Attachment 338970 Details for Bug 185055 – Patch

[patch] Patch

bug-185055-20180427061011.patch (text/plain), 5.71 KB, created by Yusuke Suzuki on 2018-04-26 22:10:14 PDT

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Creator: Yusuke Suzuki

Created: 2018-04-26 22:10:14 PDT

Size: 5.71 KB

patch

obsolete

>Subversion Revision: 231073
>diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
>index 41d8c24ed07ac8a673368a02756d85253c0fc300..e2d05f645323cb858290055c8635f3ebd854bb9a 100644
>--- a/Source/JavaScriptCore/ChangeLog
>+++ b/Source/JavaScriptCore/ChangeLog
>@@ -1,3 +1,28 @@
>+2018-04-26  Yusuke Suzuki  <utatane.tea@gmail.com>
>+
>+        [JSC][ARM64][Linux] Add collectCPUFeatures using auxiliary vector
>+        https://bugs.webkit.org/show_bug.cgi?id=185055
>+
>+        Reviewed by NOBODY (OOPS!).
>+
>+        This patch is paving the way to emitting jscvt instruction if possible.
>+        To do that, we need to determine jscvt instruction is supported in the
>+        given CPU.
>+
>+        We add a function collectCPUFeatures, which is responsible to collect
>+        CPU features if necessary. In Linux, we can use auxiliary vector to get
>+        the information without parsing /proc/cpuinfo.
>+
>+        Currently, nobody calls this function. It is later called when we emit
>+        jscvt instruction. To make it possible, we also need to add disassembler
>+        support too.
>+
>+        * assembler/AbstractMacroAssembler.h:
>+        * assembler/MacroAssemblerARM64.cpp:
>+        (JSC::MacroAssemblerARM64::collectCPUFeatures):
>+        * assembler/MacroAssemblerARM64.h:
>+        * assembler/MacroAssemblerX86Common.h:
>+
> 2018-04-26  Jer Noble  <jer.noble@apple.com>
> 
>         WK_COCOA_TOUCH all the things.
>diff --git a/Source/JavaScriptCore/assembler/AbstractMacroAssembler.h b/Source/JavaScriptCore/assembler/AbstractMacroAssembler.h
>index cf03f68b98670bc7336c8e70cca0e7cb07fdf3c5..9f4aaee6b560fe85810eb7494ad4b3c251fa20e5 100644
>--- a/Source/JavaScriptCore/assembler/AbstractMacroAssembler.h
>+++ b/Source/JavaScriptCore/assembler/AbstractMacroAssembler.h
>@@ -82,6 +82,12 @@ class AbstractMacroAssembler : public AbstractMacroAssemblerBase {
>     template<PtrTag tag> using CodePtr = MacroAssemblerCodePtr<tag>;
>     template<PtrTag tag> using CodeRef = MacroAssemblerCodeRef<tag>;
> 
>+    enum class CPUIDCheckState {
>+        NotChecked,
>+        Clear,
>+        Set
>+    };
>+
>     class Jump;
> 
>     typedef typename AssemblerType::RegisterID RegisterID;
>diff --git a/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp b/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp
>index ed343304a350fa6da3740f257a51d4b5768857d9..edfb4422577fee1d1fd906a898495152c30f6ddd 100644
>--- a/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp
>+++ b/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp
>@@ -31,6 +31,11 @@
> #include "ProbeContext.h"
> #include <wtf/InlineASM.h>
> 
>+#if OS(LINUX)
>+#include <asm/hwcap.h>
>+#include <sys/auxv.h>
>+#endif
>+
> namespace JSC {
> 
> #if ENABLE(MASM_PROBE)
>@@ -526,6 +531,34 @@ void MacroAssembler::probe(Probe::Function function, void* arg)
> 
