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Commit 7d22e898 by J"orn Rennecke Committed by Joern Rennecke
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PR rtl-optimization/20070 / part1 

	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.

From-SVN: r108480
parent 80e6edb0
Showing with 1491 additions and 190 deletions
gcc/ChangeLog
2005-12-13 J"orn Rennecke <joern.rennecke@st.com>
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.
2005-12-13 J"orn Rennecke <joern.rennecke@st.com>
* rtlhooks.c (gen_lowpart_general): Handle SUBREGs of floating point
values.
......
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 */
gcc/cfgcleanup.c
......@@ -60,7 +60,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
static bool first_pass;
static bool try_crossjump_to_edge (int, edge, edge);
static bool try_crossjump_bb (int, basic_block);
static bool outgoing_edges_match (int, basic_block, basic_block);
static bool outgoing_edges_match (int *, struct equiv_info *);
static void merge_blocks_move_predecessor_nojumps (basic_block, basic_block);
static void merge_blocks_move_successor_nojumps (basic_block, basic_block);
......@@ -879,20 +879,20 @@ merge_blocks_move (edge e, basic_block b, basic_block c, int mode)
}
/* Return true iff the condbranches at the end of BB1 and BB2 match. */
static bool
condjump_equiv_p (basic_block bb1, basic_block bb2)
bool
condjump_equiv_p (struct equiv_info *info, bool call_init)
{
edge b1, f1, b2, f2;
basic_block bb1 = info->x_block;
basic_block bb2 = info->y_block;
edge b1 = BRANCH_EDGE (bb1);
edge b2 = BRANCH_EDGE (bb2);
edge f1 = FALLTHRU_EDGE (bb1);
edge f2 = FALLTHRU_EDGE (bb2);
bool reverse, match;
rtx set1, set2, cond1, cond2;
rtx src1, src2;
enum rtx_code code1, code2;
b1 = BRANCH_EDGE (bb1);
b2 = BRANCH_EDGE (bb2);
f1 = FALLTHRU_EDGE (bb1);
f2 = FALLTHRU_EDGE (bb2);
/* Get around possible forwarders on fallthru edges. Other cases
should be optimized out already. */
if (FORWARDER_BLOCK_P (f1->dest))
......@@ -923,8 +923,10 @@ condjump_equiv_p (basic_block bb1, basic_block bb2)
!= (XEXP (SET_SRC (set2), 1) == pc_rtx))
reverse = !reverse;
cond1 = XEXP (SET_SRC (set1), 0);
cond2 = XEXP (SET_SRC (set2), 0);
src1 = SET_SRC (set1);
src2 = SET_SRC (set2);
cond1 = XEXP (src1, 0);
cond2 = XEXP (src2, 0);
code1 = GET_CODE (cond1);
if (reverse)
code2 = reversed_comparison_code (cond2, BB_END (bb2));
......@@ -934,15 +936,35 @@ condjump_equiv_p (basic_block bb1, basic_block bb2)
if (code2 == UNKNOWN)
return false;
if (call_init && !struct_equiv_init (STRUCT_EQUIV_START | info->mode, info))
gcc_unreachable ();
/* Make the sources of the pc sets unreadable so that when we call
insns_match_p it won't process them.
The death_notes_match_p from insns_match_p won't see the local registers
used for the pc set, but that could only cause missed optimizations when
there are actually condjumps that use stack registers. */
SET_SRC (set1) = pc_rtx;
SET_SRC (set2) = pc_rtx;
/* Verify codes and operands match. */
match = ((code1 == code2
&& rtx_renumbered_equal_p (XEXP (cond1, 0), XEXP (cond2, 0))
&& rtx_renumbered_equal_p (XEXP (cond1, 1), XEXP (cond2, 1)))
|| (code1 == swap_condition (code2)
&& rtx_renumbered_equal_p (XEXP (cond1, 1),
XEXP (cond2, 0))
&& rtx_renumbered_equal_p (XEXP (cond1, 0),
XEXP (cond2, 1))));
if (code1 == code2)
{
match = (insns_match_p (BB_END (bb1), BB_END (bb2), info)
&& rtx_equiv_p (&XEXP (cond1, 0), XEXP (cond2, 0), 1, info)
&& rtx_equiv_p (&XEXP (cond1, 1), XEXP (cond2, 1), 1, info));
}
else if (code1 == swap_condition (code2))
{
match = (insns_match_p (BB_END (bb1), BB_END (bb2), info)
&& rtx_equiv_p (&XEXP (cond1, 1), XEXP (cond2, 0), 1, info)
&& rtx_equiv_p (&XEXP (cond1, 0), XEXP (cond2, 1), 1, info));
}
else
match = false;
SET_SRC (set1) = src1;
SET_SRC (set2) = src2;
match &= verify_changes (0);
/* If we return true, we will join the blocks. Which means that
we will only have one branch prediction bit to work with. Thus
......@@ -971,7 +993,7 @@ condjump_equiv_p (basic_block bb1, basic_block bb2)
"Outcomes of branch in bb %i and %i differ too much (%i %i)\n",
bb1->index, bb2->index, b1->probability, prob2);
return false;
match = false;
}
}
......@@ -979,17 +1001,25 @@ condjump_equiv_p (basic_block bb1, basic_block bb2)
fprintf (dump_file, "Conditionals in bb %i and %i match.\n",
bb1->index, bb2->index);
if (!match)
cancel_changes (0);
return match;
}
/* Return true iff outgoing edges of BB1 and BB2 match, together with
the branch instruction. This means that if we commonize the control
flow before end of the basic block, the semantic remains unchanged.
/* Return true iff outgoing edges of INFO->y_block and INFO->x_block match,
together with the branch instruction. This means that if we commonize the
control flow before end of the basic block, the semantic remains unchanged.
If we need to compare jumps, we set STRUCT_EQUIV_MATCH_JUMPS in *MODE,
and pass *MODE to struct_equiv_init or assign it to INFO->mode, as
appropriate.
We may assume that there exists one edge with a common destination. */
static bool
outgoing_edges_match (int mode, basic_block bb1, basic_block bb2)
outgoing_edges_match (int *mode, struct equiv_info *info)
{
basic_block bb1 = info->y_block;
basic_block bb2 = info->x_block;
int nehedges1 = 0, nehedges2 = 0;
edge fallthru1 = 0, fallthru2 = 0;
edge e1, e2;
......@@ -1005,6 +1035,7 @@ outgoing_edges_match (int mode, basic_block bb1, basic_block bb2)
& (EDGE_COMPLEX | EDGE_FAKE)) == 0
&& (!JUMP_P (BB_END (bb2)) || simplejump_p (BB_END (bb2))));
*mode |= STRUCT_EQUIV_MATCH_JUMPS;
/* Match conditional jumps - this may get tricky when fallthru and branch
edges are crossed. */
if (EDGE_COUNT (bb1->succs) == 2
......@@ -1015,7 +1046,8 @@ outgoing_edges_match (int mode, basic_block bb1, basic_block bb2)
|| !any_condjump_p (BB_END (bb2))
|| !onlyjump_p (BB_END (bb2)))
return false;
return condjump_equiv_p (bb1, bb2);
info->mode = *mode;
return condjump_equiv_p (info, true);
}
/* Generic case - we are seeing a computed jump, table jump or trapping
......@@ -1063,31 +1095,22 @@ outgoing_edges_match (int mode, basic_block bb1, basic_block bb2)
identical = false;
}
if (identical)
if (identical
&& struct_equiv_init (STRUCT_EQUIV_START | *mode, info))
{
replace_label_data rr;
bool match;
/* Temporarily replace references to LABEL1 with LABEL2
/* Indicate that LABEL1 is to be replaced with LABEL2
in BB1->END so that we could compare the instructions. */
rr.r1 = label1;
rr.r2 = label2;
rr.update_label_nuses = false;
for_each_rtx (&BB_END (bb1), replace_label, &rr);
info->y_label = label1;
info->x_label = label2;
match = insns_match_p (mode, BB_END (bb1), BB_END (bb2));
match = insns_match_p (BB_END (bb1), BB_END (bb2), info);
if (dump_file && match)
fprintf (dump_file,
"Tablejumps in bb %i and %i match.\n",
bb1->index, bb2->index);
/* Set the original label in BB1->END because when deleting
a block whose end is a tablejump, the tablejump referenced
from the instruction is deleted too. */
rr.r1 = label2;
rr.r2 = label1;
for_each_rtx (&BB_END (bb1), replace_label, &rr);
return match;
}
}
......@@ -1097,7 +1120,8 @@ outgoing_edges_match (int mode, basic_block bb1, basic_block bb2)
/* First ensure that the instructions match. There may be many outgoing
edges so this test is generally cheaper. */
if (!insns_match_p (mode, BB_END (bb1), BB_END (bb2)))
if (!struct_equiv_init (STRUCT_EQUIV_START | *mode, info)
|| !insns_match_p (BB_END (bb1), BB_END (bb2), info))
return false;
/* Search the outgoing edges, ensure that the counts do match, find possible
......@@ -1163,14 +1187,13 @@ outgoing_edges_match (int mode, basic_block bb1, basic_block bb2)
static bool
try_crossjump_to_edge (int mode, edge e1, edge e2)
{
int nmatch;
int nmatch, i;
basic_block src1 = e1->src, src2 = e2->src;
basic_block redirect_to, redirect_from, to_remove;
rtx newpos1, newpos2;
edge s;
edge_iterator ei;
newpos1 = newpos2 = NULL_RTX;
struct equiv_info info;
rtx x_active, y_active;
/* If we have partitioned hot/cold basic blocks, it is a bad idea
to try this optimization.
