[mips][loong64][regexp] Fix regexp test failures

Port commit bba7c09a
  [regexp] Allow reentrant irregexp execution

Port commit 4bbfc4b7
  [regexp] Remove the `stack` parameter from regexp matchers

Port commit c1700c56
  [regexp] Fix UAF in RegExpMacroAssembler

Bug: v8:11382
Change-Id: Ie2e95d7b19ecbd740e8d8a4130c725416abc114a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3185562Reviewed-by: Liu yu <liuyu@loongson.cn>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Cr-Commit-Position: refs/heads/main@{#77090}

src/regexp/loong64/regexp-macro-assembler-loong64.cc

@@ -6,14 +6,12 @@
 
 #include "src/regexp/loong64/regexp-macro-assembler-loong64.h"
 
-#include "src/codegen/assembler-inl.h"
 #include "src/codegen/macro-assembler.h"
+#include "src/heap/factory.h"
 #include "src/logging/log.h"
-#include "src/objects/objects-inl.h"
-#include "src/regexp/regexp-macro-assembler.h"
+#include "src/objects/code-inl.h"
 #include "src/regexp/regexp-stack.h"
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/strings/unicode.h"
 
 namespace v8 {
 namespace internal {
@@ -48,19 +46,18 @@ namespace internal {
  *  - fp[0..63]  s0..s7          Callee-saved registers s0..s7.
  *  --- frame pointer ----
  *  - fp[-8]  direct_call        (1 = direct call from JS, 0 = from runtime)    kDirectCall
- *  - fp[-16] stack_base         (Top of backtracking stack).                   kStackHighEnd
- *  - fp[-24] capture array size (may fit multiple sets of matches)             kNumOutputRegisters
- *  - fp[-32] int* capture_array (int[num_saved_registers_], for output).       kRegisterOutput
- *  - fp[-40] end of input       (address of end of string).                    kInputEnd
- *  - fp[-48] start of input     (address of first character in string).        kInputStart
- *  - fp[-56] start index        (character index of start).                    kStartIndex
- *  - fp[-64] void* input_string (location of a handle containing the string).  kInputString
- *  - fp[-72] success counter    (only for global regexps to count matches).    kSuccessfulCaptures
- *  - fp[-80] Offset of location before start of input (effectively character   kStringStartMinusOne
+ *  - fp[-16] capture array size (may fit multiple sets of matches)             kNumOutputRegisters
+ *  - fp[-24] int* capture_array (int[num_saved_registers_], for output).       kRegisterOutput
+ *  - fp[-32] end of input       (address of end of string).                    kInputEnd
+ *  - fp[-40] start of input     (address of first character in string).        kInputStart
+ *  - fp[-48] start index        (character index of start).                    kStartIndex
+ *  - fp[-56] void* input_string (location of a handle containing the string).  kInputString
+ *  - fp[-64] success counter    (only for global regexps to count matches).    kSuccessfulCaptures
+ *  - fp[-72] Offset of location before start of input (effectively character   kStringStartMinusOne
  *            position -1). Used to initialize capture registers to a
  *            non-position.
  *  --------- The following output registers are 32-bit values. ---------
- *  - fp[-88] register 0         (Only positions must be stored in the first    kRegisterZero
+ *  - fp[-80] register 0         (Only positions must be stored in the first    kRegisterZero
  *  -         register 1          num_saved_registers_ registers)
  *  -         ...
  *  -         register num_registers-1
@@ -79,7 +76,6 @@ namespace internal {
  *              Address end,
  *              int* capture_output_array,
  *              int num_capture_registers,
- *              byte* stack_area_base,
  *              bool direct_call = false,
  *              Isolate* isolate);
  * The call is performed by NativeRegExpMacroAssembler::Execute()
@@ -96,8 +92,10 @@ RegExpMacroAssemblerLOONG64::RegExpMacroAssemblerLOONG64(Isolate* isolate,
                                                          Zone* zone, Mode mode,
                                                          int registers_to_save)
     : NativeRegExpMacroAssembler(isolate, zone),
-      masm_(new MacroAssembler(isolate, CodeObjectRequired::kYes,
-                               NewAssemblerBuffer(kRegExpCodeSize))),
+      masm_(std::make_unique<MacroAssembler>(
+          isolate, CodeObjectRequired::kYes,
+          NewAssemblerBuffer(kRegExpCodeSize))),
+      no_root_array_scope_(masm_.get()),
       mode_(mode),
       num_registers_(registers_to_save),
       num_saved_registers_(registers_to_save),
@@ -107,8 +105,6 @@ RegExpMacroAssemblerLOONG64::RegExpMacroAssemblerLOONG64(Isolate* isolate,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
-  masm_->set_root_array_available(false);
-
   DCHECK_EQ(0, registers_to_save % 2);
   __ jmp(&entry_label_);  // We'll write the entry code later.
   // If the code gets too big or corrupted, an internal exception will be
@@ -120,7 +116,6 @@ RegExpMacroAssemblerLOONG64::RegExpMacroAssemblerLOONG64(Isolate* isolate,
 }
 
