#define PREFETCH_EXTREME_STRIDE 4096
#endif
+/* Define a limit to how far apart indices can be and still be merged
+ into a single prefetch. */
+#ifndef PREFETCH_EXTREME_DIFFERENCE
+#define PREFETCH_EXTREME_DIFFERENCE 4096
+#endif
+
+/* Issue prefetch instructions before the loop to fetch data to be used
+ in the first few loop iterations. */
+#ifndef PREFETCH_BEFORE_LOOP
+#define PREFETCH_BEFORE_LOOP 1
+#endif
+
/* Do not handle reversed order prefetches (negative stride). */
#ifndef PREFETCH_NO_REVERSE_ORDER
#define PREFETCH_NO_REVERSE_ORDER 1
#endif
-/* Prefetch even if the GIV is not always executed. */
-#ifndef PREFETCH_NOT_ALWAYS
-#define PREFETCH_NOT_ALWAYS 0
+/* Prefetch even if the GIV is in conditional code. */
+#ifndef PREFETCH_CONDITIONAL
+#define PREFETCH_CONDITIONAL 1
#endif
/* If the loop requires more prefetches than the target can process in
scan_loop (loop, flags);
}
- /* If there were lexical blocks inside the loop, they have been
- replicated. We will now have more than one NOTE_INSN_BLOCK_BEG
- and NOTE_INSN_BLOCK_END for each such block. We must duplicate
- the BLOCKs as well. */
- if (write_symbols != NO_DEBUG)
- reorder_blocks ();
-
end_alias_analysis ();
/* Clean up. */
unconditional jump, otherwise the code at the top of the
loop might never be executed. Unconditional jumps are
followed by a barrier then the loop_end. */
- && ! (GET_CODE (p) == JUMP_INSN && JUMP_LABEL (p) == loop->top
+ && ! (GET_CODE (p) == JUMP_INSN && JUMP_LABEL (p) == loop->top
&& NEXT_INSN (NEXT_INSN (p)) == loop_end
&& any_uncondjump_p (p)))
maybe_never = 1;
start_sequence ();
emit_move_insn (m->set_dest, m->set_src);
- temp = get_insns ();
- seq = gen_sequence ();
+ seq = get_insns ();
end_sequence ();
- add_label_notes (m->set_src, temp);
+ add_label_notes (m->set_src, seq);
i1 = loop_insn_hoist (loop, seq);
if (! find_reg_note (i1, REG_EQUAL, NULL_RTX))
abort ();
if (tem != reg)
emit_move_insn (reg, tem);
- sequence = gen_sequence ();
+ sequence = get_insns ();
end_sequence ();
i1 = loop_insn_hoist (loop, sequence);
}
use the REG_EQUAL note. */
start_sequence ();
emit_move_insn (m->set_dest, m->set_src);
- temp = get_insns ();
- seq = gen_sequence ();
+ seq = get_insns ();
end_sequence ();
- add_label_notes (m->set_src, temp);
+ add_label_notes (m->set_src, seq);
i1 = loop_insn_hoist (loop, seq);
if (! find_reg_note (i1, REG_EQUAL, NULL_RTX))
loop_info->pre_header_has_call = 0;
loop_info->has_call = 0;
loop_info->has_nonconst_call = 0;
+ loop_info->has_prefetch = 0;
loop_info->has_volatile = 0;
loop_info->has_tablejump = 0;
loop_info->has_multiple_exit_targets = 0;
HOST_WIDE_INT index;
HOST_WIDE_INT stride; /* Prefetch stride in bytes in each
iteration. */
- unsigned int bytes_accesed; /* Sum of sizes of all acceses to this
+ unsigned int bytes_accessed; /* Sum of sizes of all acceses to this
prefetch area in one iteration. */
unsigned int total_bytes; /* Total bytes loop will access in this block.
