#ifndef INTERNAL_BITS_H /* -*- C -*- */ #define INTERNAL_BITS_H /** * @file * @brief Internal header for bitwise integer algorithms. * @author \@shyouhei * @copyright This file is a part of the programming language Ruby. * Permission is hereby granted, to either redistribute and/or * modify this file, provided that the conditions mentioned in the * file COPYING are met. Consult the file for details. * @see Henry S. Warren Jr., "Hacker's Delight" (2nd ed.), 2013. * @see SEI CERT C Coding Standard INT32-C. "Ensure that operations on * signed integers do not result in overflow" * @see https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html * @see https://clang.llvm.org/docs/LanguageExtensions.html#builtin-rotateleft * @see https://clang.llvm.org/docs/LanguageExtensions.html#builtin-rotateright * @see https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/byteswap-uint64-byteswap-ulong-byteswap-ushort * @see https://docs.microsoft.com/en-us/cpp/intrinsics/bitscanforward-bitscanforward64 * @see https://docs.microsoft.com/en-us/cpp/intrinsics/bitscanreverse-bitscanreverse64 * @see https://docs.microsoft.com/en-us/cpp/intrinsics/lzcnt16-lzcnt-lzcnt64 * @see https://docs.microsoft.com/en-us/cpp/intrinsics/popcnt16-popcnt-popcnt64 * @see https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_lzcnt_u32 * @see https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_tzcnt_u32 */ #include "ruby/config.h" #include /* for CHAR_BITS */ #include /* for uintptr_t */ #include "internal/compilers.h" /* for MSC_VERSION_SINCE */ #if MSC_VERSION_SINCE(1310) # include /* for _byteswap_uint64 */ #endif #if defined(__x86_64__) && defined(__LZCNT__) && ! defined(MJIT_HEADER) # /* Rule out MJIT_HEADER, which does not interface well with */ # include /* for _lzcnt_u64 */ #endif #if MSC_VERSION_SINCE(1400) # include /* for the following intrinsics */ # pragma intrinsic(_BitScanForward) # pragma intrinsic(_BitScanReverse) # ifdef _WIN64 # pragma intrinsic(_BitScanForward64) # pragma intrinsic(_BitScanReverse64) # endif #endif #include "ruby/ruby.h" /* for VALUE */ #include "internal/static_assert.h" /* for STATIC_ASSERT */ /* The most significant bit of the lower part of half-long integer. * If sizeof(long) == 4, this is 0x8000. * If sizeof(long) == 8, this is 0x80000000. */ #define HALF_LONG_MSB ((SIGNED_VALUE)1<<((SIZEOF_LONG*CHAR_BIT-1)/2)) #define SIGNED_INTEGER_TYPE_P(T) (0 > ((T)0)-1) #define SIGNED_INTEGER_MIN(T) \ ((sizeof(T) == sizeof(int8_t)) ? ((T)INT8_MIN) : \ ((sizeof(T) == sizeof(int16_t)) ? ((T)INT16_MIN) : \ ((sizeof(T) == sizeof(int32_t)) ? ((T)INT32_MIN) : \ ((sizeof(T) == sizeof(int64_t)) ? ((T)INT64_MIN) : \ 0)))) #define SIGNED_INTEGER_MAX(T) ((T)(SIGNED_INTEGER_MIN(T) ^ ((T)~(T)0))) #define UNSIGNED_INTEGER_MAX(T) ((T)~(T)0) #if __has_builtin(__builtin_mul_overflow_p) # define MUL_OVERFLOW_P(a, b) \ __builtin_mul_overflow_p((a), (b), (__typeof__(a * b))0) #elif __has_builtin(__builtin_mul_overflow) # define MUL_OVERFLOW_P(a, b) \ __extension__ ({ __typeof__(a) c; __builtin_mul_overflow((a), (b), &c); }) #endif #define MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, min, max) ( \ (a) == 0 ? 