 RegExpMacroAssemblerLOONG64::~RegExpMacroAssemblerLOONG64() {
-  delete masm_;
   // Unuse labels in case we throw away the assembler without calling GetCode.
   entry_label_.Unuse();
   start_label_.Unuse();
@@ -336,7 +331,7 @@ void RegExpMacroAssemblerLOONG64::CheckNotBackReferenceIgnoreCase(
     __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
 
     {
-      AllowExternalCallThatCantCauseGC scope(masm_);
+      AllowExternalCallThatCantCauseGC scope(masm_.get());
       ExternalReference function =
           unicode ? ExternalReference::re_case_insensitive_compare_unicode(
                         isolate())
@@ -592,6 +587,44 @@ void RegExpMacroAssemblerLOONG64::Fail() {
   __ jmp(&exit_label_);
 }
 
+void RegExpMacroAssemblerLOONG64::LoadRegExpStackPointerFromMemory(
+    Register dst) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_stack_pointer(isolate());
+  __ li(dst, ref);
+  __ Ld_d(dst, MemOperand(dst, 0));
+}
+
+void RegExpMacroAssemblerLOONG64::StoreRegExpStackPointerToMemory(
+    Register src, Register scratch) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_stack_pointer(isolate());
+  __ li(scratch, ref);
+  __ St_d(src, MemOperand(scratch, 0));
+}
+
+void RegExpMacroAssemblerLOONG64::PushRegExpBasePointer(Register scratch1,
+                                                        Register scratch2) {
+  LoadRegExpStackPointerFromMemory(scratch1);
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(scratch2, ref);
+  __ Ld_d(scratch2, MemOperand(scratch2, 0));
+  __ Sub_d(scratch2, scratch1, scratch2);
+  __ St_d(scratch2, MemOperand(frame_pointer(), kRegExpStackBasePointer));
+}
+
+void RegExpMacroAssemblerLOONG64::PopRegExpBasePointer(Register scratch1,
+                                                       Register scratch2) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ Ld_d(scratch1, MemOperand(frame_pointer(), kRegExpStackBasePointer));
+  __ li(scratch2, ref);
+  __ Ld_d(scratch2, MemOperand(scratch2, 0));
+  __ Add_d(scratch1, scratch1, scratch2);
+  StoreRegExpStackPointerToMemory(scratch1, scratch2);
+}
+
 Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
   Label return_v0;
   if (0 /* todo masm_->has_exception()*/) {
@@ -608,7 +641,7 @@ Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
 
     // Tell the system that we have a stack frame.  Because the type is MANUAL,
     // no is generated.
-    FrameScope scope(masm_, StackFrame::MANUAL);
+    FrameScope scope(masm_.get(), StackFrame::MANUAL);
 
     // Actually emit code to start a new stack frame.
     // Push arguments
@@ -637,6 +670,13 @@ Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
     __ Push(a0);  // Make room for "string start - 1" constant.
     STATIC_ASSERT(kBacktrackCount == kStringStartMinusOne - kSystemPointerSize);
     __ Push(a0);  // The backtrack counter
+    STATIC_ASSERT(kRegExpStackBasePointer ==
+                  kBacktrackCount - kSystemPointerSize);
+    __ Push(a0);  // The regexp stack base ptr.
+
+    // Store the regexp base pointer - we'll later restore it / write it to
+    // memory when returning from this irregexp code object.
+    PushRegExpBasePointer(a0, a1);
 
     // Check if we have space on the stack for registers.
     Label stack_limit_hit;
@@ -717,8 +757,7 @@ Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
     }
 
     // Initialize backtrack stack pointer.
-    __ Ld_d(backtrack_stackpointer(),
-            MemOperand(frame_pointer(), kStackHighEnd));
+    LoadRegExpStackPointerFromMemory(backtrack_stackpointer());
 
