mirror of
https://sourceware.org/git/glibc.git
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bef2a827a5
In commit 46b5e98ef6 ("x86: Add seperate non-temporal tunable for
memset") a tunable threshold for enabling non-temporal memset was added,
but only for Intel hardware.
Since that commit, new benchmark results suggest that non-temporal
memset is beneficial on AMD, as well, so allow this tunable to be set
for AMD.
See:
https://docs.google.com/spreadsheets/d/1opzukzvum4n6-RUVHTGddV6RjAEil4P2uMjjQGLbLcU/edit?usp=sharing
which has been updated to include data using different stategies for
large memset on AMD Zen2, Zen3, and Zen4.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
1068 lines
37 KiB
C
1068 lines
37 KiB
C
/* Initialize x86 cache info.
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Copyright (C) 2020-2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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static const struct intel_02_cache_info
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{
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unsigned char idx;
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unsigned char assoc;
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unsigned char linesize;
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unsigned char rel_name;
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unsigned int size;
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} intel_02_known [] =
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{
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#define M(sc) ((sc) - _SC_LEVEL1_ICACHE_SIZE)
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{ 0x06, 4, 32, M(_SC_LEVEL1_ICACHE_SIZE), 8192 },
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{ 0x08, 4, 32, M(_SC_LEVEL1_ICACHE_SIZE), 16384 },
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{ 0x09, 4, 32, M(_SC_LEVEL1_ICACHE_SIZE), 32768 },
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{ 0x0a, 2, 32, M(_SC_LEVEL1_DCACHE_SIZE), 8192 },
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{ 0x0c, 4, 32, M(_SC_LEVEL1_DCACHE_SIZE), 16384 },
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{ 0x0d, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 16384 },
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{ 0x0e, 6, 64, M(_SC_LEVEL1_DCACHE_SIZE), 24576 },
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{ 0x21, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 },
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{ 0x22, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 524288 },
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{ 0x23, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 1048576 },
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{ 0x25, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 },
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{ 0x29, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 },
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{ 0x2c, 8, 64, M(_SC_LEVEL1_DCACHE_SIZE), 32768 },
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{ 0x30, 8, 64, M(_SC_LEVEL1_ICACHE_SIZE), 32768 },
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{ 0x39, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 131072 },
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{ 0x3a, 6, 64, M(_SC_LEVEL2_CACHE_SIZE), 196608 },
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{ 0x3b, 2, 64, M(_SC_LEVEL2_CACHE_SIZE), 131072 },
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{ 0x3c, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 },
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{ 0x3d, 6, 64, M(_SC_LEVEL2_CACHE_SIZE), 393216 },
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{ 0x3e, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x3f, 2, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 },
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{ 0x41, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 131072 },
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{ 0x42, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 262144 },
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{ 0x43, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x44, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 1048576 },
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{ 0x45, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 2097152 },
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{ 0x46, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 },
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{ 0x47, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 },
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{ 0x48, 12, 64, M(_SC_LEVEL2_CACHE_SIZE), 3145728 },
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{ 0x49, 16, 64, M(_SC_LEVEL2_CACHE_SIZE), 4194304 },
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{ 0x4a, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 6291456 },
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{ 0x4b, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 },
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{ 0x4c, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 12582912 },
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{ 0x4d, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 16777216 },
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{ 0x4e, 24, 64, M(_SC_LEVEL2_CACHE_SIZE), 6291456 },
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{ 0x60, 8, 64, M(_SC_LEVEL1_DCACHE_SIZE), 16384 },
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{ 0x66, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 8192 },
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{ 0x67, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 16384 },
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{ 0x68, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 32768 },
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{ 0x78, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 1048576 },
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{ 0x79, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 131072 },
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{ 0x7a, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 },
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{ 0x7b, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x7c, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 1048576 },
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{ 0x7d, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 2097152 },
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{ 0x7f, 2, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x80, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x82, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 262144 },
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{ 0x83, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x84, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 1048576 },
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{ 0x85, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 2097152 },
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{ 0x86, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 },
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{ 0x87, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 1048576 },
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{ 0xd0, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 524288 },
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{ 0xd1, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 1048576 },
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{ 0xd2, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 },
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{ 0xd6, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 1048576 },
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{ 0xd7, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 },
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{ 0xd8, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 },
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{ 0xdc, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 },
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{ 0xdd, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 },
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{ 0xde, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 },
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{ 0xe2, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 },
