store_info and read_info_type in dse.c represented the ranges as
start/end, but a lot of the internal code used offset/width instead.
Using offset/width throughout fits better with the poly_int.h
range-checking functions.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* dse.c (store_info, read_info_type): Replace begin and end with
offset and width.
(print_range): New function.
(set_all_positions_unneeded, any_positions_needed_p)
(check_mem_read_rtx, scan_stores, scan_reads, dse_step5): Update
accordingly.
(record_store): Likewise. Optimize the case in which all positions
are unneeded.
(get_stored_val): Replace read_begin and read_end with read_offset
and read_width.
(replace_read): Update call accordingly.
Index: gcc/dse.c
===================================================================
--- gcc/dse.c 2017-10-23 11:47:11.273428262 +0100
+++ gcc/dse.c 2017-10-23 11:47:48.294155952 +0100
@@ -243,9 +243,12 @@ struct store_info
/* Canonized MEM address for use by canon_true_dependence. */
rtx mem_addr;
- /* The offset of the first and byte before the last byte associated
- with the operation. */
- HOST_WIDE_INT begin, end;
+ /* The offset of the first byte associated with the operation. */
+ HOST_WIDE_INT offset;
+
+ /* The number of bytes covered by the operation. This is always exact
+ and known (rather than -1). */
+ HOST_WIDE_INT width;
union
{
@@ -261,7 +264,7 @@ struct store_info
bitmap bmap;
/* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is
- equal to END - BEGIN, the whole store is unused. */
+ equal to WIDTH, the whole store is unused. */
int count;
} large;
} positions_needed;
@@ -304,10 +307,11 @@ struct read_info_type
/* The id of the mem group of the base address. */
int group_id;
- /* The offset of the first and byte after the last byte associated
- with the operation. If begin == end == 0, the read did not have
- a constant offset. */
- int begin, end;
+ /* The offset of the first byte associated with the operation. */
+ HOST_WIDE_INT offset;
+
+ /* The number of bytes covered by the operation, or -1 if not known. */
+ HOST_WIDE_INT width;
/* The mem being read. */
rtx mem;
@@ -586,6 +590,18 @@ static deferred_change *deferred_change_
/* The number of bits used in the global bitmaps. */
static unsigned int current_position;
+
+/* Print offset range [OFFSET, OFFSET + WIDTH) to FILE. */
+
+static void
+print_range (FILE *file, poly_int64 offset, poly_int64 width)
+{
+ fprintf (file, "[");
+ print_dec (offset, file, SIGNED);
+ fprintf (file, "..");
+ print_dec (offset + width, file, SIGNED);
+ fprintf (file, ")");
+}
/*----------------------------------------------------------------------------
Zeroth step.
@@ -1212,10 +1228,9 @@ set_all_positions_unneeded (store_info *
{
if (__builtin_expect (s_info->is_large, false))
{
- int pos, end = s_info->end - s_info->begin;
- for (pos = 0; pos < end; pos++)
- bitmap_set_bit (s_info->positions_needed.large.bmap, pos);
- s_info->positions_needed.large.count = end;
+ bitmap_set_range (s_info->positions_needed.large.bmap,
+ 0, s_info->width);
+ s_info->positions_needed.large.count = s_info->width;
}
else
s_info->positions_needed.small_bitmask = HOST_WIDE_INT_0U;
@@ -1227,8 +1242,7 @@ set_all_positions_unneeded (store_info *
any_positions_needed_p (store_info *s_info)
{
if (__builtin_expect (s_info->is_large, false))
- return (s_info->positions_needed.large.count
- < s_info->end - s_info->begin);
+ return s_info->positions_needed.large.count < s_info->width;
else
return (s_info->positions_needed.small_bitmask != HOST_WIDE_INT_0U);
}
@@ -1355,8 +1369,12 @@ record_store (rtx body, bb_info_t bb_inf
set_usage_bits (group, offset, width, expr);
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n",
- group_id, (int)offset, (int)(offset+width));
+ {
+ fprintf (dump_file, " processing const base store gid=%d",
+ group_id);
+ print_range (dump_file, offset, width);
+ fprintf (dump_file, "\n");
+ }
}
else
{
@@ -1368,8 +1386,11 @@ record_store (rtx body, bb_info_t bb_inf
group_id = -1;
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " processing cselib store [%d..%d)\n",
- (int)offset, (int)(offset+width));
+ {
+ fprintf (dump_file, " processing cselib store ");