     __ jmp(&start_label_);
 
@@ -820,6 +859,10 @@ Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
     }
 
     __ bind(&return_v0);
+    // Restore the original regexp stack pointer value (effectively, pop the
+    // stored base pointer).
+    PopRegExpBasePointer(a1, a2);
+
     // Skip sp past regexp registers and local variables..
     __ mov(sp, frame_pointer());
     // Restore registers s0..s7 and return (restoring ra to pc).
@@ -838,6 +881,8 @@ Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
     if (check_preempt_label_.is_linked()) {
       SafeCallTarget(&check_preempt_label_);
       // Put regexp engine registers on stack.
+      StoreRegExpStackPointerToMemory(backtrack_stackpointer(), a1);
+
       RegList regexp_registers_to_retain = current_input_offset().bit() |
                                            current_character().bit() |
                                            backtrack_stackpointer().bit();
@@ -848,34 +893,36 @@ Handle<HeapObject> RegExpMacroAssemblerLOONG64::GetCode(Handle<String> source) {
       // result as return value.
       __ Branch(&return_v0, ne, a0, Operand(zero_reg));
 
+      LoadRegExpStackPointerFromMemory(backtrack_stackpointer());
+
       // String might have moved: Reload end of string from frame.
       __ Ld_d(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
       __ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
+
       SafeReturn();
     }
 
     // Backtrack stack overflow code.
     if (stack_overflow_label_.is_linked()) {
       SafeCallTarget(&stack_overflow_label_);
+      StoreRegExpStackPointerToMemory(backtrack_stackpointer(), a1);
       // Reached if the backtrack-stack limit has been hit.
       // Put regexp engine registers on stack first.
       RegList regexp_registers =
           current_input_offset().bit() | current_character().bit();
       __ MultiPush(regexp_registers);
 
-      // Call GrowStack(backtrack_stackpointer(), &stack_base)
-      static const int num_arguments = 3;
-      __ PrepareCallCFunction(num_arguments, a0);
-      __ mov(a0, backtrack_stackpointer());
-      __ Add_d(a1, frame_pointer(), Operand(kStackHighEnd));
-      __ li(a2, Operand(ExternalReference::isolate_address(masm_->isolate())));
+      // Call GrowStack(isolate).
+      static const int kNumArguments = 1;
+      __ PrepareCallCFunction(kNumArguments, a0);
+      __ li(a0, Operand(ExternalReference::isolate_address(masm_->isolate())));
       ExternalReference grow_stack =
           ExternalReference::re_grow_stack(masm_->isolate());
-      __ CallCFunction(grow_stack, num_arguments);
+      __ CallCFunction(grow_stack, kNumArguments);
       // Restore regexp registers.
       __ MultiPop(regexp_registers);
-      // If return nullptr, we have failed to grow the stack, and
-      // must exit with a stack-overflow exception.
+      // If nullptr is returned, we have failed to grow the stack, and must exit
+      // with a stack-overflow exception.
       __ Branch(&exit_with_exception, eq, a0, Operand(zero_reg));
       // Otherwise use return value as new stack pointer.
       __ mov(backtrack_stackpointer(), a0);
@@ -956,7 +1003,7 @@ void RegExpMacroAssemblerLOONG64::PushBacktrack(Label* label) {
     int target = label->pos();
     __ li(a0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
   } else {
-    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
+    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_.get());
     Label after_constant;
     __ Branch(&after_constant);
     int offset = masm_->pc_offset();
@@ -991,9 +1038,21 @@ void RegExpMacroAssemblerLOONG64::ReadCurrentPositionFromRegister(int reg) {
   __ Ld_d(current_input_offset(), register_location(reg));
 }
 
+void RegExpMacroAssemblerLOONG64::WriteStackPointerToRegister(int reg) {
+  ExternalReference stack_top_address =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(a0, stack_top_address);
+  __ Ld_d(a0, MemOperand(a0, 0));
+  __ Sub_d(a0, backtrack_stackpointer(), a0);
+  __ St_d(a0, register_location(reg));
+}
+
 void RegExpMacroAssemblerLOONG64::ReadStackPointerFromRegister(int reg) {
-  __ Ld_d(backtrack_stackpointer(), register_location(reg));
-  __ Ld_d(a0, MemOperand(frame_pointer(), kStackHighEnd));
+  ExternalReference stack_top_address =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(backtrack_stackpointer(), stack_top_address);
+  __ Ld_d(backtrack_stackpointer(), MemOperand(backtrack_stackpointer(), 0));
+  __ Ld_d(a0, register_location(reg));
   __ Add_d(backtrack_stackpointer(), backtrack_stackpointer(), Operand(a0));
 }
 
