Various improvements regarding the way we print code code comments.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 246 matching lines @@
 }
 
 
 bool LCodeGen::GenerateBody() {
   ASSERT(is_generating());
   bool emit_instructions = true;
   for (current_instruction_ = 0;
        !is_aborted() && current_instruction_ < instructions_->length();
        current_instruction_++) {
     LInstruction* instr = instructions_->at(current_instruction_);
+
+    // Don't emit code for basic blocks with a replacement.
     if (instr->IsLabel()) {
-      LLabel* label = LLabel::cast(instr);
-      emit_instructions = !label->HasReplacement();
+      emit_instructions = !LLabel::cast(instr)->HasReplacement();
+    }
+    if (!emit_instructions) continue;
+
+    if (FLAG_code_comments && instr->HasInterestingComment(this)) {
+      Comment(";;; <%d,%d> %s",
+              current_instruction_,
+              instr->hydrogen_value()->id(),
+              instr->Mnemonic());
     }
 
-    if (emit_instructions) {
-      if (FLAG_code_comments) {
-        HValue* hydrogen = instr->hydrogen_value();
-        if (hydrogen != NULL) {
-          if (hydrogen->IsChange()) {
-            HValue* changed_value = HChange::cast(hydrogen)->value();
-            int use_id = 0;
-            const char* use_mnemo = "dead";
-            if (hydrogen->UseCount() >= 1) {
-              HValue* use_value = hydrogen->uses().value();
-              use_id = use_value->id();
-              use_mnemo = use_value->Mnemonic();
-            }
-            Comment(";;; @%d: %s. <of #%d %s for #%d %s>",
-                    current_instruction_, instr->Mnemonic(),
-                    changed_value->id(), changed_value->Mnemonic(),
-                    use_id, use_mnemo);
-          } else {
-            Comment(";;; @%d: %s. <#%d>", current_instruction_,
-                    instr->Mnemonic(), hydrogen->id());
-          }
-        } else {
-          Comment(";;; @%d: %s.", current_instruction_, instr->Mnemonic());
-        }
-      }
-      instr->CompileToNative(this);
-    }
+    instr->CompileToNative(this);
   }
   EnsureSpaceForLazyDeopt();
   return !is_aborted();
 }
 
 
 bool LCodeGen::GenerateDeferredCode() {
   ASSERT(is_generating());
   if (deferred_.length() > 0) {
     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
       LDeferredCode* code = deferred_[i];
+      Comment(";;; <%d,%d> "
+              "-------------------- Deferred %s --------------------",
+              code->instruction_index(),
+              code->instr()->hydrogen_value()->id(),
+              code->instr()->Mnemonic());
       __ bind(code->entry());
       if (NeedsDeferredFrame()) {
-        Comment(";;; Deferred build frame @%d: %s.",
-                code->instruction_index(),
-                code->instr()->Mnemonic());
+        Comment(";;; Build frame");
         ASSERT(!frame_is_built_);
         ASSERT(info()->IsStub());
         frame_is_built_ = true;
         __ stm(db_w, sp, cp.bit() | fp.bit() | lr.bit());
         __ mov(scratch0(), Operand(Smi::FromInt(StackFrame::STUB)));
         __ push(scratch0());
         __ add(fp, sp, Operand(2 * kPointerSize));
+        Comment(";;; Deferred code");
       }
-      Comment(";;; Deferred code @%d: %s.",
-              code->instruction_index(),
-              code->instr()->Mnemonic());
       code->Generate();
       if (NeedsDeferredFrame()) {
-        Comment(";;; Deferred destroy frame @%d: %s.",
-                code->instruction_index(),
-                code->instr()->Mnemonic());
+        Comment(";;; Destroy frame");
         ASSERT(frame_is_built_);
         __ pop(ip);
         __ ldm(ia_w, sp, cp.bit() | fp.bit() | lr.bit());
         frame_is_built_ = false;
       }
       __ jmp(code->exit());
     }
   }
 
