Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(16)

Unified Diff: src/arm/codegen-arm.cc

Issue 10837037: Age code to allow reclaiming old unexecuted functions (Closed) Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge
Patch Set: Review feedback Created 8 years, 1 month ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « src/arm/codegen-arm.h ('k') | src/arm/full-codegen-arm.cc » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/arm/codegen-arm.cc
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index 09166c3c014eaef0b30adecb948c2c66639662ec..209e1516d14c6d96c6ae854239607f7f772fbddd 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -452,6 +452,92 @@ void StringCharLoadGenerator::Generate(MacroAssembler* masm,
#undef __
+// add(r0, pc, Operand(-8))
+static const uint32_t kCodeAgePatchFirstInstruction = 0xe24f0008;
+
+static byte* GetNoCodeAgeSequence(uint32_t* length) {
+ // The sequence of instructions that is patched out for aging code is the
+ // following boilerplate stack-building prologue that is found in FUNCTIONS
+ static bool initialized = false;
+ static uint32_t sequence[kNoCodeAgeSequenceLength];
+ byte* byte_sequence = reinterpret_cast<byte*>(sequence);
+ *length = kNoCodeAgeSequenceLength * Assembler::kInstrSize;
+ if (!initialized) {
+ CodePatcher patcher(byte_sequence, kNoCodeAgeSequenceLength);
+ patcher.masm()->stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
+ patcher.masm()->LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+ patcher.masm()->add(fp, sp, Operand(2 * kPointerSize));
+ initialized = true;
+ }
+ return byte_sequence;
+}
+
+
+byte* Code::FindPlatformCodeAgeSequence() {
+ byte* start = instruction_start();
+ uint32_t young_length;
+ byte* young_sequence = GetNoCodeAgeSequence(&young_length);
+ if (!memcmp(start, young_sequence, young_length) ||
+ Memory::uint32_at(start) == kCodeAgePatchFirstInstruction) {
+ return start;
+ } else {
+ byte* start_after_strict = NULL;
+ if (kind() == FUNCTION) {
+ start_after_strict = start + kSizeOfFullCodegenStrictModePrologue;
+ } else {
+ ASSERT(kind() == OPTIMIZED_FUNCTION);
+ start_after_strict = start + kSizeOfOptimizedStrictModePrologue;
+ }
+ ASSERT(!memcmp(start_after_strict, young_sequence, young_length) ||
+ Memory::uint32_at(start_after_strict) ==
+ kCodeAgePatchFirstInstruction);
+ return start_after_strict;
+ }
+}
+
+
+bool Code::IsYoungSequence(byte* sequence) {
+ uint32_t young_length;
+ byte* young_sequence = GetNoCodeAgeSequence(&young_length);
+ bool result = !memcmp(sequence, young_sequence, young_length);
+ ASSERT(result ||
+ Memory::uint32_at(sequence) == kCodeAgePatchFirstInstruction);
+ return result;
+}
+
+
+void Code::GetCodeAgeAndParity(byte* sequence, Age* age,
+ MarkingParity* parity) {
+ if (IsYoungSequence(sequence)) {
+ *age = kNoAge;
+ *parity = NO_MARKING_PARITY;
+ } else {
+ Address target_address = Memory::Address_at(
+ sequence + Assembler::kInstrSize * (kNoCodeAgeSequenceLength - 1));
+ Code* stub = GetCodeFromTargetAddress(target_address);
+ GetCodeAgeAndParity(stub, age, parity);
+ }
+}
+
+
+void Code::PatchPlatformCodeAge(byte* sequence,
+ Code::Age age,
+ MarkingParity parity) {
+ uint32_t young_length;
+ byte* young_sequence = GetNoCodeAgeSequence(&young_length);
+ if (age == kNoAge) {
+ memcpy(sequence, young_sequence, young_length);
+ CPU::FlushICache(sequence, young_length);
+ } else {
+ Code* stub = GetCodeAgeStub(age, parity);
+ CodePatcher patcher(sequence, young_length / Assembler::kInstrSize);
+ patcher.masm()->add(r0, pc, Operand(-8));
+ patcher.masm()->ldr(pc, MemOperand(pc, -4));
+ patcher.masm()->dd(reinterpret_cast<uint32_t>(stub->instruction_start()));
+ }
+}
+
+
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_ARM
« no previous file with comments | « src/arm/codegen-arm.h ('k') | src/arm/full-codegen-arm.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698