[Lldb-commits] [lldb] r297685 - [debugserver] This is a small cleanup patch to AVX support detection
Chris Bieneman via lldb-commits
lldb-commits at lists.llvm.org
Mon Mar 13 16:19:05 PDT 2017
Author: cbieneman
Date: Mon Mar 13 18:19:04 2017
New Revision: 297685
URL: http://llvm.org/viewvc/llvm-project?rev=297685&view=rev
Log:
[debugserver] This is a small cleanup patch to AVX support detection
Summary:
The first Sandybridge iMacs with AVX support shipped in Spring 2011 with Snow Leopard as their OS. Unfortunately due to a kernel bug debugging AVX code was not really possible until 10.7.4.
The old code here checked the kernel build number to determine when to support AVX, but that code was incorrect. It verified that the kernel build number was greater than xnu-2020, which is the build of the kernel that had the fix for 10.8. The fix was also back ported to 10.7.4. Which means all publicly available OS builds 10.7.4 and later have working AVX support.
This new patch verifies that the host OS is greater than or equal to 10.7.4 by checking that the build number is greater than or equal to 11Exx.
The patch also removes the HasAVX assembly blob in favor of querying the kernel via sysctl for the hardware features.
Using sysctl is slower, however since the code is executed once and the result cached it is a better approach because it is possible for the kernel to disable AVX support on hardware that supports it, so listening to the kernel is a better approach for the debugger to take.
Reviewers: jasonmolenda, spyffe
Subscribers: lldb-commits, mgorny
Differential Revision: https://reviews.llvm.org/D30918
Removed:
lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.h
lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.s
Modified:
lldb/trunk/tools/debugserver/debugserver.xcodeproj/project.pbxproj
lldb/trunk/tools/debugserver/source/MacOSX/CMakeLists.txt
lldb/trunk/tools/debugserver/source/MacOSX/i386/DNBArchImplI386.h
lldb/trunk/tools/debugserver/source/MacOSX/x86_64/DNBArchImplX86_64.cpp
Modified: lldb/trunk/tools/debugserver/debugserver.xcodeproj/project.pbxproj
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/debugserver.xcodeproj/project.pbxproj?rev=297685&r1=297684&r2=297685&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/debugserver.xcodeproj/project.pbxproj (original)
+++ lldb/trunk/tools/debugserver/debugserver.xcodeproj/project.pbxproj Mon Mar 13 18:19:04 2017
@@ -94,10 +94,8 @@
456F67641AD46CE9002850C2 /* CFBundle.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 2695DD910D3EBFF6007E4CA2 /* CFBundle.cpp */; };
456F67651AD46CE9002850C2 /* PseudoTerminal.cpp in Sources */ = {isa = PBXBuildFile; fileRef = AF67ABFF0D34604D0022D128 /* PseudoTerminal.cpp */; };
456F67671AD46CE9002850C2 /* DNBArch.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 264D5D571293835600ED4C01 /* DNBArch.cpp */; };
- 456F67681AD46CE9002850C2 /* HasAVX.s in Sources */ = {isa = PBXBuildFile; fileRef = 4971AE7113D10F4F00649E37 /* HasAVX.s */; };
456F67691AD46CE9002850C2 /* DNBArchImplARM64.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 266B5ECF1460A68200E43F0A /* DNBArchImplARM64.cpp */; };
456F676B1AD46CE9002850C2 /* CoreFoundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 26ACA3340D3E956300A2120B /* CoreFoundation.framework */; settings = {ATTRIBUTES = (Required, ); }; };
- 4971AE7213D10F4F00649E37 /* HasAVX.s in Sources */ = {isa = PBXBuildFile; fileRef = 4971AE7113D10F4F00649E37 /* HasAVX.s */; };
49D404621E39260F00570CDC /* Foundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 49D404611E39260F00570CDC /* Foundation.framework */; };
AF48558C1D75126800D19C07 /* StdStringExtractor.cpp in Sources */ = {isa = PBXBuildFile; fileRef = AF48558B1D75126800D19C07 /* StdStringExtractor.cpp */; };
AF48558D1D75127500D19C07 /* StdStringExtractor.cpp in Sources */ = {isa = PBXBuildFile; fileRef = AF48558B1D75126800D19C07 /* StdStringExtractor.cpp */; };
@@ -210,8 +208,6 @@
26CF99A31142EB7400011AAB /* DNBArchImplX86_64.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = DNBArchImplX86_64.h; sourceTree = "<group>"; };
26E6B9DA0D1329010037ECDD /* RNBDefs.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RNBDefs.h; sourceTree = "<group>"; };
