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src/include/port/simd.h
580 строк
14 KB
Nathan Bossart
Remove switch statements in vector8_shift_{left,right}.
06 июл 2026, 19:40
06 июл 2026, 19:40
763ee7e
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/*------------------------------------------------------------------------- * * simd.h * Support for platform-specific vector operations. * * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/port/simd.h * * NOTES * - VectorN in this file refers to a register where the element operands * are N bits wide. The vector width is platform-specific, so users that care * about that will need to inspect "sizeof(VectorN)". * *------------------------------------------------------------------------- */ #ifndef SIMD_H #define SIMD_H #if defined(USE_SSE2) /* * We use emmintrin.h rather than the comprehensive header immintrin.h in * order to exclude extensions beyond SSE2. This is because MSVC, at least, * will allow the use of intrinsics that haven't been enabled at compile * time. */ #include <emmintrin.h> typedef __m128i Vector8; typedef __m128i Vector32; #elif defined(USE_NEON) #include <arm_neon.h> typedef uint8x16_t Vector8; typedef uint32x4_t Vector32; #else /* * If no SIMD instructions are available, we can in some cases emulate vector * operations using bitwise operations on unsigned integers. Note that many * of the functions in this file presently do not have non-SIMD * implementations. In particular, none of the functions involving Vector32 * are implemented without SIMD since it's likely not worthwhile to represent * two 32-bit integers using a uint64. */ #define USE_NO_SIMD typedef uint64 Vector8; #endif /* load/store operations */ static inline void vector8_load(Vector8 *v, const uint8 *s); #ifndef USE_NO_SIMD static inline void vector32_load(Vector32 *v, const uint32 *s); #endif /* assignment operations */ static inline Vector8 vector8_broadcast(const uint8 c); #ifndef USE_NO_SIMD static inline Vector32 vector32_broadcast(const uint32 c); #endif /* element-wise comparisons to a scalar */ static inline bool vector8_has(const Vector8 v, const uint8 c); static inline bool vector8_has_zero(const Vector8 v); static inline bool vector8_has_le(const Vector8 v, const uint8 c); static inline bool vector8_is_highbit_set(const Vector8 v); #ifndef USE_NO_SIMD static inline bool vector32_is_highbit_set(const Vector32 v); static inline uint32 vector8_highbit_mask(const Vector8 v); #endif /* arithmetic operations */ static inline Vector8 vector8_or(const Vector8 v1, const Vector8 v2); #ifndef USE_NO_SIMD static inline Vector32 vector32_or(const Vector32 v1, const Vector32 v2); #endif /* * comparisons between vectors * * Note: These return a vector rather than boolean, which is why we don't * have non-SIMD implementations. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_eq(const Vector8 v1, const Vector8 v2); static inline Vector8 vector8_min(const Vector8 v1, const Vector8 v2); static inline Vector32 vector32_eq(const Vector32 v1, const Vector32 v2); #endif /* * Load a chunk of memory into the given vector. */ static inline void vector8_load(Vector8 *v, const uint8 *s) { #if defined(USE_SSE2) *v = _mm_loadu_si128((const __m128i *) s); #elif defined(USE_NEON) *v = vld1q_u8(s); #else memcpy(v, s, sizeof(Vector8)); #endif } #ifndef USE_NO_SIMD static inline void vector32_load(Vector32 *v, const uint32 *s) { #ifdef USE_SSE2 *v = _mm_loadu_si128((const __m128i *) s); #elif defined(USE_NEON) *v = vld1q_u32(s); #endif } #endif /* ! USE_NO_SIMD */ /* * Store a vector into the given memory address. */ #ifndef USE_NO_SIMD static inline void vector8_store(uint8 *s, Vector8 v) { #ifdef USE_SSE2 _mm_storeu_si128((Vector8 *) s, v); #elif defined(USE_NEON) vst1q_u8(s, v); #endif } #endif /* ! USE_NO_SIMD */ /* * Create a vector with all elements set to the same value. */ static inline Vector8 vector8_broadcast(const uint8 c) { #if defined(USE_SSE2) return _mm_set1_epi8(c); #elif defined(USE_NEON) return vdupq_n_u8(c); #else return ~UINT64CONST(0) / 0xFF * c; #endif } #ifndef USE_NO_SIMD static inline Vector32 vector32_broadcast(const uint32 c) { #ifdef USE_SSE2 return _mm_set1_epi32(c); #elif defined(USE_NEON) return vdupq_n_u32(c); #endif } #endif /* ! USE_NO_SIMD */ /* * Return true if any elements in the vector are equal to the given scalar. */ static inline bool vector8_has(const Vector8 v, const uint8 c) { bool result; /* pre-compute the result for assert checking */ #ifdef USE_ASSERT_CHECKING bool assert_result = false; for (Size i = 0; i < sizeof(Vector8); i++) { if (((const