Reland - Arm64: Ensure that csp is always aligned to 16 byte values even if jssp is not.

src/arm64/code-stubs-arm64.cc

Index: src/arm64/code-stubs-arm64.cc
diff --git a/src/arm64/code-stubs-arm64.cc b/src/arm64/code-stubs-arm64.cc
index a2dd220586d6b7c5e0111ad18b19afe4646e0c23..fec89369a6ab4ae17288aa2297b4630c64c03dd4 100644
--- a/src/arm64/code-stubs-arm64.cc
+++ b/src/arm64/code-stubs-arm64.cc
@@ -4661,22 +4661,31 @@ void StubFailureTrampolineStub::Generate(MacroAssembler* masm) {
 }
 
 
-// The entry hook is a "BumpSystemStackPointer" instruction (sub), followed by
-// a "Push lr" instruction, followed by a call.
-static const unsigned int kProfileEntryHookCallSize =
-    Assembler::kCallSizeWithRelocation + (2 * kInstructionSize);
+static unsigned int GetProfileEntryHookCallSize(MacroAssembler* masm) {
+  // The entry hook is a "BumpSystemStackPointer" instruction (sub),
+  // followed by a "Push lr" instruction, followed by a call.
+  unsigned int size =
+      Assembler::kCallSizeWithRelocation + (2 * kInstructionSize);
+  if (CpuFeatures::IsSupported(ALWAYS_ALIGN_CSP)) {
+    // If ALWAYS_ALIGN_CSP then there will be an extra bic instruction in
+    // "BumpSystemStackPointer".
+    size += kInstructionSize;
+  }
+  return size;
+}
 
 
 void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
   if (masm->isolate()->function_entry_hook() != NULL) {
     ProfileEntryHookStub stub(masm->isolate());
     Assembler::BlockConstPoolScope no_const_pools(masm);
+    DontEmitDebugCodeScope no_debug_code(masm);
     Label entry_hook_call_start;
     __ Bind(&entry_hook_call_start);
     __ Push(lr);
     __ CallStub(&stub);
     ASSERT(masm->SizeOfCodeGeneratedSince(&entry_hook_call_start) ==
-           kProfileEntryHookCallSize);
+           GetProfileEntryHookCallSize(masm));
 
     __ Pop(lr);
   }
@@ -4694,7 +4703,7 @@ void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
   const int kNumSavedRegs = kCallerSaved.Count();
 
   // Compute the function's address as the first argument.
-  __ Sub(x0, lr, kProfileEntryHookCallSize);
+  __ Sub(x0, lr, GetProfileEntryHookCallSize(masm));
 
 #if V8_HOST_ARCH_ARM64
   uintptr_t entry_hook =