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{ 0xe3, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 },
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{ 0xe4, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 },
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{ 0xea, 24, 64, M(_SC_LEVEL3_CACHE_SIZE), 12582912 },
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{ 0xeb, 24, 64, M(_SC_LEVEL3_CACHE_SIZE), 18874368 },
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{ 0xec, 24, 64, M(_SC_LEVEL3_CACHE_SIZE), 25165824 },
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};
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#define nintel_02_known (sizeof (intel_02_known) / sizeof (intel_02_known [0]))
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static int
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intel_02_known_compare (const void *p1, const void *p2)
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{
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const struct intel_02_cache_info *i1;
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const struct intel_02_cache_info *i2;
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i1 = (const struct intel_02_cache_info *) p1;
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i2 = (const struct intel_02_cache_info *) p2;
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if (i1->idx == i2->idx)
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return 0;
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return i1->idx < i2->idx ? -1 : 1;
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}
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static long int
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__attribute__ ((noinline))
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intel_check_word (int name, unsigned int value, bool *has_level_2,
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bool *no_level_2_or_3,
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const struct cpu_features *cpu_features)
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{
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if ((value & 0x80000000) != 0)
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/* The register value is reserved. */
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return 0;
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/* Fold the name. The _SC_ constants are always in the order SIZE,
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ASSOC, LINESIZE. */
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int folded_rel_name = (M(name) / 3) * 3;
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while (value != 0)
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{
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unsigned int byte = value & 0xff;
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if (byte == 0x40)
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{
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*no_level_2_or_3 = true;
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if (folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE))
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/* No need to look further. */
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break;
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}
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else if (byte == 0xff)
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{
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/* CPUID leaf 0x4 contains all the information. We need to
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iterate over it. */
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unsigned int eax;
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unsigned int ebx;
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unsigned int ecx;
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unsigned int edx;
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unsigned int round = 0;
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while (1)
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{
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__cpuid_count (4, round, eax, ebx, ecx, edx);
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enum { null = 0, data = 1, inst = 2, uni = 3 } type = eax & 0x1f;
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if (type == null)
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/* That was the end. */
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break;
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unsigned int level = (eax >> 5) & 0x7;
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if ((level == 1 && type == data
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&& folded_rel_name == M(_SC_LEVEL1_DCACHE_SIZE))
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|| (level == 1 && type == inst
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&& folded_rel_name == M(_SC_LEVEL1_ICACHE_SIZE))
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|| (level == 2 && folded_rel_name == M(_SC_LEVEL2_CACHE_SIZE))
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|| (level == 3 && folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE))
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|| (level == 4 && folded_rel_name == M(_SC_LEVEL4_CACHE_SIZE)))
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{
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unsigned int offset = M(name) - folded_rel_name;
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if (offset == 0)
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/* Cache size. */
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return (((ebx >> 22) + 1)
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* (((ebx >> 12) & 0x3ff) + 1)
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* ((ebx & 0xfff) + 1)
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* (ecx + 1));
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if (offset == 1)
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return (ebx >> 22) + 1;
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assert (offset == 2);
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return (ebx & 0xfff) + 1;
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}
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++round;
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}
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/* There is no other cache information anywhere else. */
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return -1;
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}
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else
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{
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if (byte == 0x49 && folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE))
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{
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/* Intel reused this value. For family 15, model 6 it
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specifies the 3rd level cache. Otherwise the 2nd
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level cache. */
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unsigned int family = cpu_features->basic.family;
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unsigned int model = cpu_features->basic.model;
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if (family == 15 && model == 6)
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{
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/* The level 3 cache is encoded for this model like
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the level 2 cache is for other models. Pretend
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the caller asked for the level 2 cache. */
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name = (_SC_LEVEL2_CACHE_SIZE
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+ (name - _SC_LEVEL3_CACHE_SIZE));
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folded_rel_name = M(_SC_LEVEL2_CACHE_SIZE);
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}
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}
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struct intel_02_cache_info *found;
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struct intel_02_cache_info search;
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search.idx = byte;