+ print_range (dump_file, offset, width);
+ fprintf (dump_file, "\n");
+ }
}
const_rhs = rhs = NULL_RTX;
@@ -1435,18 +1456,21 @@ record_store (rtx body, bb_info_t bb_inf
{
HOST_WIDE_INT i;
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n",
- INSN_UID (ptr->insn), s_info->group_id,
- (int)s_info->begin, (int)s_info->end);
+ {
+ fprintf (dump_file, " trying store in insn=%d gid=%d",
+ INSN_UID (ptr->insn), s_info->group_id);
+ print_range (dump_file, s_info->offset, s_info->width);
+ fprintf (dump_file, "\n");
+ }
/* Even if PTR won't be eliminated as unneeded, if both
PTR and this insn store the same constant value, we might
eliminate this insn instead. */
if (s_info->const_rhs
&& const_rhs
- && offset >= s_info->begin
- && offset + width <= s_info->end
- && all_positions_needed_p (s_info, offset - s_info->begin,
+ && known_subrange_p (offset, width,
+ s_info->offset, s_info->width)
+ && all_positions_needed_p (s_info, offset - s_info->offset,
width))
{
if (GET_MODE (mem) == BLKmode)
@@ -1462,8 +1486,7 @@ record_store (rtx body, bb_info_t bb_inf
{
rtx val;
start_sequence ();
- val = get_stored_val (s_info, GET_MODE (mem),
- offset, offset + width,
+ val = get_stored_val (s_info, GET_MODE (mem), offset, width,
BLOCK_FOR_INSN (insn_info->insn),
true);
if (get_insns () != NULL)
@@ -1474,10 +1497,18 @@ record_store (rtx body, bb_info_t bb_inf
}
}
- for (i = MAX (offset, s_info->begin);
- i < offset + width && i < s_info->end;
- i++)
- set_position_unneeded (s_info, i - s_info->begin);
+ if (known_subrange_p (s_info->offset, s_info->width, offset, width))
+ /* The new store touches every byte that S_INFO does. */
+ set_all_positions_unneeded (s_info);
+ else
+ {
+ HOST_WIDE_INT begin_unneeded = offset - s_info->offset;
+ HOST_WIDE_INT end_unneeded = begin_unneeded + width;
+ begin_unneeded = MAX (begin_unneeded, 0);
+ end_unneeded = MIN (end_unneeded, s_info->width);
+ for (i = begin_unneeded; i < end_unneeded; ++i)
+ set_position_unneeded (s_info, i);
+ }
}
else if (s_info->rhs)
/* Need to see if it is possible for this store to overwrite
@@ -1535,8 +1566,8 @@ record_store (rtx body, bb_info_t bb_inf
store_info->positions_needed.small_bitmask = lowpart_bitmask (width);
}
store_info->group_id = group_id;
- store_info->begin = offset;
- store_info->end = offset + width;
+ store_info->offset = offset;
+ store_info->width = width;
store_info->is_set = GET_CODE (body) == SET;
store_info->rhs = rhs;
store_info->const_rhs = const_rhs;
@@ -1700,39 +1731,38 @@ look_for_hardregs (rtx x, const_rtx pat
}
/* Helper function for replace_read and record_store.
- Attempt to return a value stored in STORE_INFO, from READ_BEGIN
- to one before READ_END bytes read in READ_MODE. Return NULL
+ Attempt to return a value of mode READ_MODE stored in STORE_INFO,
+ consisting of READ_WIDTH bytes starting from READ_OFFSET. Return NULL
if not successful. If REQUIRE_CST is true, return always constant. */
static rtx
get_stored_val (store_info *store_info, machine_mode read_mode,
- HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end,
+ HOST_WIDE_INT read_offset, HOST_WIDE_INT read_width,
basic_block bb, bool require_cst)
{
machine_mode store_mode = GET_MODE (store_info->mem);
- int shift;
- int access_size; /* In bytes. */
+ HOST_WIDE_INT gap;
rtx read_reg;
/* To get here the read is within the boundaries of the write so
shift will never be negative. Start out with the shift being in
bytes. */
if (store_mode == BLKmode)
- shift = 0;
+ gap = 0;
else if (BYTES_BIG_ENDIAN)
- shift = store_info->end - read_end;
+ gap = ((store_info->offset + store_info->width)
+ - (read_offset + read_width));
else
- shift = read_begin - store_info->begin;
-
- access_size = shift + GET_MODE_SIZE (read_mode);
-
- /* From now on it is bits. */
- shift *= BITS_PER_UNIT;
+ gap = read_offset - store_info->offset;
- if (shift)
- read_reg = find_shift_sequence (access_size, store_info, read_mode, shift,
- optimize_bb_for_speed_p (bb),
- require_cst);
+ if (gap != 0)
+ {
+ HOST_WIDE_INT shift = gap * BITS_PER_UNIT;
+ HOST_WIDE_INT access_size = GET_MODE_SIZE (read_mode) + gap;
+ read_reg = find_shift_sequence (access_size, store_info, read_mode,