@@ -1038,12 +1097,6 @@ void RegExpMacroAssemblerLOONG64::ClearRegisters(int reg_from, int reg_to) {
   }
 }
 
-void RegExpMacroAssemblerLOONG64::WriteStackPointerToRegister(int reg) {
-  __ Ld_d(a1, MemOperand(frame_pointer(), kStackHighEnd));
-  __ Sub_d(a0, backtrack_stackpointer(), a1);
-  __ St_d(a0, register_location(reg));
-}
-
 // Private methods:
 
 void RegExpMacroAssemblerLOONG64::CallCheckStackGuardState(Register scratch) {

src/regexp/loong64/regexp-macro-assembler-loong64.h

@@ -5,8 +5,6 @@
 #ifndef V8_REGEXP_LOONG64_REGEXP_MACRO_ASSEMBLER_LOONG64_H_
 #define V8_REGEXP_LOONG64_REGEXP_MACRO_ASSEMBLER_LOONG64_H_
 
-#include "src/base/strings.h"
-#include "src/codegen/loong64/assembler-loong64.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/regexp/regexp-macro-assembler.h"
 
@@ -93,35 +91,39 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerLOONG64
   static const int kFramePointer = 0;
 
   // Above the frame pointer - Stored registers and stack passed parameters.
-  // Registers s0 to s7, fp, and ra.
   static const int kStoredRegisters = kFramePointer;
   // Return address (stored from link register, read into pc on return).
 
   // TODO(plind): This 9 - is 8 s-regs (s0..s7) plus fp.
 
-  static const int kReturnAddress = kStoredRegisters + 9 * kPointerSize;
+  static const int kReturnAddress = kStoredRegisters + 9 * kSystemPointerSize;
   // Stack frame header.
   static const int kStackFrameHeader = kReturnAddress;
-  // Stack parameters placed by caller.
-  static const int kIsolate = kStackFrameHeader + kPointerSize;
 
   // Below the frame pointer.
   // Register parameters stored by setup code.
-  static const int kDirectCall = kFramePointer - kPointerSize;
-  static const int kStackHighEnd = kDirectCall - kPointerSize;
-  static const int kNumOutputRegisters = kStackHighEnd - kPointerSize;
-  static const int kRegisterOutput = kNumOutputRegisters - kPointerSize;
-  static const int kInputEnd = kRegisterOutput - kPointerSize;
-  static const int kInputStart = kInputEnd - kPointerSize;
-  static const int kStartIndex = kInputStart - kPointerSize;
-  static const int kInputString = kStartIndex - kPointerSize;
+  static const int kIsolate = kFramePointer - kSystemPointerSize;
+  static const int kDirectCall = kIsolate - kSystemPointerSize;
+  static const int kNumOutputRegisters = kDirectCall - kSystemPointerSize;
+  static const int kRegisterOutput = kNumOutputRegisters - kSystemPointerSize;
+  static const int kInputEnd = kRegisterOutput - kSystemPointerSize;
+  static const int kInputStart = kInputEnd - kSystemPointerSize;
+  static const int kStartIndex = kInputStart - kSystemPointerSize;
+  static const int kInputString = kStartIndex - kSystemPointerSize;
   // When adding local variables remember to push space for them in
   // the frame in GetCode.
-  static const int kSuccessfulCaptures = kInputString - kPointerSize;
-  static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
+  static const int kSuccessfulCaptures = kInputString - kSystemPointerSize;
+  static const int kStringStartMinusOne =
+      kSuccessfulCaptures - kSystemPointerSize;
   static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
+  // Stores the initial value of the regexp stack pointer in a
+  // position-independent representation (in case the regexp stack grows and
+  // thus moves).
+  static const int kRegExpStackBasePointer =
+      kBacktrackCount - kSystemPointerSize;
+
   // First register address. Following registers are below it on the stack.
-  static const int kRegisterZero = kBacktrackCount - kSystemPointerSize;
+  static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
 
   // Initial size of code buffer.
   static const int kRegExpCodeSize = 1024;
@@ -140,24 +142,24 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerLOONG64
 
   // Register holding the current input position as negative offset from
   // the end of the string.
-  inline Register current_input_offset() { return a6; }
+  static constexpr Register current_input_offset() { return a6; }
 
   // The register containing the current character after LoadCurrentCharacter.
-  inline Register current_character() { return a7; }
+  static constexpr Register current_character() { return a7; }
 
   // Register holding address of the end of the input string.
-  inline Register end_of_input_address() { return t2; }
+  static constexpr Register end_of_input_address() { return t2; }
 
