+++ /dev/null
-From 512b8836658450e73ab9bd876f9500032e25b634 Mon Sep 17 00:00:00 2001
-From: "easyaspi314 (Devin)" <easyaspi314@users.noreply.github.com>
-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 <fontaine.fabrice@gmail.com>
----
- 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 <altivec.h>
- # 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
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