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found = bsearch (&search, intel_02_known, nintel_02_known,
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sizeof (intel_02_known[0]), intel_02_known_compare);
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if (found != NULL)
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{
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if (found->rel_name == folded_rel_name)
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{
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unsigned int offset = M(name) - folded_rel_name;
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if (offset == 0)
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/* Cache size. */
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return found->size;
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if (offset == 1)
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return found->assoc;
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assert (offset == 2);
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return found->linesize;
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}
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if (found->rel_name == M(_SC_LEVEL2_CACHE_SIZE))
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*has_level_2 = true;
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}
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}
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/* Next byte for the next round. */
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value >>= 8;
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}
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/* Nothing found. */
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return 0;
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}
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static long int __attribute__ ((noinline))
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handle_intel (int name, const struct cpu_features *cpu_features)
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{
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unsigned int maxidx = cpu_features->basic.max_cpuid;
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/* Return -1 for older CPUs. */
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if (maxidx < 2)
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return -1;
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/* OK, we can use the CPUID instruction to get all info about the
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caches. */
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long int result = 0;
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bool no_level_2_or_3 = false;
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bool has_level_2 = false;
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unsigned int eax;
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unsigned int ebx;
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unsigned int ecx;
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unsigned int edx;
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__cpuid (2, eax, ebx, ecx, edx);
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/* The low byte of EAX of CPUID leaf 2 should always return 1 and it
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should be ignored. If it isn't 1, use CPUID leaf 4 instead. */
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if ((eax & 0xff) != 1)
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return intel_check_word (name, 0xff, &has_level_2, &no_level_2_or_3,
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cpu_features);
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else
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{
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eax &= 0xffffff00;
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/* Process the individual registers' value. */
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result = intel_check_word (name, eax, &has_level_2,
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&no_level_2_or_3, cpu_features);
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if (result != 0)
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return result;
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result = intel_check_word (name, ebx, &has_level_2,
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&no_level_2_or_3, cpu_features);
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if (result != 0)
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return result;
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result = intel_check_word (name, ecx, &has_level_2,
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&no_level_2_or_3, cpu_features);
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if (result != 0)
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return result;
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result = intel_check_word (name, edx, &has_level_2,
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&no_level_2_or_3, cpu_features);
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if (result != 0)
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return result;
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}
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if (name >= _SC_LEVEL2_CACHE_SIZE && name <= _SC_LEVEL3_CACHE_LINESIZE
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&& no_level_2_or_3)
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return -1;
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return 0;
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}
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static long int __attribute__ ((noinline))
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handle_amd (int name)
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{
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unsigned int eax;
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unsigned int ebx;
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unsigned int ecx = 0;
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unsigned int edx;
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unsigned int max_cpuid = 0;
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unsigned int fn = 0;
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/* No level 4 cache (yet). */
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if (name > _SC_LEVEL3_CACHE_LINESIZE)
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return 0;
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__cpuid (0x80000000, max_cpuid, ebx, ecx, edx);
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if (max_cpuid >= 0x8000001D)
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/* Use __cpuid__ '0x8000_001D' to compute cache details. */
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{
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unsigned int count = 0x1;
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if (name >= _SC_LEVEL3_CACHE_SIZE)
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count = 0x3;
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else if (name >= _SC_LEVEL2_CACHE_SIZE)
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count = 0x2;
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else if (name >= _SC_LEVEL1_DCACHE_SIZE)
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count = 0x0;
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__cpuid_count (0x8000001D, count, eax, ebx, ecx, edx);
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if (ecx != 0)
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{
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switch (name)
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{
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case _SC_LEVEL1_ICACHE_ASSOC:
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case _SC_LEVEL1_DCACHE_ASSOC:
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case _SC_LEVEL2_CACHE_ASSOC:
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case _SC_LEVEL3_CACHE_ASSOC:
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return ((ebx >> 22) & 0x3ff) + 1;
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case _SC_LEVEL1_ICACHE_LINESIZE:
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case _SC_LEVEL1_DCACHE_LINESIZE:
|
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case _SC_LEVEL2_CACHE_LINESIZE:
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case _SC_LEVEL3_CACHE_LINESIZE:
