[codegen] Remove PrepareForTailCall

This is no longer used, tail calls are dealt with inside of
VisiTailCall.

Bug: v8:11879
Change-Id: I3e5b74c61c959a6697bc3fd05c8f9aa60cce9fa7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3049570Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75931}

src/codegen/arm/macro-assembler-arm.cc

@@ -1554,54 +1554,6 @@ void TurboAssembler::MovFromFloatParameter(DwVfpRegister dst) {
   MovFromFloatResult(dst);
 }
 
-void TurboAssembler::PrepareForTailCall(Register callee_args_count,
-                                        Register caller_args_count,
-                                        Register scratch0, Register scratch1) {
-  ASM_CODE_COMMENT(this);
-  DCHECK(!AreAliased(callee_args_count, caller_args_count, scratch0, scratch1));
-
-  // Calculate the end of destination area where we will put the arguments
-  // after we drop current frame. We add kPointerSize to count the receiver
-  // argument which is not included into formal parameters count.
-  Register dst_reg = scratch0;
-  add(dst_reg, fp, Operand(caller_args_count, LSL, kPointerSizeLog2));
-  add(dst_reg, dst_reg,
-      Operand(StandardFrameConstants::kCallerSPOffset + kPointerSize));
-
-  Register src_reg = caller_args_count;
-  // Calculate the end of source area. +kPointerSize is for the receiver.
-  add(src_reg, sp, Operand(callee_args_count, LSL, kPointerSizeLog2));
-  add(src_reg, src_reg, Operand(kPointerSize));
-
-  if (FLAG_debug_code) {
-    cmp(src_reg, dst_reg);
-    Check(lo, AbortReason::kStackAccessBelowStackPointer);
-  }
-
-  // Restore caller's frame pointer and return address now as they will be
-  // overwritten by the copying loop.
-  ldr(lr, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
-  ldr(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-
-  // Now copy callee arguments to the caller frame going backwards to avoid
-  // callee arguments corruption (source and destination areas could overlap).
-
-  // Both src_reg and dst_reg are pointing to the word after the one to copy,
-  // so they must be pre-decremented in the loop.
-  Register tmp_reg = scratch1;
-  Label loop, entry;
-  b(&entry);
-  bind(&loop);
-  ldr(tmp_reg, MemOperand(src_reg, -kPointerSize, PreIndex));
-  str(tmp_reg, MemOperand(dst_reg, -kPointerSize, PreIndex));
-  bind(&entry);
-  cmp(sp, src_reg);
-  b(ne, &loop);
-
-  // Leave current frame.
-  mov(sp, dst_reg);
-}
-
 void MacroAssembler::LoadStackLimit(Register destination, StackLimitKind kind) {
   ASM_CODE_COMMENT(this);
   DCHECK(root_array_available());

src/codegen/arm/macro-assembler-arm.h

@@ -233,15 +233,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void PrepareCallCFunction(int num_reg_arguments, int num_double_registers = 0,
                             Register scratch = no_reg);
 
-  // Removes current frame and its arguments from the stack preserving
-  // the arguments and a return address pushed to the stack for the next call.
-  // Both |callee_args_count| and |caller_args_count| do not include
-  // receiver. |callee_args_count| is not modified. |caller_args_count|
-  // is trashed.
-  void PrepareForTailCall(Register callee_args_count,
-                          Register caller_args_count, Register scratch0,
-                          Register scratch1);
-
   // There are two ways of passing double arguments on ARM, depending on
   // whether soft or hard floating point ABI is used. These functions
   // abstract parameter passing for the three different ways we call

