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a057f5f8cd
The large memcpy micro benchmark in glibc shows that there is a regression with large data on Haswell machine. non-temporal store in memcpy on large data can improve performance significantly. This patch adds a threshold to use non temporal store which is 6 times of shared cache size. When size is above the threshold, non temporal store will be used, but avoid non-temporal store if there is overlap between destination and source since destination may be in cache when source is loaded. For size below 8 vector register width, we load all data into registers and store them together. Only forward and backward loops, which move 4 vector registers at a time, are used to support overlapping addresses. For forward loop, we load the last 4 vector register width of data and the first vector register width of data into vector registers before the loop and store them after the loop. For backward loop, we load the first 4 vector register width of data and the last vector register width of data into vector registers before the loop and store them after the loop. [BZ #19928] * sysdeps/x86_64/cacheinfo.c (__x86_shared_non_temporal_threshold): New. (init_cacheinfo): Set __x86_shared_non_temporal_threshold to 6 times of shared cache size. * sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S (VMOVNT): New. * sysdeps/x86_64/multiarch/memmove-avx512-unaligned-erms.S (VMOVNT): Likewise. * sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S (VMOVNT): Likewise. (VMOVU): Changed to movups for smaller code sizes. (VMOVA): Changed to movaps for smaller code sizes. * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Update comments. (PREFETCH): New. (PREFETCH_SIZE): Likewise. (PREFETCHED_LOAD_SIZE): Likewise. (PREFETCH_ONE_SET): Likewise. Rewrite to use forward and backward loops, which move 4 vector registers at a time, to support overlapping addresses and use non temporal store if size is above the threshold and there is no overlap between destination and source.
674 lines
19 KiB
C
674 lines
19 KiB
C
/* x86_64 cache info.
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Copyright (C) 2003-2016 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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<http://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <cpuid.h>
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#include <init-arch.h>
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#define is_intel GLRO(dl_x86_cpu_features).kind == arch_kind_intel
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#define is_amd GLRO(dl_x86_cpu_features).kind == arch_kind_amd
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#define max_cpuid GLRO(dl_x86_cpu_features).max_cpuid
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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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{
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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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break;
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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 = GLRO(dl_x86_cpu_features).family;
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unsigned int model = GLRO(dl_x86_cpu_features).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, unsigned int maxidx)
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{
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assert (maxidx >= 2);
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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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unsigned int cnt = 0;
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unsigned int max = 1;
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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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while (cnt++ < max)
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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;
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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 in the first round contain the number of
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rounds we have to make. At least one, the one we are already
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doing. */
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if (cnt == 1)
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{
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max = eax & 0xff;
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eax &= 0xffffff00;
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}
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/* Process the individual registers' value. */
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result = intel_check_word (name, eax, &has_level_2, &no_level_2_or_3);
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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, &no_level_2_or_3);
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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, &no_level_2_or_3);
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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, &no_level_2_or_3);
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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;
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unsigned int edx;
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__cpuid (0x80000000, eax, ebx, ecx, edx);
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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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unsigned int fn = 0x80000005 + (name >= _SC_LEVEL2_CACHE_SIZE);
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if (eax < fn)
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return 0;
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__cpuid (fn, eax, ebx, ecx, edx);
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if (name < _SC_LEVEL1_DCACHE_SIZE)
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{
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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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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:
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ecx >>= 16;
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if ((ecx & 0xff) == 0xff)
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/* Fully associative. */
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return (ecx << 2) & 0x3fc00;
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return ecx & 0xff;
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case _SC_LEVEL1_DCACHE_LINESIZE:
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return ecx & 0xff;
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case _SC_LEVEL2_CACHE_SIZE:
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return (ecx & 0xf000) == 0 ? 0 : (ecx >> 6) & 0x3fffc00;
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case _SC_LEVEL2_CACHE_ASSOC:
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switch ((ecx >> 12) & 0xf)
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{
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case 0:
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case 1:
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case 2:
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case 4:
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return (ecx >> 12) & 0xf;
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case 6:
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return 8;
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case 8:
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return 16;
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case 10:
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return 32;
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case 11:
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return 48;
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case 12:
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return 64;
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case 13:
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return 96;
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case 14:
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return 128;
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case 15:
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return ((ecx >> 6) & 0x3fffc00) / (ecx & 0xff);
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default:
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return 0;
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}
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/* NOTREACHED */
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case _SC_LEVEL2_CACHE_LINESIZE:
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return (ecx & 0xf000) == 0 ? 0 : ecx & 0xff;
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case _SC_LEVEL3_CACHE_SIZE:
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return (edx & 0xf000) == 0 ? 0 : (edx & 0x3ffc0000) << 1;
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case _SC_LEVEL3_CACHE_ASSOC:
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switch ((edx >> 12) & 0xf)
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{
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case 0:
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case 1:
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case 2:
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case 4:
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return (edx >> 12) & 0xf;
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case 6:
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return 8;
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case 8:
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return 16;
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case 10:
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return 32;
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case 11:
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return 48;
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case 12:
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return 64;
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case 13:
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return 96;
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case 14:
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return 128;
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case 15:
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return ((edx & 0x3ffc0000) << 1) / (edx & 0xff);
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default:
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return 0;
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}
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/* NOTREACHED */
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case _SC_LEVEL3_CACHE_LINESIZE:
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return (edx & 0xf000) == 0 ? 0 : edx & 0xff;
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default:
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assert (! "cannot happen");
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}
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return -1;
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}
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/* Get the value of the system variable NAME. */
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long int
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attribute_hidden
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__cache_sysconf (int name)
|
|
{
|
|
if (is_intel)
|
|
return handle_intel (name, max_cpuid);
|
|
|
|
if (is_amd)
|
|
return handle_amd (name);
|
|
|
|
// XXX Fill in more vendors.
