From: Richard Sandiford <richard.sandiford@arm.com>
To: Richard Biener <richard.guenther@gmail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [24/67] Replace a != BLKmode check with is_a <scalar_int_mode>
Date: Fri, 09 Dec 2016 14:42:00 -0000 [thread overview]
Message-ID: <8737hxdv11.fsf@e105548-lin.cambridge.arm.com> (raw)
In-Reply-To: <CAFiYyc0WUq5GRLHcnLQGqeQqLacWjx5y_HU5ppMuJbOfMr5wwQ@mail.gmail.com> (Richard Biener's message of "Fri, 9 Dec 2016 14:22:28 +0100")
Richard Biener <richard.guenther@gmail.com> writes:
> On Fri, Dec 9, 2016 at 2:08 PM, Richard Sandiford
> <richard.sandiford@arm.com> wrote:
>> This patch replaces a check against BLKmode with a check
>> of is_a <scalar_int_mode>, in a case where scalar integer
>> modes were the only useful alternatives left.
>
> So why's BLKmode no longer sth valid to check against? The check is
> only there to guard GET_MODE_ALIGNMENT / SLOW_UNALIGNED_ACCESS.
Checking against BLKmode is still valid. The patch is just rewriting
the check into an alternative form. The end goal is to operate on
scalar_int_modes in cases where we know the mode is an integer.
In this case the mode we're checking is the result of a type_for_size
call, which is defined to always return an integer type:
/* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
integer type with at least that precision. */
TBH I was a bit surprised we could see a BLKmode integer type; I thought
we disallowed types that didn't have a suitable scalar_mode_supported_p
mode. But assuming that the check is necessary, the only thing it
lets through are scalar integer modes.
Thanks,
Richard
>> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
>> index d00625b..c6b5411 100644
>> --- a/gcc/gimple-fold.c
>> +++ b/gcc/gimple-fold.c
>> @@ -713,31 +713,29 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
>> unsigned ilen = tree_to_uhwi (len);
>> if (pow2p_hwi (ilen))
>> {
>> + scalar_int_mode mode;
>> tree type = lang_hooks.types.type_for_size (ilen * 8, 1);
>> if (type
>> - && TYPE_MODE (type) != BLKmode
>> - && (GET_MODE_SIZE (TYPE_MODE (type)) * BITS_PER_UNIT
>> - == ilen * 8)
>> + && is_a <scalar_int_mode> (TYPE_MODE (type), &mode)
>> + && GET_MODE_SIZE (mode) * BITS_PER_UNIT == ilen * 8
>> /* If the destination pointer is not aligned we must be able
>> to emit an unaligned store. */
>> - && (dest_align >= GET_MODE_ALIGNMENT (TYPE_MODE (type))
>> - || !SLOW_UNALIGNED_ACCESS (TYPE_MODE (type), dest_align)
>> - || (optab_handler (movmisalign_optab, TYPE_MODE (type))
>> + && (dest_align >= GET_MODE_ALIGNMENT (mode)
>> + || !SLOW_UNALIGNED_ACCESS (mode, dest_align)
>> + || (optab_handler (movmisalign_optab, mode)
>> != CODE_FOR_nothing)))
>> {
>> tree srctype = type;
>> tree desttype = type;
>> - if (src_align < GET_MODE_ALIGNMENT (TYPE_MODE (type)))
>> + if (src_align < GET_MODE_ALIGNMENT (mode))
>> srctype = build_aligned_type (type, src_align);
>> tree srcmem = fold_build2 (MEM_REF, srctype, src, off0);
>> tree tem = fold_const_aggregate_ref (srcmem);
>> if (tem)
>> srcmem = tem;
>> - else if (src_align < GET_MODE_ALIGNMENT (TYPE_MODE (type))
>> - && SLOW_UNALIGNED_ACCESS (TYPE_MODE (type),
>> - src_align)
>> - && (optab_handler (movmisalign_optab,
>> - TYPE_MODE (type))
>> + else if (src_align < GET_MODE_ALIGNMENT (mode)
>> + && SLOW_UNALIGNED_ACCESS (mode, src_align)
>> + && (optab_handler (movmisalign_optab, mode)
>> == CODE_FOR_nothing))
>> srcmem = NULL_TREE;
>> if (srcmem)
>> @@ -753,7 +751,7 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
