========================================================================================================================
length=1, alignment=1: 20.00 (-64.10%) 14.38 (-17.95%) 16.25 (-33.33%) 11.56 ( 5.13%) 11.72 ( 3.85%) 12.19
length=1, alignment=0: 15.00 (-26.32%) 12.66 ( -6.58%) 16.09 (-35.53%) 12.19 ( -2.63%) 12.03 ( -1.32%) 11.88
length=2, alignment=2: 15.16 (-25.97%) 14.06 (-16.88%) 15.62 (-29.87%) 12.03 ( 0.00%) 11.72 ( 2.60%) 12.03
length=2, alignment=0: 14.53 (-20.78%) 12.81 ( -6.49%) 16.25 (-35.07%) 12.66 ( -5.19%) 12.03 ( 0.00%) 12.03
length=3, alignment=3: 15.00 (-21.52%) 14.38 (-16.46%) 15.78 (-27.85%) 12.03 ( 2.53%) 12.03 ( 2.53%) 12.34
length=3, alignment=0: 14.53 (-24.00%) 12.66 ( -8.00%) 16.88 (-44.00%) 12.19 ( -4.00%) 12.03 ( -2.67%) 11.72
length=4, alignment=4: 14.69 (-23.68%) 15.62 (-31.58%) 16.25 (-36.84%) 11.88 ( 0.00%) 11.72 ( 1.32%) 11.88
length=4, alignment=0: 14.84 (-20.25%) 12.66 ( -2.53%) 16.72 (-35.44%) 11.88 ( 3.80%) 12.19 ( 1.27%) 12.34
length=5, alignment=5: 14.38 (-21.05%) 14.84 (-25.00%) 15.62 (-31.58%) 11.88 ( 0.00%) 11.72 ( 1.32%) 11.88
length=5, alignment=0: 14.84 (-21.80%) 13.12 ( -7.69%) 16.41 (-34.61%) 12.03 ( 1.28%) 11.88 ( 2.56%) 12.19
length=6, alignment=6: 14.69 (-25.33%) 14.69 (-25.33%) 15.78 (-34.67%) 11.88 ( -1.33%) 11.88 ( -1.33%) 11.72
length=6, alignment=0: 14.69 (-23.68%) 13.28 (-11.84%) 16.41 (-38.16%) 12.66 ( -6.58%) 12.34 ( -3.95%) 11.88
length=7, alignment=7: 14.84 (-23.38%) 13.28 (-10.39%) 15.78 (-31.17%) 12.19 ( -1.30%) 12.03 ( 0.00%) 12.03
length=7, alignment=0: 14.53 (-19.23%) 12.81 ( -5.13%) 16.25 (-33.33%) 12.03 ( 1.28%) 12.03 ( 1.28%) 12.19
length=4, alignment=0: 14.69 (-25.33%) 12.81 ( -9.33%) 15.94 (-36.00%) 11.72 ( 0.00%) 11.88 ( -1.33%) 11.72
length=4, alignment=7: 14.69 (-22.08%) 13.28 (-10.39%) 15.94 (-32.47%) 12.03 ( 0.00%) 12.03 ( 0.00%) 12.03
length=4, alignment=2: 15.00 (-28.00%) 15.31 (-30.67%) 16.09 (-37.33%) 11.88 ( -1.33%) 12.03 ( -2.67%) 11.72
length=2, alignment=2: 14.69 (-23.68%) 14.06 (-18.42%) 15.78 (-32.89%) 12.03 ( -1.32%) 12.03 ( -1.32%) 11.88
length=8, alignment=0: 14.84 (-26.67%) 14.53 (-24.00%) 16.09 (-37.33%) 12.03 ( -2.67%) 11.72 ( 0.00%) 11.72
length=8, alignment=7: 14.22 (-19.74%) 12.97 ( -9.21%) 15.94 (-34.21%) 12.03 ( -1.32%) 11.72 ( 1.32%) 11.88
length=8, alignment=3: 14.84 (-25.00%) 17.19 (-44.74%) 15.78 (-32.89%) 11.88 ( 0.00%) 11.72 ( 1.32%) 11.88
length=5, alignment=3: 15.00 (-24.68%) 15.16 (-25.97%) 15.94 (-32.47%) 11.88 ( 1.30%) 12.03 ( 0.00%) 12.03
