A64: Move veneer emission checking in the Assembler.

src/a64/macro-assembler-a64.cc

Index: src/a64/macro-assembler-a64.cc
diff --git a/src/a64/macro-assembler-a64.cc b/src/a64/macro-assembler-a64.cc
index 5b979c2b31ed496463018ce49d4c69ac73ceabb2..f637b2bd6a1a374745ff94c36ee2eeb910de736f 100644
--- a/src/a64/macro-assembler-a64.cc
+++ b/src/a64/macro-assembler-a64.cc
@@ -558,92 +558,6 @@ void MacroAssembler::Store(const Register& rt,
 }
 
 
-bool MacroAssembler::ShouldEmitVeneer(int max_reachable_pc, int margin) {
-  // Account for the branch around the veneers and the guard.
-  int protection_offset = 2 * kInstructionSize;
-  return pc_offset() > max_reachable_pc - margin - protection_offset -
-    static_cast<int>(unresolved_branches_.size() * kMaxVeneerCodeSize);
-}
-
-
-void MacroAssembler::EmitVeneers(bool need_protection) {
-  RecordComment("[ Veneers");
-
-  Label end;
-  if (need_protection) {
-    B(&end);
-  }
-
-  EmitVeneersGuard();
-
-  {
-    InstructionAccurateScope scope(this);
-    Label size_check;
-
-    std::multimap<int, FarBranchInfo>::iterator it, it_to_delete;
-
-    it = unresolved_branches_.begin();
-    while (it != unresolved_branches_.end()) {
-      if (ShouldEmitVeneer(it->first)) {
-        Instruction* branch = InstructionAt(it->second.pc_offset_);
-        Label* label = it->second.label_;
-
-#ifdef DEBUG
-        __ bind(&size_check);
-#endif
-        // Patch the branch to point to the current position, and emit a branch
-        // to the label.
-        Instruction* veneer = reinterpret_cast<Instruction*>(pc_);
-        RemoveBranchFromLabelLinkChain(branch, label, veneer);
-        branch->SetImmPCOffsetTarget(veneer);
-        b(label);
-#ifdef DEBUG
-        ASSERT(SizeOfCodeGeneratedSince(&size_check) <=
-               static_cast<uint64_t>(kMaxVeneerCodeSize));
-        size_check.Unuse();
-#endif
-
-        it_to_delete = it++;
-        unresolved_branches_.erase(it_to_delete);
-      } else {
-        ++it;
-      }
-    }
-  }
-
-  Bind(&end);
-
-  RecordComment("]");
-}
-
-
-void MacroAssembler::EmitVeneersGuard() {
-  if (emit_debug_code()) {
-    Unreachable();
-  }
-}
-
-
-void MacroAssembler::CheckVeneers(bool need_protection) {
-  if (unresolved_branches_.empty()) {
-    return;
-  }
-
-  CHECK(pc_offset() < unresolved_branches_first_limit());
-  int margin = kVeneerDistanceMargin;
-  if (!need_protection) {
-    // Prefer emitting veneers protected by an existing instruction.
-    // The 4 divisor is a finger in the air guess. With a default margin of 2KB,
-    // that leaves 512B = 128 instructions of extra margin to avoid requiring a
-    // protective branch.
-    margin += margin / 4;
-  }
-  if (ShouldEmitVeneer(unresolved_branches_first_limit(), margin)) {
-    EmitVeneers(need_protection);
-  }
-}
-
-
 bool MacroAssembler::NeedExtraInstructionsOrRegisterBranch(
     Label *label, ImmBranchType b_type) {
   bool need_longer_range = false;
@@ -661,6 +575,10 @@ bool MacroAssembler::NeedExtraInstructionsOrRegisterBranch(
     unresolved_branches_.insert(
         std::pair<int, FarBranchInfo>(max_reachable_pc,
                                       FarBranchInfo(pc_offset(), label)));
+    // Also maintain the next pool check.
+    next_veneer_pool_check_ =
+      Min(next_veneer_pool_check_,
+          max_reachable_pc - kVeneerDistanceCheckMargin);
   }
   return need_longer_range;
 }
@@ -696,11 +614,10 @@ void MacroAssembler::B(Label* label, Condition cond) {
 
   if (need_extra_instructions) {
     b(&done, InvertCondition(cond));
-    b(label);
+    B(label);
   } else {
     b(label, cond);
   }
-  CheckVeneers(!need_extra_instructions);
   bind(&done);
 }
 