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return (ebx & 0xfff) + 1;
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case _SC_LEVEL1_ICACHE_SIZE:
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case _SC_LEVEL1_DCACHE_SIZE:
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case _SC_LEVEL2_CACHE_SIZE:
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case _SC_LEVEL3_CACHE_SIZE:
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return (((ebx >> 22) & 0x3ff) + 1) * ((ebx & 0xfff) + 1) * (ecx + 1);
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default:
|
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__builtin_unreachable ();
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}
|
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return -1;
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}
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}
|
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|
|
/* Legacy cache computation for CPUs prior to Bulldozer family.
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This is also a fail-safe mechanism for some hypervisors that
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accidentally configure __cpuid__ '0x8000_001D' to Zero. */
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fn = 0x80000005 + (name >= _SC_LEVEL2_CACHE_SIZE);
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|
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if (max_cpuid < fn)
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return 0;
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|
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__cpuid (fn, eax, ebx, ecx, edx);
|
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|
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if (name < _SC_LEVEL1_DCACHE_SIZE)
|
|
{
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name += _SC_LEVEL1_DCACHE_SIZE - _SC_LEVEL1_ICACHE_SIZE;
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ecx = edx;
|
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}
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|
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switch (name)
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{
|
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case _SC_LEVEL1_DCACHE_SIZE:
|
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return (ecx >> 14) & 0x3fc00;
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|
|
case _SC_LEVEL1_DCACHE_ASSOC:
|
|
ecx >>= 16;
|
|
if ((ecx & 0xff) == 0xff)
|
|
{
|
|
/* Fully associative. */
|
|
return (ecx << 2) & 0x3fc00;
|
|
}
|
|
return ecx & 0xff;
|
|
|
|
case _SC_LEVEL1_DCACHE_LINESIZE:
|
|
return ecx & 0xff;
|
|
|
|
case _SC_LEVEL2_CACHE_SIZE:
|
|
return (ecx & 0xf000) == 0 ? 0 : (ecx >> 6) & 0x3fffc00;
|
|
|
|
case _SC_LEVEL2_CACHE_ASSOC:
|
|
switch ((ecx >> 12) & 0xf)
|
|
{
|
|
case 0:
|
|
case 1:
|
|
case 2:
|
|
case 4:
|
|
return (ecx >> 12) & 0xf;
|
|
case 6:
|
|
return 8;
|
|
case 8:
|
|
return 16;
|
|
case 10:
|
|
return 32;
|
|
case 11:
|
|
return 48;
|
|
case 12:
|
|
return 64;
|
|
case 13:
|
|
return 96;
|
|
case 14:
|
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return 128;
|
|
case 15:
|
|
return ((ecx >> 6) & 0x3fffc00) / (ecx & 0xff);
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
case _SC_LEVEL2_CACHE_LINESIZE:
|
|
return (ecx & 0xf000) == 0 ? 0 : ecx & 0xff;
|
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|
|
case _SC_LEVEL3_CACHE_SIZE:
|
|
{
|
|
long int total_l3_cache = 0, l3_cache_per_thread = 0;
|
|
unsigned int threads = 0;
|
|
const struct cpu_features *cpu_features;
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|
|
|
if ((edx & 0xf000) == 0)
|
|
return 0;
|
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|
|
total_l3_cache = (edx & 0x3ffc0000) << 1;
|
|
cpu_features = __get_cpu_features ();
|
|
|
|
/* Figure out the number of logical threads that share L3. */
|
|
if (max_cpuid >= 0x80000008)
|
|
{
|
|
/* Get width of APIC ID. */
|
|
__cpuid (0x80000008, eax, ebx, ecx, edx);
|
|
threads = (ecx & 0xff) + 1;
|
|
}
|
|
|
|
if (threads == 0)
|
|
{
|
|
/* If APIC ID width is not available, use logical
|
|
processor count. */
|
|
__cpuid (0x00000001, eax, ebx, ecx, edx);
|
|
if ((edx & (1 << 28)) != 0)
|
|
threads = (ebx >> 16) & 0xff;
|
|
}
|
|
|
|
/* Cap usage of highest cache level to the number of
|
|
supported threads. */
|
|
if (threads > 0)
|
|
l3_cache_per_thread = total_l3_cache/threads;
|
|
|
|
/* Get shared cache per ccx for Zen architectures. */
|
|
if (cpu_features->basic.family >= 0x17)
|
|
{
|
|
long int l3_cache_per_ccx = 0;
|
|
/* Get number of threads share the L3 cache in CCX. */
|
|
__cpuid_count (0x8000001D, 0x3, eax, ebx, ecx, edx);
|
|
unsigned int threads_per_ccx = ((eax >> 14) & 0xfff) + 1;
|
|
l3_cache_per_ccx = l3_cache_per_thread * threads_per_ccx;
|
|
return l3_cache_per_ccx;
|
|
}
|
|
else
|
|
{
|
|
return l3_cache_per_thread;
|
|
}
|
|
}
|
|
|
|
case _SC_LEVEL3_CACHE_ASSOC:
|
|
switch ((edx >> 12) & 0xf)
|
|
{
|
|
case 0:
|
|
case 1:
|
|
case 2:
|
|
case 4:
|
|
return (edx >> 12) & 0xf;
|
|
case 6:
|
|
return 8;
|
|
case 8:
|
|
return 16;
|
|
case 10:
|
|
return 32;
|
|
case 11:
|
|
return 48;
|
|
case 12:
|
|
return 64;
|
|
case 13:
|
|
return 96;
|
|
case 14:
|
|
return 128;
|
|
case 15:
|
|
return ((edx & 0x3ffc0000) << 1) / (edx & 0xff);
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
case _SC_LEVEL3_CACHE_LINESIZE:
|
|
return (edx & 0xf000) == 0 ? 0 : edx & 0xff;
|
|
|
|
default:
|
|
__builtin_unreachable ();
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
|
|
static long int __attribute__ ((noinline))
|
|
handle_zhaoxin (int name)
|
|
{
|
|
unsigned int eax;
|
|
unsigned int ebx;
|
|
unsigned int ecx;
|
|
unsigned int edx;
|
|
|
|
int folded_rel_name = (M(name) / 3) * 3;
|
|
|
|
unsigned int round = 0;
|
|
while (1)
|
|
{
|
|
__cpuid_count (4, round, eax, ebx, ecx, edx);
|
|
|
|
enum { null = 0, data = 1, inst = 2, uni = 3 } type = eax & 0x1f;
|
|
if (type == null)
|
|
break;
|
|
|
|
unsigned int level = (eax >> 5) & 0x7;
|
|
|
|
if ((level == 1 && type == data
|
|
&& folded_rel_name == M(_SC_LEVEL1_DCACHE_SIZE))
|
|
|| (level == 1 && type == inst
|
|
&& folded_rel_name == M(_SC_LEVEL1_ICACHE_SIZE))
|
|
|| (level == 2 && folded_rel_name == M(_SC_LEVEL2_CACHE_SIZE))
|
|
|| (level == 3 && folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE)))
|
|
{
|
|
unsigned int offset = M(name) - folded_rel_name;
|
|
|
|
if (offset == 0)
|
|
/* Cache size. */
|
|
return (((ebx >> 22) + 1)
|
|
* (((ebx >> 12) & 0x3ff) + 1)
|
|
* ((ebx & 0xfff) + 1)
|
|
* (ecx + 1));
|
|
if (offset == 1)
|
|
return (ebx >> 22) + 1;
|
|
|
|
assert (offset == 2);
|
|
return (ebx & 0xfff) + 1;
|
|
}
|
|
|
|
++round;
|
|
}
|
|
|
|
/* Nothing found. */
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
get_common_cache_info (long int *shared_ptr, long int * shared_per_thread_ptr, unsigned int *threads_ptr,
|
|
long int core)
|
|
{
|
|
unsigned int eax;
|
|
unsigned int ebx;
|
|
unsigned int ecx;
|
|
unsigned int edx;
|
|
|
|
/* Number of logical processors sharing L2 cache. */
|
|
int threads_l2;
|
|
|
|
/* Number of logical processors sharing L3 cache. */
|
|
int threads_l3;
|
|
|
|
const struct cpu_features *cpu_features = __get_cpu_features ();
|
|
int max_cpuid = cpu_features->basic.max_cpuid;
|
|
unsigned int family = cpu_features->basic.family;
|
|
unsigned int model = cpu_features->basic.model;
|
|
long int shared = *shared_ptr;
|
|
long int shared_per_thread = *shared_per_thread_ptr;
|
|
unsigned int threads = *threads_ptr;
|
|
bool inclusive_cache = true;
|
|
bool support_count_mask = true;
|
|
|
|
/* Try L3 first. */
|
|
unsigned int level = 3;
|
|
|
|
if (cpu_features->basic.kind == arch_kind_zhaoxin && family == 6)
|
|
support_count_mask = false;
|
|
|
|
if (shared <= 0)
|
|
{
|
|
/* Try L2 otherwise. */
|
|
level = 2;
|
|
shared = core;
|
|
shared_per_thread = core;
|
|
threads_l2 = 0;
|
|
threads_l3 = -1;
|
|
}
|
|
else
|
|
{
|
|
threads_l2 = 0;
|
|
threads_l3 = 0;
|
|
}
|
|
|
|
/* A value of 0 for the HTT bit indicates there is only a single
|
|
logical processor. */
|
|
if (HAS_CPU_FEATURE (HTT))
|
|
{
|
|
/* Figure out the number of logical threads that share the
|
|
highest cache level. */
|
|
if (max_cpuid >= 4)
|
|
{
|
|
int i = 0;
|
|
|
|
/* Query until cache level 2 and 3 are enumerated. */
|
|
int check = 0x1 | (threads_l3 == 0) << 1;
|
|
do
|
|
{
|
|
__cpuid_count (4, i++, eax, ebx, ecx, edx);
|
|
|
|
/* There seems to be a bug in at least some Pentium Ds
|
|
which sometimes fail to iterate all cache parameters.
