Committed as r14-4835.
https://gcc.gnu.org/g:f08ca5903c7a02b450b93143467f70b9fd8e0085
Thanks
Gui Haochen
在 2023/10/20 16:49, Richard Sandiford 写道:
> HAO CHEN GUI <guih...@linux.ibm.com> writes:
>> Hi,
>> Vector mode instructions are efficient for compare on some targets.
>> This patch enables vector mode for compare_by_pieces. Two help
>> functions are added to check if vector mode is available for certain
>> by pieces operations and if if optabs exists for the mode and certain
>> by pieces operations. One member is added in class op_by_pieces_d to
>> record the type of operations.
>>
>> The test case is in the second patch which is rs6000 specific.
>>
>> Compared to last version, the main change is to add a target hook
>> check - scalar_mode_supported_p when retrieving the available scalar
>> modes. The mode which is not supported for a target should be skipped.
>> (e.g. TImode on ppc). Also some function names and comments are refined
>> according to reviewer's advice.
>>
>> Bootstrapped and tested on x86 and powerpc64-linux BE and LE with no
>> regressions.
>>
>> Thanks
>> Gui Haochen
>>
>> ChangeLog
>> Expand: Enable vector mode for by pieces compares
>>
>> Vector mode compare instructions are efficient for equality compare on
>> rs6000. This patch refactors the codes of by pieces operation to enable
>> vector mode for compare.
>>
>> gcc/
>> PR target/111449
>> * expr.cc (can_use_qi_vectors): New function to return true if
>> we know how to implement OP using vectors of bytes.
>> (qi_vector_mode_supported_p): New function to check if optabs
>> exists for the mode and certain by pieces operations.
>> (widest_fixed_size_mode_for_size): Replace the second argument
>> with the type of by pieces operations. Call can_use_qi_vectors
>> and qi_vector_mode_supported_p to do the check. Call
>> scalar_mode_supported_p to check if the scalar mode is supported.
>> (by_pieces_ninsns): Pass the type of by pieces operation to
>> widest_fixed_size_mode_for_size.
>> (class op_by_pieces_d): Remove m_qi_vector_mode. Add m_op to
>> record the type of by pieces operations.
>> (op_by_pieces_d::op_by_pieces_d): Change last argument to the
>> type of by pieces operations, initialize m_op with it. Pass
>> m_op to function widest_fixed_size_mode_for_size.
>> (op_by_pieces_d::get_usable_mode): Pass m_op to function
>> widest_fixed_size_mode_for_size.
>> (op_by_pieces_d::smallest_fixed_size_mode_for_size): Call
>> can_use_qi_vectors and qi_vector_mode_supported_p to do the
>> check.
>> (op_by_pieces_d::run): Pass m_op to function
>> widest_fixed_size_mode_for_size.
>> (move_by_pieces_d::move_by_pieces_d): Set m_op to MOVE_BY_PIECES.
>> (store_by_pieces_d::store_by_pieces_d): Set m_op with the op.
>> (can_store_by_pieces): Pass the type of by pieces operations to
>> widest_fixed_size_mode_for_size.
>> (clear_by_pieces): Initialize class store_by_pieces_d with
>> CLEAR_BY_PIECES.
>> (compare_by_pieces_d::compare_by_pieces_d): Set m_op to
>> COMPARE_BY_PIECES.
>
> OK, thanks. And thanks for your patience.