src/codegen/arm64/macro-assembler-arm64.cc

@@ -2215,62 +2215,6 @@ void TurboAssembler::CallForDeoptimization(
   }
 }
 
-void TurboAssembler::PrepareForTailCall(Register callee_args_count,
-                                        Register caller_args_count,
-                                        Register scratch0, Register scratch1) {
-  ASM_CODE_COMMENT(this);
-  DCHECK(!AreAliased(callee_args_count, caller_args_count, scratch0, scratch1));
-
-  // Calculate the end of destination area where we will put the arguments
-  // after we drop current frame. We add kSystemPointerSize to count the
-  // receiver argument which is not included into formal parameters count.
-  Register dst_reg = scratch0;
-  Add(dst_reg, fp, Operand(caller_args_count, LSL, kSystemPointerSizeLog2));
-  Add(dst_reg, dst_reg,
-      StandardFrameConstants::kCallerSPOffset + kSystemPointerSize);
-  // Round dst_reg up to a multiple of 16 bytes, so that we overwrite any
-  // potential padding.
-  Add(dst_reg, dst_reg, 15);
-  Bic(dst_reg, dst_reg, 15);
-
-  Register src_reg = caller_args_count;
-  // Calculate the end of source area. +kSystemPointerSize is for the receiver.
-  Add(src_reg, sp, Operand(callee_args_count, LSL, kSystemPointerSizeLog2));
-  Add(src_reg, src_reg, kSystemPointerSize);
-
-  // Round src_reg up to a multiple of 16 bytes, so we include any potential
-  // padding in the copy.
-  Add(src_reg, src_reg, 15);
-  Bic(src_reg, src_reg, 15);
-
-  if (FLAG_debug_code) {
-    Cmp(src_reg, dst_reg);
-    Check(lo, AbortReason::kStackAccessBelowStackPointer);
-  }
-
-  // Restore caller's frame pointer and return address now as they will be
-  // overwritten by the copying loop.
-  RestoreFPAndLR();
-
-  // Now copy callee arguments to the caller frame going backwards to avoid
-  // callee arguments corruption (source and destination areas could overlap).
-
-  // Both src_reg and dst_reg are pointing to the word after the one to copy,
-  // so they must be pre-decremented in the loop.
-  Register tmp_reg = scratch1;
-  Label loop, entry;
-  B(&entry);
-  bind(&loop);
-  Ldr(tmp_reg, MemOperand(src_reg, -kSystemPointerSize, PreIndex));
-  Str(tmp_reg, MemOperand(dst_reg, -kSystemPointerSize, PreIndex));
-  bind(&entry);
-  Cmp(sp, src_reg);
-  B(ne, &loop);
-
-  // Leave current frame.
-  Mov(sp, dst_reg);
-}
-
 void MacroAssembler::LoadStackLimit(Register destination, StackLimitKind kind) {
   ASM_CODE_COMMENT(this);
   DCHECK(root_array_available());

src/codegen/arm64/macro-assembler-arm64.h

@@ -555,15 +555,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   inline void Isb();
   inline void Csdb();
 
-  // Removes current frame and its arguments from the stack preserving
-  // the arguments and a return address pushed to the stack for the next call.
-  // Both |callee_args_count| and |caller_args_count| do not include
-  // receiver. |callee_args_count| is not modified. |caller_args_count| is
-  // trashed.
-  void PrepareForTailCall(Register callee_args_count,
-                          Register caller_args_count, Register scratch0,
-                          Register scratch1);
-
   inline void SmiUntag(Register dst, Register src);
   inline void SmiUntag(Register dst, const MemOperand& src);
   inline void SmiUntag(Register smi);

src/codegen/ia32/macro-assembler-ia32.cc

@@ -1431,60 +1431,6 @@ void MacroAssembler::JumpToInstructionStream(Address entry) {
   jmp(entry, RelocInfo::OFF_HEAP_TARGET);
 }
 
-void TurboAssembler::PrepareForTailCall(
-    Register callee_args_count, Register caller_args_count, Register scratch0,
-    Register scratch1, int number_of_temp_values_after_return_address) {
-  ASM_CODE_COMMENT(this);
-  DCHECK(!AreAliased(callee_args_count, caller_args_count, scratch0, scratch1));
-
-  // Calculate the destination address where we will put the return address
-  // after we drop current frame.
-  Register new_sp_reg = scratch0;
-  sub(caller_args_count, callee_args_count);
-  lea(new_sp_reg, Operand(ebp, caller_args_count, times_system_pointer_size,
-                          StandardFrameConstants::kCallerPCOffset -
-                              number_of_temp_values_after_return_address *
-                                  kSystemPointerSize));
-
-  if (FLAG_debug_code) {
-    cmp(esp, new_sp_reg);
-    Check(below, AbortReason::kStackAccessBelowStackPointer);
-  }
-
-  // Copy return address from caller's frame to current frame's return address
-  // to avoid its trashing and let the following loop copy it to the right
-  // place.
-  Register tmp_reg = scratch1;
-  mov(tmp_reg, Operand(ebp, StandardFrameConstants::kCallerPCOffset));
-  mov(Operand(esp,
-              number_of_temp_values_after_return_address * kSystemPointerSize),
-      tmp_reg);
-
-  // Restore caller's frame pointer now as it could be overwritten by
-  // the copying loop.
-  mov(ebp, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
-
-  // +2 here is to copy both receiver and return address.
-  Register count_reg = caller_args_count;
-  lea(count_reg, Operand(callee_args_count,
-                         2 + number_of_temp_values_after_return_address));
-
-  // Now copy callee arguments to the caller frame going backwards to avoid
-  // callee arguments corruption (source and destination areas could overlap).
-  Label loop, entry;
-  jmp(&entry, Label::kNear);
-  bind(&loop);
-  dec(count_reg);
-  mov(tmp_reg, Operand(esp, count_reg, times_system_pointer_size, 0));
-  mov(Operand(new_sp_reg, count_reg, times_system_pointer_size, 0), tmp_reg);
-  bind(&entry);
-  cmp(count_reg, Immediate(0));
-  j(not_equal, &loop, Label::kNear);
-
-  // Leave current frame.
-  mov(esp, new_sp_reg);
-}
-
 void MacroAssembler::CompareStackLimit(Register with, StackLimitKind kind) {
   ASM_CODE_COMMENT(this);
   DCHECK(root_array_available());

src/codegen/ia32/macro-assembler-ia32.h

@@ -203,19 +203,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
     SmiUntag(output);
   }
 
