero, don't record any equivalence made in - the insn. It means that INSN is inside libcall block. In this - case LIBCALL_INSN is the corresponding insn with REG_LIBCALL. */ + of available values. */ /* Data on one SET contained in the instruction. */ @@ -3962,8 +3957,6 @@ struct set ENUM_BITFIELD(machine_mode) mode : 8; /* A constant equivalent for SET_SRC, if any. */ rtx src_const; - /* Original SET_SRC value used for libcall notes. */ - rtx orig_src; /* Hash value of constant equivalent for SET_SRC. */ unsigned src_const_hash; /* Table entry for constant equivalent for SET_SRC, if any. */ @@ -3973,7 +3966,7 @@ struct set }; static void -cse_insn (rtx insn, rtx libcall_insn) +cse_insn (rtx insn) { rtx x = PATTERN (insn); int i; @@ -4170,7 +4163,6 @@ cse_insn (rtx insn, rtx libcall_insn) rtx src = SET_SRC (sets[i].rtl); rtx new = canon_reg (src, insn); - sets[i].orig_src = src; validate_change (insn, &SET_SRC (sets[i].rtl), new, 1); if (GET_CODE (dest) == ZERO_EXTRACT) @@ -4821,22 +4813,6 @@ cse_insn (rtx insn, rtx libcall_insn) { rtx new = canon_reg (SET_SRC (sets[i].rtl), insn); - /* If we just made a substitution inside a libcall, then we - need to make the same substitution in any notes attached - to the RETVAL insn. */ - if (libcall_insn - && (REG_P (sets[i].orig_src) - || GET_CODE (sets[i].orig_src) == SUBREG - || MEM_P (sets[i].orig_src))) - { - rtx note = find_reg_equal_equiv_note (libcall_insn); - if (note != 0) - XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), - sets[i].orig_src, - copy_rtx (new)); - df_notes_rescan (libcall_insn); - } - /* The result of apply_change_group can be ignored; see canon_reg. */ @@ -5175,27 +5151,19 @@ cse_insn (rtx insn, rtx libcall_insn) if (sets[i].src_elt == 0) { - /* Don't put a hard register source into the table if this is - the last insn of a libcall. In this case, we only need - to put src_eqv_elt in src_elt. */ - if (! find_reg_note (insn, REG_RETVAL, NULL_RTX)) - { - struct table_elt *elt; + struct table_elt *elt; - /* Note that these insert_regs calls cannot remove - any of the src_elt's, because they would have failed to - match if not still valid. */ - if (insert_regs (src, classp, 0)) - { - rehash_using_reg (src); - sets[i].src_hash = HASH (src, mode); - } - elt = insert (src, classp, sets[i].src_hash, mode); - elt->in_memory = sets[i].src_in_memory; - sets[i].src_elt = classp = elt; + /* Note that these insert_regs calls cannot remove + any of the src_elt's, because they would have failed to + match if not still valid. */ + if (insert_regs (src, classp, 0)) + { + rehash_using_reg (src); + sets[i].src_hash = HASH (src, mode); } - else - sets[i].src_elt = classp; + elt = insert (src, classp, sets[i].src_hash, mode); + elt->in_memory = sets[i].src_in_memory; + sets[i].src_elt = classp = elt; } if (sets[i].src_const && sets[i].src_const_elt == 0 && src != sets[i].src_const @@ -5392,11 +5360,6 @@ cse_insn (rtx insn, rtx libcall_insn) size of it, and can't be sure that other BLKmode values have the same or smaller size. */ || GET_MODE (dest) == BLKmode - /* Don't record values of destinations set inside a libcall block - since we might delete the libcall. Things should have been set - up so we won't want to reuse such a value, but we play it safe - here. */ - || libcall_insn /* If we didn't put a REG_EQUAL value or a source into the hash table, there is no point is recording DEST. */ || sets[i].src_elt == 0 @@ -5540,11 +5503,7 @@ cse_insn (rtx insn, rtx libcall_insn) then be used in the sequel and we may be changing a two-operand insn into a three-operand insn. - Also do not do this if we are operating on a copy of INSN. - - Also don't do this if INSN ends a libcall; this would cause an unrelated - register to be set in the middle of a libcall, and we then get bad code - if the libcall is deleted. */ + Also do not do this if we are operating on a copy of INSN. */ if (n_sets == 1 && sets[0].rtl && REG_P (SET_DEST (sets[0].rtl)) && NEXT_INSN (PREV_INSN (insn)) == insn @@ -5555,8 +5514,7 @@ cse_insn (rtx insn, rtx libcall_insn) int src_q = REG_QTY (REGNO (SET_SRC (sets[0].rtl))); struct qty_table_elem *src_ent = &qty_table[src_q]; - if ((src_ent->first_reg == REGNO (SET_DEST (sets[0].rtl))) - && ! find_reg_note (insn, REG_RETVAL, NULL_RTX)) + if (src_ent->first_reg == REGNO (SET_DEST (sets[0].rtl))) { /* Scan for