Further improve deopt reason output.

* Make the detailed deopt reason mandatory on x64, other platforms
  will follow in separate CLs.

* Extracted and improved jump table entry sharing logic: When
  --trace-deopt is on, we get separate entries for different deopt
  reasons. This enables us to distinguish the several reasons single
  instructions can have.

* Don't emit superfluous jump table comments: The bailout ID is still
  visible, and the jump table entry number is not interesting (but
  easy to determine if really needed).

* Unify the internal name of the jump table member across platforms.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/595513002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24123 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-codegen-arm.cc

@@ -319,29 +319,25 @@ bool LCodeGen::GenerateJumpTable() {
   // Each entry in the jump table generates one instruction and inlines one
   // 32bit data after it.
   if (!is_int24((masm()->pc_offset() / Assembler::kInstrSize) +
-      deopt_jump_table_.length() * 7)) {
+                jump_table_.length() * 7)) {
     Abort(kGeneratedCodeIsTooLarge);
   }
 
-  if (deopt_jump_table_.length() > 0) {
+  if (jump_table_.length() > 0) {
     Label needs_frame, call_deopt_entry;
 
     Comment(";;; -------------------- Jump table --------------------");
-    Address base = deopt_jump_table_[0].address;
+    Address base = jump_table_[0].address;
 
     Register entry_offset = scratch0();
 
-    int length = deopt_jump_table_.length();
+    int length = jump_table_.length();
     for (int i = 0; i < length; i++) {
-      Deoptimizer::JumpTableEntry* table_entry = &deopt_jump_table_[i];
+      Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
       __ bind(&table_entry->label);
 
-      Deoptimizer::BailoutType type = table_entry->bailout_type;
-      DCHECK(type == deopt_jump_table_[0].bailout_type);
+      DCHECK_EQ(jump_table_[0].bailout_type, table_entry->bailout_type);
       Address entry = table_entry->address;
-      int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
-      DCHECK_NE(Deoptimizer::kNotDeoptimizationEntry, id);
-      Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
       DeoptComment(table_entry->reason);
 
       // Second-level deopt table entries are contiguous and small, so instead
@@ -909,17 +905,15 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
     DeoptComment(reason);
     __ Call(entry, RelocInfo::RUNTIME_ENTRY);
   } else {
+    Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
+                                            !frame_is_built_);
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
-    if (deopt_jump_table_.is_empty() ||
-        (deopt_jump_table_.last().address != entry) ||
-        (deopt_jump_table_.last().bailout_type != bailout_type) ||
-        (deopt_jump_table_.last().needs_frame != !frame_is_built_)) {
-      Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
-                                              !frame_is_built_);
-      deopt_jump_table_.Add(table_entry, zone());
+    if (jump_table_.is_empty() ||
+        !table_entry.IsEquivalentTo(jump_table_.last())) {
+      jump_table_.Add(table_entry, zone());
     }
-    __ b(condition, &deopt_jump_table_.last().label);
+    __ b(condition, &jump_table_.last().label);
   }
 }
 

src/arm/lithium-codegen-arm.h

@@ -26,7 +26,7 @@ class LCodeGen: public LCodeGenBase {
   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
       : LCodeGenBase(chunk, assembler, info),
         deoptimizations_(4, info->zone()),
-        deopt_jump_table_(4, info->zone()),
+        jump_table_(4, info->zone()),
         deoptimization_literals_(8, info->zone()),
         inlined_function_count_(0),
         scope_(info->scope()),
@@ -332,7 +332,7 @@ class LCodeGen: public LCodeGenBase {
   void EmitVectorLoadICRegisters(T* instr);
 
   ZoneList<LEnvironment*> deoptimizations_;
-  ZoneList<Deoptimizer::JumpTableEntry> deopt_jump_table_;
+  ZoneList<Deoptimizer::JumpTableEntry> jump_table_;
   ZoneList<Handle<Object> > deoptimization_literals_;
   int inlined_function_count_;
   Scope* const scope_;

src/arm64/lithium-codegen-arm64.cc

@@ -839,11 +839,7 @@ bool LCodeGen::GenerateJumpTable() {
       Deoptimizer::JumpTableEntry* table_entry = jump_table_[i];
       __ Bind(&table_entry->label);
 