|
|
Do not loop indefinitely here, stop in this case and
|
|
assume there is no such information. */
|
|
if (cpu_features->basic.kind == arch_kind_intel
|
|
&& (eax & 0x1f) == 0 )
|
|
goto intel_bug_no_cache_info;
|
|
|
|
switch ((eax >> 5) & 0x7)
|
|
{
|
|
default:
|
|
break;
|
|
case 2:
|
|
if ((check & 0x1))
|
|
{
|
|
/* Get maximum number of logical processors
|
|
sharing L2 cache. */
|
|
threads_l2 = (eax >> 14) & 0x3ff;
|
|
check &= ~0x1;
|
|
}
|
|
break;
|
|
case 3:
|
|
if ((check & (0x1 << 1)))
|
|
{
|
|
/* Get maximum number of logical processors
|
|
sharing L3 cache. */
|
|
threads_l3 = (eax >> 14) & 0x3ff;
|
|
|
|
/* Check if L2 and L3 caches are inclusive. */
|
|
inclusive_cache = (edx & 0x2) != 0;
|
|
check &= ~(0x1 << 1);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
while (check);
|
|
|
|
/* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
|
|
numbers of addressable IDs for logical processors sharing
|
|
the cache, instead of the maximum number of threads
|
|
sharing the cache. */
|
|
if (max_cpuid >= 11 && support_count_mask)
|
|
{
|
|
/* Find the number of logical processors shipped in
|
|
one core and apply count mask. */
|
|
i = 0;
|
|
|
|
/* Count SMT only if there is L3 cache. Always count
|
|
core if there is no L3 cache. */
|
|
int count = ((threads_l2 > 0 && level == 3)
|
|
| ((threads_l3 > 0
|
|
|| (threads_l2 > 0 && level == 2)) << 1));
|
|
|
|
while (count)
|
|
{
|
|
__cpuid_count (11, i++, eax, ebx, ecx, edx);
|
|
|
|
int shipped = ebx & 0xff;
|
|
int type = ecx & 0xff00;
|
|
if (shipped == 0 || type == 0)
|
|
break;
|
|
else if (type == 0x100)
|
|
{
|
|
/* Count SMT. */
|
|
if ((count & 0x1))
|
|
{
|
|
int count_mask;
|
|
|
|
/* Compute count mask. */
|
|
asm ("bsr %1, %0"
|
|
: "=r" (count_mask) : "g" (threads_l2));
|
|
count_mask = ~(-1 << (count_mask + 1));
|
|
threads_l2 = (shipped - 1) & count_mask;
|
|
count &= ~0x1;
|
|
}
|
|
}
|
|
else if (type == 0x200)
|
|
{
|
|
/* Count core. */
|
|
if ((count & (0x1 << 1)))
|
|
{
|
|
int count_mask;
|
|
int threads_core
|
|
= (level == 2 ? threads_l2 : threads_l3);
|
|
|
|
/* Compute count mask. */
|
|
asm ("bsr %1, %0"
|
|
: "=r" (count_mask) : "g" (threads_core));
|
|
count_mask = ~(-1 << (count_mask + 1));
|
|
threads_core = (shipped - 1) & count_mask;
|
|
if (level == 2)
|
|
threads_l2 = threads_core;
|
|
else
|
|
threads_l3 = threads_core;
|
|
count &= ~(0x1 << 1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (threads_l2 > 0)
|
|
threads_l2 += 1;
|
|
if (threads_l3 > 0)
|
|
threads_l3 += 1;
|
|
if (level == 2)
|
|
{
|
|
if (threads_l2)
|
|
{
|
|
threads = threads_l2;
|
|
if (cpu_features->basic.kind == arch_kind_intel
|
|
&& threads > 2
|
|
&& family == 6)
|
|
switch (model)
|
|
{
|
|
case 0x37:
|
|
case 0x4a:
|
|
case 0x4d:
|
|
case 0x5a:
|
|
case 0x5d:
|
|
/* Silvermont has L2 cache shared by 2 cores. */
|
|
threads = 2;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if (threads_l3)
|
|
threads = threads_l3;
|
|
}
|
|
else
|
|
{
|
|
intel_bug_no_cache_info:
|
|
/* Assume that all logical threads share the highest cache
|
|
level. */
|
|
threads = ((cpu_features->features[CPUID_INDEX_1].cpuid.ebx >> 16)
|
|
& 0xff);
|
|
}
|
|
/* Get per-thread size of highest level cache. */
|
|
if (shared_per_thread > 0 && threads > 0)
|
|
shared_per_thread /= threads;
|
|
}
|
|
|
|
/* Account for non-inclusive L2 and L3 caches. */
|
|
if (!inclusive_cache)
|
|
{
|
|
long int core_per_thread = threads_l2 > 0 ? (core / threads_l2) : core;
|
|
shared_per_thread += core_per_thread;
|
|
shared += core;
|
|
}
|
|
|
|
*shared_ptr = shared;
|
|
*shared_per_thread_ptr = shared_per_thread;
|
|
*threads_ptr = threads;
|
|
}
|
|
|
|
static void
|
|
dl_init_cacheinfo (struct cpu_features *cpu_features)
|
|
{
|
|
/* Find out what brand of processor. */
|
|
long int data = -1;
|
|
long int shared = -1;
|
|
long int shared_per_thread = -1;
|
|
unsigned int threads = 0;
|
|
unsigned long int level1_icache_size = -1;
|
|
unsigned long int level1_icache_linesize = -1;
|
|
unsigned long int level1_dcache_size = -1;
|
|
unsigned long int level1_dcache_assoc = -1;
|
|
unsigned long int level1_dcache_linesize = -1;