This is set only for loops with known
iteration counts and is 0xffffffff
otherwise. */
+ int prefetch_in_loop; /* Number of prefetch insns in loop. */
+ int prefetch_before_loop; /* Number of prefetch insns before loop. */
unsigned int write : 1; /* 1 for read/write prefetches. */
- unsigned int prefetch_in_loop : 1;
- /* 1 for those chosen for prefetching. */
- unsigned int prefetch_before_loop : 1;
- /* 1 for those chosen for prefetching. */
};
/* Data used by check_store function. */
/* In case our parameter was constant, remove extra zero from the
expression. */
if (XEXP (exp, 0) == const0_rtx)
- *x = XEXP (exp, 1);
+ *x = XEXP (exp, 1);
else if (XEXP (exp, 1) == const0_rtx)
- *x = XEXP (exp, 0);
+ *x = XEXP (exp, 0);
}
return addval;
int num_prefetches = 0;
int num_real_prefetches = 0;
int num_real_write_prefetches = 0;
- int ahead;
+ int num_prefetches_before = 0;
+ int num_write_prefetches_before = 0;
+ int ahead = 0;
int i;
struct iv_class *bl;
struct induction *iv;
if (PREFETCH_NO_CALL && LOOP_INFO (loop)->has_call)
{
if (loop_dump_stream)
- fprintf (loop_dump_stream, "Prefetch: ignoring loop - has call.\n");
+ fprintf (loop_dump_stream, "Prefetch: ignoring loop: has call.\n");
return;
}
+ /* Don't prefetch in loops known to have few iterations. */
if (PREFETCH_NO_LOW_LOOPCNT
&& LOOP_INFO (loop)->n_iterations
&& LOOP_INFO (loop)->n_iterations <= PREFETCH_LOW_LOOPCNT)
{
if (loop_dump_stream)
fprintf (loop_dump_stream,
- "Prefetch: ignoring loop - not enought iterations.\n");
+ "Prefetch: ignoring loop: not enough iterations.\n");
return;
}
BIVs that are executed multiple times; such BIVs ought to be
handled in the nested loop. We accept not_every_iteration BIVs,
since these only result in larger strides and make our
- heuristics more conservative.
- ??? What does the last sentence mean? */
+ heuristics more conservative. */
if (GET_CODE (biv->add_val) != CONST_INT)
{
if (loop_dump_stream)
{
fprintf (loop_dump_stream,
- "Prefetch: biv %i ignored: non-constant addition at insn %i:",
+ "Prefetch: ignoring biv %d: non-constant addition at insn %d:",
REGNO (biv->src_reg), INSN_UID (biv->insn));
print_rtl (loop_dump_stream, biv->add_val);
fprintf (loop_dump_stream, "\n");
if (loop_dump_stream)
{
fprintf (loop_dump_stream,
- "Prefetch: biv %i ignored: maybe_multiple at insn %i:",
+ "Prefetch: ignoring biv %d: maybe_multiple at insn %i:",
REGNO (biv->src_reg), INSN_UID (biv->insn));
print_rtl (loop_dump_stream, biv->add_val);
fprintf (loop_dump_stream, "\n");
rtx temp;
HOST_WIDE_INT index = 0;
int add = 1;
- HOST_WIDE_INT stride;
+ HOST_WIDE_INT stride = 0;
+ int stride_sign = 1;
struct check_store_data d;
+ const char *ignore_reason = NULL;
int size = GET_MODE_SIZE (GET_MODE (iv));
- /* There are several reasons why an induction variable is not
- interesting to us. */
- if (iv->giv_type != DEST_ADDR
- /* We are interested only in constant stride memory references
- in order to be able to compute density easily. */
- || GET_CODE (iv->mult_val) != CONST_INT
- /* Don't handle reversed order prefetches, since they are usually
- ineffective. Later we may be able to reverse such BIVs. */
- || (PREFETCH_NO_REVERSE_ORDER
- && (stride = INTVAL (iv->mult_val) * basestride) < 0)
- /* Prefetching of accesses with such an extreme stride is probably
- not worthwhile, either. */
- || (PREFETCH_NO_EXTREME_STRIDE
- && stride > PREFETCH_EXTREME_STRIDE)
+ /* See whether an induction variable is interesting to us and if
+ not, report the reason. */
+ if (iv->giv_type != DEST_ADDR)
+ ignore_reason = "giv is not a destination address";
+
