From 512b8836658450e73ab9bd876f9500032e25b634 Mon Sep 17 00:00:00 2001 From: "easyaspi314 (Devin)" Date: Tue, 20 Aug 2019 21:06:11 -0400 Subject: [PATCH] [PPC64] Fix VSX, POWER8 support, and disable POWER7. The VSX codepath is now working on POWER8 and is fully enabled. The little endian code has been verified on POWER8E, although a big endian machine was not available. This uses vpermxor from POWER8 to shuffle on big endian. There are a few other fixes as well to unify endian memes. [Retrieved from: https://github.com/Cyan4973/xxHash/commit/512b8836658450e73ab9bd876f9500032e25b634] Signed-off-by: Fabrice Fontaine --- xxh3.h | 115 ++++++++++++++++++++++++++++++++++++++++++++----------- xxhsum.c | 6 ++- 2 files changed, 96 insertions(+), 25 deletions(-) diff --git a/xxh3.h b/xxh3.h index 77dc955..d5fede8 100644 --- a/xxh3.h +++ b/xxh3.h @@ -91,7 +91,7 @@ && (defined(__ARM_NEON__) || defined(__ARM_NEON)) \ && defined(__LITTLE_ENDIAN__) /* ARM big endian is a thing */ # define XXH_VECTOR XXH_NEON -# elif defined(__PPC64__) && defined(__VSX__) && defined(__GNUC__) +# elif defined(__PPC64__) && defined(__POWER8_VECTOR__) && defined(__GNUC__) # define XXH_VECTOR XXH_VSX # else # define XXH_VECTOR XXH_SCALAR @@ -122,24 +122,85 @@ # define XXH_mult32to64(x, y) ((U64)((x) & 0xFFFFFFFF) * (U64)((y) & 0xFFFFFFFF)) #endif -/* VSX stuff */ +/* VSX stuff. It's a lot because VSX support is mediocre across compilers and + * there is a lot of mischief with endianness. */ #if XXH_VECTOR == XXH_VSX # include # undef vector typedef __vector unsigned long long U64x2; +typedef __vector unsigned char U8x16; typedef __vector unsigned U32x4; + +#ifndef XXH_VSX_BE +# ifdef __BIG_ENDIAN__ +# define XXH_VSX_BE 1 +# elif defined(__VEC_ELEMENT_REG_ORDER__) && __VEC_ELEMENT_REG_ORDER__ == __ORDER_BIG_ENDIAN__ +# warning "-maltivec=be is not recommended. Please use native endianness." +# define XXH_VSX_BE 1 +# else +# define XXH_VSX_BE 0 +# endif +#endif + +/* We need some helpers for big endian mode. */ +#if XXH_VSX_BE +/* A wrapper for POWER9's vec_revb. */ +# ifdef __POWER9_VECTOR__ +# define XXH_vec_revb vec_revb +# else +XXH_FORCE_INLINE U64x2 XXH_vec_revb(U64x2 val) +{ + U8x16 const vByteSwap = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00, + 0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 }; + return vec_perm(val, val, vByteSwap); +} +# endif + +/* Power8 Crypto gives us vpermxor which is very handy for + * PPC64EB. + * + * U8x16 vpermxor(U8x16 a, U8x16 b, U8x16 mask) + * { + * U8x16 ret; + * for (int i = 0; i < 16; i++) { + * ret[i] = a[mask[i] & 0xF] ^ b[mask[i] >> 4]; + * } + * return ret; + * } + * + * Because both of the main loops load the key, swap, and xor it with data, + * we can combine the key swap into this instruction. + */ +# ifdef vec_permxor +# define XXH_vec_permxor vec_permxor +# else +# define XXH_vec_permxor __builtin_crypto_vpermxor +# endif +#endif +/* + * Because we reinterpret the multiply, there are endian memes: vec_mulo actually becomes + * vec_mule. + * + * Additionally, the intrinsic wasn't added until GCC 8, despite existing for a while. + * Clang has an easy way to control this, we can just use the builtin which doesn't swap. + * GCC needs inline assembly. */ +#if __has_builtin(__builtin_altivec_vmuleuw) +# define XXH_vec_mulo __builtin_altivec_vmulouw +# define XXH_vec_mule __builtin_altivec_vmuleuw +#else /* Adapted from https://github.com/google/highwayhash/blob/master/highwayhash/hh_vsx.h. */ -XXH_FORCE_INLINE U64x2 XXH_vsxMultOdd(U32x4 a, U32x4 b) { +XXH_FORCE_INLINE U64x2 XXH_vec_mulo(U32x4 a, U32x4 b) { U64x2 result; __asm__("vmulouw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b)); return result; } -XXH_FORCE_INLINE U64x2 XXH_vsxMultEven(U32x4 a, U32x4 b) { +XXH_FORCE_INLINE U64x2 XXH_vec_mule(U32x4 a, U32x4 b) { U64x2 result; __asm__("vmuleuw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b)); return result; } #endif +#endif /* ========================================== @@ -558,38 +619,41 @@ XXH3_accumulate_512( void* XXH_RESTRICT acc, } } -#elif (XXH_VECTOR == XXH_VSX) && 0 /* <=========================== DISABLED : MUST BE VALIDATED */ - /* note : vsx code path currently not tested in CI (limitation of cross-compiler and/or emulator) - * for vsx code path to be shipped and supported, it is critical to create a CI test for it */ +#elif (XXH_VECTOR == XXH_VSX) U64x2* const xacc = (U64x2*) acc; /* presumed aligned */ U64x2 const* const xdata = (U64x2 const*) data; /* no alignment restriction */ U64x2 const* const xkey = (U64x2 const*) key; /* no alignment restriction */ U64x2 const v32 = { 32, 32 }; - +#if XXH_VSX_BE + U8x16 const vXorSwap = { 0x07, 0x16, 0x25, 0x34, 0x43, 0x52, 0x61, 0x70, + 0x8F, 0x9E, 0xAD, 0xBC, 0xCB, 0xDA, 0xE9, 0xF8 }; +#endif size_t i; for (i = 0; i < STRIPE_LEN / sizeof(U64x2); i++) { /* data_vec = xdata[i]; */ /* key_vec = xkey[i]; */ -#ifdef __BIG_ENDIAN__ +#if XXH_VSX_BE /* byteswap */ - U64x2 const data_vec = vec_revb(vec_vsx_ld(0, xdata + i)); /* note : vec_revb is power9+ */ - U64x2 const key_vec = vec_revb(vec_vsx_ld(0, xkey + i)); /* note : vec_revb is power9+ */ + U64x2 const data_vec = XXH_vec_revb(vec_vsx_ld(0, xdata + i)); + U64x2 const key_raw = vec_vsx_ld(0, xkey + i); + /* See comment above. data_key = data_vec ^ swap(xkey[i]); */ + U64x2 const data_key = (U64x2)XXH_vec_permxor((U8x16)data_vec, (U8x16)key_raw, vXorSwap); #else U64x2 const data_vec = vec_vsx_ld(0, xdata + i); U64x2 const key_vec = vec_vsx_ld(0, xkey + i); -#endif U64x2 const data_key = data_vec ^ key_vec; +#endif /* shuffled = (data_key << 32) | (data_key >> 32); */ U32x4 const shuffled = (U32x4)vec_rl(data_key, v32); /* product = ((U64x2)data_key & 0xFFFFFFFF) * ((U64x2)shuffled & 0xFFFFFFFF); */ - U64x2 const product = XXH_vsxMultOdd((U32x4)data_key, shuffled); - + U64x2 const product = XXH_vec_mulo((U32x4)data_key, shuffled); xacc[i] += product; if (accWidth == XXH3_acc_64bits) { xacc[i] += data_vec; } else { /* XXH3_acc_128bits */ - U64x2 const data_swapped = vec_permi(data_vec, data_vec, 2); /* <===== untested !!! */ + /* swap high and low halves */ + U64x2 const data_swapped = vec_xxpermdi(data_vec, data_vec, 2); xacc[i] += data_swapped; } } @@ -716,26 +780,31 @@ XXH3_scrambleAcc(void* XXH_RESTRICT acc, const void* XXH_RESTRICT key) U64x2 const v47 = { 47, 47 }; U32x4 const prime = { PRIME32_1, PRIME32_1, PRIME32_1, PRIME32_1 }; size_t i; - +#if XXH_VSX_BE + /* endian swap */ + U8x16 const vXorSwap = { 0x07, 0x16, 0x25, 0x34, 0x43, 0x52, 0x61, 0x70, + 0x8F, 0x9E, 0xAD, 0xBC, 0xCB, 0xDA, 0xE9, 0xF8 }; +#endif for (i = 0; i < STRIPE_LEN / sizeof(U64x2); i++) { U64x2 const acc_vec = xacc[i]; U64x2 const data_vec = acc_vec ^ (acc_vec >> v47); /* key_vec = xkey[i]; */ -#ifdef __BIG_ENDIAN__ - /* swap 32-bit words */ - U64x2 const key_vec = vec_rl(vec_vsx_ld(0, xkey + i), v32); +#if XXH_VSX_BE + /* swap bytes words */ + U64x2 const key_raw = vec_vsx_ld(0, xkey + i); + U64x2 const data_key = (U64x2)XXH_vec_permxor((U8x16)data_vec, (U8x16)key_raw, vXorSwap); #else U64x2 const key_vec = vec_vsx_ld(0, xkey + i); -#endif U64x2 const data_key = data_vec ^ key_vec; +#endif /* data_key *= PRIME32_1 */ /* prod_lo = ((U64x2)data_key & 0xFFFFFFFF) * ((U64x2)prime & 0xFFFFFFFF); */ - U64x2 const prod_lo = XXH_vsxMultOdd((U32x4)data_key, prime); + U64x2 const prod_even = XXH_vec_mule((U32x4)data_key, prime); /* prod_hi = ((U64x2)data_key >> 32) * ((U64x2)prime >> 32); */ - U64x2 const prod_hi = XXH_vsxMultEven((U32x4)data_key, prime); - xacc[i] = prod_lo + (prod_hi << v32); + U64x2 const prod_odd = XXH_vec_mulo((U32x4)data_key, prime); + xacc[i] = prod_odd + (prod_even << v32); } #else /* scalar variant of Scrambler - universal */ diff --git a/xxhsum.c b/xxhsum.c index 19685aa..c979966 100644 --- a/xxhsum.c +++ b/xxhsum.c @@ -224,8 +224,10 @@ static unsigned BMK_isLittleEndian(void) # define ARCH "arm" # endif #elif defined(__powerpc64__) || defined(__ppc64__) || defined(__PPC64__) -# if defined(__GNUC__) && defined(__VSX__) -# define ARCH "ppc64 + VSX" +# if defined(__GNUC__) && defined(__POWER9_VECTOR__) +# define ARCH "ppc64 + POWER9 vector" +# elif defined(__GNUC__) && defined(__POWER8_VECTOR__) +# define ARCH "ppc64 + POWER8 vector" # else # define ARCH "ppc64" # endif