length=16, alignment=0: 16.41 (-17.98%) 15.47 (-11.24%) 16.09 (-15.73%) 12.19 ( 12.36%) 13.59 ( 2.25%) 13.91
length=16, alignment=7: 16.25 (-14.29%) 15.62 ( -9.89%) 16.09 (-13.19%) 12.34 ( 13.19%) 13.44 ( 5.49%) 14.22
length=16, alignment=4: 16.09 (-17.05%) 17.19 (-25.00%) 15.62 (-13.64%) 12.03 ( 12.50%) 13.59 ( 1.14%) 13.75
length=10, alignment=4: 15.31 (-27.27%) 16.41 (-36.36%) 15.78 (-31.17%) 11.88 ( 1.30%) 12.50 ( -3.90%) 12.03
length=32, alignment=0: 15.94 ( -5.15%) 18.28 (-20.62%) 18.59 (-22.68%) 14.22 ( 6.18%) 13.44 ( 11.34%) 15.16
length=32, alignment=7: 15.16 ( -4.30%) 18.44 (-26.88%) 17.19 (-18.28%) 12.81 ( 11.83%) 13.12 ( 9.68%) 14.53
length=32, alignment=5: 15.31 ( -7.69%) 20.94 (-47.25%) 16.41 (-15.38%) 12.34 ( 13.19%) 12.81 ( 9.89%) 14.22
length=21, alignment=5: 16.09 (-17.05%) 18.28 (-32.95%) 15.94 (-15.91%) 12.03 ( 12.50%) 13.12 ( 4.55%) 13.75
length=64, alignment=0: 18.59 ( -4.39%) 23.12 (-29.82%) 19.22 ( -7.90%) 15.62 ( 12.28%) 15.94 ( 10.53%) 17.81
length=64, alignment=7: 18.12 (-10.48%) 23.91 (-45.71%) 19.69 (-20.00%) 14.69 ( 10.48%) 14.53 ( 11.43%) 16.41
length=64, alignment=6: 17.19 ( -1.85%) 23.12 (-37.04%) 24.06 (-42.59%) 14.69 ( 12.96%) 14.53 ( 13.89%) 16.88
length=42, alignment=6: 18.91 (-16.35%) 20.16 (-24.04%) 17.19 ( -5.77%) 14.06 ( 13.46%) 15.94 ( 1.92%) 16.25
length=128, alignment=0: 21.09 ( 4.25%) 32.81 (-48.94%) 21.72 ( 1.42%) 19.22 ( 12.77%) 19.22 ( 12.77%) 22.03
length=128, alignment=7: 19.38 ( 10.14%) 32.66 (-51.45%) 21.72 ( -0.72%) 19.22 ( 10.87%) 18.44 ( 14.49%) 21.56
length=128, alignment=7: 18.75 ( 12.41%) 31.09 (-45.26%) 19.69 ( 8.03%) 19.22 ( 10.22%) 18.44 ( 13.87%) 21.41
length=85, alignment=7: 21.72 (-17.80%) 26.56 (-44.07%) 24.22 (-31.36%) 17.03 ( 7.63%) 16.56 ( 10.17%) 18.44
length=256, alignment=0: 30.16 ( 3.50%) 64.22 (-105.50%) 25.94 ( 17.00%) 26.88 ( 14.00%) 26.56 ( 15.00%) 31.25
length=256, alignment=7: 28.75 ( 7.07%) 51.25 (-65.66%) 28.75 ( 7.07%) 27.19 ( 12.12%) 27.66 ( 10.61%) 30.94
length=256, alignment=8: 29.06 ( 5.58%) 65.47 (-112.69%) 25.62 ( 16.75%) 27.03 ( 12.18%) 27.81 ( 9.64%) 30.78
length=170, alignment=8: 24.53 ( 4.85%) 38.28 (-48.48%) 22.66 ( 12.12%) 23.59 ( 8.48%) 22.19 ( 13.94%) 25.78
length=512, alignment=0: 45.47 ( 9.91%) 94.22 (-86.69%) 37.50 ( 25.70%) 43.75 ( 13.31%) 43.44 ( 13.93%) 50.47
length=512, alignment=7: 44.84 ( 10.03%) 94.22 (-89.03%) 38.28 ( 23.20%) 43.91 ( 11.91%) 44.06 ( 11.60%) 49.84