>
> Richard
>
>> patch.diff
>> diff --git a/gcc/expr.cc b/gcc/expr.cc
>> index 2c9930ec674..ad5f9dd8ec2 100644
>> --- a/gcc/expr.cc
>> +++ b/gcc/expr.cc
>> @@ -988,18 +988,44 @@ alignment_for_piecewise_move (unsigned int max_pieces,
>> unsigned int align)
>> return align;
>> }
>>
>> -/* Return the widest QI vector, if QI_MODE is true, or integer mode
>> - that is narrower than SIZE bytes. */
>> +/* Return true if we know how to implement OP using vectors of bytes. */
>> +static bool
>> +can_use_qi_vectors (by_pieces_operation op)
>> +{
>> + return (op == COMPARE_BY_PIECES
>> + || op == SET_BY_PIECES
>> + || op == CLEAR_BY_PIECES);
>> +}
>> +
>> +/* Return true if optabs exists for the mode and certain by pieces
>> + operations. */
>> +static bool
>> +qi_vector_mode_supported_p (fixed_size_mode mode, by_pieces_operation op)
>> +{
>> + if ((op == SET_BY_PIECES || op == CLEAR_BY_PIECES)
>> + && optab_handler (vec_duplicate_optab, mode) != CODE_FOR_nothing)
>> + return true;
>> +
>> + if (op == COMPARE_BY_PIECES
>> + && optab_handler (mov_optab, mode) != CODE_FOR_nothing
>> + && can_compare_p (EQ, mode, ccp_jump))
>> + return true;
>>
>> + return false;
>> +}
>> +
>> +/* Return the widest mode that can be used to perform part of an
>> + operation OP on SIZE bytes. Try to use QI vector modes where
>> + possible. */
>> static fixed_size_mode
>> -widest_fixed_size_mode_for_size (unsigned int size, bool qi_vector)
>> +widest_fixed_size_mode_for_size (unsigned int size, by_pieces_operation op)
>> {
>> fixed_size_mode result = NARROWEST_INT_MODE;
>>
>> gcc_checking_assert (size > 1);
>>
>> /* Use QI vector only if size is wider than a WORD. */
>> - if (qi_vector && size > UNITS_PER_WORD)
>> + if (can_use_qi_vectors (op) && size > UNITS_PER_WORD)
>> {
>> machine_mode mode;
>> fixed_size_mode candidate;
>> @@ -1009,8 +1035,7 @@ widest_fixed_size_mode_for_size (unsigned int size,
>> bool qi_vector)
>> {
>> if (GET_MODE_SIZE (candidate) >= size)
>> break;
>> - if (optab_handler (vec_duplicate_optab, candidate)
>> - != CODE_FOR_nothing)
>> + if (qi_vector_mode_supported_p (candidate, op))
>> result = candidate;
>> }
>>
>> @@ -1019,9 +1044,14 @@ widest_fixed_size_mode_for_size (unsigned int size,
>> bool qi_vector)
>> }
>>
>> opt_scalar_int_mode tmode;
>> + scalar_int_mode mode;
>> FOR_EACH_MODE_IN_CLASS (tmode, MODE_INT)
>> - if (GET_MODE_SIZE (tmode.require ()) < size)
>> - result = tmode.require ();
>> + {
>> + mode = tmode.require ();
>> + if (GET_MODE_SIZE (mode) < size
>> + && targetm.scalar_mode_supported_p (mode))
>> + result = mode;
>> + }
>>
>> return result;
>> }
>> @@ -1061,8 +1091,7 @@ by_pieces_ninsns (unsigned HOST_WIDE_INT l, unsigned
>> int align,
>> {
>> /* NB: Round up L and ALIGN to the widest integer mode for
>> MAX_SIZE. */
>> - mode = widest_fixed_size_mode_for_size (max_size,
>> - op == SET_BY_PIECES);
>> + mode = widest_fixed_size_mode_for_size (max_size, op);
>> if (optab_handler (mov_optab, mode) != CODE_FOR_nothing)
>> {
>> unsigned HOST_WIDE_INT up = ROUND_UP (l, GET_MODE_SIZE (mode));
>> @@ -1076,8 +1105,7 @@ by_pieces_ninsns (unsigned HOST_WIDE_INT l, unsigned
>> int align,
>>