-      Deoptimizer::BailoutType type = table_entry->bailout_type;
       Address entry = table_entry->address;
-      int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
-      DCHECK_NE(Deoptimizer::kNotDeoptimizationEntry, id);
-      Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
       DeoptComment(table_entry->reason);
 
       // Second-level deopt table entries are contiguous and small, so instead
@@ -1053,14 +1049,13 @@ void LCodeGen::DeoptimizeBranch(
     DeoptComment(reason);
     __ Call(entry, RelocInfo::RUNTIME_ENTRY);
   } else {
+    Deoptimizer::JumpTableEntry* table_entry =
+        new (zone()) Deoptimizer::JumpTableEntry(entry, reason, bailout_type,
+                                                 !frame_is_built_);
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
-    if (jump_table_.is_empty() || (jump_table_.last()->address != entry) ||
-        (jump_table_.last()->bailout_type != bailout_type) ||
-        (jump_table_.last()->needs_frame != !frame_is_built_)) {
-      Deoptimizer::JumpTableEntry* table_entry =
-          new (zone()) Deoptimizer::JumpTableEntry(entry, reason, bailout_type,
-                                                   !frame_is_built_);
+    if (jump_table_.is_empty() ||
+        !table_entry->IsEquivalentTo(*jump_table_.last())) {
       jump_table_.Add(table_entry, zone());
     }
     __ B(&jump_table_.last()->label, branch_type, reg, bit);

src/deoptimizer.h

@@ -104,6 +104,15 @@ class Deoptimizer : public Malloced {
   struct Reason {
     Reason(int r, const char* m, const char* d)
         : raw_position(r), mnemonic(m), detail(d) {}
+
+    bool operator==(const Reason& other) const {
+      return raw_position == other.raw_position &&
+             CStringEquals(mnemonic, other.mnemonic) &&
+             CStringEquals(detail, other.detail);
+    }
+
+    bool operator!=(const Reason& other) const { return !(*this == other); }
+
     int raw_position;
     const char* mnemonic;
     const char* detail;
@@ -117,6 +126,13 @@ class Deoptimizer : public Malloced {
           reason(the_reason),
           bailout_type(type),
           needs_frame(frame) {}
+
+    bool IsEquivalentTo(const JumpTableEntry& other) const {
+      return address == other.address && bailout_type == other.bailout_type &&
+             needs_frame == other.needs_frame &&
+             (!FLAG_trace_deopt || reason == other.reason);
+    }
+
     Label label;
     Address address;
     Reason reason;

src/ia32/lithium-codegen-ia32.cc

@@ -386,10 +386,6 @@ bool LCodeGen::GenerateJumpTable() {
     Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
     __ bind(&table_entry->label);
     Address entry = table_entry->address;
-    Deoptimizer::BailoutType type = table_entry->bailout_type;
-    int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
-    DCHECK_NE(Deoptimizer::kNotDeoptimizationEntry, id);
-    Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
     DeoptComment(table_entry->reason);
     if (table_entry->needs_frame) {
       DCHECK(!info()->saves_caller_doubles());
@@ -874,14 +870,12 @@ void LCodeGen::DeoptimizeIf(Condition cc, LInstruction* instr,
     DeoptComment(reason);
     __ call(entry, RelocInfo::RUNTIME_ENTRY);
   } else {
+    Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
+                                            !frame_is_built_);
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
     if (jump_table_.is_empty() ||
-        jump_table_.last().address != entry ||
-        jump_table_.last().needs_frame != !frame_is_built_ ||
-        jump_table_.last().bailout_type != bailout_type) {
-      Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
-                                              !frame_is_built_);
+        !table_entry.IsEquivalentTo(jump_table_.last())) {
       jump_table_.Add(table_entry, zone());
     }
     if (cc == no_condition) {

src/mips/lithium-codegen-mips.cc

@@ -324,25 +324,21 @@ bool LCodeGen::GenerateDeferredCode() {
 
 
 bool LCodeGen::GenerateJumpTable() {
-  if (deopt_jump_table_.length() > 0) {
+  if (jump_table_.length() > 0) {
     Label needs_frame, call_deopt_entry;
 