......@@ -1217,19 +1240,66 @@ try_crossjump_to_edge (int mode, edge e1, edge e2)
return false;
/* Look for the common insn sequence, part the first ... */
if (!outgoing_edges_match (mode, src1, src2))
info.x_block = src2;
info.y_block = src1;
if (!outgoing_edges_match (&mode, &info))
return false;
/* ... and part the second. */
nmatch = flow_find_cross_jump (mode, src1, src2, &newpos1, &newpos2);
info.input_cost = optimize_size ? COSTS_N_INSNS (1) : -1;
nmatch = struct_equiv_block_eq (STRUCT_EQUIV_START | mode, &info);
/* Don't proceed with the crossjump unless we found a sufficient number
of matching instructions or the 'from' block was totally matched
(such that its predecessors will hopefully be redirected and the
block removed). */
if ((nmatch < PARAM_VALUE (PARAM_MIN_CROSSJUMP_INSNS))
&& (newpos1 != BB_HEAD (src1)))
if (!nmatch)
return false;
if ((nmatch -info.cur.input_count < PARAM_VALUE (PARAM_MIN_CROSSJUMP_INSNS))
&& (info.cur.y_start != BB_HEAD (src1)))
return false;
while (info.need_rerun)
{
nmatch = struct_equiv_block_eq (STRUCT_EQUIV_RERUN | mode, &info);
if (!nmatch)
return false;
if ((nmatch -info.cur.input_count < PARAM_VALUE (PARAM_MIN_CROSSJUMP_INSNS))
&& (info.cur.y_start != BB_HEAD (src1)))
return false;
}
nmatch = struct_equiv_block_eq (STRUCT_EQUIV_FINAL | mode, &info);
if ((nmatch -info.cur.input_count < PARAM_VALUE (PARAM_MIN_CROSSJUMP_INSNS))
&& (info.cur.y_start != BB_HEAD (src1)))
return false;
/* Skip possible basic block header. */
x_active = info.cur.x_start;
if (LABEL_P (x_active))
x_active = NEXT_INSN (x_active);
if (NOTE_P (x_active))
x_active = NEXT_INSN (x_active);
y_active = info.cur.y_start;
if (LABEL_P (y_active))
y_active = NEXT_INSN (y_active);
if (NOTE_P (y_active))
y_active = NEXT_INSN (y_active);
/* In order for this code to become active, either we have to be called
before reload, or struct_equiv_block_eq needs to add register scavenging
code to allocate input_reg after reload. */
if (info.input_reg)
{
emit_insn_before (gen_move_insn (info.input_reg, info.x_input),
x_active);
emit_insn_before (gen_move_insn (info.input_reg, info.y_input),
y_active);
}
for (i = 0; i < info.cur.local_count; i++)
if (info.local_rvalue[i])
emit_insn_before (gen_move_insn (info.x_local[i], info.y_local[i]),
y_active);
/* Here we know that the insns in the end of SRC1 which are common with SRC2
will be deleted.
......@@ -1265,30 +1335,36 @@ try_crossjump_to_edge (int mode, edge e1, edge e2)
/* Avoid splitting if possible. We must always split when SRC2 has
EH predecessor edges, or we may end up with basic blocks with both
normal and EH predecessor edges. */
if (newpos2 == BB_HEAD (src2)
if (info.cur.x_start == BB_HEAD (src2)
&& !(EDGE_PRED (src2, 0)->flags & EDGE_EH))
redirect_to = src2;
else
{
if (newpos2 == BB_HEAD (src2))
if (info.cur.x_start == BB_HEAD (src2))
{
/* Skip possible basic block header. */
if (LABEL_P (newpos2))
newpos2 = NEXT_INSN (newpos2);
if (NOTE_P (newpos2))
newpos2 = NEXT_INSN (newpos2);
if (LABEL_P (info.cur.x_start))
info.cur.x_start = NEXT_INSN (info.cur.x_start);
if (NOTE_P (info.cur.x_start))
info.cur.x_start = NEXT_INSN (info.cur.x_start);
}
if (dump_file)
fprintf (dump_file, "Splitting bb %i before %i insns\n",
src2->index, nmatch);
redirect_to = split_block (src2, PREV_INSN (newpos2))->dest;
redirect_to = split_block (src2, PREV_INSN (info.cur.x_start))->dest;
COPY_REG_SET (info.y_block->il.rtl->global_live_at_end,
info.x_block->il.rtl->global_live_at_end);
}
if (dump_file)
fprintf (dump_file,
"Cross jumping from bb %i to bb %i; %i common insns\n",
src1->index, src2->index, nmatch);
{
fprintf (dump_file, "Cross jumping from bb %i to bb %i; %i common insns",
src1->index, src2->index, nmatch);
if (info.cur.local_count)
fprintf (dump_file, ", %i local registers", info.cur.local_count);
fprintf (dump_file, "\n");
}
redirect_to->count += src1->count;
redirect_to->frequency += src1->frequency;
......@@ -1352,14 +1428,7 @@ try_crossjump_to_edge (int mode, edge e1, edge e2)
/* Edit SRC1 to go to REDIRECT_TO at NEWPOS1. */
/* Skip possible basic block header. */
if (LABEL_P (newpos1))
newpos1 = NEXT_INSN (newpos1);
if (NOTE_P (newpos1))
newpos1 = NEXT_INSN (newpos1);
redirect_from = split_block (src1, PREV_INSN (newpos1))->src;
redirect_from = split_block (src1, PREV_INSN (y_active))->src;
to_remove = single_succ (redirect_from);
redirect_edge_and_branch_force (single_succ_edge (redirect_from), redirect_to);
......
