Reviewers: Benedikt Meurer, ulan,
Message:
RegExpCEntryStub and DirectCEntryStub provide the same functionality.
DirectCEntryStub has also been updated to be more friendly with branch
predictors.
Description:
ARM: replace RegExpCEntryStub with DirectCEntryStub.
RegExpCEntryStub is therefore removed.
BUG=none
TEST=none
Please review this at https://codereview.chromium.org/23468015/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+29, -70 lines):
M src/arm/code-stubs-arm.h
M src/arm/code-stubs-arm.cc
M src/arm/regexp-macro-assembler-arm.h
M src/arm/regexp-macro-assembler-arm.cc
M src/code-stubs.h
Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index
310cf3e3d7a6ee9ff886974d586bfe327e92dbba..4b964adcba219e7ff362f28bb15aee92d7b155be
100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -6143,6 +6143,11 @@ void ICCompareStub::GenerateMiss(MacroAssembler*
masm) {
void DirectCEntryStub::Generate(MacroAssembler* masm) {
+ // Place the return address on the stack, making the call
+ // GC safe. The RegExp backend also relies on this.
+ __ str(lr, MemOperand(sp, 0));
+ __ blx(ip); // Call the C++ function.
+ __ VFPEnsureFPSCRState(r2);
__ ldr(pc, MemOperand(sp, 0));
}
@@ -6151,21 +6156,9 @@ void DirectCEntryStub::GenerateCall(MacroAssembler*
masm,
Register target) {
intptr_t code =
reinterpret_cast<intptr_t>(GetCode(masm->isolate()).location());
+ __ Move(ip, target);
__ mov(lr, Operand(code, RelocInfo::CODE_TARGET));
-
- // Prevent literal pool emission during calculation of return address.
- Assembler::BlockConstPoolScope block_const_pool(masm);
-
- // Push return address (accessible to GC through exit frame pc).
- // Note that using pc with str is deprecated.
- Label start;
- __ bind(&start);
- __ add(ip, pc, Operand(Assembler::kInstrSize));
- __ str(ip, MemOperand(sp, 0));
- __ Jump(target); // Call the C++ function.
- ASSERT_EQ(Assembler::kInstrSize + Assembler::kPcLoadDelta,
- masm->SizeOfCodeGeneratedSince(&start));
- __ VFPEnsureFPSCRState(r2);
+ __ blx(lr); // Call the stub.
}
Index: src/arm/code-stubs-arm.h
diff --git a/src/arm/code-stubs-arm.h b/src/arm/code-stubs-arm.h
index
bee3e1e1268bbb511892c03d93938b9b8416fd5e..e7e7bfc00dbb0b530052073cff255c0b8b49a7d7
100644
--- a/src/arm/code-stubs-arm.h
+++ b/src/arm/code-stubs-arm.h
@@ -465,23 +465,6 @@ class RecordWriteStub: public PlatformCodeStub {
};
-// Enter C code from generated RegExp code in a way that allows
-// the C code to fix the return address in case of a GC.
-// Currently only needed on ARM.
-class RegExpCEntryStub: public PlatformCodeStub {
- public:
- RegExpCEntryStub() {}
- virtual ~RegExpCEntryStub() {}
- void Generate(MacroAssembler* masm);
-
- private:
- Major MajorKey() { return RegExpCEntry; }
- int MinorKey() { return 0; }
-
- bool NeedsImmovableCode() { return true; }
-};
-
-
// Trampoline stub to call into native code. To call safely into native
code
// in the presence of compacting GC (which can move code objects) we need
to
// keep the code which called into native pinned in the memory. Currently
the
Index: src/arm/regexp-macro-assembler-arm.cc
diff --git a/src/arm/regexp-macro-assembler-arm.cc
b/src/arm/regexp-macro-assembler-arm.cc
index
189ea8d777989e85d708bffb509b010445994c1f..c9995f4a1a3aa31d3eb827798f29ce475e2c9424
100644
--- a/src/arm/regexp-macro-assembler-arm.cc
+++ b/src/arm/regexp-macro-assembler-arm.cc
@@ -1055,16 +1055,34 @@ void
RegExpMacroAssemblerARM::WriteStackPointerToRegister(int reg) {
// Private methods:
void RegExpMacroAssemblerARM::CallCheckStackGuardState(Register scratch) {
- static const int num_arguments = 3;
- __ PrepareCallCFunction(num_arguments, scratch);
+ __ PrepareCallCFunction(3, scratch);
+
// RegExp code frame pointer.