     Comment(";;; -------------------- Jump table --------------------");
-    Address base = deopt_jump_table_[0].address;
+    Address base = jump_table_[0].address;
 
     Register entry_offset = t9;
 
-    int length = deopt_jump_table_.length();
+    int length = jump_table_.length();
     for (int i = 0; i < length; i++) {
-      Deoptimizer::JumpTableEntry* table_entry = &deopt_jump_table_[i];
+      Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
       __ bind(&table_entry->label);
 
-      Deoptimizer::BailoutType type = table_entry->bailout_type;
-      DCHECK(type == deopt_jump_table_[0].bailout_type);
+      DCHECK(table_entry->bailout_type == jump_table_[0].bailout_type);
       Address entry = table_entry->address;
-      int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
-      DCHECK_NE(Deoptimizer::kNotDeoptimizationEntry, id);
-      Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
       DeoptComment(table_entry->reason);
 
       // Second-level deopt table entries are contiguous and small, so instead
@@ -872,17 +868,15 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
     DeoptComment(reason);
     __ Call(entry, RelocInfo::RUNTIME_ENTRY, condition, src1, src2);
   } else {
+    Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
+                                            !frame_is_built_);
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
-    if (deopt_jump_table_.is_empty() ||
-        (deopt_jump_table_.last().address != entry) ||
-        (deopt_jump_table_.last().bailout_type != bailout_type) ||
-        (deopt_jump_table_.last().needs_frame != !frame_is_built_)) {
-      Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
-                                              !frame_is_built_);
-      deopt_jump_table_.Add(table_entry, zone());
+    if (jump_table_.is_empty() ||
+        !table_entry.IsEquivalentTo(jump_table_.last())) {
+      jump_table_.Add(table_entry, zone());
     }
-    __ Branch(&deopt_jump_table_.last().label, condition, src1, src2);
+    __ Branch(&jump_table_.last().label, condition, src1, src2);
   }
 }
 

src/mips/lithium-codegen-mips.h

@@ -25,7 +25,7 @@ class LCodeGen: public LCodeGenBase {
   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
       : LCodeGenBase(chunk, assembler, info),
         deoptimizations_(4, info->zone()),
-        deopt_jump_table_(4, info->zone()),
+        jump_table_(4, info->zone()),
         deoptimization_literals_(8, info->zone()),
         inlined_function_count_(0),
         scope_(info->scope()),
@@ -364,7 +364,7 @@ class LCodeGen: public LCodeGenBase {
   void EmitVectorLoadICRegisters(T* instr);
 
   ZoneList<LEnvironment*> deoptimizations_;
-  ZoneList<Deoptimizer::JumpTableEntry> deopt_jump_table_;
+  ZoneList<Deoptimizer::JumpTableEntry> jump_table_;
   ZoneList<Handle<Object> > deoptimization_literals_;
   int inlined_function_count_;
   Scope* const scope_;