>> gimple_set_vuse (new_stmt, gimple_vuse (stmt));
>> gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
>> }
>> - if (dest_align < GET_MODE_ALIGNMENT (TYPE_MODE (type)))
>> + if (dest_align < GET_MODE_ALIGNMENT (mode))
>> desttype = build_aligned_type (type, dest_align);
>> new_stmt
>> = gimple_build_assign (fold_build2 (MEM_REF, desttype,
>>
next prev parent reply other threads:[~2016-12-09 14:42 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-09 12:48 [0/67] Add wrapper classes for machine_modes Richard Sandiford
2016-12-09 12:50 ` [1/67] Add an E_ prefix to mode names and update case statements Richard Sandiford
2016-12-09 12:52 ` [2/67] Make machine_mode a class Richard Sandiford
2016-12-15 22:34 ` Trevor Saunders
2016-12-09 12:53 ` [3/67] Add GDB pretty printer for machine mode classes Richard Sandiford
2016-12-09 12:54 ` [4/67] Add FOR_EACH iterators for modes Richard Sandiford
2016-12-09 12:55 ` [5/67] Small tweak to array_value_type Richard Sandiford
2016-12-09 12:55 ` [6/67] Make GET_MODE_WIDER return an opt_mode Richard Sandiford
2016-12-09 12:57 ` [7/67] Add scalar_float_mode Richard Sandiford
2016-12-09 14:19 ` David Malcolm
2016-12-09 14:30 ` Richard Sandiford
2016-12-09 12:57 ` [8/67] Simplify gen_trunc/extend_conv_libfunc Richard Sandiford
2016-12-09 12:58 ` [9/67] Add SCALAR_FLOAT_TYPE_MODE Richard Sandiford
2016-12-09 12:59 ` [10/67] Make assemble_real take a scalar_float_mode Richard Sandiford
2016-12-09 13:00 ` [11/67] Add a float_mode_for_size helper function Richard Sandiford
2016-12-09 13:00 ` [12/67] Use opt_scalar_float_mode when iterating over float modes Richard Sandiford
2016-12-09 13:00 ` [0/67] Add wrapper classes for machine_modes Richard Biener
2016-12-09 13:54 ` Richard Sandiford
2016-12-09 13:01 ` [13/67] Make floatn_mode return an opt_scalar_float_mode Richard Sandiford
2016-12-09 13:02 ` [14/67] Make libgcc_floating_mode_supported_p take a scalar_float_mode Richard Sandiford
2016-12-09 13:03 ` [15/67] Add scalar_int_mode Richard Sandiford
2016-12-09 13:03 ` [16/67] Add scalar_int_mode_pod Richard Sandiford
2016-12-09 13:04 ` [17/67] Add an int_mode_for_size helper function Richard Sandiford
2016-12-09 13:05 ` [18/67] Make int_mode_for_mode return an opt_scalar_int_mode Richard Sandiford
2016-12-09 13:05 ` [19/67] Add a smallest_int_mode_for_size helper function Richard Sandiford
2016-12-09 13:06 ` [20/67] Replace MODE_INT checks with is_int_mode Richard Sandiford
2016-12-09 13:07 ` [21/67] Replace SCALAR_INT_MODE_P checks with is_a <scalar_int_mode> Richard Sandiford
2016-12-09 13:07 ` [22/67] Replace !VECTOR_MODE_P " Richard Sandiford
2016-12-09 13:08 ` [23/67] Replace != VOIDmode checks " Richard Sandiford
2016-12-09 13:08 ` [24/67] Replace a != BLKmode check " Richard Sandiford
2016-12-09 13:22 ` Richard Biener
2016-12-09 14:42 ` Richard Sandiford [this message]
2016-12-09 13:09 ` [25/67] Use is_a <scalar_int_mode> for bitmask optimisations Richard Sandiford
2016-12-09 13:10 ` [26/67] Use is_a <scalar_int_mode> in subreg/extract simplifications Richard Sandiford
2016-12-09 13:10 ` [27/67] Use is_a <scalar_int_mode> before LOAD_EXTEND_OP Richard Sandiford
2016-12-09 13:11 ` [28/67] Use is_a <scalar_int_mode> for miscellaneous types of test Richard Sandiford
2016-12-09 13:12 ` [29/67] Make some *_loc_descriptor helpers take scalar_int_mode Richard Sandiford
2016-12-09 13:12 ` [30/67] Use scalar_int_mode for doubleword splits Richard Sandiford