-  // Removes current frame and its arguments from the stack preserving the
-  // arguments and a return address pushed to the stack for the next call. Both
-  // |callee_args_count| and |caller_args_count| do not include receiver.
-  // |callee_args_count| is not modified. |caller_args_count| is trashed.
-  // |number_of_temp_values_after_return_address| specifies the number of words
-  // pushed to the stack after the return address. This is to allow "allocation"
-  // of scratch registers that this function requires by saving their values on
-  // the stack.
-  void PrepareForTailCall(Register callee_args_count,
-                          Register caller_args_count, Register scratch0,
-                          Register scratch1,
-                          int number_of_temp_values_after_return_address);
-
   // Before calling a C-function from generated code, align arguments on stack.
   // After aligning the frame, arguments must be stored in esp[0], esp[4],
   // etc., not pushed. The argument count assumes all arguments are word sized.

src/codegen/x64/macro-assembler-x64.cc

@@ -2920,55 +2920,6 @@ void MacroAssembler::EmitDecrementCounter(StatsCounter* counter, int value) {
   }
 }
 
-void TurboAssembler::PrepareForTailCall(Register callee_args_count,
-                                        Register caller_args_count,
-                                        Register scratch0, Register scratch1) {
-  ASM_CODE_COMMENT(this);
-  DCHECK(!AreAliased(callee_args_count, caller_args_count, scratch0, scratch1));
-
-  // Calculate the destination address where we will put the return address
-  // after we drop current frame.
-  Register new_sp_reg = scratch0;
-  subq(caller_args_count, callee_args_count);
-  leaq(new_sp_reg, Operand(rbp, caller_args_count, times_system_pointer_size,
-                           StandardFrameConstants::kCallerPCOffset));
-
-  if (FLAG_debug_code) {
-    cmpq(rsp, new_sp_reg);
-    Check(below, AbortReason::kStackAccessBelowStackPointer);
-  }
-
-  // Copy return address from caller's frame to current frame's return address
-  // to avoid its trashing and let the following loop copy it to the right
-  // place.
-  Register tmp_reg = scratch1;
-  movq(tmp_reg, Operand(rbp, StandardFrameConstants::kCallerPCOffset));
-  movq(Operand(rsp, 0), tmp_reg);
-
-  // Restore caller's frame pointer now as it could be overwritten by
-  // the copying loop.
-  movq(rbp, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
-
-  // +2 here is to copy both receiver and return address.
-  Register count_reg = caller_args_count;
-  leaq(count_reg, Operand(callee_args_count, 2));
-
-  // Now copy callee arguments to the caller frame going backwards to avoid
-  // callee arguments corruption (source and destination areas could overlap).
-  Label loop, entry;
-  jmp(&entry, Label::kNear);
-  bind(&loop);
-  decq(count_reg);
-  movq(tmp_reg, Operand(rsp, count_reg, times_system_pointer_size, 0));
-  movq(Operand(new_sp_reg, count_reg, times_system_pointer_size, 0), tmp_reg);
-  bind(&entry);
-  cmpq(count_reg, Immediate(0));
-  j(not_equal, &loop, Label::kNear);
-
-  // Leave current frame.
-  movq(rsp, new_sp_reg);
-}
-
 void MacroAssembler::InvokeFunction(Register function, Register new_target,
                                     Register actual_parameter_count,
                                     InvokeType type) {

src/codegen/x64/macro-assembler-x64.h

@@ -571,14 +571,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   }
 #endif
 
-  // Removes current frame and its arguments from the stack preserving the
-  // arguments and a return address pushed to the stack for the next call.  Both
-  // |callee_args_count| and |caller_args_count| do not include receiver.
-  // |callee_args_count| is not modified. |caller_args_count| is trashed.
-  void PrepareForTailCall(Register callee_args_count,
-                          Register caller_args_count, Register scratch0,
-                          Register scratch1);
-
   void InitializeRootRegister() {
     ExternalReference isolate_root = ExternalReference::isolate_root(isolate());
     Move(kRootRegister, isolate_root);