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authoramylaar <amylaar@138bc75d-0d04-0410-961f-82ee72b054a4>2005-12-13 13:04:18 +0000
committeramylaar <amylaar@138bc75d-0d04-0410-961f-82ee72b054a4>2005-12-13 13:04:18 +0000
commitcd7f40a2f5ead133a4c885634022f711eae2c009 (patch)
treee701881426d487009dc1064a87c21abe61a14c8a /gcc/basic-block.h
parente392cde316bbbe5967d1572def874ce354fd06e0 (diff)
downloadgcc-cd7f40a2f5ead133a4c885634022f711eae2c009.tar.gz
PR rtl-optimization/20070 / part1
* flow.c (update_life_info): If PROP_POST_REGSTACK is set, call count_or_remove_death_notes with kill == -1. (mark_set_1): Don't add REG_DEAD / REG_UNUSED notes for stack registers if PROP_POST_REGSTACK is set. (mark_used_reg): Likewise. (count_or_remove_death_notes): If kill is -1, don't remove REG_DEAD / REG_UNUSED notes for stack regs. * cfgcleanup.c (condjump_equiv_p): Change parameters and processing to match rtx_equiv_p machinery. Change caller. (outgoing_edges_match): Likewise. (try_crossjump_to_edge): Use struct_equiv_block_eq instead of flow_find_cross_jump. * basic-block.h (PROP_POST_REGSTACK, STRUCT_EQUIV_START): Define. (STRUCT_EQUIV_RERUN, STRUCT_EQUIV_FINAL): Likewise. (STRUCT_EQUIV_NEED_FULL_BLOCK, STRUCT_EQUIV_MATCH_JUMPS): Likewise. (STRUCT_EQUIV_MAX_LOCAL): Likewise. (struct struct_equiv_checkpoint, struct equiv_info): Likewise. (insns_match_p): Update prototype. (flow_find_cross_jump): Remove prototype. (struct_equiv_block_eq, struct_equiv_init): Declare. (rtx_equiv_p, condjump_equiv_p): Likewise. * struct-equiv.c: Include reload.h. (IMPOSSIBLE_MOVE_FACTOR): Define. (assign_reg_reg_set, struct_equiv_make_checkpoint): New functions. (struct_equiv_improve_checkpoint): Likewise. (struct_equiv_restore_checkpoint, rtx_equiv_p): Likewise. (set_dest_equiv_p, set_dest_addr_equiv_p, struct_equiv_init): Likewise. (struct_equiv_merge, find_dying_input): Likewise. (resolve_input_conflict, note_local_live): Likewise. (death_notes_match_p): Change parameters and processing to match rtx_equiv_p machinery. Change caller. (insns_match_p): Likewise. (flow_find_cross_jump): Replace with: (struct_equiv_block_eq). Back out this change: 2005-03-07 Kazu Hirata <kazu@cs.umass.edu> * recog.c (verify_changes): Make it static. * recog.h: Remove the corresponding prototype. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@108480 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/basic-block.h')
-rw-r--r--gcc/basic-block.h179
1 files changed, 177 insertions, 2 deletions
diff --git a/gcc/basic-block.h b/gcc/basic-block.h
index 9a88e8d3c0c..a3cecae8b6f 100644
--- a/gcc/basic-block.h
+++ b/gcc/basic-block.h
@@ -807,6 +807,9 @@ enum update_life_extent
to flag analysis of asms. */
#define PROP_DEAD_INSN 1024 /* Internal flag used within flow.c
to flag analysis of dead insn. */
+#define PROP_POST_REGSTACK 2048 /* We run after reg-stack and need
+ to preserve REG_DEAD notes for
+ stack regs. */
#define PROP_FINAL (PROP_DEATH_NOTES | PROP_LOG_LINKS \
| PROP_REG_INFO | PROP_KILL_DEAD_CODE \
| PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
@@ -831,6 +834,17 @@ enum update_life_extent
#define CLEANUP_CFGLAYOUT 128 /* Do cleanup in cfglayout mode. */
#define CLEANUP_LOG_LINKS 256 /* Update log links. */
+/* The following are ORed in on top of the CLEANUP* flags in calls to
+ struct_equiv_block_eq. */
+#define STRUCT_EQUIV_START 512 /* Initializes the search range. */
+#define STRUCT_EQUIV_RERUN 1024 /* Rerun to find register use in
+ found equivalence. */
+#define STRUCT_EQUIV_FINAL 2048 /* Make any changes necessary to get
+ actual equivalence. */
+#define STRUCT_EQUIV_NEED_FULL_BLOCK 4096 /* struct_equiv_block_eq is required
+ to match only full blocks */
+#define STRUCT_EQUIV_MATCH_JUMPS 8192 /* Also include the jumps at the end of the block in the comparison. */
+
extern void life_analysis (FILE *, int);
extern int update_life_info (sbitmap, enum update_life_extent, int);
extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
@@ -992,7 +1006,168 @@ extern basic_block get_bb_copy (basic_block);
#include "cfghooks.h"
/* In struct-equiv.c */
-extern bool insns_match_p (int, rtx, rtx);
-extern int flow_find_cross_jump (int, basic_block, basic_block, rtx *, rtx *);
+
+/* Constants used to size arrays in struct equiv_info (currently only one).