gcc/flow.c
......@@ -643,7 +643,8 @@ update_life_info (sbitmap blocks, enum update_life_extent extent,
/* If asked, remove notes from the blocks we'll update. */
if (extent == UPDATE_LIFE_GLOBAL_RM_NOTES)
count_or_remove_death_notes (blocks, 1);
count_or_remove_death_notes (blocks,
prop_flags & PROP_POST_REGSTACK ? -1 : 1);
}
/* Clear log links in case we are asked to (re)compute them. */
......@@ -2926,7 +2927,13 @@ mark_set_1 (struct propagate_block_info *pbi, enum rtx_code code, rtx reg, rtx c
if (flags & PROP_REG_INFO)
REG_N_DEATHS (regno_first) += 1;
if (flags & PROP_DEATH_NOTES)
if (flags & PROP_DEATH_NOTES
#ifdef STACK_REGS
&& (!(flags & PROP_POST_REGSTACK)
|| !IN_RANGE (REGNO (reg), FIRST_STACK_REG,
LAST_STACK_REG))
#endif
)
{
/* Note that dead stores have already been deleted
when possible. If we get here, we have found a
......@@ -2939,7 +2946,13 @@ mark_set_1 (struct propagate_block_info *pbi, enum rtx_code code, rtx reg, rtx c
}
else
{
if (flags & PROP_DEATH_NOTES)
if (flags & PROP_DEATH_NOTES
#ifdef STACK_REGS
&& (!(flags & PROP_POST_REGSTACK)
|| !IN_RANGE (REGNO (reg), FIRST_STACK_REG,
LAST_STACK_REG))
#endif
)
{
/* This is a case where we have a multi-word hard register
and some, but not all, of the words of the register are
......@@ -2998,7 +3011,12 @@ mark_set_1 (struct propagate_block_info *pbi, enum rtx_code code, rtx reg, rtx c
here and count it. */
else if (GET_CODE (reg) == SCRATCH)
{
if (flags & PROP_DEATH_NOTES)
if (flags & PROP_DEATH_NOTES
#ifdef STACK_REGS
&& (!(flags & PROP_POST_REGSTACK)
|| !IN_RANGE (REGNO (reg), FIRST_STACK_REG, LAST_STACK_REG))
#endif
)
REG_NOTES (insn)
= alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn));
}
......@@ -3764,6 +3782,10 @@ mark_used_reg (struct propagate_block_info *pbi, rtx reg,
if (! some_was_live)
{
if ((pbi->flags & PROP_DEATH_NOTES)
#ifdef STACK_REGS
&& (!(pbi->flags & PROP_POST_REGSTACK)
|| !IN_RANGE (REGNO (reg), FIRST_STACK_REG, LAST_STACK_REG))
#endif
&& ! find_regno_note (insn, REG_DEAD, regno_first))
REG_NOTES (insn)
= alloc_EXPR_LIST (REG_DEAD, reg, REG_NOTES (insn));
......@@ -4385,7 +4407,9 @@ struct tree_opt_pass pass_recompute_reg_usage =
/* Optionally removes all the REG_DEAD and REG_UNUSED notes from a set of
blocks. If BLOCKS is NULL, assume the universal set. Returns a count
of the number of registers that died. */
of the number of registers that died.
If KILL is 1, remove old REG_DEAD / REG_UNUSED notes. If it is 0, don't.
if it is -1, remove them unless they pertain to a stack reg. */
int
count_or_remove_death_notes (sbitmap blocks, int kill)
......@@ -4457,7 +4481,14 @@ count_or_remove_death_notes_bb (basic_block bb, int kill)
/* Fall through. */
case REG_UNUSED:
if (kill)
if (kill > 0
|| (kill
#ifdef STACK_REGS
&& (!REG_P (XEXP (link, 0))
|| !IN_RANGE (REGNO (XEXP (link, 0)),
FIRST_STACK_REG, LAST_STACK_REG))
#endif
))
{
rtx next = XEXP (link, 1);
free_EXPR_LIST_node (link);
......
gcc/recog.c
......@@ -339,7 +339,7 @@ num_changes_pending (void)
/* Tentatively apply the changes numbered NUM and up.
Return 1 if all changes are valid, zero otherwise. */
static int
int
verify_changes (int num)
{
int i;
......
gcc/recog.h
......@@ -76,6 +76,7 @@ extern int asm_operand_ok (rtx, const char *);
extern int validate_change (rtx, rtx *, rtx, int);
extern int validate_change_maybe_volatile (rtx, rtx *, rtx);
extern int insn_invalid_p (rtx);
extern int verify_changes (int);
extern void confirm_change_group (void);
extern int apply_change_group (void);
extern int num_validated_changes (void);
......
gcc/struct-equiv.c
......@@ -19,7 +19,60 @@ along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
/* This file contains helper functions for Cross jumping (tail merging). */
/* Try to match two basic blocks - or their ends - for structural equivalence.
We scan the blocks from their ends backwards, and expect that insns are
identical, except for certain cases involving registers. A mismatch
We scan the blocks from their ends backwards, hoping to find a match, I.e.
insns are identical, except for certain cases involving registers. A
mismatch between register number RX (used in block X) and RY (used in the
same way in block Y) can be handled in one of the following cases:
1. RX and RY are local to their respective blocks; they are set there and
die there. If so, they can effectively be ignored.
2. RX and RY die in their blocks, but live at the start. If any path
gets redirected through X instead of Y, the caller must emit
compensation code to move RY to RX. If there are overlapping inputs,
the function resolve_input_conflict ensures that this can be done.
Information about these registers are tracked in the X_LOCAL, Y_LOCAL,
LOCAL_COUNT and LOCAL_RVALUE fields.
3. RX and RY live throughout their blocks, including the start and the end.
Either RX and RY must be identical, or we have to replace all uses in
block X with a new pseudo, which is stored in the INPUT_REG field. The
caller can then use block X instead of block Y by copying RY to the new
pseudo.
The main entry point to this file is struct_equiv_block_eq. This function
uses a struct equiv_info to accept some of its inputs, to keep track of its
internal state, to pass down to its helper functions, and to communicate
some of the results back to the caller.
Most scans will result in a failure to match a sufficient number of insns
to make any optimization worth while, therefore the process is geared more
to quick scanning rather than the ability to exactly backtrack when we
find a mismatch. The information gathered is still meaningful to make a
preliminary decision if we want to do an optimization, we might only
slightly overestimate the number of matchable insns, and underestimate
the number of inputs an miss an input conflict. Sufficient information
is gathered so that when we make another pass, we won't have to backtrack
at the same point.
Another issue is that information in memory atttributes and/or REG_NOTES
might have to be merged or discarded to make a valid match. We don't want
to discard such information when we are not certain that we want to merge
the two (partial) blocks.
For these reasons, struct_equiv_block_eq has to be called first with the
STRUCT_EQUIV_START bit set in the mode parameter. This will calculate the
number of matched insns and the number and types of inputs. If the
need_rerun field is set, the results are only tentative, and the caller
has to call again with STRUCT_EQUIV_RERUN till need_rerun is false in
order to get a reliable match.
To install the changes necessary for the match, the function has to be
called again with STRUCT_EQUIV_FINAL.
While scanning an insn, we process first all the SET_DESTs, then the
SET_SRCes, then the REG_NOTES, in order to keep the register liveness
information consistent.
If we were to mix up the order for sources / destinations in an insn where
a source is also a destination, we'd end up being mistaken to think that
the register is not live in the preceding insn. */
#include "config.h"
#include "system.h"
......@@ -34,8 +87,26 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
#include "tm_p.h"
#include "target.h"
#include "emit-rtl.h"
#include "reload.h"
static void merge_memattrs (rtx, rtx);
static bool set_dest_equiv_p (rtx x, rtx y, struct equiv_info *info);
static bool set_dest_addr_equiv_p (rtx x, rtx y, struct equiv_info *info);
static void find_dying_inputs (struct equiv_info *info);
static bool resolve_input_conflict (struct equiv_info *info);
/* After reload, some moves, as indicated by SECONDARY_RELOAD_CLASS and
SECONDARY_MEMORY_NEEDED, cannot be done directly. For our purposes, we
consider them impossible to generate after reload (even though some
might be synthesized when you throw enough code at them).
Since we don't know while procesing a cross-jump if a local register
that is currently live will eventually be live and thus be an input,
we keep track of potential inputs that would require an impossible move
by using a prohibitively high cost for them.
This number, multiplied with the larger of STRUCT_EQUIV_MAX_LOCAL and
FIRST_PSEUDO_REGISTER, must fit in the input_cost field of
struct equiv_info. */
#define IMPOSSIBLE_MOVE_FACTOR 20000
......@@ -129,18 +200,638 @@ merge_memattrs (rtx x, rtx y)
return;
}
/* In SET, assign the bit for the register number of REG the value VALUE.
If REG is a hard register, do so for all its consituent registers.
