Changeset 44514 in webkit for trunk/JavaScriptCore/wtf/Platform.h

Timestamp:

Jun 8, 2009, 6:40:59 PM (16 years ago)

Author:

[email protected]

Message:

2009-06-08 Gavin Barraclough <​[email protected]>

Reviewed by Geoff Garen.

Add (incomplete) support to YARR for running with the jit enabled
on Arm thumb2 platforms. Adds new Assembler/MacroAssembler classes,
along with cache flushing support, tweaks to MacroAssemblerCodePtr
to support decorated thumb code pointers, and new enter/exit code
to YARR jit for the platform.

Support for this platform is still under development - the assembler
currrently only supports planting and linking jumps with a 16Mb range.
As such, initially commiting in a disabled state.

• JavaScriptCore.xcodeproj/project.pbxproj:

Add new assembler files.

• assembler/ARMv7Assembler.h: Added.

Add new Assembler.

• assembler/AbstractMacroAssembler.h:

Tweaks to ensure sizes of pointer values planted in JIT code do not change.

• assembler/MacroAssembler.h:

On ARMv7 platforms use MacroAssemblerARMv7.

• assembler/MacroAssemblerARMv7.h: Added.

Add new MacroAssembler.

• assembler/MacroAssemblerCodeRef.h: (JSC::FunctionPtr::FunctionPtr):

Add better ASSERT.

(JSC::ReturnAddressPtr::ReturnAddressPtr):

Add better ASSERT.

(JSC::MacroAssemblerCodePtr::MacroAssemblerCodePtr):

On ARMv7, MacroAssemblerCodePtr's mush be 'decorated' with a low bit set,
to indicate to the processor that the code is thumb code, not traditional
32-bit ARM.

(JSC::MacroAssemblerCodePtr::dataLocation):

On ARMv7, decoration must be removed.

• jit/ExecutableAllocator.h: (JSC::ExecutableAllocator::makeWritable):

Reformatted, no change.

(JSC::ExecutableAllocator::makeExecutable):

When marking code executable also cache flush it, where necessary.

(JSC::ExecutableAllocator::MakeWritable::MakeWritable):

Only use the null implementation of this class if both !ASSEMBLER_WX_EXCLUSIVE
and running on x86(_64) - on other platforms we may also need ensure that
makeExecutable is called at the end to flush caches.

(JSC::ExecutableAllocator::reprotectRegion):

Reformatted, no change.

(JSC::ExecutableAllocator::cacheFlush):

Cache flush a region of memory, or platforms where this is necessary.

• wtf/Platform.h:

Add changes necessary to allow YARR jit to build on this platform, disabled.

• yarr/RegexJIT.cpp: (JSC::Yarr::RegexGenerator::generateEnter): (JSC::Yarr::RegexGenerator::generateReturn):

Add support to these methods for ARMv7.

File:

• trunk/JavaScriptCore/wtf/Platform.h (modified) (3 diffs)

trunk/JavaScriptCore/wtf/Platform.h

@@ -229 +229 @@
 #endif
 #endif
+#if defined(__ARM_ARCH_7A__)
+#define WTF_PLATFORM_ARM_V7 1
+#endif
 
 /* PLATFORM(X86) */
@@ -556 +559 @@
 #if (!defined(ENABLE_YARR_JIT) && PLATFORM(X86) && PLATFORM(MAC)) \
  || (!defined(ENABLE_YARR_JIT) && PLATFORM(X86_64) && PLATFORM(MAC)) \
+ /* Under development, temporarily disabled until 16Mb link range limit in assembler is fixed. */ \
+ || (!defined(ENABLE_YARR_JIT) && PLATFORM(ARM_V7) && PLATFORM(IPHONE) && 0) \
  || (!defined(ENABLE_YARR_JIT) && PLATFORM(X86) && PLATFORM(WIN))
 #define ENABLE_YARR 1
@@ -570 +575 @@
 /* Setting this flag prevents the assembler from using RWX memory; this may improve
    security but currectly comes at a significant performance cost. */
+#if PLATFORM(ARM_V7) && PLATFORM(IPHONE)
+#define ENABLE_ASSEMBLER_WX_EXCLUSIVE 1
+#else
 #define ENABLE_ASSEMBLER_WX_EXCLUSIVE 0
+#endif
 
 #if !defined(ENABLE_PAN_SCROLLING) && PLATFORM(WIN_OS)