   // Force constant pool emission at the end of the deferred code to make
@@ skipping 10 matching lines @@
   // immediate of a branch instruction.
   // To simplify we consider the code size from the first instruction to the
   // end of the jump table. We also don't consider the pc load delta.
   // 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)) {
     Abort("Generated code is too large");
   }
 
-  __ RecordComment("[ Deoptimisation jump table");
+  if (deopt_jump_table_.length() > 0) {
+    Comment(";;; -------------------- Jump table --------------------");
+  }
   Label table_start;
   __ bind(&table_start);
   Label needs_frame_not_call;
   Label needs_frame_is_call;
   for (int i = 0; i < deopt_jump_table_.length(); i++) {
     __ bind(&deopt_jump_table_[i].label);
     Address entry = deopt_jump_table_[i].address;
     bool is_lazy_deopt = deopt_jump_table_[i].is_lazy_deopt;
     Deoptimizer::BailoutType type =
         is_lazy_deopt ? Deoptimizer::LAZY : Deoptimizer::EAGER;
@@ skipping 40 matching lines @@
     } else {
       if (is_lazy_deopt) {
         __ mov(lr, Operand(pc), LeaveCC, al);
         __ mov(pc, Operand(ExternalReference::ForDeoptEntry(entry)));
       } else {
         __ mov(pc, Operand(ExternalReference::ForDeoptEntry(entry)));
       }
     }
     masm()->CheckConstPool(false, false);
   }
-  __ RecordComment("]");
 
   // Force constant pool emission at the end of the deopt jump table to make
   // sure that no constant pools are emitted after.
   masm()->CheckConstPool(true, false);
 
   // The deoptimization jump table is the last part of the instruction
   // sequence. Mark the generated code as done unless we bailed out.
   if (!is_aborted()) status_ = DONE;
   return !is_aborted();
 }
@@ skipping 607 matching lines @@
       pointers, Safepoint::kWithRegistersAndDoubles, arguments, deopt_mode);
 }
 
 
 void LCodeGen::RecordPosition(int position) {
   if (position == RelocInfo::kNoPosition) return;
   masm()->positions_recorder()->RecordPosition(position);
 }
 
 
+static const char* LabelType(LLabel* label) {
+  if (label->is_loop_header()) return " (loop header)";
+  if (label->is_osr_entry()) return " (OSR entry)";
+  return "";
+}
+
+
 void LCodeGen::DoLabel(LLabel* label) {
-  Comment(";;; -------------------- B%d%s --------------------",
+  Comment(";;; <%d,%d> -------------------- B%d%s --------------------",
+          current_instruction_,
+          label->hydrogen_value()->id(),
           label->block_id(),
-          label->is_loop_header() ? " (loop header)" : "");
+          LabelType(label));
   __ bind(label->label());
   current_block_ = label->block_id();
   DoGap(label);
 }
 
 
 void LCodeGen::DoParallelMove(LParallelMove* move) {
   resolver_.Resolve(move);
 }
 
@@ skipping 1104 matching lines @@
 
   BinaryOpStub stub(instr->op(), NO_OVERWRITE);
   // Block literal pool emission to ensure nop indicating no inlined smi code
   // is in the correct position.
   Assembler::BlockConstPoolScope block_const_pool(masm());
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
   __ nop();  // Signals no inlined code.
 }
 
 
-int LCodeGen::GetNextEmittedBlock() {
+int LCodeGen::GetNextEmittedBlock() const {
   for (int i = current_block_ + 1; i < graph()->blocks()->length(); ++i) {
     if (!chunk_->GetLabel(i)->HasReplacement()) return i;
   }
   return -1;
 }
 
 
 void LCodeGen::EmitBranch(int left_block, int right_block, Condition cc) {
   int next_block = GetNextEmittedBlock();
   right_block = chunk_->LookupDestination(right_block);
@@ skipping 3809 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal