On Tue, Apr 4, 2017 at 3:08 PM, Brian Brooks <brian.bro...@arm.com> wrote:
> On 04/04 22:17:48, Maxim Uvarov wrote:
>> On 04/04/17 21:48, Brian Brooks wrote:
>> > Signed-off-by: Ola Liljedahl <ola.liljed...@arm.com>
>> > Reviewed-by: Brian Brooks <brian.bro...@arm.com>
>> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
>> > ---
>> > platform/linux-generic/include/odp_bitset.h | 155
>> > ++++++++++++++++++++++++++++
>> > 1 file changed, 155 insertions(+)
>> > create mode 100644 platform/linux-generic/include/odp_bitset.h
>> >
>> > diff --git a/platform/linux-generic/include/odp_bitset.h
>> > b/platform/linux-generic/include/odp_bitset.h
>> > new file mode 100644
>> > index 00000000..db004267
>> > --- /dev/null
>> > +++ b/platform/linux-generic/include/odp_bitset.h
>> > @@ -0,0 +1,155 @@
>> > +/* Copyright (c) 2017, ARM Limited
>> > + * All rights reserved.
>> > + *
>> > + * SPDX-License-Identifier: BSD-3-Clause
>> > + */
>>
>>
>> Should be Linaro copyright and patches needs to be resend from Linaro
>> address.
>
> Can you raise this concern through the appropriate channels?
Per the Linaro membership agreement, contributions from assignees may
be from company addresses, but assignees should use their linaro.org
e-mail addresses.
The Linaro copyright is part of the contributor's agreement. You can
retain the ARM copyright as well. See, for example,
odp_traffic_mngr.c, which contains both an EZchip and a Linaro
copyright.
>
>> > +
>> > +#ifndef _ODP_BITSET_H_
>> > +#define _ODP_BITSET_H_
>> > +
>> > +/******************************************************************************
>> > + * bitset abstract data type
>> > +
>> > *****************************************************************************/
>> > +/* This could be a struct of scalars to support larger bit sets */
>> > +
>> > +#if ATOM_BITSET_SIZE <= 32
>> > +
>> > +typedef uint32_t bitset_t;
>> > +
>> > +static inline bitset_t bitset_mask(uint32_t bit)
>> > +{
>> > + return 1UL << bit;
>> > +}
>> > +
>> > +/* Return first-bit-set with StdC ffs() semantics */
>> > +static inline uint32_t bitset_ffs(bitset_t b)
>> > +{
>> > + return __builtin_ffsl(b);
>> > +}
>> > +
>> > +/* Load-exclusive with memory ordering */
>> > +static inline bitset_t bitset_ldex(bitset_t *bs, int mo)
>> > +{
>> > + return LDXR32(bs, mo);
>>
>> is it arm specific?
>
> Can you please explain?
>
>> > +}
>> > +
>> > +#elif ATOM_BITSET_SIZE <= 64
>> > +
>> > +typedef uint64_t bitset_t;
>> > +
>> > +static inline bitset_t bitset_mask(uint32_t bit)
>> > +{
>> > + return 1ULL << bit;
>> > +}
>> > +
>> > +/* Return first-bit-set with StdC ffs() semantics */
>> > +static inline uint32_t bitset_ffs(bitset_t b)
>> > +{
>> > + return __builtin_ffsll(b);
>> > +}
>> > +
>> > +/* Load-exclusive with memory ordering */
>> > +static inline bitset_t bitset_ldex(bitset_t *bs, int mo)
>> > +{
>> > + return LDXR64(bs, mo);
>> > +}
>> > +
>> > +#elif ATOM_BITSET_SIZE <= 128
>> > +
>> > +#if __SIZEOF_INT128__ == 16
>> > +typedef unsigned __int128 bitset_t;
>> > +
>>
>> so bitset_t can be 32 or 64 or 128. That might be difficult. And sort of
>> this needs to be done at ./configure stage, I think.
>
> Can you please explain?