+ /* We are interested only in constant stride memory references
+ in order to be able to compute density easily. */
+ else if (GET_CODE (iv->mult_val) != CONST_INT)
+ ignore_reason = "stride is not constant";
+
+ else
+ {
+ stride = INTVAL (iv->mult_val) * basestride;
+ if (stride < 0)
+ {
+ stride = -stride;
+ stride_sign = -1;
+ }
+
+ /* On some targets, reversed order prefetches are not
+ worthwhile. */
+ if (PREFETCH_NO_REVERSE_ORDER && stride_sign < 0)
+ ignore_reason = "reversed order stride";
+
+ /* Prefetch of accesses with an extreme stride might not be
+ worthwhile, either. */
+ else if (PREFETCH_NO_EXTREME_STRIDE
+ && stride > PREFETCH_EXTREME_STRIDE)
+ ignore_reason = "extreme stride";
+
/* Ignore GIVs with varying add values; we can't predict the
value for the next iteration. */
- || !loop_invariant_p (loop, iv->add_val)
+ else if (!loop_invariant_p (loop, iv->add_val))
+ ignore_reason = "giv has varying add value";
+
/* Ignore GIVs in the nested loops; they ought to have been
handled already. */
- || iv->maybe_multiple)
+ else if (iv->maybe_multiple)
+ ignore_reason = "giv is in nested loop";
+ }
+
+ if (ignore_reason != NULL)
{
if (loop_dump_stream)
- fprintf (loop_dump_stream, "Prefetch: Ignoring giv at %i\n",
- INSN_UID (iv->insn));
+ fprintf (loop_dump_stream,
+ "Prefetch: ignoring giv at %d: %s.\n",
+ INSN_UID (iv->insn), ignore_reason);
continue;
}
/* Determine the pointer to the basic array we are examining. It is
the sum of the BIV's initial value and the GIV's add_val. */
- index = 0;
-
address = copy_rtx (iv->add_val);
temp = copy_rtx (bl->initial_value);
address = simplify_gen_binary (PLUS, Pmode, temp, address);
index = remove_constant_addition (&address);
- index += size;
d.mem_write = 0;
d.mem_address = *iv->location;
/* When the GIV is not always executed, we might be better off by
not dirtying the cache pages. */
- if (PREFETCH_NOT_ALWAYS || iv->always_executed)
+ if (PREFETCH_CONDITIONAL || iv->always_executed)
note_stores (PATTERN (iv->insn), check_store, &d);
+ else
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream, "Prefetch: Ignoring giv at %d: %s\n",
+ INSN_UID (iv->insn), "in conditional code.");
+ continue;
+ }
/* Attempt to find another prefetch to the same array and see if we
can merge this one. */
just with small difference in constant indexes), merge
the prefetches. Just do the later and the earlier will
get prefetched from previous iteration.
- 4096 is artificial threshold. It should not be too small,
+ The artificial threshold should not be too small,
but also not bigger than small portion of memory usually
traversed by single loop. */
- if (index >= info[i].index && index - info[i].index < 4096)
+ if (index >= info[i].index
+ && index - info[i].index < PREFETCH_EXTREME_DIFFERENCE)
{
info[i].write |= d.mem_write;
- info[i].bytes_accesed += size;
+ info[i].bytes_accessed += size;
info[i].index = index;
info[i].giv = iv;
info[i].class = bl;
break;
}
- if (index < info[i].index && info[i].index - index < 4096)
+ if (index < info[i].index
+ && info[i].index - index < PREFETCH_EXTREME_DIFFERENCE)
{
info[i].write |= d.mem_write;
- info[i].bytes_accesed += size;
+ info[i].bytes_accessed += size;
add = 0;
break;
}
info[num_prefetches].stride = stride;
info[num_prefetches].base_address = address;
info[num_prefetches].write = d.mem_write;
- info[num_prefetches].bytes_accesed = size;
+ info[num_prefetches].bytes_accessed = size;
num_prefetches++;
if (num_prefetches >= MAX_PREFETCHES)
{
for (i = 0; i < num_prefetches; i++)
{
- /* Attempt to calculate the number of bytes fetched by the loop.