>> while (max_size > 1 && l > 0)
>> {
>> - mode = widest_fixed_size_mode_for_size (max_size,
>> - op == SET_BY_PIECES);
>> + mode = widest_fixed_size_mode_for_size (max_size, op);
>> enum insn_code icode;
>>
>> unsigned int modesize = GET_MODE_SIZE (mode);
>> @@ -1317,8 +1345,8 @@ class op_by_pieces_d
>> bool m_push;
>> /* True if targetm.overlap_op_by_pieces_p () returns true. */
>> bool m_overlap_op_by_pieces;
>> - /* True if QI vector mode can be used. */
>> - bool m_qi_vector_mode;
>> + /* The type of operation that we're performing. */
>> + by_pieces_operation m_op;
>>
>> /* Virtual functions, overriden by derived classes for the specific
>> operation. */
>> @@ -1331,7 +1359,7 @@ class op_by_pieces_d
>> public:
>> op_by_pieces_d (unsigned int, rtx, bool, rtx, bool, by_pieces_constfn,
>> void *, unsigned HOST_WIDE_INT, unsigned int, bool,
>> - bool = false);
>> + by_pieces_operation);
>> void run ();
>> };
>>
>> @@ -1349,11 +1377,11 @@ op_by_pieces_d::op_by_pieces_d (unsigned int
>> max_pieces, rtx to,
>> void *from_cfn_data,
>> unsigned HOST_WIDE_INT len,
>> unsigned int align, bool push,
>> - bool qi_vector_mode)
>> + by_pieces_operation op)
>> : m_to (to, to_load, NULL, NULL),
>> m_from (from, from_load, from_cfn, from_cfn_data),
>> m_len (len), m_max_size (max_pieces + 1),
>> - m_push (push), m_qi_vector_mode (qi_vector_mode)
>> + m_push (push), m_op (op)
>> {
>> int toi = m_to.get_addr_inc ();
>> int fromi = m_from.get_addr_inc ();
>> @@ -1375,8 +1403,7 @@ op_by_pieces_d::op_by_pieces_d (unsigned int
>> max_pieces, rtx to,
>> {
>> /* Find the mode of the largest comparison. */
>> fixed_size_mode mode
>> - = widest_fixed_size_mode_for_size (m_max_size,
>> - m_qi_vector_mode);
>> + = widest_fixed_size_mode_for_size (m_max_size, m_op);
>>
>> m_from.decide_autoinc (mode, m_reverse, len);
>> m_to.decide_autoinc (mode, m_reverse, len);
>> @@ -1401,7 +1428,7 @@ op_by_pieces_d::get_usable_mode (fixed_size_mode mode,
>> unsigned int len)
>> if (len >= size && prepare_mode (mode, m_align))
>> break;
>> /* widest_fixed_size_mode_for_size checks SIZE > 1. */
>> - mode = widest_fixed_size_mode_for_size (size, m_qi_vector_mode);
>> + mode = widest_fixed_size_mode_for_size (size, m_op);
>> }
>> while (1);
>> return mode;
>> @@ -1414,7 +1441,7 @@ fixed_size_mode
>> op_by_pieces_d::smallest_fixed_size_mode_for_size (unsigned int size)
>> {
>> /* Use QI vector only for > size of WORD. */
>> - if (m_qi_vector_mode && size > UNITS_PER_WORD)
>> + if (can_use_qi_vectors (m_op) && size > UNITS_PER_WORD)
>> {
>> machine_mode mode;
>> fixed_size_mode candidate;
>> @@ -1427,8 +1454,7 @@ op_by_pieces_d::smallest_fixed_size_mode_for_size
>> (unsigned int size)
>> break;
>>
>> if (GET_MODE_SIZE (candidate) >= size
>> - && (optab_handler (vec_duplicate_optab, candidate)
>> - != CODE_FOR_nothing))
>> + && qi_vector_mode_supported_p (candidate, m_op))
>> return candidate;
>> }
>> }
>> @@ -1451,7 +1477,7 @@ op_by_pieces_d::run ()
>>
>> /* widest_fixed_size_mode_for_size checks M_MAX_SIZE > 1. */
>> fixed_size_mode mode
>> - = widest_fixed_size_mode_for_size (m_max_size, m_qi_vector_mode);
>> + = widest_fixed_size_mode_for_size (m_max_size, m_op);