+ When these limits are exceeded, struct_equiv returns zero.
+ The maximum number of pseudo registers that are different in the two blocks,
+ but appear in equivalent places and are dead at the end (or where one of
+ a pair is dead at the end). */
+#define STRUCT_EQUIV_MAX_LOCAL 16
+/* The maximum number of references to an input register that struct_equiv
+ can handle. */
+
+/* Structure used to track state during struct_equiv that can be rolled
+ back when we find we can't match an insn, or if we want to match part
+ of it in a different way.
+ This information pertains to the pair of partial blocks that has been
+ matched so far. Since this pair is structurally equivalent, this is
+ conceptually just one partial block expressed in two potentially
+ different ways. */
+struct struct_equiv_checkpoint
+{
+ int ninsns; /* Insns are matched so far. */
+ int local_count; /* Number of block-local registers. */
+ int input_count; /* Number of inputs to the block. */
+
+ /* X_START and Y_START are the first insns (in insn stream order)
+ of the partial blocks that have been considered for matching so far.
+ Since we are scanning backwards, they are also the instructions that
+ are currently considered - or the last ones that have been considered -
+ for matching (Unless we tracked back to these because a preceding
+ instruction failed to match). */
+ rtx x_start, y_start;
+
+ /* INPUT_VALID indicates if we have actually set up X_INPUT / Y_INPUT
+ during the current pass; we keep X_INPUT / Y_INPUT around between passes
+ so that we can match REG_EQUAL / REG_EQUIV notes referring to these. */
+ bool input_valid;
+
+ /* Some information would be expensive to exactly checkpoint, so we
+ merely increment VERSION any time information about local
+ registers, inputs and/or register liveness changes. When backtracking,
+ it is decremented for changes that can be undone, and if a discrepancy
+ remains, NEED_RERUN in the relevant struct equiv_info is set to indicate
+ that a new pass should be made over the entire block match to get
+ accurate register information. */
+ int version;
+};
+
+/* A struct equiv_info is used to pass information to struct_equiv and
+ to gather state while two basic blocks are checked for structural
+ equivalence. */
+
+struct equiv_info
+{
+ /* Fields set up by the caller to struct_equiv_block_eq */
+
+ basic_block x_block, y_block; /* The two blocks being matched. */
+
+ /* MODE carries the mode bits from cleanup_cfg if we are called from
+ try_crossjump_to_edge, and additionally it carries the
+ STRUCT_EQUIV_* bits described above. */
+ int mode;
+
+ /* INPUT_COST is the cost that adding an extra input to the matched blocks
+ is supposed to have, and is taken into account when considering if the
+ matched sequence should be extended backwards. input_cost < 0 means
+ don't accept any inputs at all. */
+ int input_cost;
+
+
+ /* Fields to track state inside of struct_equiv_block_eq. Some of these
+ are also outputs. */
+
+ /* X_INPUT and Y_INPUT are used by struct_equiv to record a register that
+ is used as an input parameter, i.e. where different registers are used
+ as sources. This is only used for a register that is live at the end
+ of the blocks, or in some identical code at the end of the blocks;
+ Inputs that are dead at the end go into X_LOCAL / Y_LOCAL. */
+ rtx x_input, y_input;
+ /* When a previous pass has identified a valid input, INPUT_REG is set
+ by struct_equiv_block_eq, and it is henceforth replaced in X_BLOCK
+ for the input. */
+ rtx input_reg;
+
+ /* COMMON_LIVE keeps track of the registers which are currently live
+ (as we scan backwards from the end) and have the same numbers in both
+ blocks. N.B. a register that is in common_live is unsuitable to become
