On 04/04 22:17:48, Maxim Uvarov wrote:
> On 04/04/17 21:48, Brian Brooks wrote:
> > Signed-off-by: Ola Liljedahl <[email protected]>
> > Reviewed-by: Brian Brooks <[email protected]>
> > Reviewed-by: Honnappa Nagarahalli <[email protected]>
> > ---
> > 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?
> > +
> > +#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
> >
>