Return the number of registers that have become included (as a positive
number) or excluded (as a negative number). */
static int
assign_reg_reg_set (regset set, rtx reg, int value)
{
unsigned regno = REGNO (reg);
int nregs, i, old;
if (regno >= FIRST_PSEUDO_REGISTER)
{
gcc_assert (!reload_completed);
nregs = 1;
}
else
nregs = hard_regno_nregs[regno][GET_MODE (reg)];
for (old = 0, i = nregs; --i >= 0; regno++)
{
if ((value != 0) == REGNO_REG_SET_P (set, regno))
continue;
if (value)
old++, SET_REGNO_REG_SET (set, regno);
else
old--, CLEAR_REGNO_REG_SET (set, regno);
}
return old;
}
/* Record state about current inputs / local registers / liveness
in *P. */
static inline void
struct_equiv_make_checkpoint (struct struct_equiv_checkpoint *p,
struct equiv_info *info)
{
*p = info->cur;
}
/* Call struct_equiv_make_checkpoint (P, INFO) if the current partial block
is suitable to split off - i.e. there is no dangling cc0 user - and
if the current cost of the common instructions, minus the cost for
setting up the inputs, is higher than what has been recorded before
in CHECKPOINT[N]. Also, if we do so, confirm or cancel any pending
changes. */
static void
struct_equiv_improve_checkpoint (struct struct_equiv_checkpoint *p,
struct equiv_info *info)
{
#ifdef HAVE_cc0
if (reg_mentioned_p (cc0_rtx, info->x_start) && !sets_cc0_p (info->x_start))
return;
#endif
if (info->cur.input_count >= IMPOSSIBLE_MOVE_FACTOR)
return;
if (info->input_cost >= 0
? (COSTS_N_INSNS(info->cur.ninsns - p->ninsns)
> info->input_cost * (info->cur.input_count - p->input_count))
: info->cur.ninsns > p->ninsns && !info->cur.input_count)
{
if (info->check_input_conflict && ! resolve_input_conflict (info))
return;
/* We have a profitable set of changes. If this is the final pass,
commit them now. Otherwise, we don't know yet if we can make any
change, so put the old code back for now. */
if (info->mode & STRUCT_EQUIV_FINAL)
confirm_change_group ();
else
cancel_changes (0);
struct_equiv_make_checkpoint (p, info);
}
}
/* Restore state about current inputs / local registers / liveness
from P. */
static void
struct_equiv_restore_checkpoint (struct struct_equiv_checkpoint *p,
struct equiv_info *info)
{
info->cur.ninsns = p->ninsns;
info->cur.x_start = p->x_start;
info->cur.y_start = p->y_start;
info->cur.input_count = p->input_count;
info->cur.input_valid = p->input_valid;
while (info->cur.local_count > p->local_count)
{
info->cur.local_count--;
info->cur.version--;
if (REGNO_REG_SET_P (info->x_local_live,
REGNO (info->x_local[info->cur.local_count])))
{
assign_reg_reg_set (info->x_local_live,
info->x_local[info->cur.local_count], 0);
assign_reg_reg_set (info->y_local_live,
info->y_local[info->cur.local_count], 0);
info->cur.version--;
}
}
if (info->cur.version != p->version)
info->need_rerun = true;
}
/* Update register liveness to reflect that X is now life (if rvalue is
nonzero) or dead (if rvalue is zero) in INFO->x_block, and likewise Y
in INFO->y_block. Return the number of registers the liveness of which
changed in each block (as a negative number if registers became dead). */
static int
note_local_live (struct equiv_info *info, rtx x, rtx y, int rvalue)
{
int x_change = assign_reg_reg_set (info->x_local_live, x, rvalue);
int y_change = assign_reg_reg_set (info->y_local_live, y, rvalue);
gcc_assert (x_change == y_change);
if (y_change)
{
if (reload_completed)
{
unsigned x_regno ATTRIBUTE_UNUSED = REGNO (x);
unsigned y_regno = REGNO (y);
enum machine_mode x_mode = GET_MODE (x);
if (secondary_reload_class (0, REGNO_REG_CLASS (y_regno), x_mode, x)
!= NO_REGS
#ifdef SECONDARY_MEMORY_NEEDED
|| SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (y_regno),
REGNO_REG_CLASS (x_regno), x_mode)
#endif
)
y_change *= IMPOSSIBLE_MOVE_FACTOR;
}
info->cur.input_count += y_change;
info->cur.version++;
}
return x_change;
}
/* Check if *XP is equivalent to Y. Until an an unreconcilable difference is
found, use in-group changes with validate_change on *XP to make register
assignments agree. It is the (not necessarily direct) callers
responsibility to verify / confirm / cancel these changes, as appropriate.
RVALUE indicates if the processed piece of rtl is used as a destination, in
which case we can't have different registers being an input. Returns
nonzero if the two blocks have been identified as equivalent, zero otherwise.
RVALUE == 0: destination
RVALUE == 1: source
RVALUE == -1: source, ignore SET_DEST of SET / clobber. */
bool
rtx_equiv_p (rtx *xp, rtx y, int rvalue, struct equiv_info *info)
{
rtx x = *xp;
enum rtx_code code;
int length;
const char *format;
int i;
if (!y || !x)
return x == y;
code = GET_CODE (y);
if (code != REG && x == y)
return true;
if (GET_CODE (x) != code
|| GET_MODE (x) != GET_MODE (y))
return false;
/* ??? could extend to allow CONST_INT inputs. */
switch (code)
{
case SUBREG:
gcc_assert (!reload_completed
|| !info->live_update);
break;
case REG:
{
unsigned x_regno = REGNO (x);
unsigned y_regno = REGNO (y);
int x_common_live, y_common_live;
if (reload_completed
&& (x_regno >= FIRST_PSEUDO_REGISTER
|| y_regno >= FIRST_PSEUDO_REGISTER))
{
/* We should only see this in REG_NOTEs. */
gcc_assert (!info->live_update);
/* Returning false will cause us to remove the notes. */
return false;
}
#ifdef STACK_REGS
/* After reg-stack, can only accept literal matches of stack regs. */
if (info->mode & CLEANUP_POST_REGSTACK
&& (IN_RANGE (x_regno, FIRST_STACK_REG, LAST_STACK_REG)
|| IN_RANGE (y_regno, FIRST_STACK_REG, LAST_STACK_REG)))
return x_regno == y_regno;
#endif
/* If the register is a locally live one in one block, the
corresponding one must be locally live in the other, too, and
match of identical regnos doesn't apply. */
if (REGNO_REG_SET_P (info->x_local_live, x_regno))
{
if (!REGNO_REG_SET_P (info->y_local_live, y_regno))
return false;
}
else if (REGNO_REG_SET_P (info->y_local_live, y_regno))
return false;
else if (x_regno == y_regno)
{
if (!rvalue && info->cur.input_valid
&& (reg_overlap_mentioned_p (x, info->x_input)
|| reg_overlap_mentioned_p (x, info->y_input)))
return false;
/* Update liveness information. */
if (info->live_update
&& assign_reg_reg_set (info->common_live, x, rvalue))
info->cur.version++;
return true;
}
x_common_live = REGNO_REG_SET_P (info->common_live, x_regno);
y_common_live = REGNO_REG_SET_P (info->common_live, y_regno);
if (x_common_live != y_common_live)
return false;
else if (x_common_live)
{
if (! rvalue || info->input_cost < 0 || no_new_pseudos)
return false;
/* If info->live_update is not set, we are processing notes.
We then allow a match with x_input / y_input found in a
previous pass. */
if (info->live_update && !info->cur.input_valid)
{
info->cur.input_valid = true;
info->x_input = x;
info->y_input = y;
info->cur.input_count += optimize_size ? 2 : 1;
if (info->input_reg
&& GET_MODE (info->input_reg) != GET_MODE (info->x_input))
info->input_reg = NULL_RTX;
if (!info->input_reg)
info->input_reg = gen_reg_rtx (GET_MODE (info->x_input));
}
else if ((info->live_update
? ! info->cur.input_valid : ! info->x_input)
|| ! rtx_equal_p (x, info->x_input)
|| ! rtx_equal_p (y, info->y_input))
return false;
validate_change (info->cur.x_start, xp, info->input_reg, 1);
}
else
{
int x_nregs = (x_regno >= FIRST_PSEUDO_REGISTER
? 1 : hard_regno_nregs[x_regno][GET_MODE (x)]);
int y_nregs = (y_regno >= FIRST_PSEUDO_REGISTER
? 1 : hard_regno_nregs[y_regno][GET_MODE (y)]);
int size = GET_MODE_SIZE (GET_MODE (x));
enum machine_mode x_mode = GET_MODE (x);
unsigned x_regno_i, y_regno_i;
int x_nregs_i, y_nregs_i, size_i;
int local_count = info->cur.local_count;
/* This might be a register local to each block. See if we have
it already registered. */
for (i = local_count - 1; i >= 0; i--)
{
x_regno_i = REGNO (info->x_local[i]);
x_nregs_i = (x_regno_i >= FIRST_PSEUDO_REGISTER
? 1 : hard_regno_nregs[x_regno_i][GET_MODE (x)]);
y_regno_i = REGNO (info->y_local[i]);
y_nregs_i = (y_regno_i >= FIRST_PSEUDO_REGISTER
? 1 : hard_regno_nregs[y_regno_i][GET_MODE (y)]);
size_i = GET_MODE_SIZE (GET_MODE (info->x_local[i]));
/* If we have a new pair of registers that is wider than an
old pair and enclosing it with matching offsets,
remove the old pair. If we find a matching, wider, old
pair, use the old one. If the width is the same, use the
old one if the modes match, but the new if they don't.