0 : \ (a) == -1 ? (b) < -(max) : \ (a) > 0 ? \ ((b) > 0 ? (max) / (a) < (b) : (min) / (a) > (b)) : \ ((b) > 0 ? (min) / (a) < (b) : (max) / (a) > (b))) #if __has_builtin(__builtin_mul_overflow_p) /* __builtin_mul_overflow_p can take bitfield */ /* and GCC permits bitfields for integers other than int */ # define MUL_OVERFLOW_FIXNUM_P(a, b) \ __extension__ ({ \ struct { long fixnum : sizeof(long) * CHAR_BIT - 1; } c; \ __builtin_mul_overflow_p((a), (b), c.fixnum); \ }) #else # define MUL_OVERFLOW_FIXNUM_P(a, b) \ MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, FIXNUM_MIN, FIXNUM_MAX) #endif #ifdef MUL_OVERFLOW_P # define MUL_OVERFLOW_LONG_LONG_P(a, b) MUL_OVERFLOW_P(a, b) # define MUL_OVERFLOW_LONG_P(a, b) MUL_OVERFLOW_P(a, b) # define MUL_OVERFLOW_INT_P(a, b) MUL_OVERFLOW_P(a, b) #else # define MUL_OVERFLOW_LONG_LONG_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, LLONG_MIN, LLONG_MAX) # define MUL_OVERFLOW_LONG_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, LONG_MIN, LONG_MAX) # define MUL_OVERFLOW_INT_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, INT_MIN, INT_MAX) #endif #ifdef HAVE_UINT128_T # define bit_length(x) \ (unsigned int) \ (sizeof(x) <= sizeof(int32_t) ? 32 - nlz_int32((uint32_t)(x)) : \ sizeof(x) <= sizeof(int64_t) ? 64 - nlz_int64((uint64_t)(x)) : \ 128 - nlz_int128((uint128_t)(x))) #else # define bit_length(x) \ (unsigned int) \ (sizeof(x) <= sizeof(int32_t) ? 32 - nlz_int32((uint32_t)(x)) : \ 64 - nlz_int64((uint64_t)(x))) #endif #ifndef swap16 # define swap16 ruby_swap16 #endif #ifndef swap32 # define swap32 ruby_swap32 #endif #ifndef swap64 # define swap64 ruby_swap64 #endif static inline uint16_t ruby_swap16(uint16_t); static inline uint32_t ruby_swap32(uint32_t); static inline uint64_t ruby_swap64(uint64_t); static inline unsigned nlz_int(unsigned x); static inline unsigned nlz_long(unsigned long x); static inline unsigned nlz_long_long(unsigned long long x); static inline unsigned nlz_intptr(uintptr_t x); static inline unsigned nlz_int32(uint32_t x); static inline unsigned nlz_int64(uint64_t x); #ifdef HAVE_UINT128_T static inline unsigned nlz_int128(uint128_t x); #endif static inline unsigned rb_popcount32(uint32_t x); static inline unsigned rb_popcount64(uint64_t x); static inline unsigned rb_popcount_intptr(uintptr_t x); static inline int ntz_int32(uint32_t x); static inline int ntz_int64(uint64_t x); static inline int ntz_intptr(uintptr_t x); static inline VALUE RUBY_BIT_ROTL(VALUE, int); static inline VALUE RUBY_BIT_ROTR(VALUE, int); static inline uint16_t ruby_swap16(uint16_t x) { #if __has_builtin(__builtin_bswap16) return __builtin_bswap16(x); #elif MSC_VERSION_SINCE(1310) return _byteswap_ushort(x); #else return (x << 8) | (x >> 8); #endif } static inline uint32_t ruby_swap32(uint32_t x) { #if __has_builtin(__builtin_bswap32) return __builtin_bswap32(x); #elif MSC_VERSION_SINCE(1310) return _byteswap_ulong(x); #else x = ((x & 0x0000FFFF) << 16) | ((x & 0xFFFF0000) >> 16); x = ((x & 0x00FF00FF) << 8) | ((x & 0xFF00FF00) >> 8); return x; #endif } static inline uint64_t ruby_swap64(uint64_t x) { #if __has_builtin(__builtin_bswap64) return __builtin_bswap64(x); #elif MSC_VERSION_SINCE(1310) return _byteswap_uint64(x); #else x = ((x & 0x00000000FFFFFFFFULL) << 32) | ((x & 0xFFFFFFFF00000000ULL) >> 32); x = ((x & 0x0000FFFF0000FFFFULL) << 16) | ((x & 0xFFFF0000FFFF0000ULL) >> 16); x = ((x & 0x00FF00FF00FF00FFULL) << 8) | ((x & 0xFF00FF00FF00FF00ULL) >> 8); return x; #endif } static inline unsigned int nlz_int32(uint32_t x) { #if defined(_MSC_VER) && defined(__AVX2__) /* Note: It seems there is no such tihng like __LZCNT__ predefined in MSVC. * AMD CPUs have had this instruction for decades (since K10) but for * Intel, Haswell is the oldest one. We need to use __AVX2__ for maximum * safety. */ return (unsigned int)__lzcnt(x); #elif defined(__x86_64__) && defined(__LZCNT__) && ! defined(MJIT_HEADER) return (unsigned int)_lzcnt_u32(x); #elif