456F67721AD46CE9002850C2 /* debugserver-nonui */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = "debugserver-nonui"; sourceTree = BUILT_PRODUCTS_DIR; };
- 4971AE7013D10F4F00649E37 /* HasAVX.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = HasAVX.h; sourceTree = "<group>"; };
- 4971AE7113D10F4F00649E37 /* HasAVX.s */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.asm; path = HasAVX.s; sourceTree = "<group>"; };
49D404611E39260F00570CDC /* Foundation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Foundation.framework; path = System/Library/Frameworks/Foundation.framework; sourceTree = SDKROOT; };
49F530111331519C008956F6 /* MachRegisterStatesI386.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MachRegisterStatesI386.h; sourceTree = "<group>"; };
49F5301213316D7F008956F6 /* MachRegisterStatesX86_64.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MachRegisterStatesX86_64.h; sourceTree = "<group>"; };
@@ -413,8 +409,6 @@
26C637E90C71334A0024798E /* i386 */,
26C637FA0C71334A0024798E /* ppc */,
26CF99A11142EB7400011AAB /* x86_64 */,
- 4971AE7013D10F4F00649E37 /* HasAVX.h */,
- 4971AE7113D10F4F00649E37 /* HasAVX.s */,
26C637E80C71334A0024798E /* dbgnub-mig.defs */,
AFEC3363194A8B0B00FF05C6 /* Genealogy.cpp */,
AF0934BA18E12B92005A11FD /* Genealogy.h */,
@@ -626,7 +620,6 @@
23562ED91D342B0000AB2BD4 /* LogMessage.cpp in Sources */,
26CE05F1115C387C0022F371 /* PseudoTerminal.cpp in Sources */,
264D5D581293835600ED4C01 /* DNBArch.cpp in Sources */,
- 4971AE7213D10F4F00649E37 /* HasAVX.s in Sources */,
237821B01D4917D20028B7A1 /* LogFilterExactMatch.cpp in Sources */,
266B5ED11460A68200E43F0A /* DNBArchImplARM64.cpp in Sources */,
);
@@ -679,7 +672,6 @@
456F67641AD46CE9002850C2 /* CFBundle.cpp in Sources */,
456F67651AD46CE9002850C2 /* PseudoTerminal.cpp in Sources */,
456F67671AD46CE9002850C2 /* DNBArch.cpp in Sources */,
- 456F67681AD46CE9002850C2 /* HasAVX.s in Sources */,
23AC04D01D2F58AF0072351D /* LogFilterRegex.cpp in Sources */,
456F67691AD46CE9002850C2 /* DNBArchImplARM64.cpp in Sources */,
);
Modified: lldb/trunk/tools/debugserver/source/MacOSX/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/CMakeLists.txt?rev=297685&r1=297684&r2=297685&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/CMakeLists.txt (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/CMakeLists.txt Mon Mar 13 18:19:04 2017
@@ -29,7 +29,6 @@ add_custom_command(OUTPUT ${DEBUGSERVER_
)
add_lldb_tool(debugserver INCLUDE_IN_FRAMEWORK
- HasAVX.s
CFBundle.cpp
CFString.cpp
Genealogy.cpp
Removed: lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.h?rev=297684&view=auto
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.h (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.h (removed)
@@ -1,27 +0,0 @@
-//===-- HasAVX.h ------------------------------------------------*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef HasAVX_h
-#define HasAVX_h
-
-#if defined(__i386__) || defined(__x86_64__)
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-int HasAVX();
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
-
-#endif
Removed: lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.s
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.s?rev=297684&view=auto
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.s (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/HasAVX.s (removed)
@@ -1,50 +0,0 @@
-//===-- HasAVX.s ---------------------------------------*- x86 Assembly -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#if defined (__i386__) || defined (__x86_64__)
-
-.globl _HasAVX
-
-_HasAVX:
-#if defined (__x86_64__)
- pushq %rbp
- movq %rsp, %rbp
- pushq %rbx
-#else
- pushl %ebp
- movl %esp, %ebp
- pushl %ebx
-#endif
- mov $1, %eax
- cpuid // clobbers ebx
- and $0x018000000, %ecx
- cmp $0x018000000, %ecx
- jne not_supported
- mov $0, %ecx
-.byte 0x0f, 0x01, 0xd0 // xgetbv, for those assemblers that don't know it
- and $0x06, %eax
- cmp $0x06, %eax
- jne not_supported
- mov $1, %eax
- jmp done
-not_supported:
- mov $0, %eax
-done:
-#if defined (__x86_64__)
- popq %rbx
- movq %rbp, %rsp
- popq %rbp
-#else
- popl %ebx
- movl %ebp, %esp
- popl %ebp
-#endif
- ret // return
-
-#endif
Modified: lldb/trunk/tools/debugserver/source/MacOSX/i386/DNBArchImplI386.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/i386/DNBArchImplI386.h?rev=297685&r1=297684&r2=297685&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/i386/DNBArchImplI386.h (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/i386/DNBArchImplI386.h Mon Mar 13 18:19:04 2017
