[Mesa-dev] [PATCH 07/15] util/bitset: Add C++ wrapper for static-size bitsets.
Francisco Jerez
currojerez at riseup.net
Thu Feb 15 18:25:17 UTC 2018
Eric Engestrom <eric.engestrom at imgtec.com> writes:
> On Wednesday, 2018-02-14 13:18:29 -0800, Francisco Jerez wrote:
>> ---
>> src/util/bitset.h | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 114 insertions(+)
>>
>> diff --git a/src/util/bitset.h b/src/util/bitset.h
>> index 2404ce7f630..7bb5f3c83cf 100644
>> --- a/src/util/bitset.h
>> +++ b/src/util/bitset.h
>> @@ -132,4 +132,118 @@ __bitset_next_set(unsigned i, BITSET_WORD *tmp,
>> for (__tmp = *(__set), __i = 0; \
>> (__i = __bitset_next_set(__i, &__tmp, __set, __size)) < __size;)
>>
>> +#ifdef __cplusplus
>> +
>> +/**
>> + * Simple C++ wrapper of a bitset type of static size, with value semantics
>> + * and basic bitwise arithmetic operators. The operators defined below are
>> + * expected to have the same semantics as the same operator applied to other
>> + * fundamental integer types. T is the name of the struct to instantiate
>> + * it as, and N is the number of bits in the bitset.
>> + */
>
> Any reason not to use std::bitset<N> for this?
> http://en.cppreference.com/w/cpp/utility/bitset
>
It would be nice, but I don't think std::bitset is guaranteed to be a
standard layout type which the next patch relies on.
>> +#define DECLARE_BITSET_T(T, N) struct T { \
>> + /* XXX - Replace this with an implicitly-defined \
>> + * constructor when support for C++11 defaulted \
>> + * constructors can be assumed (available on GCC 4.4 and \
>> + * later) in order to make the object trivially \
>> + * constructible like a fundamental integer type for \
>> + * convenience. \
>> + */ \
>> + T() \
>> + { \
>> + } \
>> + \
>> + T(BITSET_WORD x) \
>> + { \
>> + for (unsigned i = 0; i < BITSET_WORDS(N); i++, x = 0) \
>> + words[i] = x; \
>> + } \
>> + \
>> + EXPLICIT_CONVERSION \
>> + operator bool() const \
>> + { \
>> + for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
>> + if (words[i]) \
>> + return true; \
>> + return false; \
>> + } \
>> + \
>> + friend bool \
>> + operator==(const T &b, const T &c) \
>> + { \
>> + return BITSET_EQUAL(b.words, c.words); \
>> + } \
>> + \
>> + friend bool \
>> + operator!=(const T &b, const T &c) \
>> + { \
>> + return !(b == c); \
>> + } \
>> + \
>> + friend T \
>> + operator~(const T &b) \
>> + { \
>> + T c; \
>> + for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
>> + c.words[i] = ~b.words[i]; \
>> + return c; \
>> + } \
>> + \
>> + T & \
>> + operator|=(const T &b) \
>> + { \
>> + for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
>> + words[i] |= b.words[i]; \
>> + return *this; \
>> + } \
>> + \
>> + friend T \
>> + operator|(const T &b, const T &c) \
>> + { \
>> + T d = b; \
>> + d |= c; \
>> + return d; \
>> + } \
>> + \
>> + T & \
>> + operator&=(const T &b) \
>> + { \
>> + for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
>> + words[i] &= b.words[i]; \
>> + return *this; \
>> + } \
>> + \
>> + friend T \
>> + operator&(const T &b, const T &c) \
>> + { \
>> + T d = b; \
>> + d &= c; \
>> + return d; \
>> + } \
>> + \
>> + bool \
>> + test(unsigned i) const \
>> + { \
>> + return BITSET_TEST(words, i); \
>> + } \
>> + \
>> + T & \
>> + set(unsigned i) \
>> + { \
>> + BITSET_SET(words, i); \
>> + return *this; \
>> + } \
>> + \
>> + T & \
>> + clear(unsigned i) \
>> + { \
>> + BITSET_CLEAR(words, i); \
>> + return *this; \
>> + } \
>> + \
>> + BITSET_WORD words[BITSET_WORDS(N)]; \
>> + }
>> +
>> +#endif
>> +
>> #endif
>> --
>> 2.16.1
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
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