PPC: Limit unbound label tracking to branch references.

src/ppc/assembler-ppc-inl.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 447 matching lines @@
   rm_ = rm;
   rmode_ = kRelocInfo_NONEPTR;  // PPC -why doesn't ARM do this?
 }
 
 void Assembler::CheckBuffer() {
   if (buffer_space() <= kGap) {
     GrowBuffer();
   }
 }
 
+void Assembler::TrackBranch() {
+  DCHECK(!trampoline_emitted_);
+  int count = tracked_branch_count_++;
+  if (count == 0) {
+    // We leave space (kMaxBlockTrampolineSectionSize)
+    // for BlockTrampolinePoolScope buffer.
+    next_trampoline_check_ =
+        pc_offset() + kMaxCondBranchReach - kMaxBlockTrampolineSectionSize;
+  } else {
+    next_trampoline_check_ -= kTrampolineSlotsSize;
+  }
+}
+
+void Assembler::UntrackBranch() {
+  DCHECK(!trampoline_emitted_);
+  DCHECK(tracked_branch_count_ > 0);
+  int count = --tracked_branch_count_;
+  if (count == 0) {
+    // Reset
+    next_trampoline_check_ = kMaxInt;
+  } else {
+    next_trampoline_check_ += kTrampolineSlotsSize;
+  }
+}
+
 void Assembler::CheckTrampolinePoolQuick() {
-  if (pc_offset() >= next_buffer_check_) {
+  if (pc_offset() >= next_trampoline_check_) {
     CheckTrampolinePool();
   }
 }
 
 void Assembler::emit(Instr x) {
   CheckBuffer();
   *reinterpret_cast<Instr*>(pc_) = x;
   pc_ += kInstrSize;
   CheckTrampolinePoolQuick();
 }
@@ skipping 241 matching lines @@
     }
 #endif
     return;
   }
   UNREACHABLE();
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_PPC_ASSEMBLER_PPC_INL_H_