>
>> > +static inline bitset_t bitset_mask(uint32_t bit)
>> > +{
>> > + if (bit < 64)
>> > + return 1ULL << bit;
>> > + else
>> > + return (unsigned __int128)(1ULL << (bit - 64)) << 64;
>> > +}
>>
>> you set 32 bit mast to 128 bit value, other 96 bits unreachable. Why is
>> that needed?
>
> 'bit' represents a bit position in the scalar type. Unfortunately GCC
> doesn't support 128-bit numeric literals, so you have to generate the
> mask using 'ull' and then cast that to the scalar type and then shift
> that even further. Please take another look.
>
>> > +
>> > +/* Return first-bit-set with StdC ffs() semantics */
>> > +static inline uint32_t bitset_ffs(bitset_t b)
>> > +{
>> > + if ((uint64_t)b != 0)
>> > + return __builtin_ffsll((uint64_t)b);
>> > + else if ((b >> 64) != 0)
>> > + return __builtin_ffsll((uint64_t)(b >> 64)) + 64;
>> > + else
>> > + return 0;
>> > +}
>> > +
>> > +/* Load-exclusive with memory ordering */
>> > +static inline bitset_t bitset_ldex(bitset_t *bs, int mo)
>> > +{
>> > + return LDXR128(bs, mo);
>> > +}
>> > +
>> > +#else
>> > +#error __int128 not supported by compiler
>>
>>
>> this should be captured at configure stage, not while compiling project
>> code.
>
> When you use the macros provided by the compiler, e.g. system-specific
> macros, you can eliminate the dependency on the build system.. for achieving
> the same thing. This is an advantage.
>
>> Maxim.
>>
>> > +#endif
>> > +
>> > +#else
>> > +#error Unsupported size of bit sets (ATOM_BITSET_SIZE)
>> > +#endif
>> > +
>> > +/* Atomic load with memory ordering */
>> > +static inline bitset_t atom_bitset_load(bitset_t *bs, int mo)
>> > +{
>> > + return __atomic_load_n(bs, mo);
>> > +}
>> > +
>> > +/* Atomic bit set with memory ordering */
>> > +static inline void atom_bitset_set(bitset_t *bs, uint32_t bit, int mo)
>> > +{
>> > + (void)__atomic_fetch_or(bs, bitset_mask(bit), mo);
>> > +}
>> > +
>> > +/* Atomic bit clear with memory ordering */
>> > +static inline void atom_bitset_clr(bitset_t *bs, uint32_t bit, int mo)
>> > +{
>> > + (void)__atomic_fetch_and(bs, ~bitset_mask(bit), mo);
>> > +}
>> > +
>> > +/* Atomic exchange with memory ordering */
>> > +static inline bitset_t atom_bitset_xchg(bitset_t *bs, bitset_t neu, int
>> > mo)
>> > +{
>> > + return __atomic_exchange_n(bs, neu, mo);
>> > +}
>> > +
>> > +/* Return a & ~b */
>> > +static inline bitset_t bitset_andn(bitset_t a, bitset_t b)
>> > +{
>> > + return a & ~b;
>> > +}
>> > +
>> > +static inline bool bitset_is_eql(bitset_t a, bitset_t b)
>> > +{
>> > + return a == b;
>> > +}
>> > +
>> > +static inline bitset_t bitset_clr(bitset_t bs, uint32_t bit)
>> > +{
>> > + return bs & ~bitset_mask(bit);
>> > +}
>> > +
>> > +static inline bitset_t bitset_set(bitset_t bs, uint32_t bit)
>> > +{
>> > + return bs | bitset_mask(bit);
>> > +}
>> > +
>> > +static inline bitset_t bitset_null(void)
>> > +{
>> > + return 0U;
>> > +}
>> > +
>> > +static inline bool bitset_is_null(bitset_t a)
>> > +{
>> > + return a == 0U;
>> > +}
>> > +
>> > +static inline bool bitset_is_set(bitset_t a, uint32_t bit)
>> > +{
>> > + return (a & bitset_mask(bit)) != 0;
>> > +}
>> > +
>> > +#endif
>> >
>>