We don't want to get too fancy with subreg_regno_offset
here, so we just test two straightforwad cases each. */
if (info->live_update
&& (x_mode != GET_MODE (info->x_local[i])
? size >= size_i : size > size_i))
{
/* If the new pair is fully enclosing a matching
existing pair, remove the old one. N.B. because
we are removing one entry here, the check below
if we have space for a new entry will succeed. */
if ((x_regno <= x_regno_i
&& x_regno + x_nregs >= x_regno_i + x_nregs_i
&& x_nregs == y_nregs && x_nregs_i == y_nregs_i
&& x_regno - x_regno_i == y_regno - y_regno_i)
|| (x_regno == x_regno_i && y_regno == y_regno_i
&& x_nregs >= x_nregs_i && y_nregs >= y_nregs_i))
{
info->cur.local_count = --local_count;
info->x_local[i] = info->x_local[local_count];
info->y_local[i] = info->y_local[local_count];
continue;
}
}
else
{
/* If the new pair is fully enclosed within a matching
existing pair, succeed. */
if (x_regno >= x_regno_i
&& x_regno + x_nregs <= x_regno_i + x_nregs_i
&& x_nregs == y_nregs && x_nregs_i == y_nregs_i
&& x_regno - x_regno_i == y_regno - y_regno_i)
break;
if (x_regno == x_regno_i && y_regno == y_regno_i
&& x_nregs <= x_nregs_i && y_nregs <= y_nregs_i)
break;
}
/* Any other overlap causes a match failure. */
if (x_regno + x_nregs > x_regno_i
&& x_regno_i + x_nregs_i > x_regno)
return false;
if (y_regno + y_nregs > y_regno_i
&& y_regno_i + y_nregs_i > y_regno)
return false;
}
if (i < 0)
{
/* Not found. Create a new entry if possible. */
if (!info->live_update
|| info->cur.local_count >= STRUCT_EQUIV_MAX_LOCAL)
return false;
info->x_local[info->cur.local_count] = x;
info->y_local[info->cur.local_count] = y;
info->cur.local_count++;
info->cur.version++;
}
note_local_live (info, x, y, rvalue);
}
return true;
}
case SET:
gcc_assert (rvalue < 0);
/* Ignore the destinations role as a destination. Still, we have
to consider input registers embedded in the addresses of a MEM.
N.B., we process the rvalue aspect of STRICT_LOW_PART /
ZERO_EXTEND / SIGN_EXTEND along with their lvalue aspect. */
if(!set_dest_addr_equiv_p (SET_DEST (x), SET_DEST (y), info))
return false;
/* Process source. */
return rtx_equiv_p (&SET_SRC (x), SET_SRC (y), 1, info);
case PRE_MODIFY:
/* Process destination. */
if (!rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 0, info))
return false;
/* Process source. */
return rtx_equiv_p (&XEXP (x, 1), XEXP (y, 1), 1, info);
case POST_MODIFY:
{
rtx x_dest0, x_dest1;
/* Process destination. */
x_dest0 = XEXP (x, 0);
gcc_assert (REG_P (x_dest0));
if (!rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 0, info))
return false;
x_dest1 = XEXP (x, 0);
/* validate_change might have changed the destination. Put it back
so that we can do a valid source match. */
XEXP (x, 0) = x_dest0;
if (!rtx_equiv_p (&XEXP (x, 1), XEXP (y, 1), 0, info))
return false;
gcc_assert (x_dest1 == XEXP (x, 0));
/* Process source. */
return rtx_equiv_p (&XEXP (x, 1), XEXP (y, 1), 1, info);
if (!rtx_equiv_p (&XEXP(x, 0), XEXP (y, 0), 0, info))
return false;
/* Process both subexpressions as inputs. */
break;
}
case CLOBBER:
gcc_assert (rvalue < 0);
return true;
/* Some special forms are also rvalues when they appear in lvalue
positions. However, we must ont try to match a register after we
have already altered it with validate_change, consider the rvalue
aspect while we process the lvalue. */
case STRICT_LOW_PART:
case ZERO_EXTEND:
case SIGN_EXTEND:
{
rtx x_inner, y_inner;
enum rtx_code code;
int change;
if (rvalue)
break;
x_inner = XEXP (x, 0);
y_inner = XEXP (y, 0);
if (GET_MODE (x_inner) != GET_MODE (y_inner))
return false;
code = GET_CODE (x_inner);
if (code != GET_CODE (y_inner))
return false;
/* The address of a MEM is an input that will be processed during
rvalue == -1 processing. */
if (code == SUBREG)
{
if (SUBREG_BYTE (x_inner) != SUBREG_BYTE (y_inner))
return false;
x = x_inner;
x_inner = SUBREG_REG (x_inner);
y_inner = SUBREG_REG (y_inner);
if (GET_MODE (x_inner) != GET_MODE (y_inner))
return false;
code = GET_CODE (x_inner);
if (code != GET_CODE (y_inner))
return false;
}
if (code == MEM)
return true;
gcc_assert (code == REG);
if (! rtx_equiv_p (&XEXP (x, 0), y_inner, rvalue, info))
return false;
if (REGNO (x_inner) == REGNO (y_inner))
{
change = assign_reg_reg_set (info->common_live, x_inner, 1);
info->cur.version++;
}
else
change = note_local_live (info, x_inner, y_inner, 1);
gcc_assert (change);
return true;
}
/* The AUTO_INC / POST_MODIFY / PRE_MODIFY sets are modelled to take
place during input processing, however, that is benign, since they
are paired with reads. */
case MEM:
return !rvalue || rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), rvalue, info);
case POST_INC: case POST_DEC: case PRE_INC: case PRE_DEC:
return (rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 0, info)
&& rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 1, info));
case PARALLEL:
gcc_assert (rvalue < 0);
break;
case LABEL_REF:
/* Check special tablejump match case. */
if (XEXP (y, 0) == info->y_label)
return (XEXP (x, 0) == info->x_label);
/* We can't assume nonlocal labels have their following insns yet. */
if (LABEL_REF_NONLOCAL_P (x) || LABEL_REF_NONLOCAL_P (y))
return XEXP (x, 0) == XEXP (y, 0);
/* Two label-refs are equivalent if they point at labels
in the same position in the instruction stream. */
return (next_real_insn (XEXP (x, 0))
== next_real_insn (XEXP (y, 0)));
case SYMBOL_REF:
return XSTR (x, 0) == XSTR (y, 0);
/* Some rtl is guaranteed to be shared, or unique; If we didn't match
EQ equality above, they aren't the same. */
case CONST_INT:
case CODE_LABEL:
return false;
default:
break;
}
/* For commutative operations, the RTX match if the operands match in any
order. */
if (targetm.commutative_p (x, UNKNOWN))
return ((rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), rvalue, info)
&& rtx_equiv_p (&XEXP (x, 1), XEXP (y, 1), rvalue, info))
|| (rtx_equiv_p (&XEXP (x, 0), XEXP (y, 1), rvalue, info)
&& rtx_equiv_p (&XEXP (x, 1), XEXP (y, 0), rvalue, info)));
/* Process subexpressions - this is similar to rtx_equal_p. */
length = GET_RTX_LENGTH (code);
format = GET_RTX_FORMAT (code);
for (i = 0; i < length; ++i)
{
switch (format[i])
{
case 'w':
if (XWINT (x, i) != XWINT (y, i))
return false;
break;
case 'n':
case 'i':
if (XINT (x, i) != XINT (y, i))
return false;
break;
case 'V':
case 'E':
if (XVECLEN (x, i) != XVECLEN (y, i))
return false;
if (XVEC (x, i) != 0)
{
int j;
for (j = 0; j < XVECLEN (x, i); ++j)
{
if (! rtx_equiv_p (&XVECEXP (x, i, j), XVECEXP (y, i, j),
rvalue, info))
return false;
}
}
break;
case 'e':
if (! rtx_equiv_p (&XEXP (x, i), XEXP (y, i), rvalue, info))
return false;
break;
case 'S':
case 's':
if ((XSTR (x, i) || XSTR (y, i))
&& (! XSTR (x, i) || ! XSTR (y, i)
|| strcmp (XSTR (x, i), XSTR (y, i))))
return false;
break;
case 'u':
/* These are just backpointers, so they don't matter. */
break;
case '0':
case 't':
break;
/* It is believed that rtx's at this level will never
contain anything but integers and other rtx's,
except for within LABEL_REFs and SYMBOL_REFs. */
default:
gcc_unreachable ();
}
}
return true;
}
/* Do only the rtx_equiv_p SET_DEST processing for SETs and CLOBBERs.