>> mode = get_usable_mode (mode, length);
>>
>> by_pieces_prev to_prev = { nullptr, mode };
>> @@ -1516,8 +1542,7 @@ op_by_pieces_d::run ()
>> else
>> {
>> /* widest_fixed_size_mode_for_size checks SIZE > 1. */
>> - mode = widest_fixed_size_mode_for_size (size,
>> - m_qi_vector_mode);
>> + mode = widest_fixed_size_mode_for_size (size, m_op);
>> mode = get_usable_mode (mode, length);
>> }
>> }
>> @@ -1543,7 +1568,7 @@ class move_by_pieces_d : public op_by_pieces_d
>> move_by_pieces_d (rtx to, rtx from, unsigned HOST_WIDE_INT len,
>> unsigned int align)
>> : op_by_pieces_d (MOVE_MAX_PIECES, to, false, from, true, NULL,
>> - NULL, len, align, PUSHG_P (to))
>> + NULL, len, align, PUSHG_P (to), MOVE_BY_PIECES)
>> {
>> }
>> rtx finish_retmode (memop_ret);
>> @@ -1632,15 +1657,16 @@ move_by_pieces (rtx to, rtx from, unsigned
>> HOST_WIDE_INT len,
>> class store_by_pieces_d : public op_by_pieces_d
>> {
>> insn_gen_fn m_gen_fun;
>> +
>> void generate (rtx, rtx, machine_mode) final override;
>> bool prepare_mode (machine_mode, unsigned int) final override;
>>
>> public:
>> store_by_pieces_d (rtx to, by_pieces_constfn cfn, void *cfn_data,
>> unsigned HOST_WIDE_INT len, unsigned int align,
>> - bool qi_vector_mode)
>> + by_pieces_operation op)
>> : op_by_pieces_d (STORE_MAX_PIECES, to, false, NULL_RTX, true, cfn,
>> - cfn_data, len, align, false, qi_vector_mode)
>> + cfn_data, len, align, false, op)
>> {
>> }
>> rtx finish_retmode (memop_ret);
>> @@ -1729,8 +1755,8 @@ can_store_by_pieces (unsigned HOST_WIDE_INT len,
>> max_size = STORE_MAX_PIECES + 1;
>> while (max_size > 1 && l > 0)
>> {
>> - fixed_size_mode mode
>> - = widest_fixed_size_mode_for_size (max_size, memsetp);
>> + auto op = memsetp ? SET_BY_PIECES : STORE_BY_PIECES;
>> + auto mode = widest_fixed_size_mode_for_size (max_size, op);
>>
>> icode = optab_handler (mov_optab, mode);
>> if (icode != CODE_FOR_nothing
>> @@ -1793,7 +1819,7 @@ store_by_pieces (rtx to, unsigned HOST_WIDE_INT len,
>> optimize_insn_for_speed_p ()));
>>
>> store_by_pieces_d data (to, constfun, constfundata, len, align,
>> - memsetp);
>> + memsetp ? SET_BY_PIECES : STORE_BY_PIECES);
>> data.run ();
>>
>> if (retmode != RETURN_BEGIN)
>> @@ -1814,7 +1840,7 @@ clear_by_pieces (rtx to, unsigned HOST_WIDE_INT len,
>> unsigned int align)
>> /* Use builtin_memset_read_str to support vector mode broadcast. */
>> char c = 0;
>> store_by_pieces_d data (to, builtin_memset_read_str, &c, len, align,
>> - true);
>> + CLEAR_BY_PIECES);
>> data.run ();
>> }
>>
>> @@ -1832,12 +1858,13 @@ class compare_by_pieces_d : public op_by_pieces_d
>> void generate (rtx, rtx, machine_mode) final override;
>> bool prepare_mode (machine_mode, unsigned int) final override;
>> void finish_mode (machine_mode) final override;
>> +
>> public:
>> compare_by_pieces_d (rtx op0, rtx op1, by_pieces_constfn op1_cfn,
>> void *op1_cfn_data, HOST_WIDE_INT len, int align,
>> rtx_code_label *fail_label)
>> : op_by_pieces_d (COMPARE_MAX_PIECES, op0, true, op1, true, op1_cfn,
>> - op1_cfn_data, len, align, false)
>> + op1_cfn_data, len, align, false, COMPARE_BY_PIECES)
>> {
>> m_fail_label = fail_label;
>> }
