CpuProfiler: slightly reduce the size of JumpTable code on arm64.

src/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/arm64/lithium-codegen-arm64.h"
 #include "src/arm64/lithium-gap-resolver-arm64.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 824 matching lines @@
   // sure that no constant pools are emitted after deferred code because
   // deferred code generation is the last step which generates code. The two
   // following steps will only output data used by crakshaft.
   masm()->CheckConstPool(true, false);
 
   return !is_aborted();
 }
 
 
 bool LCodeGen::GenerateJumpTable() {
-  Label needs_frame, restore_caller_doubles, call_deopt_entry;
+  Label needs_frame, call_deopt_entry;
 
   if (jump_table_.length() > 0) {
     Comment(";;; -------------------- Jump table --------------------");
     Address base = jump_table_[0]->address;
 
     UseScratchRegisterScope temps(masm());
     Register entry_offset = temps.AcquireX();
 
     int length = jump_table_.length();
     for (int i = 0; i < length; i++) {
       Deoptimizer::JumpTableEntry* table_entry = jump_table_[i];
       __ Bind(&table_entry->label);
 
       Address entry = table_entry->address;
       DeoptComment(table_entry->deopt_info);
 
       // Second-level deopt table entries are contiguous and small, so instead
       // of loading the full, absolute address of each one, load the base
       // address and add an immediate offset.
       __ Mov(entry_offset, entry - base);
 
       if (table_entry->needs_frame) {
         DCHECK(!info()->saves_caller_doubles());
+        Comment(";;; call deopt with frame");
         // Save lr before Bl, fp will be adjusted in the needs_frame code.
-        __ Push(lr, fp, cp);
+        __ Push(lr, fp);
         // Reuse the existing needs_frame code.
         __ Bl(&needs_frame);
-      } else if (info()->saves_caller_doubles()) {
-        DCHECK(info()->IsStub());
-        // Reuse the existing restore_caller_doubles code.
-        __ Bl(&restore_caller_doubles);
       } else {
         // There is nothing special to do, so just continue to the second-level
         // table.
         __ Bl(&call_deopt_entry);
       }
 
-      bool last_entry = (i + 1) == length;
-      masm()->CheckConstPool(false, last_entry);
+      masm()->CheckConstPool(false, false);
     }
 
     if (needs_frame.is_linked()) {
       // This variant of deopt can only be used with stubs. Since we don't
       // have a function pointer to install in the stack frame that we're
       // building, install a special marker there instead.
       DCHECK(info()->IsStub());
 
+      Comment(";;; needs_frame common code");
       UseScratchRegisterScope temps(masm());
       Register stub_marker = temps.AcquireX();
       __ Bind(&needs_frame);
       __ Mov(stub_marker, Smi::FromInt(StackFrame::STUB));
-      __ Push(stub_marker);
+      __ Push(cp, stub_marker);
       __ Add(fp, __ StackPointer(), 2 * kPointerSize);
-      if (restore_caller_doubles.is_linked()) {
-        __ B(&call_deopt_entry);
-      }
     }
 
-    if (restore_caller_doubles.is_linked()) {
-      __ Bind(&restore_caller_doubles);
+    // Generate common code for calling the second-level deopt table.
+    __ Bind(&call_deopt_entry);
+
+    if (info()->saves_caller_doubles()) {
+      DCHECK(info()->IsStub());
       RestoreCallerDoubles();
     }
 
-    // Generate common code for calling the second-level deopt table.
     Register deopt_entry = temps.AcquireX();
-    __ Bind(&call_deopt_entry);
     __ Mov(deopt_entry, Operand(reinterpret_cast<uint64_t>(base),
                                 RelocInfo::RUNTIME_ENTRY));
     __ Add(deopt_entry, deopt_entry, entry_offset);
     __ Br(deopt_entry);
   }
 
   // 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);
 
@@ skipping 5185 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 
 } }  // namespace v8::internal