- Avoid overflow. */
+ int density;
+
+ /* Attempt to calculate the total number of bytes fetched by all
+ iterations of the loop. Avoid overflow. */
if (LOOP_INFO (loop)->n_iterations
- && ((unsigned HOST_WIDE_INT) (0xffffffff / info[i].stride)
+ && ((unsigned HOST_WIDE_INT) (0xffffffff / info[i].stride)
>= LOOP_INFO (loop)->n_iterations))
info[i].total_bytes = info[i].stride * LOOP_INFO (loop)->n_iterations;
else
info[i].total_bytes = 0xffffffff;
- /* Prefetch is worthwhile only when the loads/stores are dense. */
- if (PREFETCH_ONLY_DENSE_MEM
- && info[i].bytes_accesed * 256 / info[i].stride > PREFETCH_DENSE_MEM
- && (info[i].total_bytes / PREFETCH_BLOCK
- >= PREFETCH_BLOCKS_BEFORE_LOOP_MIN))
- {
- info[i].prefetch_before_loop = 1;
- info[i].prefetch_in_loop
- = (info[i].total_bytes / PREFETCH_BLOCK
- > PREFETCH_BLOCKS_BEFORE_LOOP_MAX);
- }
+ density = info[i].bytes_accessed * 100 / info[i].stride;
+
+ /* Prefetch might be worthwhile only when the loads/stores are dense. */
+ if (PREFETCH_ONLY_DENSE_MEM)
+ if (density * 256 > PREFETCH_DENSE_MEM * 100
+ && (info[i].total_bytes / PREFETCH_BLOCK
+ >= PREFETCH_BLOCKS_BEFORE_LOOP_MIN))
+ {
+ info[i].prefetch_before_loop = 1;
+ info[i].prefetch_in_loop
+ = (info[i].total_bytes / PREFETCH_BLOCK
+ > PREFETCH_BLOCKS_BEFORE_LOOP_MAX);
+ }
+ else
+ {
+ info[i].prefetch_in_loop = 0, info[i].prefetch_before_loop = 0;
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Prefetch: ignoring giv at %d: %d%% density is too low.\n",
+ INSN_UID (info[i].giv->insn), density);
+ }
else
- info[i].prefetch_in_loop = 0, info[i].prefetch_before_loop = 0;
+ info[i].prefetch_in_loop = 1, info[i].prefetch_before_loop = 1;
- if (info[i].prefetch_in_loop)
+ /* Find how many prefetch instructions we'll use within the loop. */
+ if (info[i].prefetch_in_loop != 0)
{
- num_real_prefetches += ((info[i].stride + PREFETCH_BLOCK - 1)
+ info[i].prefetch_in_loop = ((info[i].stride + PREFETCH_BLOCK - 1)
/ PREFETCH_BLOCK);
+ num_real_prefetches += info[i].prefetch_in_loop;
if (info[i].write)
- num_real_write_prefetches
- += (info[i].stride + PREFETCH_BLOCK - 1) / PREFETCH_BLOCK;
+ num_real_write_prefetches += info[i].prefetch_in_loop;
}
}
- if (loop_dump_stream)
+ /* Determine how many iterations ahead to prefetch within the loop, based
+ on how many prefetches we currently expect to do within the loop. */
+ if (num_real_prefetches != 0)
{
- for (i = 0; i < num_prefetches; i++)
+ if ((ahead = SIMULTANEOUS_PREFETCHES / num_real_prefetches) == 0)
{
- fprintf (loop_dump_stream, "Prefetch insn %i address: ",
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Prefetch: ignoring prefetches within loop: ahead is zero; %d < %d\n",
+ SIMULTANEOUS_PREFETCHES, num_real_prefetches);
+ num_real_prefetches = 0, num_real_write_prefetches = 0;
+ }
+ }
+ /* We'll also use AHEAD to determine how many prefetch instructions to
+ emit before a loop, so don't leave it zero. */
+ if (ahead == 0)
+ ahead = PREFETCH_BLOCKS_BEFORE_LOOP_MAX;
+
+ for (i = 0; i < num_prefetches; i++)
+ {
+ /* Update if we've decided not to prefetch anything within the loop. */
+ if (num_real_prefetches == 0)
+ info[i].prefetch_in_loop = 0;
+
+ /* Find how many prefetch instructions we'll use before the loop. */
+ if (info[i].prefetch_before_loop != 0)
+ {