|
|
|
|
/* CPU not known, we have no information. */
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Data cache size for use in memory and string routines, typically
|
|
L1 size, rounded to multiple of 256 bytes. */
|
|
long int __x86_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
|
|
long int __x86_data_cache_size attribute_hidden = 32 * 1024;
|
|
/* Similar to __x86_data_cache_size_half, but not rounded. */
|
|
long int __x86_raw_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
|
|
/* Similar to __x86_data_cache_size, but not rounded. */
|
|
long int __x86_raw_data_cache_size attribute_hidden = 32 * 1024;
|
|
/* Shared cache size for use in memory and string routines, typically
|
|
L2 or L3 size, rounded to multiple of 256 bytes. */
|
|
long int __x86_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2;
|
|
long int __x86_shared_cache_size attribute_hidden = 1024 * 1024;
|
|
/* Similar to __x86_shared_cache_size_half, but not rounded. */
|
|
long int __x86_raw_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2;
|
|
/* Similar to __x86_shared_cache_size, but not rounded. */
|
|
long int __x86_raw_shared_cache_size attribute_hidden = 1024 * 1024;
|
|
|
|
/* Threshold to use non temporal store. */
|
|
long int __x86_shared_non_temporal_threshold attribute_hidden;
|
|
|
|
#ifndef DISABLE_PREFETCHW
|
|
/* PREFETCHW support flag for use in memory and string routines. */
|
|
int __x86_prefetchw attribute_hidden;
|
|
#endif
|
|
|
|
|
|
static void
|
|
__attribute__((constructor))
|
|
init_cacheinfo (void)
|
|
{
|
|
/* Find out what brand of processor. */
|
|
unsigned int eax;
|
|
unsigned int ebx;
|
|
unsigned int ecx;
|
|
unsigned int edx;
|
|
int max_cpuid_ex;
|
|
long int data = -1;
|
|
long int shared = -1;
|
|
unsigned int level;
|
|
unsigned int threads = 0;
|
|
|
|
if (is_intel)
|
|
{
|
|
data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, max_cpuid);
|
|
|
|
/* Try L3 first. */
|
|
level = 3;
|
|
shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, max_cpuid);
|
|
|
|
if (shared <= 0)
|
|
{
|
|
/* Try L2 otherwise. */
|
|
level = 2;
|
|
shared = handle_intel (_SC_LEVEL2_CACHE_SIZE, max_cpuid);
|
|
}
|
|
|
|
/* Figure out the number of logical threads that share the
|
|
highest cache level. */
|
|
if (max_cpuid >= 4)
|
|
{
|
|
unsigned int family = GLRO(dl_x86_cpu_features).family;
|
|
unsigned int model = GLRO(dl_x86_cpu_features).model;
|
|
|
|
int i = 0;
|
|
|
|
/* Query until desired cache level is enumerated. */
|
|
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 ((eax & 0x1f) == 0)
|
|
goto intel_bug_no_cache_info;
|
|
}
|
|
while (((eax >> 5) & 0x7) != level);
|
|
|
|
threads = (eax >> 14) & 0x3ff;
|
|
|
|
/* If max_cpuid >= 11, THREADS is the maximum number of
|
|
addressable IDs for logical processors sharing the
|
|
cache, instead of the maximum number of threads
|
|
sharing the cache. */
|
|
if (threads && max_cpuid >= 11)
|
|
{
|
|
/* Find the number of logical processors shipped in
|
|
one core and apply count mask. */
|
|
i = 0;
|
|
while (1)
|
|
{
|
|
__cpuid_count (11, i++, eax, ebx, ecx, edx);
|
|
|
|
int shipped = ebx & 0xff;
|
|
int type = ecx & 0xff0;