length=512, alignment=9: 44.53 ( 11.49%) 97.03 (-92.86%) 37.97 ( 24.53%) 43.44 ( 13.66%) 43.91 ( 12.73%) 50.31
length=341, alignment=9: 35.94 ( 8.37%) 71.72 (-82.87%) 30.62 ( 21.91%) 32.19 ( 17.93%) 34.38 ( 12.35%) 39.22
length=1024, alignment=0: 78.75 ( 11.27%) 168.28 (-89.61%) 61.09 ( 31.16%) 103.12 (-16.20%) 76.41 ( 13.91%) 88.75
length=1024, alignment=7: 76.88 ( 11.83%) 168.28 (-93.01%) 62.03 ( 28.85%) 105.94 (-21.51%) 77.50 ( 11.11%) 87.19
length=1024, alignment=10: 77.81 ( 11.23%) 170.78 (-94.83%) 61.88 ( 29.41%) 102.66 (-17.11%) 77.66 ( 11.41%) 87.66
length=682, alignment=10: 60.31 ( 9.18%) 125.94 (-89.65%) 45.31 ( 31.76%) 55.16 ( 16.94%) 58.44 ( 12.00%) 66.41
length=2048, alignment=0: 145.94 ( 13.84%) 316.09 (-86.62%) 110.78 ( 34.59%) 143.59 ( 15.22%) 144.69 ( 14.58%) 169.38
length=2048, alignment=7: 145.31 ( 16.44%) 316.09 (-81.76%) 111.09 ( 36.12%) 144.53 ( 16.89%) 143.28 ( 17.61%) 173.91
length=2048, alignment=11: 144.84 ( 16.86%) 319.38 (-83.32%) 111.25 ( 36.14%) 144.38 ( 17.13%) 143.59 ( 17.58%) 174.22
length=1365, alignment=11: 101.41 ( 17.01%) 221.41 (-81.20%) 78.59 ( 35.68%) 100.94 ( 17.39%) 100.78 ( 17.52%) 122.19
length=4096, alignment=0: 280.00 ( 10.62%) 617.19 (-97.01%) 221.88 ( 29.18%) 301.41 ( 3.79%) 278.44 ( 11.12%) 313.28
length=4096, alignment=7: 283.75 ( 12.61%) 618.44 (-90.47%) 208.12 ( 35.90%) 292.34 ( 9.96%) 277.81 ( 14.44%) 324.69
length=4096, alignment=12: 283.59 ( 12.87%) 621.25 (-90.88%) 208.12 ( 36.05%) 293.75 ( 9.75%) 277.34 ( 14.79%) 325.47
length=2730, alignment=12: 202.66 ( 8.85%) 424.06 (-90.72%) 142.34 ( 35.98%) 203.91 ( 8.29%) 201.88 ( 9.21%) 222.34
---
sysdeps/aarch64/multiarch/Makefile | 2 +-
sysdeps/aarch64/multiarch/ifunc-impl-list.c | 1 +
sysdeps/aarch64/multiarch/strlen.c | 7 +-
sysdeps/aarch64/multiarch/strlen_kunpeng.S | 178 ++++++++++++++++++++++++++++
4 files changed, 186 insertions(+), 2 deletions(-)
create mode 100644 sysdeps/aarch64/multiarch/strlen_kunpeng.S
@@ -3,5 +3,5 @@ sysdep_routines += memcpy_generic memcpy_thunderx memcpy_thunderx2 \
memcpy_falkor memmove_falkor \
memset_generic memset_falkor memset_emag \
memchr_generic memchr_nosimd \
- strlen_generic strlen_asimd
+ strlen_generic strlen_asimd strlen_kunpeng
endif
@@ -60,6 +60,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL (i, name, strlen,
IFUNC_IMPL_ADD (array, i, strlen, 1, __strlen_asimd)
+ IFUNC_IMPL_ADD (array, i, strlen, 1, __strlen_kunpeng)
IFUNC_IMPL_ADD (array, i, strlen, 1, __strlen_generic))