+ int n = info[i].total_bytes / PREFETCH_BLOCK;
+ if (n > ahead)
+ n = ahead;
+ info[i].prefetch_before_loop = n;
+ num_prefetches_before += n;
+ if (info[i].write)
+ num_write_prefetches_before += n;
+ }
+
+ if (loop_dump_stream)
+ {
+ if (info[i].prefetch_in_loop == 0
+ && info[i].prefetch_before_loop == 0)
+ continue;
+ fprintf (loop_dump_stream, "Prefetch insn: %d",
INSN_UID (info[i].giv->insn));
- print_rtl (loop_dump_stream, info[i].base_address);
- fprintf (loop_dump_stream, " Index: ");
+ fprintf (loop_dump_stream,
+ "; in loop: %d; before: %d; %s\n",
+ info[i].prefetch_in_loop,
+ info[i].prefetch_before_loop,
+ info[i].write ? "read/write" : "read only");
+ fprintf (loop_dump_stream,
+ " density: %d%%; bytes_accessed: %u; total_bytes: %u\n",
+ (int) (info[i].bytes_accessed * 100 / info[i].stride),
+ info[i].bytes_accessed, info[i].total_bytes);
+ fprintf (loop_dump_stream, " index: ");
fprintf (loop_dump_stream, HOST_WIDE_INT_PRINT_DEC, info[i].index);
- fprintf (loop_dump_stream, " stride: ");
+ fprintf (loop_dump_stream, "; stride: ");
fprintf (loop_dump_stream, HOST_WIDE_INT_PRINT_DEC, info[i].stride);
- fprintf (loop_dump_stream,
- " density: %i%% total_bytes: %u%sin loop: %s before: %s\n",
- (int) (info[i].bytes_accesed * 100 / info[i].stride),
- info[i].total_bytes,
- info[i].write ? " read/write " : " read only ",
- info[i].prefetch_in_loop ? "yes" : "no",
- info[i].prefetch_before_loop ? "yes" : "no");
+ fprintf (loop_dump_stream, "; address: ");
+ print_rtl (loop_dump_stream, info[i].base_address);
+ fprintf (loop_dump_stream, "\n");
}
-
- fprintf (loop_dump_stream, "Real prefetches needed: %i (write: %i)\n",
- num_real_prefetches, num_real_write_prefetches);
}
- if (!num_real_prefetches)
- return;
-
- ahead = SIMULTANEOUS_PREFETCHES / num_real_prefetches;
+ if (num_real_prefetches + num_prefetches_before > 0)
+ {
+ /* Record that this loop uses prefetch instructions. */
+ LOOP_INFO (loop)->has_prefetch = 1;
- if (!ahead)
- return;
+ if (loop_dump_stream)
+ {
+ fprintf (loop_dump_stream, "Real prefetches needed within loop: %d (write: %d)\n",
+ num_real_prefetches, num_real_write_prefetches);
+ fprintf (loop_dump_stream, "Real prefetches needed before loop: %d (write: %d)\n",
+ num_prefetches_before, num_write_prefetches_before);
+ }
+ }
for (i = 0; i < num_prefetches; i++)
{
- if (info[i].prefetch_in_loop)
- {
- int y;
+ int y;
- for (y = 0; y < ((info[i].stride + PREFETCH_BLOCK - 1)
- / PREFETCH_BLOCK); y++)
+ for (y = 0; y < info[i].prefetch_in_loop; y++)
+ {
+ rtx loc = copy_rtx (*info[i].giv->location);
+ rtx insn;
+ int bytes_ahead = PREFETCH_BLOCK * (ahead + y);
+ rtx before_insn = info[i].giv->insn;
+ rtx prev_insn = PREV_INSN (info[i].giv->insn);
+ rtx seq;
+
+ /* We can save some effort by offsetting the address on
+ architectures with offsettable memory references. */
+ if (offsettable_address_p (0, VOIDmode, loc))
+ loc = plus_constant (loc, bytes_ahead);
+ else
{
- rtx loc = copy_rtx (*info[i].giv->location);
- rtx insn;
- int bytes_ahead = PREFETCH_BLOCK * (ahead + y);
- rtx before_insn = info[i].giv->insn;
- rtx prev_insn = PREV_INSN (info[i].giv->insn);
-
- /* We can save some effort by offsetting the address on
- architectures with offsettable memory references. */
- if (offsettable_address_p (0, VOIDmode, loc))