   // Register holding the frame address. Local variables, parameters and
   // regexp registers are addressed relative to this.
-  inline Register frame_pointer() { return fp; }
+  static constexpr Register frame_pointer() { return fp; }
 
   // The register containing the backtrack stack top. Provides a meaningful
   // name to the register.
-  inline Register backtrack_stackpointer() { return t0; }
+  static constexpr Register backtrack_stackpointer() { return t0; }
 
   // Register holding pointer to the current code object.
-  inline Register code_pointer() { return a5; }
+  static constexpr Register code_pointer() { return a5; }
 
   // Byte size of chars in the string to match (decided by the Mode argument).
   inline int char_size() { return static_cast<int>(mode_); }
@@ -182,19 +184,26 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerLOONG64
   // and increments it by a word size.
   inline void Pop(Register target);
 
+  void LoadRegExpStackPointerFromMemory(Register dst);
+  void StoreRegExpStackPointerToMemory(Register src, Register scratch);
+  void PushRegExpBasePointer(Register scratch1, Register scratch2);
+  void PopRegExpBasePointer(Register scratch1, Register scratch2);
+
   Isolate* isolate() const { return masm_->isolate(); }
 
-  MacroAssembler* masm_;
+  const std::unique_ptr<MacroAssembler> masm_;
+
+  const NoRootArrayScope no_root_array_scope_;
 
   // Which mode to generate code for (Latin1 or UC16).
-  Mode mode_;
+  const Mode mode_;
 
   // One greater than maximal register index actually used.
   int num_registers_;
 
   // Number of registers to output at the end (the saved registers
   // are always 0..num_saved_registers_-1).
-  int num_saved_registers_;
+  const int num_saved_registers_;
 
   // Labels used internally.
   Label entry_label_;

src/regexp/mips/regexp-macro-assembler-mips.cc

@@ -6,14 +6,12 @@
 
 #include "src/regexp/mips/regexp-macro-assembler-mips.h"
 
-#include "src/codegen/assembler-inl.h"
 #include "src/codegen/macro-assembler.h"
+#include "src/codegen/mips/assembler-mips-inl.h"
 #include "src/logging/log.h"
-#include "src/objects/objects-inl.h"
-#include "src/regexp/regexp-macro-assembler.h"
+#include "src/objects/code-inl.h"
 #include "src/regexp/regexp-stack.h"
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/strings/unicode.h"
 
 namespace v8 {
 namespace internal {
@@ -39,11 +37,9 @@ namespace internal {
  *
  * The stack will have the following structure:
  *
- *  - fp[60]  Isolate* isolate   (address of the current isolate)
- *  - fp[56]  direct_call  (if 1, direct call from JavaScript code,
+ *  - fp[56]  Isolate* isolate   (address of the current isolate)
+ *  - fp[52]  direct_call  (if 1, direct call from JavaScript code,
  *                          if 0, call through the runtime system).
- *  - fp[52]  stack_area_base (High end of the memory area to use as
- *                             backtracking stack).
  *  - fp[48]  capture array size (may fit multiple sets of matches)
  *  - fp[44]  int* capture_array (int[num_saved_registers_], for output).
  *  --- sp when called ---
@@ -80,7 +76,6 @@ namespace internal {
  *              Address end,
  *              int* capture_output_array,
  *              int num_capture_registers,
- *              byte* stack_area_base,
  *              bool direct_call = false,
  *              Isolate* isolate);
  * The call is performed by NativeRegExpMacroAssembler::Execute()
@@ -95,8 +90,10 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
                                                    Mode mode,
                                                    int registers_to_save)
     : NativeRegExpMacroAssembler(isolate, zone),
-      masm_(new MacroAssembler(isolate, CodeObjectRequired::kYes,
-                               NewAssemblerBuffer(kRegExpCodeSize))),
+      masm_(std::make_unique<MacroAssembler>(
+          isolate, CodeObjectRequired::kYes,
+          NewAssemblerBuffer(kRegExpCodeSize))),
+      no_root_array_scope_(masm_.get()),
       mode_(mode),
       num_registers_(registers_to_save),
       num_saved_registers_(registers_to_save),
@@ -106,8 +103,6 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
-  masm_->set_root_array_available(false);
-
   DCHECK_EQ(0, registers_to_save % 2);
   __ jmp(&entry_label_);   // We'll write the entry code later.
   // If the code gets too big or corrupted, an internal exception will be
@@ -119,7 +114,6 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
 }
 