Since we are scanning backwards, this the first step in processing each
insn. Return true for success. */
static bool
set_dest_equiv_p (rtx x, rtx y, struct equiv_info *info)
{
if (!x || !y)
return x == y;
if (GET_CODE (x) != GET_CODE (y))
return false;
else if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
return rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 0, info);
else if (GET_CODE (x) == PARALLEL)
{
int j;
if (XVECLEN (x, 0) != XVECLEN (y, 0))
return false;
for (j = 0; j < XVECLEN (x, 0); ++j)
{
rtx xe = XVECEXP (x, 0, j);
rtx ye = XVECEXP (y, 0, j);
if (GET_CODE (xe) != GET_CODE (ye))
return false;
if ((GET_CODE (xe) == SET || GET_CODE (xe) == CLOBBER)
&& ! rtx_equiv_p (&XEXP (xe, 0), XEXP (ye, 0), 0, info))
return false;
}
}
return true;
}
/* Process MEMs in SET_DEST destinations. We must not process this together
with REG SET_DESTs, but must do it separately, lest when we see
[(set (reg:SI foo) (bar))
(set (mem:SI (reg:SI foo) (baz)))]
struct_equiv_block_eq could get confused to assume that (reg:SI foo)
is not live before this instruction. */
static bool
set_dest_addr_equiv_p (rtx x, rtx y, struct equiv_info *info)
{
enum rtx_code code = GET_CODE (x);
int length;
const char *format;
int i;
if (code != GET_CODE (y))
return false;
if (code == MEM)
return rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 1, info);
/* Process subexpressions. */
length = GET_RTX_LENGTH (code);
format = GET_RTX_FORMAT (code);
for (i = 0; i < length; ++i)
{
switch (format[i])
{
case 'V':
case 'E':
if (XVECLEN (x, i) != XVECLEN (y, i))
return false;
if (XVEC (x, i) != 0)
{
int j;
for (j = 0; j < XVECLEN (x, i); ++j)
{
if (! set_dest_addr_equiv_p (XVECEXP (x, i, j),
XVECEXP (y, i, j), info))
return false;
}
}
break;
case 'e':
if (! set_dest_addr_equiv_p (XEXP (x, i), XEXP (y, i), info))
return false;
break;
default:
break;
}
}
return true;
}
/* Check if the set of REG_DEAD notes attached to I1 and I2 allows us to
go ahead with merging I1 and I2, which otherwise look fine. */
go ahead with merging I1 and I2, which otherwise look fine.
Inputs / local registers for the inputs of I1 and I2 have already been
set up. */
static bool
death_notes_match_p (rtx i1 ATTRIBUTE_UNUSED, rtx i2 ATTRIBUTE_UNUSED,
int mode ATTRIBUTE_UNUSED)
struct equiv_info *info ATTRIBUTE_UNUSED)
{
#ifdef STACK_REGS
/* If cross_jump_death_matters is not 0, the insn's mode
indicates whether or not the insn contains any stack-like
regs. */
indicates whether or not the insn contains any stack-like regs. */
if ((mode & CLEANUP_POST_REGSTACK) && stack_regs_mentioned (i1))
if ((info->mode & CLEANUP_POST_REGSTACK) && stack_regs_mentioned (i1))
{
/* If register stack conversion has already been done, then
death notes must also be compared before it is certain that
......@@ -158,7 +849,18 @@ death_notes_match_p (rtx i1 ATTRIBUTE_UNUSED, rtx i2 ATTRIBUTE_UNUSED,
for (note = REG_NOTES (i2); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_DEAD && STACK_REG_P (XEXP (note, 0)))
SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0)));
{
unsigned regno = REGNO (XEXP (note, 0));
int i;
for (i = info->cur.local_count - 1; i >= 0; i--)
if (regno == REGNO (info->y_local[i]))
{
regno = REGNO (info->x_local[i]);
break;
}
SET_HARD_REG_BIT (i2_regset, regno);
}
GO_IF_HARD_REG_EQUAL (i1_regset, i2_regset, done);
......@@ -174,19 +876,17 @@ death_notes_match_p (rtx i1 ATTRIBUTE_UNUSED, rtx i2 ATTRIBUTE_UNUSED,
/* Return true if I1 and I2 are equivalent and thus can be crossjumped. */
bool
insns_match_p (int mode, rtx i1, rtx i2)
insns_match_p (rtx i1, rtx i2, struct equiv_info *info)
{
rtx p1, p2;
int rvalue_change_start;
struct struct_equiv_checkpoint before_rvalue_change;
/* Verify that I1 and I2 are equivalent. */
if (GET_CODE (i1) != GET_CODE (i2))
return false;
p1 = PATTERN (i1);
p2 = PATTERN (i2);
if (GET_CODE (p1) != GET_CODE (p2))
return false;
info->cur.x_start = i1;
info->cur.y_start = i2;
/* If this is a CALL_INSN, compare register usage information.
If we don't check this on stack register machines, the two
......@@ -198,17 +898,36 @@ insns_match_p (int mode, rtx i1, rtx i2)
??? We take the simple route for now and assume that if they're
equal, they were constructed identically. */
if (CALL_P (i1)
&& (!rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1),
CALL_INSN_FUNCTION_USAGE (i2))
|| SIBLING_CALL_P (i1) != SIBLING_CALL_P (i2)))
return false;
if (!death_notes_match_p (i1, i2, mode))
return false;
if (reload_completed
? rtx_renumbered_equal_p (p1, p2) : rtx_equal_p (p1, p2))
if (CALL_P (i1))
{
if (SIBLING_CALL_P (i1) != SIBLING_CALL_P (i2)
|| ! set_dest_equiv_p (PATTERN (i1), PATTERN (i2), info)
|| ! set_dest_equiv_p (CALL_INSN_FUNCTION_USAGE (i1),
CALL_INSN_FUNCTION_USAGE (i2), info)
|| ! rtx_equiv_p (&CALL_INSN_FUNCTION_USAGE (i1),
CALL_INSN_FUNCTION_USAGE (i2), -1, info))
{
cancel_changes (0);
return false;
}
}
else if (INSN_P (i1))
{
if (! set_dest_equiv_p (PATTERN (i1), PATTERN (i2), info))
{
cancel_changes (0);
return false;
}
}
rvalue_change_start = num_validated_changes ();
struct_equiv_make_checkpoint (&before_rvalue_change, info);
/* Check death_notes_match_p *after* the inputs have been processed,
so that local inputs will already have been set up. */
if (! INSN_P (i1)
|| (!bitmap_bit_p (info->equiv_used, info->cur.ninsns)
&& rtx_equiv_p (&PATTERN (i1), PATTERN (i2), -1, info)
&& death_notes_match_p (i1, i2, info)
&& verify_changes (0)))
return true;
/* Do not do EQUIV substitution after reload. First, we're undoing the
......@@ -218,10 +937,14 @@ insns_match_p (int mode, rtx i1, rtx i2)
targets to disallow the troublesome insns after splitting. */
if (!reload_completed)
{
/* The following code helps take care of G++ cleanups. */
rtx equiv1 = find_reg_equal_equiv_note (i1);
rtx equiv2 = find_reg_equal_equiv_note (i2);
rtx equiv1, equiv2;
cancel_changes (rvalue_change_start);
struct_equiv_restore_checkpoint (&before_rvalue_change, info);
/* The following code helps take care of G++ cleanups. */
equiv1 = find_reg_equal_equiv_note (i1);
equiv2 = find_reg_equal_equiv_note (i2);
if (equiv1 && equiv2
/* If the equivalences are not to a constant, they may
reference pseudos that no longer exist, so we can't
......@@ -232,131 +955,390 @@ insns_match_p (int mode, rtx i1, rtx i2)
{
rtx s1 = single_set (i1);
rtx s2 = single_set (i2);
if (s1 != 0 && s2 != 0
&& rtx_renumbered_equal_p (SET_DEST (s1), SET_DEST (s2)))
if (s1 != 0 && s2 != 0)
{
validate_change (i1, &SET_SRC (s1), XEXP (equiv1, 0), 1);
validate_change (i2, &SET_SRC (s2), XEXP (equiv2, 0), 1);
if (! rtx_renumbered_equal_p (p1, p2))
cancel_changes (0);
else if (apply_change_group ())
return true;
/* Only inspecting the new SET_SRC is not good enough,
because there may also be bare USEs in a single_set
PARALLEL. */
if (rtx_equiv_p (&PATTERN (i1), PATTERN (i2), -1, info)
&& death_notes_match_p (i1, i2, info)
&& verify_changes (0))
{
/* Mark this insn so that we'll use the equivalence in
all subsequent passes. */
bitmap_set_bit (info->equiv_used, info->cur.ninsns);
return true;
}
}
}
}
cancel_changes (0);
return false;
}
/* Look through the insns at the end of BB1 and BB2 and find the longest
sequence that are equivalent. Store the first insns for that sequence
in *F1 and *F2 and return the sequence length.