- loc = plus_constant (loc, bytes_ahead);
- else
- {
- rtx reg = gen_reg_rtx (Pmode);
- loop_iv_add_mult_emit_before (loop, loc, const1_rtx,
- GEN_INT (bytes_ahead), reg,
- 0, before_insn);
- loc = reg;
- }
+ rtx reg = gen_reg_rtx (Pmode);
+ loop_iv_add_mult_emit_before (loop, loc, const1_rtx,
+ GEN_INT (bytes_ahead), reg,
+ 0, before_insn);
+ loc = reg;
+ }
- /* Make sure the address operand is valid for prefetch. */
- if (! (*insn_data[(int)CODE_FOR_prefetch].operand[0].predicate)
- (loc,
- insn_data[(int)CODE_FOR_prefetch].operand[0].mode))
- loc = force_reg (Pmode, loc);
- emit_insn_before (gen_prefetch (loc, GEN_INT (info[i].write),
- GEN_INT (3)),
- before_insn);
-
- /* Check all insns emitted and record the new GIV
- information. */
- insn = NEXT_INSN (prev_insn);
- while (insn != before_insn)
- {
- insn = check_insn_for_givs (loop, insn,
- info[i].giv->always_executed,
- info[i].giv->maybe_multiple);
- insn = NEXT_INSN (insn);
- }
+ start_sequence ();
+ /* Make sure the address operand is valid for prefetch. */
+ if (! (*insn_data[(int)CODE_FOR_prefetch].operand[0].predicate)
+ (loc, insn_data[(int)CODE_FOR_prefetch].operand[0].mode))
+ loc = force_reg (Pmode, loc);
+ emit_insn (gen_prefetch (loc, GEN_INT (info[i].write),
+ GEN_INT (3)));
+ seq = get_insns ();
+ end_sequence ();
+ emit_insn_before (seq, before_insn);
+
+ /* Check all insns emitted and record the new GIV
+ information. */
+ insn = NEXT_INSN (prev_insn);
+ while (insn != before_insn)
+ {
+ insn = check_insn_for_givs (loop, insn,
+ info[i].giv->always_executed,
+ info[i].giv->maybe_multiple);
+ insn = NEXT_INSN (insn);
}
}
- if (info[i].prefetch_before_loop)
+ if (PREFETCH_BEFORE_LOOP)
{
- int y;
-
- /* Emit INSNs before the loop to fetch the first cache lines. */
- for (y = 0;
- (!info[i].prefetch_in_loop || y < ahead)
- && y * PREFETCH_BLOCK < (int) info[i].total_bytes; y ++)
+ /* Emit insns before the loop to fetch the first cache lines or,
+ if we're not prefetching within the loop, everything we expect
+ to need. */
+ for (y = 0; y < info[i].prefetch_before_loop; y++)
{
rtx reg = gen_reg_rtx (Pmode);
rtx loop_start = loop->start;
+ rtx init_val = info[i].class->initial_value;
rtx add_val = simplify_gen_binary (PLUS, Pmode,
info[i].giv->add_val,
GEN_INT (y * PREFETCH_BLOCK));
- loop_iv_add_mult_emit_before (loop, info[i].class->initial_value,
+ /* Functions called by LOOP_IV_ADD_EMIT_BEFORE expect a
+ non-constant INIT_VAL to have the same mode as REG, which
+ in this case we know to be Pmode. */
+ if (GET_MODE (init_val) != Pmode && !CONSTANT_P (init_val))
+ init_val = convert_to_mode (Pmode, init_val, 0);
+ loop_iv_add_mult_emit_before (loop, init_val,
info[i].giv->mult_val,
- add_val, reg, 0, loop_start);
+ add_val, reg, 0, loop_start);
emit_insn_before (gen_prefetch (reg, GEN_INT (info[i].write),
GEN_INT (3)),
loop_start);
LOOP and INSN parameters pass MAYBE_MULTIPLE and NOT_EVERY_ITERATION to the
callback.
- NOT_EVERY_ITERATION if current insn is not executed at least once for every
- loop iteration except for the last one.
+ NOT_EVERY_ITERATION is 1 if current insn is not known to be executed at
+ least once for every loop iteration except for the last one.
MAYBE_MULTIPLE is 1 if current insn may be executed more than once for every
loop iteration.