+ a local reg. */
+ regset common_live;
+ /* Likewise, X_LOCAL_LIVE / Y_LOCAL_LIVE keep track of registers that are
+ local to one of the blocks; these registers must not be accepted as
+ identical when encountered in both blocks. */
+ regset x_local_live, y_local_live;
+
+ /* EQUIV_USED indicates for which insns a REG_EQUAL or REG_EQUIV note is
+ being used, to avoid having to backtrack in the next pass, so that we
+ get accurate life info for this insn then. For each such insn,
+ the bit with the number corresponding to the CUR.NINSNS value at the
+ time of scanning is set. */
+ bitmap equiv_used;
+
+ /* Current state that can be saved & restored easily. */
+ struct struct_equiv_checkpoint cur;
+ /* BEST_MATCH is used to store the best match so far, weighing the
+ cost of matched insns COSTS_N_INSNS (CUR.NINSNS) against the cost
+ CUR.INPUT_COUNT * INPUT_COST of setting up the inputs. */
+ struct struct_equiv_checkpoint best_match;
+ /* If a checkpoint restore failed, or an input conflict newly arises,
+ NEED_RERUN is set. This has to be tested by the caller to re-run
+ the comparison if the match appears otherwise sound. The state kept in
+ x_start, y_start, equiv_used and check_input_conflict ensures that
+ we won't loop indefinetly. */
+ bool need_rerun;
+ /* If there is indication of an input conflict at the end,
+ CHECK_INPUT_CONFLICT is set so that we'll check for input conflicts
+ for each insn in the next pass. This is needed so that we won't discard
+ a partial match if there is a longer match that has to be abandoned due
+ to an input conflict. */
+ bool check_input_conflict;
+ /* HAD_INPUT_CONFLICT is set if CHECK_INPUT_CONFLICT was already set and we
+ have passed a point where there were multiple dying inputs. This helps
+ us decide if we should set check_input_conflict for the next pass. */
+ bool had_input_conflict;
+
+ /* LIVE_UPDATE controls if we want to change any life info at all. We
+ set it to false during REG_EQUAL / REG_EUQIV note comparison of the final
+ pass so that we don't introduce new registers just for the note; if we
+ can't match the notes without the current register information, we drop
+ them. */
+ bool live_update;
+
+ /* X_LOCAL and Y_LOCAL are used to gather register numbers of register pairs
+ that are local to X_BLOCK and Y_BLOCK, with CUR.LOCAL_COUNT being the index
+ to the next free entry. */
+ rtx x_local[STRUCT_EQUIV_MAX_LOCAL], y_local[STRUCT_EQUIV_MAX_LOCAL];
+ /* LOCAL_RVALUE is nonzero if the corresponding X_LOCAL / Y_LOCAL entry
+ was a source operand (including STRICT_LOW_PART) for the last invocation
+ of struct_equiv mentioning it, zero if it was a destination-only operand.
+ Since we are scanning backwards, this means the register is input/local
+ for the (partial) block scanned so far. */
+ bool local_rvalue[STRUCT_EQUIV_MAX_LOCAL];
+
+
+ /* Additional fields that are computed for the convenience of the caller. */
+
+ /* DYING_INPUTS is set to the number of local registers that turn out
+ to be inputs to the (possibly partial) block. */
+ int dying_inputs;
+ /* X_END and Y_END are the last insns in X_BLOCK and Y_BLOCK, respectively,
+ that are being compared. A final jump insn will not be included. */
+ rtx x_end, y_end;
+
+ /* If we are matching tablejumps, X_LABEL in X_BLOCK coresponds to
+ Y_LABEL in Y_BLOCK. */
+ rtx x_label, y_label;
+
+};
+
+extern bool insns_match_p (rtx, rtx, struct equiv_info *);
+extern int struct_equiv_block_eq (int, struct equiv_info *);
+extern bool struct_equiv_init (int, struct equiv_info *);
+extern bool rtx_equiv_p (rtx *, rtx, int, struct equiv_info *);
+
+/* In cfgrtl.c */
+extern bool condjump_equiv_p (struct equiv_info *, bool);
#endif /* GCC_BASIC_BLOCK_H */