return i;
@@ -32,9 +32,14 @@ extern __typeof (__redirect_strlen) __strlen;
extern __typeof (__redirect_strlen) __strlen_generic attribute_hidden;
extern __typeof (__redirect_strlen) __strlen_asimd attribute_hidden;
+extern __typeof (__redirect_strlen) __strlen_kunpeng attribute_hidden;
libc_ifunc (__strlen,
- (USE_ASIMD_STRLEN () ? __strlen_asimd : __strlen_generic));
+ (USE_ASIMD_STRLEN ()
+ ? __strlen_asimd
+ : (IS_KUNPENG(midr)
+ ? __strlen_kunpeng
+ :__strlen_generic)));
# undef strlen
strong_alias (__strlen, strlen);
new file mode 100644
@@ -0,0 +1,178 @@
+/* Optimized strlen for Huawei Kunpeng processor.
+ Copyright (C) 2018-2019 Free Software Foundation, Inc.
+
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+/* Assumptions:
+
+ ARMv8-a, AArch64, ASIMD, unaligned accesses, min page size 4k. */
+
+/* To test the page crossing code path more thoroughly, compile with
+ -DTEST_PAGE_CROSS - this will force all calls through the slower
+ entry path. This option is not intended for production use. */
+
+/* Arguments and results. */
+#define srcin x0
+#define len x0
+
+/* Locals and temporaries. */
+#define src x1
+#define data1 x2
+#define data2 x3
+#define has_nul1 x4
+#define has_nul2 x5
+#define tmp1 x4
+#define tmp2 x5
+#define tmp3 x6
+#define tmp4 x7
+#define zeroones x8
+#define dataq q2
+#define datav v2
+#define datab2 b3
+#define dataq2 q3
+#define datav2 v3
+
+#define REP8_01 0x0101010101010101
+#define REP8_7f 0x7f7f7f7f7f7f7f7f
+
+#ifdef TEST_PAGE_CROSS
+# define MIN_PAGE_SIZE 16
+#else
+# define MIN_PAGE_SIZE 4096
+#endif
+
+ /* Since strings are short on average, we check the first 16 bytes
+ of the string for a NUL character. In order to do an unaligned load
+ safely we have to do a page cross check first. If there is a NUL
+ byte we calculate the length from the 2 8-byte words using
+ conditional select to reduce branch mispredictions (it is unlikely
+ strlen_asimd will be repeatedly called on strings with the same
+ length).
+
+ If the string is longer than 16 bytes, we align src so don't need
+ further page cross checks, and process 16 bytes per iteration.
+
+ If the page cross check fails, we read 16 bytes from an aligned
+ address, remove any characters before the string, and continue
+ in the main loop using aligned loads. Since strings crossing a
+ page in the first 16 bytes are rare (probability of
+ 16/MIN_PAGE_SIZE ~= 0.4%), this case does not need to be optimized.