struct loop *loop;
loop_insn_callback fncall;
{
- /* This is 1 if current insn is not executed at least once for every loop
- iteration. */
int not_every_iteration = 0;
int maybe_multiple = 0;
int past_loop_latch = 0;
if (prev_nonnote_insn (loop->scan_start) != prev_nonnote_insn (loop->start))
maybe_multiple = back_branch_in_range_p (loop, loop->scan_start);
- /* Scan through loop to find all possible bivs. */
-
+ /* Scan through loop and update NOT_EVERY_ITERATION and MAYBE_MULTIPLE. */
for (p = next_insn_in_loop (loop, loop->scan_start);
p != NULL_RTX;
p = next_insn_in_loop (loop, p))
This can be any kind of jump, since we want to know if insns
will be executed if the loop is executed. */
&& !(JUMP_LABEL (p) == loop->top
- && ((NEXT_INSN (NEXT_INSN (p)) == loop->end
- && any_uncondjump_p (p))
- || (NEXT_INSN (p) == loop->end && any_condjump_p (p)))))
+ && ((NEXT_INSN (NEXT_INSN (p)) == loop->end
+ && any_uncondjump_p (p))
+ || (NEXT_INSN (p) == loop->end && any_condjump_p (p)))))
{
rtx label = 0;
#endif
if ((final_value = final_giv_value (loop, v))
- && (v->always_computable || last_use_this_basic_block (v->dest_reg, v->insn)))
+ && (v->always_executed
+ || last_use_this_basic_block (v->dest_reg, v->insn)))
{
int biv_increment_seen = 0, before_giv_insn = 0;
rtx p = v->insn;
result = expand_mult_add (b, reg, m, a, GET_MODE (reg), 1);
if (reg != result)
emit_move_insn (reg, result);
- seq = gen_sequence ();
+ seq = get_insns ();
end_sequence ();
return seq;
const struct loop *loop ATTRIBUTE_UNUSED;
rtx seq;
{
+ rtx insn;
+
/* Update register info for alias analysis. */
- if (GET_CODE (seq) == SEQUENCE)
+ if (seq == NULL_RTX)
+ return;
+
+ if (INSN_P (seq))
{
- int i;
- for (i = 0; i < XVECLEN (seq, 0); ++i)
+ insn = seq;
+ while (insn != NULL_RTX)
{
- rtx set = single_set (XVECEXP (seq, 0, i));
+ rtx set = single_set (insn);
+
if (set && GET_CODE (SET_DEST (set)) == REG)
record_base_value (REGNO (SET_DEST (set)), SET_SRC (set), 0);
+
+ insn = NEXT_INSN (insn);
}
}
- else
- {
- if (GET_CODE (seq) == SET
- && GET_CODE (SET_DEST (seq)) == REG)
- record_base_value (REGNO (SET_DEST (seq)), SET_SRC (seq), 0);
- }
+ else if (GET_CODE (seq) == SET
+ && GET_CODE (SET_DEST (seq)) == REG)
+ record_base_value (REGNO (SET_DEST (seq)), SET_SRC (seq), 0);
}
}
\f
/* Test whether A * B can be computed without
- an actual multiply insn. Value is 1 if so. */
+ an actual multiply insn. Value is 1 if so.
+
+ ??? This function stinks because it generates a ton of wasted RTL
+ ??? and as a result fragments GC memory to no end. There are other
+ ??? places in the compiler which are invoked a lot and do the same
+ ??? thing, generate wasted RTL just to see if something is possible. */
static int
product_cheap_p (a, b)
rtx a;
rtx b;
{
- int i;
rtx tmp;
- int win = 1;
+ int win, n_insns;
/* If only one is constant, make it B. */
if (GET_CODE (a) == CONST_INT)
start_sequence ();
expand_mult (GET_MODE (a), a, b, NULL_RTX, 1);
- tmp = gen_sequence ();
+ tmp = get_insns ();
end_sequence ();
- if (GET_CODE (tmp) == SEQUENCE)
+ win = 1;
+ if (INSN_P (tmp))
{
- if (XVEC (tmp, 0) == 0)
- win = 1;
- else if (XVECLEN (tmp, 0) > 3)
- win = 0;
- else
- for (i = 0; i < XVECLEN (tmp, 0); i++)
- {
- rtx insn = XVECEXP (tmp, 0, i);
-
- if (GET_CODE (insn) != INSN
- || (GET_CODE (PATTERN (insn)) == SET
- && GET_CODE (SET_SRC (PATTERN (insn))) == MULT)
- || (GET_CODE (PATTERN (insn)) == PARALLEL
- && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET
- && GET_CODE (SET_SRC (XVECEXP (PATTERN (insn), 0, 0))) == MULT))
- {
- win = 0;
- break;
- }
- }
+ n_insns = 0;
+ while (tmp != NULL_RTX)
+ {
+ rtx next = NEXT_INSN (tmp);
+
+ if (++n_insns > 3
+ || GET_CODE (tmp) != INSN
+ || (GET_CODE (PATTERN (tmp)) == SET
+ && GET_CODE (SET_SRC (PATTERN (tmp))) == MULT)