__ mov(r2, frame_pointer());
// Code* of self.
__ mov(r1, Operand(masm_->CodeObject()));
- // r0 becomes return address pointer.
+
+ // We need to make room for the return address on the stack.
+ int stack_alignment = OS::ActivationFrameAlignment();
+ if (stack_alignment < kPointerSize) stack_alignment = kPointerSize;
+ __ sub(sp, sp, Operand(stack_alignment));
+
+ // r0 will point to the return address, placed by DirectCEntry.
+ __ mov(r0, sp);
+
ExternalReference stack_guard_check =
ExternalReference::re_check_stack_guard_state(isolate());
- CallCFunctionUsingStub(stack_guard_check, num_arguments);
+ __ mov(ip, Operand(stack_guard_check));
+ DirectCEntryStub stub;
+ stub.GenerateCall(masm_, ip);
+
+ // Drop the return address from the stack.
+ __ add(sp, sp, Operand(stack_alignment));
+
+ if (OS::ActivationFrameAlignment() != 0) {
+ __ ldr(sp, MemOperand(sp, 0));
+ }
+ __ mov(code_pointer(), Operand(masm_->CodeObject()));
}
@@ -1294,21 +1312,6 @@ int
RegExpMacroAssemblerARM::GetBacktrackConstantPoolEntry() {
}
-void RegExpMacroAssemblerARM::CallCFunctionUsingStub(
- ExternalReference function,
- int num_arguments) {
- // Must pass all arguments in registers. The stub pushes on the stack.
- ASSERT(num_arguments <= 4);
- __ mov(code_pointer(), Operand(function));
- RegExpCEntryStub stub;
- __ CallStub(&stub);
- if (OS::ActivationFrameAlignment() != 0) {
- __ ldr(sp, MemOperand(sp, 0));
- }
- __ mov(code_pointer(), Operand(masm_->CodeObject()));
-}
-
-
bool RegExpMacroAssemblerARM::CanReadUnaligned() {
return CpuFeatures::IsSupported(UNALIGNED_ACCESSES) && !slow_safe();
}
@@ -1351,17 +1354,6 @@ void
RegExpMacroAssemblerARM::LoadCurrentCharacterUnchecked(int cp_offset,
}
-void RegExpCEntryStub::Generate(MacroAssembler* masm_) {
- int stack_alignment = OS::ActivationFrameAlignment();
- if (stack_alignment < kPointerSize) stack_alignment = kPointerSize;
- // Stack is already aligned for call, so decrement by alignment
- // to make room for storing the link register.
- __ str(lr, MemOperand(sp, stack_alignment, NegPreIndex));
- __ mov(r0, sp);
- __ Call(r5);
- __ ldr(pc, MemOperand(sp, stack_alignment, PostIndex));
-}
-
#undef __
#endif // V8_INTERPRETED_REGEXP
Index: src/arm/regexp-macro-assembler-arm.h
diff --git a/src/arm/regexp-macro-assembler-arm.h
b/src/arm/regexp-macro-assembler-arm.h
index
1825752ebc25da4d57a053ea27e3e110af2bf14f..0874ad1ab8e77b082180b272024c926a4c1263c9
100644
--- a/src/arm/regexp-macro-assembler-arm.h
+++ b/src/arm/regexp-macro-assembler-arm.h
@@ -212,14 +212,6 @@ class RegExpMacroAssemblerARM: public
NativeRegExpMacroAssembler {
// and increments it by a word size.
inline void Pop(Register target);
- // Calls a C function and cleans up the frame alignment done by
- // by FrameAlign. The called function *is* allowed to trigger a garbage
- // collection, but may not take more than four arguments (no arguments
- // passed on the stack), and the first argument will be a pointer to the
- // return address.
- inline void CallCFunctionUsingStub(ExternalReference function,
- int num_arguments);
-
Isolate* isolate() const { return masm_->isolate(); }
MacroAssembler* masm_;
Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index
4fe4e074cc42414ca89a4e7ef753b6f0132e8fdb..3138efbde6771c6f06a987fa4fba46c15b5e3d7c
100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -102,7 +102,6 @@ namespace internal {
V(GetProperty) \
V(SetProperty) \
V(InvokeBuiltin) \
- V(RegExpCEntry) \
V(DirectCEntry)
#else
#define CODE_STUB_LIST_ARM(V)
--
--
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