To simplify callers of this function, if the blocks match exactly,
store the head of the blocks in *F1 and *F2. */
/* Set up mode and register information in INFO. Return true for success. */
bool
struct_equiv_init (int mode, struct equiv_info *info)
{
if ((info->x_block->flags | info->y_block->flags) & BB_DIRTY)
update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES,
(PROP_DEATH_NOTES
| ((mode & CLEANUP_POST_REGSTACK)
? PROP_POST_REGSTACK : 0)));
if (!REG_SET_EQUAL_P (info->x_block->il.rtl->global_live_at_end,
info->y_block->il.rtl->global_live_at_end))
{
#ifdef STACK_REGS
unsigned rn;
if (!(mode & CLEANUP_POST_REGSTACK))
return false;
/* After reg-stack. Remove bogus live info about stack regs. N.B.
these regs are not necessarily all dead - we swap random bogosity
against constant bogosity. However, clearing these bits at
least makes the regsets comparable. */
for (rn = FIRST_STACK_REG; rn < LAST_STACK_REG; rn++)
{
CLEAR_REGNO_REG_SET (info->x_block->il.rtl->global_live_at_end, rn);
CLEAR_REGNO_REG_SET (info->y_block->il.rtl->global_live_at_end, rn);
}
if (!REG_SET_EQUAL_P (info->x_block->il.rtl->global_live_at_end,
info->y_block->il.rtl->global_live_at_end))
#endif
return false;
}
info->mode = mode;
if (mode & STRUCT_EQUIV_START)
{
info->x_input = info->y_input = info->input_reg = NULL_RTX;
info->equiv_used = ALLOC_REG_SET (&reg_obstack);
info->check_input_conflict = false;
}
info->had_input_conflict = false;
info->cur.ninsns = info->cur.version = 0;
info->cur.local_count = info->cur.input_count = 0;
info->cur.x_start = info->cur.y_start = NULL_RTX;
info->x_label = info->y_label = NULL_RTX;
info->need_rerun = false;
info->live_update = true;
info->cur.input_valid = false;
info->common_live = ALLOC_REG_SET (&reg_obstack);
info->x_local_live = ALLOC_REG_SET (&reg_obstack);
info->y_local_live = ALLOC_REG_SET (&reg_obstack);
COPY_REG_SET (info->common_live, info->x_block->il.rtl->global_live_at_end);
struct_equiv_make_checkpoint (&info->best_match, info);
return true;
}
/* Insns XI and YI have been matched. Merge memory attributes and reg
notes. */
static void
struct_equiv_merge (rtx xi, rtx yi, struct equiv_info *info)
{
rtx equiv1, equiv2;
merge_memattrs (xi, yi);
/* If the merged insns have different REG_EQUAL notes, then
remove them. */
info->live_update = false;
equiv1 = find_reg_equal_equiv_note (xi);
equiv2 = find_reg_equal_equiv_note (yi);
if (equiv1 && !equiv2)
remove_note (xi, equiv1);
else if (!equiv1 && equiv2)
remove_note (yi, equiv2);
else if (equiv1 && equiv2
&& !rtx_equiv_p (&XEXP (equiv1, 0), XEXP (equiv2, 0),
1, info))
{
remove_note (xi, equiv1);
remove_note (yi, equiv2);
}
info->live_update = true;
}
/* Return number of matched insns.
This function must be called up to three times for a successful cross-jump
match:
first to find out which instructions do match. While trying to match
another instruction that doesn't match, we destroy information in info
about the actual inputs. So if there have been any before the last
match attempt, we need to call this function again to recompute the
actual inputs up to the actual start of the matching sequence.
When we are then satisfied that the cross-jump is worthwhile, we
call this function a third time to make any changes needed to make the
sequences match: apply equivalences, remove non-matching
notes and merge memory attributes. */
int
flow_find_cross_jump (int mode ATTRIBUTE_UNUSED, basic_block bb1,
basic_block bb2, rtx *f1, rtx *f2)
struct_equiv_block_eq (int mode, struct equiv_info *info)
{
rtx i1, i2, last1, last2, afterlast1, afterlast2;
int ninsns = 0;
rtx x_stop, y_stop;
rtx xi, yi;
int i;
if (mode & STRUCT_EQUIV_START)
{
x_stop = BB_HEAD (info->x_block);
y_stop = BB_HEAD (info->y_block);
if (!x_stop || !y_stop)
return 0;
}
else
{
x_stop = info->cur.x_start;
y_stop = info->cur.y_start;
}
if (!struct_equiv_init (mode, info))
gcc_unreachable ();
/* Skip simple jumps at the end of the blocks. Complex jumps still
need to be compared for equivalence, which we'll do below. */
i1 = BB_END (bb1);
last1 = afterlast1 = last2 = afterlast2 = NULL_RTX;
if (onlyjump_p (i1)
|| (returnjump_p (i1) && !side_effects_p (PATTERN (i1))))
xi = BB_END (info->x_block);
if (onlyjump_p (xi)
|| (returnjump_p (xi) && !side_effects_p (PATTERN (xi))))
{
last1 = i1;
i1 = PREV_INSN (i1);
info->cur.x_start = xi;
xi = PREV_INSN (xi);
}
i2 = BB_END (bb2);
if (onlyjump_p (i2)
|| (returnjump_p (i2) && !side_effects_p (PATTERN (i2))))
yi = BB_END (info->y_block);
if (onlyjump_p (yi)
|| (returnjump_p (yi) && !side_effects_p (PATTERN (yi))))
{
last2 = i2;
info->cur.y_start = yi;
/* Count everything except for unconditional jump as insn. */
if (!simplejump_p (i2) && !returnjump_p (i2) && last1)
ninsns++;
i2 = PREV_INSN (i2);
/* ??? Is it right to count unconditional jumps with a clobber?