src/mips64/lithium-codegen-mips64.cc

@@ -300,21 +300,17 @@ bool LCodeGen::GenerateDeferredCode() {
 
 
 bool LCodeGen::GenerateJumpTable() {
-  if (deopt_jump_table_.length() > 0) {
+  if (jump_table_.length() > 0) {
     Comment(";;; -------------------- Jump table --------------------");
   }
   Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
   Label table_start;
   __ bind(&table_start);
   Label needs_frame;
-  for (int i = 0; i < deopt_jump_table_.length(); i++) {
-    Deoptimizer::JumpTableEntry* table_entry = &deopt_jump_table_[i];
+  for (int i = 0; i < jump_table_.length(); i++) {
+    Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
     __ bind(&table_entry->label);
     Address entry = table_entry->address;
-    Deoptimizer::BailoutType type = table_entry->bailout_type;
-    int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
-    DCHECK_NE(Deoptimizer::kNotDeoptimizationEntry, id);
-    Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
     DeoptComment(table_entry->reason);
     __ li(t9, Operand(ExternalReference::ForDeoptEntry(entry)));
     if (table_entry->needs_frame) {
@@ -822,17 +818,15 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
     DeoptComment(reason);
     __ Call(entry, RelocInfo::RUNTIME_ENTRY, condition, src1, src2);
   } else {
+    Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
+                                            !frame_is_built_);
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
-    if (deopt_jump_table_.is_empty() ||
-        (deopt_jump_table_.last().address != entry) ||
-        (deopt_jump_table_.last().bailout_type != bailout_type) ||
-        (deopt_jump_table_.last().needs_frame != !frame_is_built_)) {
-      Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
-                                              !frame_is_built_);
-      deopt_jump_table_.Add(table_entry, zone());
+    if (jump_table_.is_empty() ||
+        !table_entry.IsEquivalentTo(jump_table_.last())) {
+      jump_table_.Add(table_entry, zone());
     }
-    __ Branch(&deopt_jump_table_.last().label, condition, src1, src2);
+    __ Branch(&jump_table_.last().label, condition, src1, src2);
   }
 }
 

src/mips64/lithium-codegen-mips64.h

@@ -25,7 +25,7 @@ class LCodeGen: public LCodeGenBase {
   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
       : LCodeGenBase(chunk, assembler, info),
         deoptimizations_(4, info->zone()),
-        deopt_jump_table_(4, info->zone()),
+        jump_table_(4, info->zone()),
         deoptimization_literals_(8, info->zone()),
         inlined_function_count_(0),
         scope_(info->scope()),
@@ -365,7 +365,7 @@ class LCodeGen: public LCodeGenBase {
   void EmitVectorLoadICRegisters(T* instr);
 
   ZoneList<LEnvironment*> deoptimizations_;
-  ZoneList<Deoptimizer::JumpTableEntry> deopt_jump_table_;
+  ZoneList<Deoptimizer::JumpTableEntry> jump_table_;
   ZoneList<Handle<Object> > deoptimization_literals_;
   int inlined_function_count_;
   Scope* const scope_;

src/utils.h

@@ -26,6 +26,13 @@ namespace internal {
 // ----------------------------------------------------------------------------
 // General helper functions
 
+
+// Same as strcmp, but can handle NULL arguments.
+inline bool CStringEquals(const char* s1, const char* s2) {
+  return (s1 == s2) || (s1 != NULL && s2 != NULL && strcmp(s1, s2) == 0);
+}
+
+
 // X must be a power of 2.  Returns the number of trailing zeros.
 inline int WhichPowerOf2(uint32_t x) {
   DCHECK(base::bits::IsPowerOfTwo32(x));

src/x64/lithium-codegen-x64.h

@@ -208,8 +208,7 @@ class LCodeGen: public LCodeGenBase {
                                             Safepoint::DeoptMode mode);
   void DeoptimizeIf(Condition cc, LInstruction* instr, const char* detail,
                     Deoptimizer::BailoutType bailout_type);
-  void DeoptimizeIf(Condition cc, LInstruction* instr,
-                    const char* detail = NULL);
+  void DeoptimizeIf(Condition cc, LInstruction* instr, const char* detail);
 
   bool DeoptEveryNTimes() {
     return FLAG_deopt_every_n_times != 0 && !info()->IsStub();

src/x87/lithium-codegen-x87.cc

@@ -1155,14 +1155,12 @@ void LCodeGen::DeoptimizeIf(Condition cc, LInstruction* instr,
     DeoptComment(reason);
     __ call(entry, RelocInfo::RUNTIME_ENTRY);
   } else {
+    Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
+                                            !frame_is_built_);
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
     if (jump_table_.is_empty() ||
-        jump_table_.last().address != entry ||
-        jump_table_.last().needs_frame != !frame_is_built_ ||
-        jump_table_.last().bailout_type != bailout_type) {
-      Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
-                                              !frame_is_built_);
+        !table_entry.IsEquivalentTo(jump_table_.last())) {
       jump_table_.Add(table_entry, zone());
     }
     if (cc == no_condition) {