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Unified Diff: base/atomicops_internals_x86_gcc.cc

Issue 1211903003: Remove old/unused atomicops code (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: also remove _gcc.h Created 5 years, 6 months ago
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Index: base/atomicops_internals_x86_gcc.cc
diff --git a/base/atomicops_internals_x86_gcc.cc b/base/atomicops_internals_x86_gcc.cc
deleted file mode 100644
index c21e96d71db1102d1b3ee5b5071c3e40ba283495..0000000000000000000000000000000000000000
--- a/base/atomicops_internals_x86_gcc.cc
+++ /dev/null
@@ -1,103 +0,0 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This module gets enough CPU information to optimize the
-// atomicops module on x86.
-
-#include <stdint.h>
-#include <string.h>
-
-#include "base/atomicops.h"
-
-// Inline cpuid instruction. In PIC compilations, %ebx contains the address
-// of the global offset table. To avoid breaking such executables, this code
-// must preserve that register's value across cpuid instructions.
-//
-// The include guards are the same as in atomicops.h.
-#if defined(__i386__)
-#define cpuid(a, b, c, d, inp) \
- asm("mov %%ebx, %%edi\n" \
- "cpuid\n" \
- "xchg %%edi, %%ebx\n" \
- : "=a" (a), "=D" (b), "=c" (c), "=d" (d) : "a" (inp))
-#elif defined(__x86_64__)
-#define cpuid(a, b, c, d, inp) \
- asm("mov %%rbx, %%rdi\n" \
- "cpuid\n" \
- "xchg %%rdi, %%rbx\n" \
- : "=a" (a), "=D" (b), "=c" (c), "=d" (d) : "a" (inp))
-#endif
-
-#if defined(cpuid) // initialize the struct only on x86
-
-// Set the flags so that code will run correctly and conservatively, so even
-// if we haven't been initialized yet, we're probably single threaded, and our
-// default values should hopefully be pretty safe.
-struct AtomicOps_x86CPUFeatureStruct AtomicOps_Internalx86CPUFeatures = {
- false, // bug can't exist before process spawns multiple threads
- false, // Chrome requires SSE2, but for transition assume not and initialize
- // this properly.
- false, // cmpxchg16b isn't present on early AMD64 CPUs.
-};
-
-namespace {
-
-// Initialize the AtomicOps_Internalx86CPUFeatures struct.
-void AtomicOps_Internalx86CPUFeaturesInit() {
- uint32_t eax;
- uint32_t ebx;
- uint32_t ecx;
- uint32_t edx;
-
- // Get vendor string (issue CPUID with eax = 0)
- cpuid(eax, ebx, ecx, edx, 0);
- char vendor[13];
- memcpy(vendor, &ebx, 4);
- memcpy(vendor + 4, &edx, 4);
- memcpy(vendor + 8, &ecx, 4);
- vendor[12] = 0;
-
- // get feature flags in ecx/edx, and family/model in eax
- cpuid(eax, ebx, ecx, edx, 1);
-
- int family = (eax >> 8) & 0xf; // family and model fields
- int model = (eax >> 4) & 0xf;
- if (family == 0xf) { // use extended family and model fields
- family += (eax >> 20) & 0xff;
- model += ((eax >> 16) & 0xf) << 4;
- }
-
- // Opteron Rev E has a bug in which on very rare occasions a locked
- // instruction doesn't act as a read-acquire barrier if followed by a
- // non-locked read-modify-write instruction. Rev F has this bug in
- // pre-release versions, but not in versions released to customers,
- // so we test only for Rev E, which is family 15, model 32..63 inclusive.
- if (strcmp(vendor, "AuthenticAMD") == 0 && // AMD
- family == 15 &&
- 32 <= model && model <= 63) {
- AtomicOps_Internalx86CPUFeatures.has_amd_lock_mb_bug = true;
- } else {
- AtomicOps_Internalx86CPUFeatures.has_amd_lock_mb_bug = false;
- }
-
- // edx bit 26 is SSE2 which we use to tell use whether we can use mfence
- AtomicOps_Internalx86CPUFeatures.has_sse2 = ((edx >> 26) & 1);
-
- // ecx bit 13 indicates whether the cmpxchg16b instruction is supported
- AtomicOps_Internalx86CPUFeatures.has_cmpxchg16b = ((ecx >> 13) & 1);
-}
-
-class AtomicOpsx86Initializer {
- public:
- AtomicOpsx86Initializer() {
- AtomicOps_Internalx86CPUFeaturesInit();
- }
-};
-
-// A global to get use initialized on startup via static initialization :/
-AtomicOpsx86Initializer g_initer;
-
-} // namespace
-
-#endif // if x86

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