[Buildroot] [PATCH 1/1] package/xxhash: fix build with power7
Fabrice Fontaine
fontaine.fabrice at gmail.com
Wed Sep 25 16:57:59 UTC 2019
Fixes:
- http://autobuild.buildroot.org/results/b431b05b9fd9b06da041162bf258189eebd12050
Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
---
...SX-POWER8-support-and-disable-POWER7.patch | 233 ++++++++++++++++++
1 file changed, 233 insertions(+)
create mode 100644 package/xxhash/0001-PPC64-Fix-VSX-POWER8-support-and-disable-POWER7.patch
diff --git a/package/xxhash/0001-PPC64-Fix-VSX-POWER8-support-and-disable-POWER7.patch b/package/xxhash/0001-PPC64-Fix-VSX-POWER8-support-and-disable-POWER7.patch
new file mode 100644
index 0000000000..11cb3414ed
--- /dev/null
+++ b/package/xxhash/0001-PPC64-Fix-VSX-POWER8-support-and-disable-POWER7.patch
@@ -0,0 +1,233 @@
+From 512b8836658450e73ab9bd876f9500032e25b634 Mon Sep 17 00:00:00 2001
+From: "easyaspi314 (Devin)" <easyaspi314 at 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 at 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
--
2.23.0
More information about the buildroot
mailing list