uint8 *) &v)[i] == c) { assert_result = true; break; } } #endif /* USE_ASSERT_CHECKING */ #if defined(USE_NO_SIMD) /* any bytes in v equal to c will evaluate to zero via XOR */ result = vector8_has_zero(v ^ vector8_broadcast(c)); #else result = vector8_is_highbit_set(vector8_eq(v, vector8_broadcast(c))); #endif Assert(assert_result == result); return result; } /* * Convenience function equivalent to vector8_has(v, 0) */ static inline bool vector8_has_zero(const Vector8 v) { #if defined(USE_NO_SIMD) /* * We cannot call vector8_has() here, because that would lead to a * circular definition. */ return vector8_has_le(v, 0); #else return vector8_has(v, 0); #endif } /* * Return true if any elements in the vector are less than or equal to the * given scalar. */ static inline bool vector8_has_le(const Vector8 v, const uint8 c) { bool result = false; #ifdef USE_SSE2 Vector8 umin; Vector8 cmpe; #endif /* pre-compute the result for assert checking */ #ifdef USE_ASSERT_CHECKING bool assert_result = false; for (Size i = 0; i < sizeof(Vector8); i++) { if (((const uint8 *) &v)[i] <= c) { assert_result = true; break; } } #endif /* USE_ASSERT_CHECKING */ #if defined(USE_NO_SIMD) /* * To find bytes <= c, we can use bitwise operations to find bytes < c+1, * but it only works if c+1 <= 128 and if the highest bit in v is not set. * Adapted from * https://graphics.stanford.edu/~seander/bithacks.html#HasLessInWord */ if ((int64) v >= 0 && c < 0x80) result = (v - vector8_broadcast(c + 1)) & ~v & vector8_broadcast(0x80); else { /* one byte at a time */ for (Size i = 0; i < sizeof(Vector8); i++) { if (((const uint8 *) &v)[i] <= c) { result = true; break; } } } #elif defined(USE_SSE2) umin = vector8_min(v, vector8_broadcast(c)); cmpe = vector8_eq(umin, v); result = vector8_is_highbit_set(cmpe); #elif defined(USE_NEON) result = vminvq_u8(v) <= c; #endif Assert(assert_result == result); return result; } /* * Returns true if any elements in the vector are greater than or equal to the * given scalar. */ #ifndef USE_NO_SIMD static inline bool vector8_has_ge(const Vector8 v, const uint8 c) { #ifdef USE_SSE2 Vector8 umax = _mm_max_epu8(v, vector8_broadcast(c)); Vector8 cmpe = vector8_eq(umax, v); return vector8_is_highbit_set(cmpe); #elif defined(USE_NEON) return vmaxvq_u8(v) >= c; #endif } #endif /* ! USE_NO_SIMD */ /* * Return true if the high bit of any element is set */ static inline bool vector8_is_highbit_set(const Vector8 v) { #ifdef USE_SSE2 return _mm_movemask_epi8(v) != 0; #elif defined(USE_NEON) return vmaxvq_u8(v) > 0x7F; #else return v & vector8_broadcast(0x80); #endif } /* * Exactly like vector8_is_highbit_set except for the input type, so it * looks at each byte separately. * * XXX x86 uses the same underlying type for 8-bit, 16-bit, and 32-bit * integer elements, but Arm does not, hence the need for a separate * function. We could instead adopt the behavior of Arm's vmaxvq_u32(), i.e. * check each 32-bit element, but that would require an additional mask * operation on x86. */ #ifndef USE_NO_SIMD static inline bool vector32_is_highbit_set(const Vector32 v) { #if defined(USE_NEON) return vector8_is_highbit_set((Vector8) v); #else return vector8_is_highbit_set(v); #endif } #endif /* ! USE_NO_SIMD */ /* * Return a bitmask formed from the high-bit of each element. */ #ifndef USE_NO_SIMD static inline uint32 vector8_highbit_mask(const Vector8 v) { #ifdef USE_SSE2 return (uint32) _mm_movemask_epi8(v); #elif defined(USE_NEON) /* * Note: It would be faster to use vget_lane_u64 and vshrn_n_u16, but that * returns a uint64, making it inconvenient to combine mask values from * multiple vectors. */ static const uint8 mask[16] = { 1 << 0, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6, 1 << 7, 1 << 0, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6, 1 << 7, }; uint8x16_t masked = vandq_u8(vld1q_u8(mask), (uint8x16_t) vshrq_n_s8((int8x16_t) v, 7)); uint8x16_t maskedhi = vextq_u8(masked, masked, 8); return (uint32) vaddvq_u16((uint16x8_t) vzip1q_u8(masked, maskedhi)); #endif } #endif /* ! USE_NO_SIMD */ /* * Return the bitwise OR of the inputs */ static inline Vector8 vector8_or(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_or_si128(v1, v2); #elif defined(USE_NEON) return vorrq_u8(v1, v2); #else return v1 | v2; #endif } #ifndef USE_NO_SIMD static inline Vector32 vector32_or(const Vector32 v1, const Vector32 v2) { #ifdef USE_SSE2 return _mm_or_si128(v1, v2); #elif defined(USE_NEON) return vorrq_u32(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Return the bitwise AND of the inputs. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_and(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_and_si128(v1, v2); #elif defined(USE_NEON) return vandq_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Return the result of adding the respective elements of the input vectors. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_add(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_add_epi8(v1, v2); #elif defined(USE_NEON) return vaddq_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Return the result of subtracting the respective elements of the input * vectors using signed saturation (i.e., if the operation would yield a value * less than -128, -128 is returned instead). For more information on * saturation arithmetic, see * https://en.wikipedia.org/wiki/Saturation_arithmetic */ #ifndef USE_NO_SIMD static inline Vector8 vector8_issub(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_subs_epi8(v1, v2); #elif defined(USE_NEON) return (Vector8) vqsubq_s8((int8x16_t) v1, (int8x16_t) v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Return a vector with all bits set in each lane where the corresponding * lanes in the inputs are equal. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_eq(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_cmpeq_epi8(v1, v2); #elif defined(USE_NEON) return vceqq_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ #ifndef USE_NO_SIMD static inline Vector32 vector32_eq(const Vector32 v1, const Vector32 v2) { #ifdef USE_SSE2 return _mm_cmpeq_epi32(v1, v2); #elif defined(USE_NEON) return vceqq_u32(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Return a vector with all bits set for each lane of v1 that is greater than * the corresponding lane of v2. NB: The comparison treats the elements as * signed. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_gt(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_cmpgt_epi8(v1, v2); #elif defined(USE_NEON) return vcgtq_s8((int8x16_t) v1, (int8x16_t) v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Given two vectors, return a vector with the minimum element of each. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_min(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_min_epu8(v1, v2); #elif defined(USE_NEON) return vminq_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Interleave elements of low halves (e.g., for SSE2, bits 0-63) of given * vectors. Bytes 0, 2, 4, etc. use v1, and bytes 1, 3, 5, etc. use v2. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_interleave_low(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_unpacklo_epi8(v1, v2); #elif defined(USE_NEON) return vzip1q_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Interleave elements of high halves (e.g., for SSE2, bits 64-127) of given * vectors. Bytes 0, 2, 4, etc. use v1, and bytes 1, 3, 5, etc. use v2. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_interleave_high(const Vector8 v1, const Vector8 v2) { #ifdef USE_SSE2 return _mm_unpackhi_epi8(v1, v2); #elif defined(USE_NEON) return vzip2q_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Pack 16-bit elements in the given vectors into a single vector of 8-bit * elements. The first half of the return vector (e.g., for SSE2, bits 0-63) * uses v1, and the second half (e.g., for SSE2, bits 64-127) uses v2. * * NB: The upper 8-bits of each 16-bit element must be zeros, else this will * produce different results on different architectures. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_pack_16(const Vector8 v1, const Vector8 v2) { Vector8 mask PG_USED_FOR_ASSERTS_ONLY; mask = vector8_interleave_low(vector8_broadcast(0), vector8_broadcast(0xff)); Assert(!vector8_has_ge(vector8_and(v1, mask), 1)); Assert(!vector8_has_ge(vector8_and(v2, mask), 1)); #ifdef USE_SSE2 return _mm_packus_epi16(v1, v2); #elif defined(USE_NEON) return vuzp1q_u8(v1, v2); #endif } #endif /* ! USE_NO_SIMD */ /* * Unsigned shift left of each 32-bit element in the vector by "i" bits. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_shift_left(const Vector8 v1, int i) { #ifdef USE_SSE2 return _mm_slli_epi32(v1, i); #elif defined(USE_NEON) return (Vector8) vshlq_u32((Vector32) v1, vdupq_n_s32(i)); #endif } #endif /* ! USE_NO_SIMD */ /* * Unsigned shift right of each 32-bit element in the vector by "i" bits. */ #ifndef USE_NO_SIMD static inline Vector8 vector8_shift_right(const Vector8 v1, int i) { #ifdef USE_SSE2 return _mm_srli_epi32(v1, i); #elif defined(USE_NEON) /* negative shift count means right shift */ return (Vector8) vshlq_u32((Vector32) v1, vdupq_n_s32(-i)); #endif } #endif /* ! USE_NO_SIMD */ #endif /* SIMD_H */