+
+ AArch64 systems have a minimum page size of 4k. We don't bother
+ checking for larger page sizes - the cost of setting up the correct
+ page size is just not worth the extra gain from a small reduction in
+ the cases taking the slow path. Note that we only care about
+ whether the first fetch, which may be misaligned, crosses a page
+ boundary. */
+
+ENTRY_ALIGN (__strlen_kunpeng, 6)
+ DELOUSE (0)
+ DELOUSE (1)
+ and tmp1, srcin, MIN_PAGE_SIZE - 1
+ mov zeroones, REP8_01
+ cmp tmp1, MIN_PAGE_SIZE - 16
+ b.gt L(page_cross)
+ ldp data1, data2, [srcin]
+#ifdef __AARCH64EB__
+ rev data1, data1
+ rev data2, data2
+#endif
+
+ sub tmp1, data1, zeroones
+ orr tmp2, data1, REP8_7f
+ sub tmp3, data2, zeroones
+ orr tmp4, data2, REP8_7f
+ bics has_nul1, tmp1, tmp2
+ bic has_nul2, tmp3, tmp4
+ ccmp has_nul2, 0, 0, eq
+ beq L(main_loop_entry)
+ csel has_nul1, has_nul1, has_nul2, cc
+ mov len, 8
+ rev has_nul1, has_nul1
+ clz tmp1, has_nul1
+ csel len, xzr, len, cc
+ add len, len, tmp1, lsr 3
+ ret
+
+L(main_loop_entry):
+ bic src, srcin, 15
+ sub src, src, 16
+
+L(main_loop):
+ ldr dataq, [src, 32]!
+L(page_cross_entry):
+ /* Get the minimum value and keep going if it is not zero. */
+ uminv datab2, datav.16b
+ mov tmp1, datav2.d[0]
+ cbz tmp1, L(tail)
+ ldr dataq, [src, 16]
+ uminv datab2, datav.16b
+ mov tmp1, datav2.d[0]
+ cbnz tmp1, L(main_loop)
+ add src, src, 16
+
+L(tail):
+#ifdef __AARCH64EB__
+ rev64 datav.16b, datav.16b
+#endif
+ /* Set te NULL byte as 0xff and the rest as 0x00, move the data into a
+ pair of scalars and then compute the length from the earliest NULL
+ byte. */
+ cmeq datav.16b, datav.16b, #0
+ mov data1, datav.d[0]
+ mov data2, datav.d[1]
+ cmp data1, 0
+ csel data1, data1, data2, ne
+ sub len, src, srcin
+ rev data1, data1
+ add tmp2, len, 8
+ clz tmp1, data1
+ csel len, len, tmp2, ne
+ add len, len, tmp1, lsr 3
+ ret
+
+ /* Load 16 bytes from [srcin & ~15] and force the bytes that precede
+ srcin to 0xff, so we ignore any NUL bytes before the string.
+ Then continue in the aligned loop. */
+L(page_cross):
+ mov tmp3, 63
+ bic src, srcin, 15
+ and tmp1, srcin, 7
+ ands tmp2, srcin, 8
+ ldr dataq, [src]
+ lsl tmp1, tmp1, 3
+ csel tmp2, tmp2, tmp1, eq
+ csel tmp1, tmp1, tmp3, eq
+ mov tmp4, -1
+#ifdef __AARCH64EB__
+ /* Big-endian. Early bytes are at MSB. */
+ lsr tmp1, tmp4, tmp1
+ lsr tmp2, tmp4, tmp2
+#else
+ /* Little-endian. Early bytes are at LSB. */
+ lsl tmp1, tmp4, tmp1
+ lsl tmp2, tmp4, tmp2
+#endif
+ mov datav2.d[0], tmp1
+ mov datav2.d[1], tmp2
+ orn datav.16b, datav.16b, datav2.16b
+ b L(page_cross_entry)
+END (__strlen_kunpeng)
+weak_alias (__strlen_kunpeng, strlen_kunpeng)
+libc_hidden_builtin_def (strlen_kunpeng)