the previous nonnote insn, but stop at a basic block boundary. */ @@ -5993,8 +5951,6 @@ cse_extended_basic_block (struct cse_basic_block_data *ebb_data) { basic_block bb; rtx insn; - rtx libcall_insn = NULL_RTX; - int no_conflict = 0; bb = ebb_data->path[path_entry].bb; @@ -6043,39 +5999,8 @@ cse_extended_basic_block (struct cse_basic_block_data *ebb_data) df_notes_rescan (insn); } - /* Track when we are inside in LIBCALL block. Inside such - a block we do not want to record destinations. The last - insn of a LIBCALL block is not considered to be part of - the block, since its destination is the result of the - block and hence should be recorded. */ - if (REG_NOTES (insn) != 0) - { - rtx p; + cse_insn (insn); - if ((p = find_reg_note (insn, REG_LIBCALL, NULL_RTX))) - libcall_insn = XEXP (p, 0); - else if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) - { - /* Keep libcall_insn for the last SET insn of - a no-conflict block to prevent changing the - destination. */ - if (!no_conflict) - libcall_insn = NULL_RTX; - else - no_conflict = -1; - } - } - - cse_insn (insn, libcall_insn); - - /* If we kept libcall_insn for a no-conflict bock, - clear it here. */ - if (no_conflict == -1) - { - libcall_insn = NULL_RTX; - no_conflict = 0; - } - /* If we haven't already found an insn where we added a LABEL_REF, check this one. */ if (INSN_P (insn) && !recorded_label_ref @@ -6112,9 +6037,6 @@ cse_extended_basic_block (struct cse_basic_block_data *ebb_data) } } - /* Make sure that libcalls don't span multiple basic blocks. */ - gcc_assert (libcall_insn == NULL_RTX); - /* With non-call exceptions, we are not always able to update the CFG properly inside cse_insn. So clean up possibly redundant EH edges here. */ @@ -6479,57 +6401,6 @@ insn_live_p (rtx insn, int *counts) return true; } -/* Return true if libcall is dead as a whole. */ - -static bool -dead_libcall_p (rtx insn, int *counts) -{ - rtx note, set, new; - - /* See if there's a REG_EQUAL note on this insn and try to - replace the source with the REG_EQUAL expression. - - We assume that insns with REG_RETVALs can only be reg->reg - copies at this point. */ - note = find_reg_note (insn, REG_EQUAL, NULL_RTX); - if (!note) - return false; - - set = single_set (insn); - if (!set) - return false; - - new = simplify_rtx (XEXP (note, 0)); - if (!new) - new = XEXP (note, 0); - - /* While changing insn, we must update the counts accordingly. */ - count_reg_usage (insn, counts, NULL_RTX, -1); - - if (validate_change (insn, &SET_SRC (set), new, 0)) - { - count_reg_usage (insn, counts, NULL_RTX, 1); - remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX)); - remove_note (insn, note); - return true; - } - - if (CONSTANT_P (new)) - { - new = force_const_mem (GET_MODE (SET_DEST (set)), new); - if (new && validate_change (insn, &SET_SRC (set), new, 0)) - { - count_reg_usage (insn, counts, NULL_RTX, 1); - remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX)); - remove_note (insn, note); - return true; - } - } - - count_reg_usage (insn, counts, NULL_RTX, 1); - return false; -} - /* Scan all the insns and delete any that are dead; i.e., they store a register that is never used or they copy a register to itself. @@ -6543,7 +6414,6 @@ delete_trivially_dead_insns (rtx insns, int nreg) { int *counts; rtx insn, prev; - int in_libcall = 0, dead_libcall = 0; int ndead = 0; timevar_push (TV_DELETE_TRIVIALLY_DEAD); @@ -6568,21 +6438,7 @@ delete_trivially_dead_insns (rtx insns, int nreg) if (!INSN_P (insn)) continue; - /* Don't delete any insns that are part of a libcall block unless - we can delete the whole libcall block. - - Flow or loop might get confused if we did that. Remember - that we are scanning backwards. */ - if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) - { - in_libcall = 1; - live_insn = 1; - dead_libcall = dead_libcall_p (insn, counts); - } - else if (in_libcall) - live_insn = ! dead_libcall; - else - live_insn = insn_live_p (insn, counts); + live_insn = insn_live_p (insn, counts); /* If this is a dead insn, delete it and show registers in it aren't being used. */ @@ -6593,12 +6449,6 @@ delete_trivially_dead_insns (rtx insns, int nreg) delete_insn_and_edges (insn); ndead++; } - - if (in_libcall && find_reg_note (insn, REG_LIBCALL, NULL_RTX)) - { - in_libcall = 0; - dead_libcall = 0; - } } if (dump_file && ndead) |