+ shift, optimize_bb_for_speed_p (bb),
+ require_cst);
+ }
else if (store_mode == BLKmode)
{
/* The store is a memset (addr, const_val, const_size). */
@@ -1835,7 +1865,7 @@ replace_read (store_info *store_info, in
start_sequence ();
bb = BLOCK_FOR_INSN (read_insn->insn);
read_reg = get_stored_val (store_info,
- read_mode, read_info->begin, read_info->end,
+ read_mode, read_info->offset, read_info->width,
bb, false);
if (read_reg == NULL_RTX)
{
@@ -1986,8 +2016,8 @@ check_mem_read_rtx (rtx *loc, bb_info_t
read_info = read_info_type_pool.allocate ();
read_info->group_id = group_id;
read_info->mem = mem;
- read_info->begin = offset;
- read_info->end = offset + width;
+ read_info->offset = offset;
+ read_info->width = width;
read_info->next = insn_info->read_rec;
insn_info->read_rec = read_info;
if (group_id < 0)
@@ -2013,8 +2043,11 @@ check_mem_read_rtx (rtx *loc, bb_info_t
fprintf (dump_file, " processing const load gid=%d[BLK]\n",
group_id);
else
- fprintf (dump_file, " processing const load gid=%d[%d..%d)\n",
- group_id, (int)offset, (int)(offset+width));
+ {
+ fprintf (dump_file, " processing const load gid=%d", group_id);
+ print_range (dump_file, offset, width);
+ fprintf (dump_file, "\n");
+ }
}
while (i_ptr)
@@ -2052,19 +2085,19 @@ check_mem_read_rtx (rtx *loc, bb_info_t
else
{
if (store_info->rhs
- && offset >= store_info->begin
- && offset + width <= store_info->end
+ && known_subrange_p (offset, width, store_info->offset,
+ store_info->width)
&& all_positions_needed_p (store_info,
- offset - store_info->begin,
+ offset - store_info->offset,
width)
&& replace_read (store_info, i_ptr, read_info,
insn_info, loc, bb_info->regs_live))
return;
/* The bases are the same, just see if the offsets
- overlap. */
- if ((offset < store_info->end)
- && (offset + width > store_info->begin))
+ could overlap. */
+ if (ranges_may_overlap_p (offset, width, store_info->offset,
+ store_info->width))
remove = true;
}
}
@@ -2119,11 +2152,10 @@ check_mem_read_rtx (rtx *loc, bb_info_t
if (store_info->rhs
&& store_info->group_id == -1
&& store_info->cse_base == base
- && width != -1
- && offset >= store_info->begin
- && offset + width <= store_info->end
+ && known_subrange_p (offset, width, store_info->offset,
+ store_info->width)
&& all_positions_needed_p (store_info,
- offset - store_info->begin, width)
+ offset - store_info->offset, width)
&& replace_read (store_info, i_ptr, read_info, insn_info, loc,
bb_info->regs_live))
return;
@@ -2775,16 +2807,19 @@ scan_stores (store_info *store_info, bit
group_info *group_info
= rtx_group_vec[store_info->group_id];
if (group_info->process_globally)
- for (i = store_info->begin; i < store_info->end; i++)
- {
- int index = get_bitmap_index (group_info, i);
- if (index != 0)
- {
- bitmap_set_bit (gen, index);
- if (kill)
- bitmap_clear_bit (kill, index);
- }
- }
+ {
+ HOST_WIDE_INT end = store_info->offset + store_info->width;
+ for (i = store_info->offset; i < end; i++)
+ {
+ int index = get_bitmap_index (group_info, i);
+ if (index != 0)
+ {
+ bitmap_set_bit (gen, index);
+ if (kill)
+ bitmap_clear_bit (kill, index);
+ }
+ }
+ }
store_info = store_info->next;
}
}
@@ -2834,9 +2869,9 @@ scan_reads (insn_info_t insn_info, bitma
{
if (i == read_info->group_id)
{
- if (read_info->begin > read_info->end)
+ if (!known_size_p (read_info->width))
{
- /* Begin > end for block mode reads. */
+ /* Handle block mode reads. */
if (kill)
bitmap_ior_into (kill, group->group_kill);
bitmap_and_compl_into (gen, group->group_kill);
@@ -2846,7 +2881,8 @@ scan_reads (insn_info_t insn_info, bitma
/* The groups are the same, just process the
offsets. */
HOST_WIDE_INT j;
- for (j = read_info->begin; j < read_info->end; j++)
+ HOST_WIDE_INT end = read_info->offset + read_info->width;
+ for (j = read_info->offset; j < end; j++)
{
int index = get_bitmap_index (group, j);
if (index != 0)
@@ -3265,7 +3301,8 @@ dse_step5 (void)
HOST_WIDE_INT i;
group_info *group_info = rtx_group_vec[store_info->group_id];
- for (i = store_info->begin; i < store_info->end; i++)
+ HOST_WIDE_INT end = store_info->offset + store_info->width;
+ for (i = store_info->offset; i < end; i++)
{
int index = get_bitmap_index (group_info, i);