> #endif // ENABLE(MASM_PROBE)
> 
>+void MacroAssemblerARM64::collectCPUFeatures()
>+{
>+    static std::once_flag onceKey;
>+    std::call_once(onceKey, [] {
>+#if OS(LINUX)
>+        // A register for describing ARM64 CPU features are only accessible in kernel mode.
>+        // Thus, some kernel support is necessary to collect CPU features. In Linux, the
>+        // kernel passes CPU feature flags in AT_HWCAP auxiliary vector which is passed
>+        // when the process starts. While this may pose a bit conservative information
>+        // (for example, the Linux kernel may add a flag for a feature after the feature
>+        // is shipped and implemented in some CPUs. In that case, even if the CPU has
>+        // that feature, the kernel does not tell it to users.), it is a stable approach.
>+        // https://www.kernel.org/doc/Documentation/arm64/elf_hwcaps.txt
>+        unsigned long hwcaps = getauxval(AT_HWCAP);
>+
>+#if !defined(HWCAP_JSCVT)
>+#define HWCAP_JSCVT (1 << 13)
>+#endif
>+
>+        s_jscvtCheckState = (hwcaps & HWCAP_JSCVT) ? CPUIDCheckState::Set : CPUIDCheckState::Clear;
>+#else
>+        s_jscvtCheckState = CPUIDCheckState::Clear;
>+#endif
>+    });
>+}
>+
>+MacroAssemblerARM64::CPUIDCheckState MacroAssemblerARM64::s_jscvtCheckState = CPUIDCheckState::NotChecked;
>+
> } // namespace JSC
> 
> #endif // ENABLE(ASSEMBLER) && CPU(ARM64)
>diff --git a/Source/JavaScriptCore/assembler/MacroAssemblerARM64.h b/Source/JavaScriptCore/assembler/MacroAssemblerARM64.h
>index 52481bb1e4220d95d8651461b1866b9c08211259..80cdd1f908cd20ae9061a658b92de1df4f15aad1 100644
>--- a/Source/JavaScriptCore/assembler/MacroAssemblerARM64.h
>+++ b/Source/JavaScriptCore/assembler/MacroAssemblerARM64.h
>@@ -4460,6 +4460,10 @@ class MacroAssemblerARM64 : public AbstractMacroAssembler<Assembler> {
>             Assembler::linkCall(code, call.m_label, function.template retaggedExecutableAddress<NoPtrTag>());
>     }
> 
>+    JS_EXPORT_PRIVATE static void collectCPUFeatures();
>+
>+    JS_EXPORT_PRIVATE static CPUIDCheckState s_jscvtCheckState;
>+
>     CachedTempRegister m_dataMemoryTempRegister;
>     CachedTempRegister m_cachedMemoryTempRegister;
>     bool m_makeJumpPatchable;
>diff --git a/Source/JavaScriptCore/assembler/MacroAssemblerX86Common.h b/Source/JavaScriptCore/assembler/MacroAssemblerX86Common.h
>index e8c859906fee12ed5e1a8906a95fa42738ba01e9..0f733256be0605a1f3faf3769499699977c23c8f 100644
>--- a/Source/JavaScriptCore/assembler/MacroAssemblerX86Common.h
>+++ b/Source/JavaScriptCore/assembler/MacroAssemblerX86Common.h
>@@ -4188,11 +4188,6 @@ class MacroAssemblerX86Common : public AbstractMacroAssembler<Assembler> {
>     static CPUID getCPUIDEx(unsigned level, unsigned count);
>     JS_EXPORT_PRIVATE static void collectCPUFeatures();
> 
>-    enum class CPUIDCheckState {
>-        NotChecked,
>-        Clear,
>-        Set
>-    };
>     JS_EXPORT_PRIVATE static CPUIDCheckState s_sse2CheckState;
>     JS_EXPORT_PRIVATE static CPUIDCheckState s_sse4_1CheckState;
>     JS_EXPORT_PRIVATE static CPUIDCheckState s_sse4_2CheckState;

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Attachments on bug 185055: 338920 | 338970