+ || (GET_CODE (PATTERN (tmp)) == PARALLEL
+ && GET_CODE (XVECEXP (PATTERN (tmp), 0, 0)) == SET
+ && GET_CODE (SET_SRC (XVECEXP (PATTERN (tmp), 0, 0))) == MULT))
+ {
+ win = 0;
+ break;
+ }
+
+ tmp = next;
+ }
}
else if (GET_CODE (tmp) == SET
&& GET_CODE (SET_SRC (tmp)) == MULT)
if ((num_nonfixed_reads <= 1
&& ! loop_info->has_nonconst_call
+ && ! loop_info->has_prefetch
&& ! loop_info->has_volatile
&& reversible_mem_store
&& (bl->giv_count + bl->biv_count + loop_info->num_mem_sets
+ num_unmoved_movables (loop) + compare_and_branch == insn_count)
&& (bl == ivs->list && bl->next == 0))
- || no_use_except_counting)
+ || (no_use_except_counting && ! loop_info->has_prefetch))
{
rtx tem;
create a sequence to hold all the insns from expand_inc. */
start_sequence ();
expand_inc (reg, new_add_val);
- tem = gen_sequence ();
+ tem = get_insns ();
end_sequence ();
p = loop_insn_emit_before (loop, 0, bl->biv->insn, tem);
emit_cmp_and_jump_insns (reg, const0_rtx, cmp_code, NULL_RTX,
GET_MODE (reg), 0,
XEXP (jump_label, 0));
- tem = gen_sequence ();
+ tem = get_insns ();
end_sequence ();
emit_jump_insn_before (tem, loop_end);
/* Start with test for not first so that INSN == REFERENCE yields not
first. */
if (q == insn || ! p)
- return 0;
+ return 0;
if (p == reference || ! q)
- return 1;
+ return 1;
/* Either of P or Q might be a NOTE. Notes have the same LUID as the
previous insn, hence the <= comparison below does not work if
if (! biv_elimination_giv_has_0_offset (bl->biv, v, insn))
continue;
+ /* Don't eliminate if the linear combination that makes up
+ the giv overflows when it is applied to ARG. */
+ if (GET_CODE (arg) == CONST_INT)
+ {
+ rtx add_val;
+
+ if (GET_CODE (v->add_val) == CONST_INT)
+ add_val = v->add_val;
+ else
+ add_val = const0_rtx;
+
+ if (const_mult_add_overflow_p (arg, v->mult_val,
+ add_val, mode, 1))
+ continue;
+ }
+
if (! eliminate_p)
return 1;
the derived constant can be directly placed in the COMPARE,
do so. */
if (GET_CODE (arg) == CONST_INT
- && GET_CODE (v->mult_val) == CONST_INT
&& GET_CODE (v->add_val) == CONST_INT)
{
- validate_change (insn, &XEXP (x, arg_operand),
- GEN_INT (INTVAL (arg)
- * INTVAL (v->mult_val)
- + INTVAL (v->add_val)), 1);
+ tem = expand_mult_add (arg, NULL_RTX, v->mult_val,
+ v->add_val, mode, 1);
}
else
{
loop_iv_add_mult_emit_before (loop, arg,
v->mult_val, v->add_val,
tem, where_bb, where_insn);
- validate_change (insn, &XEXP (x, arg_operand), tem, 1);
}
+
+ validate_change (insn, &XEXP (x, arg_operand), tem, 1);
+
if (apply_change_group ())
return 1;
}
if (LOOP_INFO (loop)->has_call)
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)
- && rtx_varies_p (gen_rtx_REG (Pmode, i), /*for_alias=*/1))
- {
- regs->array[i].may_not_optimize = 1;
- regs->array[i].set_in_loop = 1;
- }
+ && rtx_varies_p (regno_reg_rtx[i], 1))
+ {
+ regs->array[i].may_not_optimize = 1;
+ regs->array[i].set_in_loop = 1;
+ }
#ifdef AVOID_CCMODE_COPIES
/* Don't try to move insns which set CC registers if we should not
final_value = force_operand (final_value, reg);
if (final_value != reg)
emit_move_insn (reg, final_value);
- seq = gen_sequence ();
+ seq = get_insns ();
end_sequence ();
return seq;
}
fprintf (file, " Giv%d: insn %d, benefit %d, ",
i, INSN_UID (v->insn), v->benefit);
if (v->giv_type == DEST_ADDR)
- print_simple_rtl (file, v->mem);
+ print_simple_rtl (file, v->mem);
else
- print_simple_rtl (file, single_set (v->insn));
+ print_simple_rtl (file, single_set (v->insn));
fputc ('\n', file);
}
}
if (v->giv_type == DEST_REG)
fprintf (file, "Giv %d: insn %d",
- REGNO (v->dest_reg), INSN_UID (v->insn));
+ REGNO (v->dest_reg), INSN_UID (v->insn));
else
fprintf (file, "Dest address: insn %d",
INSN_UID (v->insn));
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