|
|
unsigned long int level2_cache_size = -1;
|
|
unsigned long int level2_cache_assoc = -1;
|
|
unsigned long int level2_cache_linesize = -1;
|
|
unsigned long int level3_cache_size = -1;
|
|
unsigned long int level3_cache_assoc = -1;
|
|
unsigned long int level3_cache_linesize = -1;
|
|
unsigned long int level4_cache_size = -1;
|
|
|
|
if (cpu_features->basic.kind == arch_kind_intel)
|
|
{
|
|
data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
|
|
shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
|
|
shared_per_thread = shared;
|
|
|
|
level1_icache_size
|
|
= handle_intel (_SC_LEVEL1_ICACHE_SIZE, cpu_features);
|
|
level1_icache_linesize
|
|
= handle_intel (_SC_LEVEL1_ICACHE_LINESIZE, cpu_features);
|
|
level1_dcache_size = data;
|
|
level1_dcache_assoc
|
|
= handle_intel (_SC_LEVEL1_DCACHE_ASSOC, cpu_features);
|
|
level1_dcache_linesize
|
|
= handle_intel (_SC_LEVEL1_DCACHE_LINESIZE, cpu_features);
|
|
level2_cache_size
|
|
= handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
|
|
level2_cache_assoc
|
|
= handle_intel (_SC_LEVEL2_CACHE_ASSOC, cpu_features);
|
|
level2_cache_linesize
|
|
= handle_intel (_SC_LEVEL2_CACHE_LINESIZE, cpu_features);
|
|
level3_cache_size = shared;
|
|
level3_cache_assoc
|
|
= handle_intel (_SC_LEVEL3_CACHE_ASSOC, cpu_features);
|
|
level3_cache_linesize
|
|
= handle_intel (_SC_LEVEL3_CACHE_LINESIZE, cpu_features);
|
|
level4_cache_size
|
|
= handle_intel (_SC_LEVEL4_CACHE_SIZE, cpu_features);
|
|
|
|
get_common_cache_info (&shared, &shared_per_thread, &threads,
|
|
level2_cache_size);
|
|
}
|
|
else if (cpu_features->basic.kind == arch_kind_zhaoxin)
|
|
{
|
|
data = handle_zhaoxin (_SC_LEVEL1_DCACHE_SIZE);
|
|
shared = handle_zhaoxin (_SC_LEVEL3_CACHE_SIZE);
|
|
shared_per_thread = shared;
|
|
|
|
level1_icache_size = handle_zhaoxin (_SC_LEVEL1_ICACHE_SIZE);
|
|
level1_icache_linesize = handle_zhaoxin (_SC_LEVEL1_ICACHE_LINESIZE);
|
|
level1_dcache_size = data;
|
|
level1_dcache_assoc = handle_zhaoxin (_SC_LEVEL1_DCACHE_ASSOC);
|
|
level1_dcache_linesize = handle_zhaoxin (_SC_LEVEL1_DCACHE_LINESIZE);
|
|
level2_cache_size = handle_zhaoxin (_SC_LEVEL2_CACHE_SIZE);
|
|
level2_cache_assoc = handle_zhaoxin (_SC_LEVEL2_CACHE_ASSOC);
|
|
level2_cache_linesize = handle_zhaoxin (_SC_LEVEL2_CACHE_LINESIZE);
|
|
level3_cache_size = shared;
|
|
level3_cache_assoc = handle_zhaoxin (_SC_LEVEL3_CACHE_ASSOC);
|
|
level3_cache_linesize = handle_zhaoxin (_SC_LEVEL3_CACHE_LINESIZE);
|
|
|
|
get_common_cache_info (&shared, &shared_per_thread, &threads,
|
|
level2_cache_size);
|
|
}
|
|
else if (cpu_features->basic.kind == arch_kind_amd)
|
|
{
|
|
data = handle_amd (_SC_LEVEL1_DCACHE_SIZE);
|
|
shared = handle_amd (_SC_LEVEL3_CACHE_SIZE);
|
|
|
|
level1_icache_size = handle_amd (_SC_LEVEL1_ICACHE_SIZE);
|
|
level1_icache_linesize = handle_amd (_SC_LEVEL1_ICACHE_LINESIZE);
|
|
level1_dcache_size = data;
|
|
level1_dcache_assoc = handle_amd (_SC_LEVEL1_DCACHE_ASSOC);
|
|
level1_dcache_linesize = handle_amd (_SC_LEVEL1_DCACHE_LINESIZE);
|
|
level2_cache_size = handle_amd (_SC_LEVEL2_CACHE_SIZE);;
|
|
level2_cache_assoc = handle_amd (_SC_LEVEL2_CACHE_ASSOC);
|
|
level2_cache_linesize = handle_amd (_SC_LEVEL2_CACHE_LINESIZE);
|
|
level3_cache_size = shared;
|
|
level3_cache_assoc = handle_amd (_SC_LEVEL3_CACHE_ASSOC);
|
|
level3_cache_linesize = handle_amd (_SC_LEVEL3_CACHE_LINESIZE);
|
|
level4_cache_size = handle_amd (_SC_LEVEL4_CACHE_SIZE);
|
|
|
|
if (shared <= 0)
|
|
{
|
|
/* No shared L3 cache. All we have is the L2 cache. */
|
|
shared = level2_cache_size;
|
|
}
|
|
else if (cpu_features->basic.family < 0x17)
|
|
{
|
|
/* Account for exclusive L2 and L3 caches. */
|
|
shared += level2_cache_size;
|
|
}
|
|
|
|
shared_per_thread = shared;
|
|
}
|
|
|
|
cpu_features->level1_icache_size = level1_icache_size;
|
|
cpu_features->level1_icache_linesize = level1_icache_linesize;
|
|
cpu_features->level1_dcache_size = level1_dcache_size;
|
|
cpu_features->level1_dcache_assoc = level1_dcache_assoc;
|
|
cpu_features->level1_dcache_linesize = level1_dcache_linesize;
|
|
cpu_features->level2_cache_size = level2_cache_size;
|
|
cpu_features->level2_cache_assoc = level2_cache_assoc;