@@ -16,7 +16,6 @@
#if defined(__i386__) || defined(__x86_64__)
-#include "../HasAVX.h"
#include "DNBArch.h"
#include "MachRegisterStatesI386.h"
Modified: lldb/trunk/tools/debugserver/source/MacOSX/x86_64/DNBArchImplX86_64.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/x86_64/DNBArchImplX86_64.cpp?rev=297685&r1=297684&r2=297685&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/x86_64/DNBArchImplX86_64.cpp (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/x86_64/DNBArchImplX86_64.cpp Mon Mar 13 18:19:04 2017
@@ -17,7 +17,6 @@
#include <sys/sysctl.h>
#include <sys/types.h>
-#include "../HasAVX.h"
#include "DNBLog.h"
#include "MacOSX/x86_64/DNBArchImplX86_64.h"
#include "MachProcess.h"
@@ -60,42 +59,64 @@ static bool ForceAVXRegs() {
#define FORCE_AVX_REGS (0)
#endif
-extern "C" bool CPUHasAVX() {
- enum AVXPresence { eAVXUnknown = -1, eAVXNotPresent = 0, eAVXPresent = 1 };
+bool DetectHardwareFeature(const char *feature) {
+ int answer = 0;
+ size_t answer_size = sizeof(answer);
+ int error = ::sysctlbyname(feature, &answer, &answer_size, NULL, 0);
+ return error != 0 && answer != 0;
+}
+enum AVXPresence { eAVXUnknown = -1, eAVXNotPresent = 0, eAVXPresent = 1 };
+
+bool LogAVXAndReturn(AVXPresence has_avx, int err, const char * os_ver) {
+ DNBLogThreadedIf(LOG_THREAD,
+ "CPUHasAVX(): g_has_avx = %i (err = %i, os_ver = %s)",
+ has_avx, err, os_ver);
+ return (has_avx == eAVXPresent);
+}
+
+extern "C" bool CPUHasAVX() {
static AVXPresence g_has_avx = eAVXUnknown;
- if (g_has_avx == eAVXUnknown) {
- g_has_avx = eAVXNotPresent;
+ if (g_has_avx != eAVXUnknown)
+ return LogAVXAndReturn(g_has_avx, 0, "");
+
+ g_has_avx = eAVXNotPresent;
- // Only xnu-2020 or later has AVX support, any versions before
- // this have a busted thread_get_state RPC where it would truncate
- // the thread state buffer (<rdar://problem/10122874>). So we need to
- // verify the kernel version number manually or disable AVX support.
- int mib[2];
- char buffer[1024];
- size_t length = sizeof(buffer);
- uint64_t xnu_version = 0;
- mib[0] = CTL_KERN;
- mib[1] = KERN_VERSION;
- int err = ::sysctl(mib, 2, &buffer, &length, NULL, 0);
- if (err == 0) {
- const char *xnu = strstr(buffer, "xnu-");
- if (xnu) {
- const char *xnu_version_cstr = xnu + 4;
- xnu_version = strtoull(xnu_version_cstr, NULL, 0);
- if (xnu_version >= 2020 && xnu_version != ULLONG_MAX) {
- if (::HasAVX()) {
- g_has_avx = eAVXPresent;
- }
- }
- }
- }
- DNBLogThreadedIf(LOG_THREAD, "CPUHasAVX(): g_has_avx = %i (err = %i, errno "
- "= %i, xnu_version = %llu)",
- g_has_avx, err, errno, xnu_version);
+ // OS X 10.7.3 and earlier have a bug in thread_get_state that truncated the
+ // size of the return. To work around this we have to disable AVX debugging
+ // on hosts prior to 10.7.3 (<rdar://problem/10122874>).
+ int mib[2];
+ char buffer[1024];
+ size_t length = sizeof(buffer);
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_OSVERSION;
+
+ // KERN_OSVERSION returns the build number which is a number signifying the
+ // major version, a capitol letter signifying the minor version, and numbers
+ // signifying the build (ex: on 10.12.3, the returned value is 16D32).
+ int err = ::sysctl(mib, 2, &buffer, &length, NULL, 0);
+ if (err != 0)
+ return LogAVXAndReturn(g_has_avx, err, "");
+
+ size_t first_letter = 0;
+ for (; first_letter < length; ++first_letter) {
+ // This is looking for the first uppercase letter
+ if (isupper(buffer[first_letter]))
+ break;
}
+ char letter = buffer[first_letter];
+ buffer[first_letter] = '\0';
+ auto major_ver = strtoull(buffer, NULL, 0);
+ buffer[first_letter] = letter;
+
+ // In this check we're looking to see that our major and minor version numer
+ // was >= 11E, which is the 10.7.4 release.
+ if (major_ver < 11 || (major_ver == 11 && letter < 'E'))
+ return LogAVXAndReturn(g_has_avx, err, buffer);
+ if (DetectHardwareFeature("hw.optional.avx1_0"))
+ g_has_avx = eAVXPresent;
- return (g_has_avx == eAVXPresent);
+ return LogAVXAndReturn(g_has_avx, err, buffer);
}
uint64_t DNBArchImplX86_64::GetPC(uint64_t failValue) {
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