 RegExpMacroAssemblerMIPS::~RegExpMacroAssemblerMIPS() {
-  delete masm_;
   // Unuse labels in case we throw away the assembler without calling GetCode.
   entry_label_.Unuse();
   start_label_.Unuse();
@@ -342,7 +336,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
     __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
 
     {
-      AllowExternalCallThatCantCauseGC scope(masm_);
+      AllowExternalCallThatCantCauseGC scope(masm_.get());
       ExternalReference function =
           unicode ? ExternalReference::re_case_insensitive_compare_unicode(
                         isolate())
@@ -607,6 +601,42 @@ void RegExpMacroAssemblerMIPS::Fail() {
   __ jmp(&exit_label_);
 }
 
+void RegExpMacroAssemblerMIPS::LoadRegExpStackPointerFromMemory(Register dst) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_stack_pointer(isolate());
+  __ li(dst, Operand(ref));
+  __ Lw(dst, MemOperand(dst));
+}
+
+void RegExpMacroAssemblerMIPS::StoreRegExpStackPointerToMemory(
+    Register src, Register scratch) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_stack_pointer(isolate());
+  __ li(scratch, Operand(ref));
+  __ Sw(src, MemOperand(scratch));
+}
+
+void RegExpMacroAssemblerMIPS::PushRegExpBasePointer(Register scratch1,
+                                                     Register scratch2) {
+  LoadRegExpStackPointerFromMemory(scratch1);
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(scratch2, Operand(ref));
+  __ Lw(scratch2, MemOperand(scratch2));
+  __ Subu(scratch2, scratch1, scratch2);
+  __ Sw(scratch2, MemOperand(frame_pointer(), kRegExpStackBasePointer));
+}
+
+void RegExpMacroAssemblerMIPS::PopRegExpBasePointer(Register scratch1,
+                                                    Register scratch2) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ Lw(scratch1, MemOperand(frame_pointer(), kRegExpStackBasePointer));
+  __ li(scratch2, Operand(ref));
+  __ Lw(scratch2, MemOperand(scratch2));
+  __ Addu(scratch1, scratch1, scratch2);
+  StoreRegExpStackPointerToMemory(scratch1, scratch2);
+}
 
 Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
   Label return_v0;
@@ -624,7 +654,7 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
 
     // Tell the system that we have a stack frame.  Because the type is MANUAL,
     // no is generated.
-    FrameScope scope(masm_, StackFrame::MANUAL);
+    FrameScope scope(masm_.get(), StackFrame::MANUAL);
 
     // Actually emit code to start a new stack frame.
     // Push arguments
@@ -648,6 +678,13 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     __ push(a0);  // Make room for "string start - 1" constant.
     STATIC_ASSERT(kBacktrackCount == kStringStartMinusOne - kSystemPointerSize);
     __ push(a0);
+    STATIC_ASSERT(kRegExpStackBasePointer ==
+                  kBacktrackCount - kSystemPointerSize);
+    __ push(a0);  // The regexp stack base ptr.
+
+    // Store the regexp base pointer - we'll later restore it / write it to
+    // memory when returning from this irregexp code object.
+    PushRegExpBasePointer(a0, a1);
 
     // Check if we have space on the stack for registers.
     Label stack_limit_hit;
@@ -728,7 +765,7 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     }
 
     // Initialize backtrack stack pointer.
-    __ lw(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
+    LoadRegExpStackPointerFromMemory(backtrack_stackpointer());
 
     __ jmp(&start_label_);
 
@@ -830,6 +867,10 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     }
 
     __ bind(&return_v0);
+    // Restore the original regexp stack pointer value (effectively, pop the
+    // stored base pointer).
+    PopRegExpBasePointer(a0, a1);
+
     // Skip sp past regexp registers and local variables..
     __ mov(sp, frame_pointer());
     // Restore registers s0..s7 and return (restoring ra to pc).
@@ -847,6 +888,7 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     // Preempt-code.
     if (check_preempt_label_.is_linked()) {
       SafeCallTarget(&check_preempt_label_);
+      StoreRegExpStackPointerToMemory(backtrack_stackpointer(), a0);
       // Put regexp engine registers on stack.
       RegList regexp_registers_to_retain = current_input_offset().bit() |
           current_character().bit() | backtrack_stackpointer().bit();
@@ -857,6 +899,8 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
       // result as return value.
       __ Branch(&return_v0, ne, v0, Operand(zero_reg));
 