|
|
if (shipped == 0 || type == 0)
|
|
break;
|
|
else if (type == 0x200)
|
|
{
|
|
int count_mask;
|
|
|
|
/* Compute count mask. */
|
|
asm ("bsr %1, %0"
|
|
: "=r" (count_mask) : "g" (threads));
|
|
count_mask = ~(-1 << (count_mask + 1));
|
|
threads = (shipped - 1) & count_mask;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
threads += 1;
|
|
if (threads > 2 && level == 2 && family == 6)
|
|
{
|
|
switch (model)
|
|
{
|
|
case 0x57:
|
|
/* Knights Landing has L2 cache shared by 2 cores. */
|
|
case 0x37:
|
|
case 0x4a:
|
|
case 0x4d:
|
|
case 0x5a:
|
|
case 0x5d:
|
|
/* Silvermont has L2 cache shared by 2 cores. */
|
|
threads = 2;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
intel_bug_no_cache_info:
|
|
/* Assume that all logical threads share the highest cache level. */
|
|
|
|
threads
|
|
= ((GLRO(dl_x86_cpu_features).cpuid[COMMON_CPUID_INDEX_1].ebx
|
|
>> 16) & 0xff);
|
|
}
|
|
|
|
/* Cap usage of highest cache level to the number of supported
|
|
threads. */
|
|
if (shared > 0 && threads > 0)
|
|
shared /= threads;
|
|
}
|
|
/* This spells out "AuthenticAMD". */
|
|
else if (is_amd)
|
|
{
|
|
data = handle_amd (_SC_LEVEL1_DCACHE_SIZE);
|
|
long int core = handle_amd (_SC_LEVEL2_CACHE_SIZE);
|
|
shared = handle_amd (_SC_LEVEL3_CACHE_SIZE);
|
|
|
|
/* Get maximum extended function. */
|
|
__cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx);
|
|
|
|
if (shared <= 0)
|
|
/* No shared L3 cache. All we have is the L2 cache. */
|
|
shared = core;
|
|
else
|
|
{
|
|
/* Figure out the number of logical threads that share L3. */
|
|
if (max_cpuid_ex >= 0x80000008)
|
|
{
|
|
/* Get width of APIC ID. */
|
|
__cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx);
|
|
threads = 1 << ((ecx >> 12) & 0x0f);
|
|
}
|
|
|
|
if (threads == 0)
|
|
{
|
|
/* If APIC ID width is not available, use logical
|
|
processor count. */
|
|
__cpuid (0x00000001, max_cpuid_ex, 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)
|
|
shared /= threads;
|
|
|
|
/* Account for exclusive L2 and L3 caches. */
|
|
shared += core;
|
|
}
|
|
|
|
#ifndef DISABLE_PREFETCHW
|
|
if (max_cpuid_ex >= 0x80000001)
|
|
{
|
|
__cpuid (0x80000001, eax, ebx, ecx, edx);
|
|
/* PREFETCHW || 3DNow! */
|
|
if ((ecx & 0x100) || (edx & 0x80000000))
|
|
__x86_prefetchw = -1;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
if (data > 0)
|
|
{
|
|
__x86_raw_data_cache_size_half = data / 2;
|
|
__x86_raw_data_cache_size = data;
|
|
/* Round data cache size to multiple of 256 bytes. */
|
|
data = data & ~255L;
|
|
__x86_data_cache_size_half = data / 2;
|
|
__x86_data_cache_size = data;
|
|
}
|
|
|
|
if (shared > 0)
|
|
{
|
|
__x86_raw_shared_cache_size_half = shared / 2;
|
|
__x86_raw_shared_cache_size = shared;
|
|
/* Round shared cache size to multiple of 256 bytes. */
|
|
shared = shared & ~255L;
|
|
__x86_shared_cache_size_half = shared / 2;
|
|
__x86_shared_cache_size = shared;
|
|
}
|
|
|
|
/* The large memcpy micro benchmark in glibc shows that 6 times of
|
|
shared cache size is the approximate value above which non-temporal
|
|
store becomes faster. */
|
|
__x86_shared_non_temporal_threshold = __x86_shared_cache_size * 6;
|
|
}
|