diff options
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/gcse.c | 87 |
2 files changed, 58 insertions, 37 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7e35852..a517aae 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,4 +1,12 @@ 2001-08-27 Roman Zippel <zippel@linux-m68k.org> + Richard Henderson <rth@redhat.com> + + * gcse.c (reg_first_set, reg_last_set): Replace with ... + (reg_avail_info, current_bb): ... these. + (oprs_unchanged_p, record_last_reg_set_info): Use them. + (compute_hash_table): Likewise. + +2001-08-27 Roman Zippel <zippel@linux-m68k.org> * flow.c (verify_flow_info): Use checksums to verify edges. @@ -1298,11 +1298,19 @@ compute_sets (f) /* Hash table support. */ -/* For each register, the cuid of the first/last insn in the block to set it, - or -1 if not set. */ +/* For each register, the cuid of the first/last insn in the block + that set it, or -1 if not set. */ #define NEVER_SET -1 -static int *reg_first_set; -static int *reg_last_set; + +struct reg_avail_info +{ + int last_bb; + int first_set; + int last_set; +}; + +static struct reg_avail_info *reg_avail_info; +static int current_bb; /* See whether X, the source of a set, is something we want to consider for @@ -1376,15 +1384,19 @@ oprs_unchanged_p (x, insn, avail_p) switch (code) { case REG: - if (avail_p) - return (reg_last_set[REGNO (x)] == NEVER_SET - || reg_last_set[REGNO (x)] < INSN_CUID (insn)); - else - return (reg_first_set[REGNO (x)] == NEVER_SET - || reg_first_set[REGNO (x)] >= INSN_CUID (insn)); + { + struct reg_avail_info *info = ®_avail_info[REGNO (x)]; + + if (info->last_bb != current_bb) + return 1; + if (avail_p) + return info->last_set < INSN_CUID (insn); + else + return info->first_set >= INSN_CUID (insn); + } case MEM: - if (load_killed_in_block_p (BLOCK_FOR_INSN (insn), INSN_CUID (insn), + if (load_killed_in_block_p (BASIC_BLOCK (current_bb), INSN_CUID (insn), x, avail_p)) return 0; else @@ -2328,12 +2340,15 @@ dump_hash_table (file, name, table, table_size, total_size) /* Record register first/last/block set information for REGNO in INSN. - reg_first_set records the first place in the block where the register + first_set records the first place in the block where the register is set and is used to compute "anticipatability". - reg_last_set records the last place in the block where the register + last_set records the last place in the block where the register is set and is used to compute "availability". + last_bb records the block for which first_set and last_set are + valid, as a quick test to invalidate them. + reg_set_in_block records whether the register is set in the block and is used to compute "transparency". */ @@ -2342,11 +2357,16 @@ record_last_reg_set_info (insn, regno) rtx insn; int regno; { - if (reg_first_set[regno] == NEVER_SET) - reg_first_set[regno] = INSN_CUID (insn); + struct reg_avail_info *info = ®_avail_info[regno]; + int cuid = INSN_CUID (insn); - reg_last_set[regno] = INSN_CUID (insn); - SET_BIT (reg_set_in_block[BLOCK_NUM (insn)], regno); + info->last_set = cuid; + if (info->last_bb != current_bb) + { + info->last_bb = current_bb; + info->first_set = cuid; + SET_BIT (reg_set_in_block[current_bb], regno); + } } @@ -2453,7 +2473,7 @@ static void compute_hash_table (set_p) int set_p; { - int bb; + unsigned int i; /* While we compute the hash table we also compute a bit array of which registers are set in which blocks. @@ -2473,29 +2493,25 @@ compute_hash_table (set_p) } } /* Some working arrays used to track first and last set in each block. */ - /* ??? One could use alloca here, but at some size a threshold is crossed - beyond which one should use malloc. Are we at that threshold here? */ - reg_first_set = (int *) gmalloc (max_gcse_regno * sizeof (int)); - reg_last_set = (int *) gmalloc (max_gcse_regno * sizeof (int)); + reg_avail_info = (struct reg_avail_info*) + gmalloc (max_gcse_regno * sizeof (struct reg_avail_info)); - for (bb = 0; bb < n_basic_blocks; bb++) + for (i = 0; i < max_gcse_regno; ++i) + reg_avail_info[i].last_bb = NEVER_SET; + + for (current_bb = 0; current_bb < n_basic_blocks; current_bb++) { rtx insn; unsigned int regno; int in_libcall_block; - unsigned int i; /* First pass over the instructions records information used to determine when registers and memory are first and last set. ??? hard-reg reg_set_in_block computation could be moved to compute_sets since they currently don't change. */ - for (i = 0; i < max_gcse_regno; i++) - reg_first_set[i] = reg_last_set[i] = NEVER_SET; - - - for (insn = BLOCK_HEAD (bb); - insn && insn != NEXT_INSN (BLOCK_END (bb)); + for (insn = BLOCK_HEAD (current_bb); + insn && insn != NEXT_INSN (BLOCK_END (current_bb)); insn = NEXT_INSN (insn)) { if (! INSN_P (insn)) @@ -2523,8 +2539,8 @@ compute_hash_table (set_p) /* The next pass builds the hash table. */ - for (insn = BLOCK_HEAD (bb), in_libcall_block = 0; - insn && insn != NEXT_INSN (BLOCK_END (bb)); + for (insn = BLOCK_HEAD (current_bb), in_libcall_block = 0; + insn && insn != NEXT_INSN (BLOCK_END (current_bb)); insn = NEXT_INSN (insn)) if (INSN_P (insn)) { @@ -2536,11 +2552,8 @@ compute_hash_table (set_p) } } - free (reg_first_set); - free (reg_last_set); - - /* Catch bugs early. */ - reg_first_set = reg_last_set = 0; + free (reg_avail_info); + reg_avail_info = NULL; } /* Allocate space for the set hash table. |