|
|
cpu_features->level2_cache_linesize = level2_cache_linesize;
|
|
cpu_features->level3_cache_size = level3_cache_size;
|
|
cpu_features->level3_cache_assoc = level3_cache_assoc;
|
|
cpu_features->level3_cache_linesize = level3_cache_linesize;
|
|
cpu_features->level4_cache_size = level4_cache_size;
|
|
|
|
unsigned long int cachesize_non_temporal_divisor
|
|
= cpu_features->cachesize_non_temporal_divisor;
|
|
if (cachesize_non_temporal_divisor <= 0)
|
|
cachesize_non_temporal_divisor = 4;
|
|
|
|
/* The default setting for the non_temporal threshold is [1/8, 1/2] of size
|
|
of the chip's cache (depending on `cachesize_non_temporal_divisor` which
|
|
is microarch specific. The default is 1/4). For most Intel processors
|
|
with an initial release date between 2017 and 2023, a thread's
|
|
typical share of the cache is from 18-64MB. Using a reasonable size
|
|
fraction of L3 is meant to estimate the point where non-temporal stores
|
|
begin out-competing REP MOVSB. As well the point where the fact that
|
|
non-temporal stores are forced back to main memory would already occurred
|
|
to the majority of the lines in the copy. Note, concerns about the entire
|
|
L3 cache being evicted by the copy are mostly alleviated by the fact that
|
|
modern HW detects streaming patterns and provides proper LRU hints so that
|
|
the maximum thrashing capped at 1/associativity. */
|
|
unsigned long int non_temporal_threshold
|
|
= shared / cachesize_non_temporal_divisor;
|
|
|
|
/* If the computed non_temporal_threshold <= 3/4 * per-thread L3, we most
|
|
likely have incorrect/incomplete cache info in which case, default to
|
|
3/4 * per-thread L3 to avoid regressions. */
|
|
unsigned long int non_temporal_threshold_lowbound
|
|
= shared_per_thread * 3 / 4;
|
|
if (non_temporal_threshold < non_temporal_threshold_lowbound)
|
|
non_temporal_threshold = non_temporal_threshold_lowbound;
|
|
|
|
/* If no ERMS, we use the per-thread L3 chunking. Normal cacheable stores run
|
|
a higher risk of actually thrashing the cache as they don't have a HW LRU
|
|
hint. As well, their performance in highly parallel situations is
|
|
noticeably worse. */
|
|
if (!CPU_FEATURE_USABLE_P (cpu_features, ERMS))
|
|
non_temporal_threshold = non_temporal_threshold_lowbound;
|
|
/* SIZE_MAX >> 4 because memmove-vec-unaligned-erms right-shifts the value of
|
|
'x86_non_temporal_threshold' by `LOG_4X_MEMCPY_THRESH` (4) and it is best
|
|
if that operation cannot overflow. Minimum of 0x4040 (16448) because the
|
|
L(large_memset_4x) loops need 64-byte to cache align and enough space for
|
|
at least 1 iteration of 4x PAGE_SIZE unrolled loop. Both values are
|
|
reflected in the manual. */
|
|
unsigned long int maximum_non_temporal_threshold = SIZE_MAX >> 4;
|
|
unsigned long int minimum_non_temporal_threshold = 0x4040;
|
|
|
|
/* If `non_temporal_threshold` less than `minimum_non_temporal_threshold`
|
|
it most likely means we failed to detect the cache info. We don't want
|
|
to default to `minimum_non_temporal_threshold` as such a small value,
|
|
while correct, has bad performance. We default to 64MB as reasonable
|
|
default bound. 64MB is likely conservative in that most/all systems would
|
|
choose a lower value so it should never forcing non-temporal stores when
|
|
they otherwise wouldn't be used. */
|
|
if (non_temporal_threshold < minimum_non_temporal_threshold)
|
|
non_temporal_threshold = 64 * 1024 * 1024;
|
|
else if (non_temporal_threshold > maximum_non_temporal_threshold)
|
|
non_temporal_threshold = maximum_non_temporal_threshold;
|
|
|
|
/* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8. */
|
|
unsigned int minimum_rep_movsb_threshold;
|
|
/* NB: The default REP MOVSB threshold is 4096 * (VEC_SIZE / 16) for
|
|
VEC_SIZE == 64 or 32. For VEC_SIZE == 16, the default REP MOVSB
|
|
threshold is 2048 * (VEC_SIZE / 16). */
|
|
unsigned int rep_movsb_threshold;
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
|
|
&& !CPU_FEATURE_PREFERRED_P (cpu_features, Prefer_No_AVX512))
|
|
{
|
|
rep_movsb_threshold = 4096 * (64 / 16);
|
|
minimum_rep_movsb_threshold = 64 * 8;
|
|
}
|
|