Should we count conditional returns? */
if (!simplejump_p (yi) && !returnjump_p (yi) && info->cur.x_start)
info->cur.ninsns++;
yi = PREV_INSN (yi);
}
while (true)
if (mode & STRUCT_EQUIV_MATCH_JUMPS)
{
/* Ignore notes. */
while (!INSN_P (i1) && i1 != BB_HEAD (bb1))
i1 = PREV_INSN (i1);
/* The caller is expected to have comapred the jumps already, but we
need to match them again to get any local registers and inputs. */
gcc_assert (!info->cur.x_start == !info->cur.y_start);
if (info->cur.x_start)
{
if (any_condjump_p (info->cur.x_start)
? !condjump_equiv_p (info, false)
: !insns_match_p (info->cur.x_start, info->cur.y_start, info))
gcc_unreachable ();
}
else if (any_condjump_p (xi) && any_condjump_p (yi))
{
info->cur.x_start = xi;
info->cur.y_start = yi;
xi = PREV_INSN (xi);
yi = PREV_INSN (yi);
info->cur.ninsns++;
if (!condjump_equiv_p (info, false))
gcc_unreachable ();
}
if (info->cur.x_start && info->mode & STRUCT_EQUIV_FINAL)
struct_equiv_merge (info->cur.x_start, info->cur.y_start, info);
}
while (!INSN_P (i2) && i2 != BB_HEAD (bb2))
i2 = PREV_INSN (i2);
struct_equiv_improve_checkpoint (&info->best_match, info);
info->x_end = xi;
info->y_end = yi;
if (info->cur.x_start != x_stop)
for (;;)
{
/* Ignore notes. */
while (!INSN_P (xi) && xi != x_stop)
xi = PREV_INSN (xi);
if (i1 == BB_HEAD (bb1) || i2 == BB_HEAD (bb2))
break;
while (!INSN_P (yi) && yi != y_stop)
yi = PREV_INSN (yi);
if (!insns_match_p (xi, yi, info))
break;
if (INSN_P (xi))
{
if (info->mode & STRUCT_EQUIV_FINAL)
struct_equiv_merge (xi, yi, info);
info->cur.ninsns++;
struct_equiv_improve_checkpoint (&info->best_match, info);
}
if (xi == x_stop || yi == y_stop)
{
/* If we reached the start of at least one of the blocks, but
best_match hasn't been advanced back to the first valid insn
yet, represent the increased benefit of completing the block
as an increased instruction count. */
if (info->best_match.x_start != info->cur.x_start
&& (xi == BB_HEAD (info->x_block)
|| yi == BB_HEAD (info->y_block)))
{
info->cur.ninsns++;
struct_equiv_improve_checkpoint (&info->best_match, info);
info->cur.ninsns--;
if (info->best_match.ninsns > info->cur.ninsns)
info->best_match.ninsns = info->cur.ninsns;
}
break;
}
xi = PREV_INSN (xi);
yi = PREV_INSN (yi);
}
/* If we failed to match an insn, but had some changes registered from
trying to make the insns match, we need to cancel these changes now. */
cancel_changes (0);
/* Restore to best_match to get the sequence with the best known-so-far
cost-benefit difference. */
struct_equiv_restore_checkpoint (&info->best_match, info);
/* Include preceding notes and labels in the cross-jump / if-conversion.
One, this may bring us to the head of the blocks.
Two, it keeps line number notes as matched as may be. */
if (info->cur.ninsns)
{
xi = info->cur.x_start;
yi = info->cur.y_start;
while (xi != x_stop && !INSN_P (PREV_INSN (xi)))
xi = PREV_INSN (xi);
if (!insns_match_p (mode, i1, i2))
break;
while (yi != y_stop && !INSN_P (PREV_INSN (yi)))
yi = PREV_INSN (yi);
merge_memattrs (i1, i2);
info->cur.x_start = xi;
info->cur.y_start = yi;
}
/* Don't begin a cross-jump with a NOTE insn. */
if (INSN_P (i1))
if (!info->cur.input_valid)
info->x_input = info->y_input = info->input_reg = NULL_RTX;
if (!info->need_rerun)
{
find_dying_inputs (info);
if (info->mode & STRUCT_EQUIV_FINAL)
{
if (info->check_input_conflict && ! resolve_input_conflict (info))
gcc_unreachable ();
}
else
{
/* If the merged insns have different REG_EQUAL notes, then
remove them. */
rtx equiv1 = find_reg_equal_equiv_note (i1);
rtx equiv2 = find_reg_equal_equiv_note (i2);
if (equiv1 && !equiv2)
remove_note (i1, equiv1);
else if (!equiv1 && equiv2)
remove_note (i2, equiv2);
else if (equiv1 && equiv2
&& !rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0)))
bool input_conflict = info->had_input_conflict;
if (!input_conflict
&& info->dying_inputs > 1
&& bitmap_intersect_p (info->x_local_live, info->y_local_live))
{
remove_note (i1, equiv1);
remove_note (i2, equiv2);
regset_head clobbered_regs;
INIT_REG_SET (&clobbered_regs);
for (i = 0; i < info->cur.local_count; i++)
{
if (assign_reg_reg_set (&clobbered_regs, info->y_local[i], 0))
{
input_conflict = true;
break;
}
assign_reg_reg_set (&clobbered_regs, info->x_local[i], 1);
}
CLEAR_REG_SET (&clobbered_regs);
}
afterlast1 = last1, afterlast2 = last2;
last1 = i1, last2 = i2;
ninsns++;
if (input_conflict && !info->check_input_conflict)
info->need_rerun = true;
info->check_input_conflict = input_conflict;
}
i1 = PREV_INSN (i1);
i2 = PREV_INSN (i2);
}
#ifdef HAVE_cc0
/* Don't allow the insn after a compare to be shared by
cross-jumping unless the compare is also shared. */
if (ninsns && reg_mentioned_p (cc0_rtx, last1) && ! sets_cc0_p (last1))
last1 = afterlast1, last2 = afterlast2, ninsns--;
#endif
if (info->mode & STRUCT_EQUIV_NEED_FULL_BLOCK
&& (info->cur.x_start != x_stop || info->cur.y_start != y_stop))
return 0;
return info->cur.ninsns;
}
/* Include preceding notes and labels in the cross-jump. One,
this may bring us to the head of the blocks as requested above.
Two, it keeps line number notes as matched as may be. */
if (ninsns)
{
while (last1 != BB_HEAD (bb1) && !INSN_P (PREV_INSN (last1)))
last1 = PREV_INSN (last1);
/* For each local register, set info->local_rvalue to true iff the register
is a dying input. Store the total number of these in info->dying_inputs. */
static void
find_dying_inputs (struct equiv_info *info)
{
int i;
if (last1 != BB_HEAD (bb1) && LABEL_P (PREV_INSN (last1)))
last1 = PREV_INSN (last1);
info->dying_inputs = 0;
for (i = info->cur.local_count-1; i >=0; i--)
{
rtx x = info->x_local[i];
unsigned regno = REGNO (x);
int nregs = (regno >= FIRST_PSEUDO_REGISTER
? 1 : hard_regno_nregs[regno][GET_MODE (x)]);
for (info->local_rvalue[i] = false; nregs >= 0; regno++, --nregs)
if (REGNO_REG_SET_P (info->x_local_live, regno))
{
info->dying_inputs++;
info->local_rvalue[i] = true;
break;
}
}
}
while (last2 != BB_HEAD (bb2) && !INSN_P (PREV_INSN (last2)))
last2 = PREV_INSN (last2);
/* For each local register that is a dying input, y_local[i] will be
copied to x_local[i]. We'll do this in ascending order. Try to
re-order the locals to avoid conflicts like r3 = r2; r4 = r3; .
Return true iff the re-ordering is successful, or not necessary. */
static bool
resolve_input_conflict (struct equiv_info *info)
{
int i, j, end;
int nswaps = 0;
rtx save_x_local[STRUCT_EQUIV_MAX_LOCAL];
rtx save_y_local[STRUCT_EQUIV_MAX_LOCAL];
if (last2 != BB_HEAD (bb2) && LABEL_P (PREV_INSN (last2)))
last2 = PREV_INSN (last2);
find_dying_inputs (info);
if (info->dying_inputs <= 1)
return true;
memcpy (save_x_local, info->x_local, sizeof save_x_local);
memcpy (save_y_local, info->y_local, sizeof save_y_local);
end = info->cur.local_count - 1;
for (i = 0; i <= end; i++)
{
/* Cycle detection with regsets is expensive, so we just check that
we don't exceed the maximum number of swaps needed in the acyclic
case. */
int max_swaps = end - i;
/* Check if x_local[i] will be clobbered. */
if (!info->local_rvalue[i])
continue;
/* Check if any later value needs to be copied earlier. */
for (j = i + 1; j <= end; j++)
{
rtx tmp;
*f1 = last1;
*f2 = last2;
if (!info->local_rvalue[j])
continue;
if (!reg_overlap_mentioned_p (info->x_local[i], info->y_local[j]))
continue;
if (--max_swaps < 0)
{
memcpy (info->x_local, save_x_local, sizeof save_x_local);
memcpy (info->y_local, save_y_local, sizeof save_y_local);
return false;
}
nswaps++;
tmp = info->x_local[i];
info->x_local[i] = info->x_local[j];
info->x_local[j] = tmp;
tmp = info->y_local[i];
info->y_local[i] = info->y_local[j];
info->y_local[j] = tmp;
j = i;
}
}
return ninsns;
info->had_input_conflict = true;
if (dump_file && nswaps)
fprintf (dump_file, "Resolved input conflict, %d %s.\n",
nswaps, nswaps == 1 ? "swap" : "swaps");
return true;
}
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