@@ -55,6 +55,80 @@ static void ZapCodeRange(Address start, Address end) {
5555}
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58+ void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
59+ HandleScope scope;
60+
61+ // Compute the size of relocation information needed for the code
62+ // patching in Deoptimizer::DeoptimizeFunction.
63+ int min_reloc_size = 0;
64+ Address prev_reloc_address = code->instruction_start();
65+ Address code_start_address = code->instruction_start();
66+ SafepointTable table(*code);
67+ for (unsigned i = 0; i < table.length(); ++i) {
68+ Address curr_reloc_address = code_start_address + table.GetPcOffset(i);
69+ ASSERT_GE(curr_reloc_address, prev_reloc_address);
70+ SafepointEntry safepoint_entry = table.GetEntry(i);
71+ int deoptimization_index = safepoint_entry.deoptimization_index();
72+ if (deoptimization_index != Safepoint::kNoDeoptimizationIndex) {
73+ // The gap code is needed to get to the state expected at the
74+ // bailout and we need to skip the call opcode to get to the
75+ // address that needs reloc.
76+ curr_reloc_address += safepoint_entry.gap_code_size() + 1;
77+ int pc_delta = curr_reloc_address - prev_reloc_address;
78+ // We use RUNTIME_ENTRY reloc info which has a size of 2 bytes
79+ // if encodable with small pc delta encoding and up to 6 bytes
80+ // otherwise.
81+ if (pc_delta <= RelocInfo::kMaxSmallPCDelta) {
82+ min_reloc_size += 2;
83+ } else {
84+ min_reloc_size += 6;
85+ }
86+ prev_reloc_address = curr_reloc_address;
87+ }
88+ }
89+
90+ // If the relocation information is not big enough we create a new
91+ // relocation info object that is padded with comments to make it
92+ // big enough for lazy doptimization.
93+ int reloc_length = code->relocation_info()->length();
94+ if (min_reloc_size > reloc_length) {
95+ int comment_reloc_size = RelocInfo::kMinRelocCommentSize;
96+ // Padding needed.
97+ int min_padding = min_reloc_size - reloc_length;
98+ // Number of comments needed to take up at least that much space.
99+ int additional_comments =
100+ (min_padding + comment_reloc_size - 1) / comment_reloc_size;
101+ // Actual padding size.
102+ int padding = additional_comments * comment_reloc_size;
103+ // Allocate new relocation info and copy old relocation to the end
104+ // of the new relocation info array because relocation info is
105+ // written and read backwards.
106+ Handle<ByteArray> new_reloc =
107+ Factory::NewByteArray(reloc_length + padding, TENURED);
108+ memcpy(new_reloc->GetDataStartAddress() + padding,
109+ code->relocation_info()->GetDataStartAddress(),
110+ reloc_length);
111+ // Create a relocation writer to write the comments in the padding
112+ // space. Use position 0 for everything to ensure short encoding.
113+ RelocInfoWriter reloc_info_writer(
114+ new_reloc->GetDataStartAddress() + padding, 0);
115+ intptr_t comment_string
116+ = reinterpret_cast<intptr_t>(RelocInfo::kFillerCommentString);
117+ RelocInfo rinfo(0, RelocInfo::COMMENT, comment_string);
118+ for (int i = 0; i < additional_comments; ++i) {
119+ #ifdef DEBUG
120+ byte* pos_before = reloc_info_writer.pos();
121+ #endif
122+ reloc_info_writer.Write(&rinfo);
123+ ASSERT(RelocInfo::kMinRelocCommentSize ==
124+ pos_before - reloc_info_writer.pos());
125+ }
126+ // Replace relocation information on the code object.
127+ code->set_relocation_info(*new_reloc);
128+ }
129+ }
130+
131+
58132void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
59133 AssertNoAllocation no_allocation;
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