2016-12-09 13:13 ` [31/67] Use scalar_int_mode for move2add Richard Sandiford
2016-12-09 13:14 ` [33/67] Add a NARROWEST_INT_MODE macro Richard Sandiford
2016-12-09 13:14 ` [32/67] Check is_a <scalar_int_mode> before calling valid_pointer_mode Richard Sandiford
2016-12-09 13:15 ` [34/67] Add a SCALAR_INT_TYPE_MODE macro Richard Sandiford
2016-12-09 13:16 ` [36/67] Use scalar_int_mode in the RTL iv routines Richard Sandiford
2016-12-09 13:16 ` [35/67] Add uses of as_a <scalar_int_mode> Richard Sandiford
2016-12-09 13:17 ` [37/67] Use scalar_int_mode when emitting cstores Richard Sandiford
2016-12-09 13:17 ` [38/67] Move SCALAR_INT_MODE_P out of strict_volatile_bitfield_p Richard Sandiford
2016-12-09 13:18 ` [39/67] Two changes to the get_best_mode interface Richard Sandiford
2016-12-09 13:19 ` [40/67] Use scalar_int_mode for extraction_insn fields Richard Sandiford
2016-12-09 13:20 ` [41/67] Split scalar integer handling out of force_to_mode Richard Sandiford
2016-12-09 13:20 ` [42/67] Use scalar_int_mode in simplify_shift_const_1 Richard Sandiford
2016-12-09 13:22 ` [44/67] Make simplify_and_const_int take a scalar_int_mode Richard Sandiford
2016-12-09 13:22 ` [43/67] Use scalar_int_mode in simplify_comparison Richard Sandiford
2016-12-09 13:23 ` [46/67] Make widest_int_mode_for_size return a scalar_int_mode Richard Sandiford
2016-12-09 13:23 ` [45/67] Make extract_left_shift take " Richard Sandiford
2016-12-09 13:24 ` [47/67] Make subroutines of nonzero_bits operate on scalar_int_mode Richard Sandiford
2016-12-09 13:25 ` [48/67] Make subroutines of num_sign_bit_copies " Richard Sandiford
2016-12-09 13:25 ` [49/67] Simplify nonzero/num_sign_bits hooks Richard Sandiford
2016-12-09 13:28 ` [50/67] Add helper routines for SUBREG_PROMOTED_VAR_P subregs Richard Sandiford
2016-12-09 13:30 ` [52/67] Use scalar_int_mode in extract/store_bit_field Richard Sandiford
2016-12-09 13:30 ` [51/67] Use opt_scalar_int_mode when iterating over integer modes Richard Sandiford
2016-12-09 13:31 ` [54/67] Add explicit int checks for alternative optab implementations Richard Sandiford
2016-12-09 13:31 ` [53/67] Pass a mode to const_scalar_mask_from_tree Richard Sandiford
2016-12-09 13:33 ` [56/67] Use the more specific type when two modes are known to be equal Richard Sandiford
2016-12-09 13:33 ` [55/67] Use scalar_int_mode in simplify_const_unary_operation Richard Sandiford
2016-12-09 13:34 ` [57/67] Use scalar_int_mode in expand_expr_addr_expr Richard Sandiford
2016-12-09 13:35 ` [58/67] Use scalar_int_mode in a try_combine optimisation Richard Sandiford
2016-12-09 13:36 ` [59/67] Add a rtx_jump_table_data::get_data_mode helper Richard Sandiford
2016-12-09 13:36 ` [60/67] Pass scalar_int_modes to do_jump_by_parts_* Richard Sandiford
2016-12-09 13:37 ` [61/67] Use scalar_int_mode in the AArch64 port Richard Sandiford
2016-12-09 13:38 ` [62/67] Big machine_mode to scalar_int_mode replacement Richard Sandiford
2016-12-09 13:38 ` [63/67] Simplifications after type switch Richard Sandiford
2016-12-09 13:40 ` [65/67] Use scalar_mode in the AArch64 port Richard Sandiford
2016-12-09 13:40 ` [66/67] Add a scalar_mode_pod class Richard Sandiford
2016-12-09 13:40 ` [64/67] Add a scalar_mode class Richard Sandiford
2016-12-09 13:41 ` [67/67] Add a complex_mode class Richard Sandiford
2016-12-09 18:20 ` [0/67] Add wrapper classes for machine_modes Sandra Loosemore
2017-05-05 7:08 ` Jeff Law
2017-05-24 14:33 ` Richard Sandiford
2017-06-28 17:27 ` Jeff Law
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