else if (CPU_FEATURE_PREFERRED_P (cpu_features,
|
|
AVX_Fast_Unaligned_Load))
|
|
{
|
|
rep_movsb_threshold = 4096 * (32 / 16);
|
|
minimum_rep_movsb_threshold = 32 * 8;
|
|
}
|
|
else
|
|
{
|
|
rep_movsb_threshold = 2048 * (16 / 16);
|
|
minimum_rep_movsb_threshold = 16 * 8;
|
|
}
|
|
/* NB: The default REP MOVSB threshold is 2112 on processors with fast
|
|
short REP MOVSB (FSRM). */
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, FSRM))
|
|
rep_movsb_threshold = 2112;
|
|
|
|
/* Non-temporal stores are more performant on Intel and AMD hardware above
|
|
non_temporal_threshold. Enable this for both Intel and AMD hardware. */
|
|
unsigned long int memset_non_temporal_threshold = SIZE_MAX;
|
|
if (cpu_features->basic.kind == arch_kind_intel
|
|
|| cpu_features->basic.kind == arch_kind_amd)
|
|
memset_non_temporal_threshold = non_temporal_threshold;
|
|
|
|
/* For AMD CPUs that support ERMS (Zen3+), REP MOVSB is in a lot of
|
|
cases slower than the vectorized path (and for some alignments,
|
|
it is really slow, check BZ #30994). */
|
|
if (cpu_features->basic.kind == arch_kind_amd)
|
|
rep_movsb_threshold = non_temporal_threshold;
|
|
|
|
/* The default threshold to use Enhanced REP STOSB. */
|
|
unsigned long int rep_stosb_threshold = 2048;
|
|
|
|
long int tunable_size;
|
|
|
|
tunable_size = TUNABLE_GET (x86_data_cache_size, long int, NULL);
|
|
/* NB: Ignore the default value 0. */
|
|
if (tunable_size != 0)
|
|
data = tunable_size;
|
|
|
|
tunable_size = TUNABLE_GET (x86_shared_cache_size, long int, NULL);
|
|
/* NB: Ignore the default value 0. */
|
|
if (tunable_size != 0)
|
|
shared = tunable_size;
|
|
|
|
tunable_size = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL);
|
|
if (tunable_size > minimum_non_temporal_threshold
|
|
&& tunable_size <= maximum_non_temporal_threshold)
|
|
non_temporal_threshold = tunable_size;
|
|
|
|
tunable_size = TUNABLE_GET (x86_memset_non_temporal_threshold, long int, NULL);
|
|
if (tunable_size > minimum_non_temporal_threshold
|
|
&& tunable_size <= maximum_non_temporal_threshold)
|
|
memset_non_temporal_threshold = tunable_size;
|
|
|
|
tunable_size = TUNABLE_GET (x86_rep_movsb_threshold, long int, NULL);
|
|
if (tunable_size > minimum_rep_movsb_threshold)
|
|
rep_movsb_threshold = tunable_size;
|
|
|
|
/* NB: The default value of the x86_rep_stosb_threshold tunable is the
|
|
same as the default value of __x86_rep_stosb_threshold and the
|
|
minimum value is fixed. */
|
|
rep_stosb_threshold = TUNABLE_GET (x86_rep_stosb_threshold,
|
|
long int, NULL);
|
|
if (cpu_features->basic.kind == arch_kind_amd
|
|
&& !TUNABLE_IS_INITIALIZED (x86_rep_stosb_threshold))
|
|
/* For AMD Zen3+ architecture, the performance of the vectorized loop is
|
|
slightly better than ERMS. */
|
|
rep_stosb_threshold = SIZE_MAX;
|
|
|
|
TUNABLE_SET_WITH_BOUNDS (x86_data_cache_size, data, 0, SIZE_MAX);
|
|
TUNABLE_SET_WITH_BOUNDS (x86_shared_cache_size, shared, 0, SIZE_MAX);
|
|
TUNABLE_SET_WITH_BOUNDS (x86_non_temporal_threshold, non_temporal_threshold,
|
|
minimum_non_temporal_threshold,
|
|
maximum_non_temporal_threshold);
|
|
TUNABLE_SET_WITH_BOUNDS (
|
|
x86_memset_non_temporal_threshold, memset_non_temporal_threshold,
|
|
minimum_non_temporal_threshold, maximum_non_temporal_threshold);
|
|
TUNABLE_SET_WITH_BOUNDS (x86_rep_movsb_threshold, rep_movsb_threshold,
|
|
minimum_rep_movsb_threshold, SIZE_MAX);
|
|
TUNABLE_SET_WITH_BOUNDS (x86_rep_stosb_threshold, rep_stosb_threshold, 1,
|
|
SIZE_MAX);
|
|
|
|
unsigned long int rep_movsb_stop_threshold;
|
|
/* Setting the upper bound of ERMS to the computed value of
|
|
non-temporal threshold for all architectures. */
|
|
rep_movsb_stop_threshold = non_temporal_threshold;
|
|
|
|
cpu_features->data_cache_size = data;
|
|
cpu_features->shared_cache_size = shared;
|
|
cpu_features->non_temporal_threshold = non_temporal_threshold;
|
|
cpu_features->memset_non_temporal_threshold = memset_non_temporal_threshold;
|
|
cpu_features->rep_movsb_threshold = rep_movsb_threshold;
|
|
cpu_features->rep_stosb_threshold = rep_stosb_threshold;
|
|
cpu_features->rep_movsb_stop_threshold = rep_movsb_stop_threshold;
|
|
}
|