PPC/s390: [liveedit] reimplement frame restarting.

src/s390/macro-assembler-s390.cc

 // Copyright 2014 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 <assert.h>  // For assert
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/base/bits.h"
@@ skipping 1454 matching lines @@
 
 void MacroAssembler::DebugBreak() {
   LoadImmP(r2, Operand::Zero());
   mov(r3,
       Operand(ExternalReference(Runtime::kHandleDebuggerStatement, isolate())));
   CEntryStub ces(isolate(), 1);
   DCHECK(AllowThisStubCall(&ces));
   Call(ces.GetCode(), RelocInfo::DEBUGGER_STATEMENT);
 }
 
+void MacroAssembler::MaybeDropFrames() {
+  // Check whether we need to drop frames to restart a function on the stack.
+  ExternalReference restart_fp =
+      ExternalReference::debug_restart_fp_address(isolate());
+  mov(r3, Operand(restart_fp));
+  LoadP(r3, MemOperand(r3));
+  CmpP(r3, Operand::Zero());
+  Jump(isolate()->builtins()->FrameDropperTrampoline(), RelocInfo::CODE_TARGET,
+       ne);
+}
+
 void MacroAssembler::PushStackHandler() {
   // Adjust this code if not the case.
   STATIC_ASSERT(StackHandlerConstants::kSize == 1 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
 
   // Link the current handler as the next handler.
   mov(r7, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
 
   // Buy the full stack frame for 5 slots.
   lay(sp, MemOperand(sp, -StackHandlerConstants::kSize));
@@ skipping 3725 matching lines @@
   }
   if (mag.shift > 0) ShiftRightArith(result, result, Operand(mag.shift));
   ExtractBit(r0, dividend, 31);
   AddP(result, r0);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390