MSC_VERSION_SINCE(1400) /* &&! defined(__AVX2__) */ unsigned long r; return _BitScanReverse(&r, x) ? (31 - (int)r) : 32; #elif __has_builtin(__builtin_clz) STATIC_ASSERT(sizeof_int, sizeof(int) * CHAR_BIT == 32); return x ? (unsigned int)__builtin_clz(x) : 32; #else uint32_t y; unsigned n = 32; y = x >> 16; if (y) {n -= 16; x = y;} y = x >> 8; if (y) {n -= 8; x = y;} y = x >> 4; if (y) {n -= 4; x = y;} y = x >> 2; if (y) {n -= 2; x = y;} y = x >> 1; if (y) {return n - 2;} return (unsigned int)(n - x); #endif } static inline unsigned int nlz_int64(uint64_t x) { #if defined(_MSC_VER) && defined(__AVX2__) return (unsigned int)__lzcnt64(x); #elif defined(__x86_64__) && defined(__LZCNT__) && ! defined(MJIT_HEADER) return (unsigned int)_lzcnt_u64(x); #elif defined(_WIN64) && MSC_VERSION_SINCE(1400) /* &&! defined(__AVX2__) */ unsigned long r; return _BitScanReverse64(&r, x) ? (63u - (unsigned int)r) : 64; #elif __has_builtin(__builtin_clzl) if (x == 0) { return 64; } else if (sizeof(long) * CHAR_BIT == 64) { return (unsigned int)__builtin_clzl((unsigned long)x); } else if (sizeof(long long) * CHAR_BIT == 64) { return (unsigned int)__builtin_clzll((unsigned long long)x); } else { /* :FIXME: Is there a way to make this branch a compile-time error? */ __builtin_unreachable(); } #else uint64_t y; unsigned int n = 64; y = x >> 32; if (y) {n -= 32; x = y;} y = x >> 16; if (y) {n -= 16; x = y;} y = x >> 8; if (y) {n -= 8; x = y;} y = x >> 4; if (y) {n -= 4; x = y;} y = x >> 2; if (y) {n -= 2; x = y;} y = x >> 1; if (y) {return n - 2;} return (unsigned int)(n - x); #endif } #ifdef HAVE_UINT128_T static inline unsigned int nlz_int128(uint128_t x) { uint64_t y = (uint64_t)(x >> 64); if (x == 0) { return 128; } else if (y == 0) { return (unsigned int)nlz_int64(x) + 64; } else { return (unsigned int)nlz_int64(y); } } #endif static inline unsigned int nlz_int(unsigned int x) { if (sizeof(unsigned int) * CHAR_BIT == 32) { return nlz_int32((uint32_t)x); } else if (sizeof(unsigned int) * CHAR_BIT == 64) { return nlz_int64((uint64_t)x); } else { UNREACHABLE_RETURN(~0); } } static inline unsigned int nlz_long(unsigned long x) { if (sizeof(unsigned long) * CHAR_BIT == 32) { return nlz_int32((uint32_t)x); } else if (sizeof(unsigned long) * CHAR_BIT == 64) { return nlz_int64((uint64_t)x); } else { UNREACHABLE_RETURN(~0); } } static inline unsigned int nlz_long_long(unsigned long long x) { if (sizeof(unsigned long long) * CHAR_BIT == 64) { return nlz_int64((uint64_t)x); } #ifdef HAVE_UINT128_T else if (sizeof(unsigned long long) * CHAR_BIT == 128) { return nlz_int128((uint128_t)x); } #endif else { UNREACHABLE_RETURN(~0); } } static inline unsigned int nlz_intptr(uintptr_t x) { if (sizeof(uintptr_t) == sizeof(unsigned int)) { return nlz_int((unsigned int)x); } if (sizeof(uintptr_t) == sizeof(unsigned long)) { return nlz_long((unsigned long)x); } if (sizeof(uintptr_t) == sizeof(unsigned long long)) { return nlz_long_long((unsigned long long)x); } else { UNREACHABLE_RETURN(~0); } } static inline unsigned int rb_popcount32(uint32_t x) { #if defined(_MSC_VER) && defined(__AVX__) /* Note: CPUs since Nehalem and Barcelona have had this instruction so SSE * 4.2 should suffice, but it seems there is no such thing like __SSE_4_2__ * predefined macro in MSVC. They do have __AVX__ so use it instead. */ return (unsigned int)__popcnt(x); #elif __has_builtin(__builtin_popcount) STATIC_ASSERT(sizeof_int, sizeof(int) * CHAR_BIT >= 32); return (unsigned int)__builtin_popcount(x); #else x = (x & 0x55555555) + (x >> 1 & 0x55555555); x = (x & 0x33333333) + (x >> 2 & 0x33333333); x = (x & 0x0f0f0f0f) + (x >> 4 & 0x0f0f0f0f); x = (x & 0x001f001f) + (x >> 8 & 0x001f001f); x = (x & 0x0000003f) + (x >>16 & 0x0000003f); return (unsigned int)x; #endif } static inline unsigned int rb_popcount64(uint64_t x) { #if defined(_MSC_VER) && defined(__AVX__) return (unsigned int)__popcnt64(x); #elif __has_builtin(__builtin_popcount) if (sizeof(long) * CHAR_BIT == 64) { return (unsigned int)__builtin_popcountl((unsigned long)x); } else if (sizeof(long long) * CHAR_BIT == 64) { return (unsigned int)__builtin_popcountll((unsigned long long)x); } else { /* :FIXME: Is there a way to make this branch a compile-time error? */ __builtin_unreachable(); } #else x = (x & 0x5555555555555555) + (x >> 1 & 0x5555555555555555); x = (x & 0x3333333333333333) + (x >> 2 & 0x3333333333333333); x = (x & 0x0707070707070707) + (x >> 4 & 0x0707070707070707); x = (x & 0x001f001f001f001f) + (x >> 8 & 0x001f001f001f001f); x = (x & 0x0000003f0000003f) + (x >>16 & 0x0000003f0000003f); x = (x & 0x000000000000007f) + (x >>32 & 0x000000000000007f); return (unsigned int)x; #endif } static inline unsigned int rb_popcount_intptr(uintptr_t x) { if (sizeof(uintptr_t) * CHAR_BIT == 64) { return rb_popcount64((uint64_t)x); } else if (sizeof(uintptr_t) * CHAR_BIT == 32) { return rb_popcount32((uint32_t)x); } else { UNREACHABLE_RETURN(~0); } } static inline int ntz_int32(uint32_t x) { #if defined(__x86_64__) && defined(__BMI__) && ! defined(MJIT_HEADER) return (unsigned)_tzcnt_u32(x); #elif MSC_VERSION_SINCE(1400) /* :FIXME: Is there any way to issue TZCNT instead of BSF, apart from using * assembly? Because issueing LZCNT seems possible (see nlz.h). */ unsigned long r; return _BitScanForward(&r, x) ? (int)r : 32; #elif __has_builtin(__builtin_ctz) STATIC_ASSERT(sizeof_int, sizeof(int) * CHAR_BIT == 32); return x ? (unsigned)__builtin_ctz(x) : 32; #else return rb_popcount32((~x) & (x-1)); #endif } static inline int ntz_int64(uint64_t x) { #if defined(__x86_64__) && defined(__BMI__) && ! defined(MJIT_HEADER) return (unsigned)_tzcnt_u64(x); #elif defined(_WIN64) && MSC_VERSION_SINCE(1400) unsigned long r; return _BitScanForward64(&r, x) ? (int)r : 64; #elif __has_builtin(__builtin_ctzl) if (x == 0) { return 64; } else if (sizeof(long) * CHAR_BIT == 64) { return (unsigned)__builtin_ctzl((unsigned long)x); } else if (sizeof(long long) * CHAR_BIT == 64) { return (unsigned)__builtin_ctzll((unsigned long long)x); } else { /* :FIXME: Is there a way to make this branch a compile-time error? */ __builtin_unreachable(); } #else return rb_popcount64((~x) & (x-1)); #endif } static inline int ntz_intptr(uintptr_t x) { if (sizeof(uintptr_t) * CHAR_BIT == 64) { return ntz_int64((uint64_t)x); } else if (sizeof(uintptr_t) * CHAR_BIT == 32) { return ntz_int32((uint32_t)x); } else { UNREACHABLE_RETURN(~0); } } static inline VALUE RUBY_BIT_ROTL(VALUE v, int n) { #if __has_builtin(__builtin_rotateleft32) && (SIZEOF_VALUE * CHAR_BIT == 32) return __builtin_rotateleft32(v, n); #elif __has_builtin(__builtin_rotateleft64) && (SIZEOF_VALUE * CHAR_BIT == 64) return __builtin_rotateleft64(v, n); #else const int m = sizeof(VALUE) * CHAR_BIT; return (v << n) | (v >> (m - n)); #endif } static inline VALUE RUBY_BIT_ROTR(VALUE v, int n) { #if __has_builtin(__builtin_rotateright32) && (SIZEOF_VALUE * CHAR_BIT == 32) return __builtin_rotateright32(v, n); #elif __has_builtin(__builtin_rotateright64) && (SIZEOF_VALUE * CHAR_BIT == 64) return __builtin_rotateright64(v, n); #else const int m = sizeof(VALUE) * CHAR_BIT; return (v << (m - n)) | (v >> n); #endif } #endif /* INTERNAL_BITS_H */