@@ -714,11 +631,10 @@ void MacroAssembler::Tbnz(const Register& rt, unsigned bit_pos, Label* label) {
 
   if (need_extra_instructions) {
     tbz(rt, bit_pos, &done);
-    b(label);
+    B(label);
   } else {
     tbnz(rt, bit_pos, label);
   }
-  CheckVeneers(!need_extra_instructions);
   bind(&done);
 }
 
@@ -732,11 +648,10 @@ void MacroAssembler::Tbz(const Register& rt, unsigned bit_pos, Label* label) {
 
   if (need_extra_instructions) {
     tbnz(rt, bit_pos, &done);
-    b(label);
+    B(label);
   } else {
     tbz(rt, bit_pos, label);
   }
-  CheckVeneers(!need_extra_instructions);
   bind(&done);
 }
 
@@ -750,11 +665,10 @@ void MacroAssembler::Cbnz(const Register& rt, Label* label) {
 
   if (need_extra_instructions) {
     cbz(rt, &done);
-    b(label);
+    B(label);
   } else {
     cbnz(rt, label);
   }
-  CheckVeneers(!need_extra_instructions);
   bind(&done);
 }
 
@@ -768,11 +682,10 @@ void MacroAssembler::Cbz(const Register& rt, Label* label) {
 
   if (need_extra_instructions) {
     cbnz(rt, &done);
-    b(label);
+    B(label);
   } else {
     cbz(rt, label);
   }
-  CheckVeneers(!need_extra_instructions);
   bind(&done);
 }
 
@@ -2009,7 +1922,7 @@ void MacroAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode) {
 
 
 void MacroAssembler::Call(Register target) {
-  BlockConstPoolScope scope(this);
+  BlockPoolsScope scope(this);
 #ifdef DEBUG
   Label start_call;
   Bind(&start_call);
@@ -2024,7 +1937,7 @@ void MacroAssembler::Call(Register target) {
 
 
 void MacroAssembler::Call(Label* target) {
-  BlockConstPoolScope scope(this);
+  BlockPoolsScope scope(this);
 #ifdef DEBUG
   Label start_call;
   Bind(&start_call);
@@ -2041,7 +1954,7 @@ void MacroAssembler::Call(Label* target) {
 // MacroAssembler::CallSize is sensitive to changes in this function, as it
 // requires to know how many instructions are used to branch to the target.
 void MacroAssembler::Call(Address target, RelocInfo::Mode rmode) {
-  BlockConstPoolScope scope(this);
+  BlockPoolsScope scope(this);
 #ifdef DEBUG
   Label start_call;
   Bind(&start_call);
@@ -4679,7 +4592,7 @@ void MacroAssembler::Abort(BailoutReason reason) {
 
     // Emit the message string directly in the instruction stream.
     {
-      BlockConstPoolScope scope(this);
+      BlockPoolsScope scope(this);
       Bind(&msg_address);
       EmitStringData(GetBailoutReason(reason));
     }
@@ -4871,7 +4784,7 @@ void MacroAssembler::PrintfNoPreserve(const char * format,
   Adr(x0, &format_address);
 
   // Emit the format string directly in the instruction stream.
-  { BlockConstPoolScope scope(this);
+  { BlockPoolsScope scope(this);
     Label after_data;
     B(&after_data);
     Bind(&format_address);
@@ -5036,7 +4949,7 @@ bool MacroAssembler::IsCodeAgeSequence(byte* sequence) {
 
 void InlineSmiCheckInfo::Emit(MacroAssembler* masm, const Register& reg,
                               const Label* smi_check) {
-  Assembler::BlockConstPoolScope scope(masm);
+  Assembler::BlockPoolsScope scope(masm);
   if (reg.IsValid()) {
     ASSERT(smi_check->is_bound());
     ASSERT(reg.Is64Bits());