+      LoadRegExpStackPointerFromMemory(backtrack_stackpointer());
+
       // String might have moved: Reload end of string from frame.
       __ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
       __ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
@@ -866,25 +910,24 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     // Backtrack stack overflow code.
     if (stack_overflow_label_.is_linked()) {
       SafeCallTarget(&stack_overflow_label_);
+      StoreRegExpStackPointerToMemory(backtrack_stackpointer(), a0);
       // Reached if the backtrack-stack limit has been hit.
       // Put regexp engine registers on stack first.
       RegList regexp_registers = current_input_offset().bit() |
           current_character().bit();
       __ MultiPush(regexp_registers);
 
-      // Call GrowStack(backtrack_stackpointer(), &stack_base)
-      static const int num_arguments = 3;
-      __ PrepareCallCFunction(num_arguments, a0);
-      __ mov(a0, backtrack_stackpointer());
-      __ Addu(a1, frame_pointer(), Operand(kStackHighEnd));
-      __ li(a2, Operand(ExternalReference::isolate_address(masm_->isolate())));
+      // Call GrowStack(isolate).
+      static constexpr int kNumArguments = 1;
+      __ PrepareCallCFunction(kNumArguments, a0);
+      __ li(a0, Operand(ExternalReference::isolate_address(masm_->isolate())));
       ExternalReference grow_stack =
           ExternalReference::re_grow_stack(masm_->isolate());
-      __ CallCFunction(grow_stack, num_arguments);
+      __ CallCFunction(grow_stack, kNumArguments);
       // Restore regexp registers.
       __ MultiPop(regexp_registers);
-      // If return nullptr, we have failed to grow the stack, and
-      // must exit with a stack-overflow exception.
+      // If nullptr is returned, we have failed to grow the stack, and must exit
+      // with a stack-overflow exception.
       __ Branch(&exit_with_exception, eq, v0, Operand(zero_reg));
       // Otherwise use return value as new stack pointer.
       __ mov(backtrack_stackpointer(), v0);
@@ -976,7 +1019,7 @@ void RegExpMacroAssemblerMIPS::PushBacktrack(Label* label) {
     int target = label->pos();
     __ li(a0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
   } else {
-    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
+    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_.get());
     Label after_constant;
     __ Branch(&after_constant);
     int offset = masm_->pc_offset();
@@ -1013,10 +1056,21 @@ void RegExpMacroAssemblerMIPS::ReadCurrentPositionFromRegister(int reg) {
   __ lw(current_input_offset(), register_location(reg));
 }
 
+void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(a0, Operand(ref));
+  __ Lw(a0, MemOperand(a0));
+  __ Subu(a0, backtrack_stackpointer(), a0);
+  __ Sw(a0, register_location(reg));
+}
 
 void RegExpMacroAssemblerMIPS::ReadStackPointerFromRegister(int reg) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(a0, Operand(ref));
+  __ Lw(a0, MemOperand(a0));
   __ lw(backtrack_stackpointer(), register_location(reg));
-  __ lw(a0, MemOperand(frame_pointer(), kStackHighEnd));
   __ Addu(backtrack_stackpointer(), backtrack_stackpointer(), Operand(a0));
 }
 
@@ -1068,14 +1122,6 @@ void RegExpMacroAssemblerMIPS::ClearRegisters(int reg_from, int reg_to) {
   }
 }
 
-
-void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
-  __ lw(a1, MemOperand(frame_pointer(), kStackHighEnd));
-  __ Subu(a0, backtrack_stackpointer(), a1);
-  __ sw(a0, register_location(reg));
-}
-
-
 bool RegExpMacroAssemblerMIPS::CanReadUnaligned() {
   return false;
 }

src/regexp/mips/regexp-macro-assembler-mips.h

@@ -5,9 +5,7 @@
 #ifndef V8_REGEXP_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
 #define V8_REGEXP_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
 
-#include "src/base/strings.h"
 #include "src/codegen/macro-assembler.h"
-#include "src/codegen/mips/assembler-mips.h"
 #include "src/regexp/regexp-macro-assembler.h"
 
 namespace v8 {
@@ -94,7 +92,6 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   static const int kFramePointer = 0;
 
   // Above the frame pointer - Stored registers and stack passed parameters.
-  // Registers s0 to s7, fp, and ra.
   static const int kStoredRegisters = kFramePointer;
   // Return address (stored from link register, read into pc on return).
   static const int kReturnAddress = kStoredRegisters + 9 * kPointerSize;
@@ -103,8 +100,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   // Stack parameters placed by caller.
   static const int kRegisterOutput = kStackFrameHeader + 20;
   static const int kNumOutputRegisters = kRegisterOutput + kPointerSize;
-  static const int kStackHighEnd = kNumOutputRegisters + kPointerSize;
-  static const int kDirectCall = kStackHighEnd + kPointerSize;
+  static const int kDirectCall = kNumOutputRegisters + kPointerSize;
   static const int kIsolate = kDirectCall + kPointerSize;
 
   // Below the frame pointer.
@@ -118,8 +114,14 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   static const int kSuccessfulCaptures = kInputString - kPointerSize;
   static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
   static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
+  // Stores the initial value of the regexp stack pointer in a
+  // position-independent representation (in case the regexp stack grows and
+  // thus moves).
+  static const int kRegExpStackBasePointer =
+      kBacktrackCount - kSystemPointerSize;
+
   // First register address. Following registers are below it on the stack.
-  static const int kRegisterZero = kBacktrackCount - kSystemPointerSize;
+  static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
 
   // Initial size of code buffer.
   static const int kRegExpCodeSize = 1024;
@@ -130,7 +132,6 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   // Check whether we are exceeding the stack limit on the backtrack stack.
   void CheckStackLimit();
 
-
   // Generate a call to CheckStackGuardState.
   void CallCheckStackGuardState(Register scratch);
 
@@ -139,27 +140,27 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
 
   // Register holding the current input position as negative offset from
   // the end of the string.
-  inline Register current_input_offset() { return t2; }
+  static constexpr Register current_input_offset() { return t2; }
 
   // The register containing the current character after LoadCurrentCharacter.
-  inline Register current_character() { return t3; }
+  static constexpr Register current_character() { return t3; }
 
   // Register holding address of the end of the input string.
-  inline Register end_of_input_address() { return t6; }
+  static constexpr Register end_of_input_address() { return t6; }
 
   // Register holding the frame address. Local variables, parameters and
   // regexp registers are addressed relative to this.
-  inline Register frame_pointer() { return fp; }
+  static constexpr Register frame_pointer() { return fp; }
 
   // The register containing the backtrack stack top. Provides a meaningful
   // name to the register.
-  inline Register backtrack_stackpointer() { return t4; }
+  static constexpr Register backtrack_stackpointer() { return t4; }
 
   // Register holding pointer to the current code object.
-  inline Register code_pointer() { return t1; }
+  static constexpr Register code_pointer() { return t1; }
 
   // Byte size of chars in the string to match (decided by the Mode argument).
-  inline int char_size() { return static_cast<int>(mode_); }
+  inline int char_size() const { return static_cast<int>(mode_); }
 
   // Equivalent to a conditional branch to the label, unless the label
   // is nullptr, in which case it is a conditional Backtrack.
@@ -185,19 +186,25 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   // and increments it by a word size.
   inline void Pop(Register target);
 
+  void LoadRegExpStackPointerFromMemory(Register dst);
+  void StoreRegExpStackPointerToMemory(Register src, Register scratch);
+  void PushRegExpBasePointer(Register scratch1, Register scratch2);
+  void PopRegExpBasePointer(Register scratch1, Register scratch2);
+
   Isolate* isolate() const { return masm_->isolate(); }
 
-  MacroAssembler* masm_;
+  const std::unique_ptr<MacroAssembler> masm_;
+  const NoRootArrayScope no_root_array_scope_;
 
   // Which mode to generate code for (Latin1 or UC16).
-  Mode mode_;
+  const Mode mode_;
 
   // One greater than maximal register index actually used.
   int num_registers_;
 
   // Number of registers to output at the end (the saved registers
   // are always 0..num_saved_registers_-1).
-  int num_saved_registers_;
+  const int num_saved_registers_;
 
   // Labels used internally.
   Label entry_label_;

src/regexp/mips64/regexp-macro-assembler-mips64.cc

@@ -6,14 +6,13 @@
 
 #include "src/regexp/mips64/regexp-macro-assembler-mips64.h"
 
-#include "src/codegen/assembler-inl.h"
 #include "src/codegen/macro-assembler.h"
+#include "src/codegen/mips64/assembler-mips64-inl.h"
+#include "src/heap/factory.h"
 #include "src/logging/log.h"
-#include "src/objects/objects-inl.h"
-#include "src/regexp/regexp-macro-assembler.h"
+#include "src/objects/code-inl.h"
 #include "src/regexp/regexp-stack.h"
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/strings/unicode.h"
 
 namespace v8 {
 namespace internal {
@@ -83,19 +82,18 @@ namespace internal {
  *  - fp[0..63]  s0..s7          Callee-saved registers s0..s7.
  *  --- frame pointer ----
  *  - fp[-8]  direct_call        (1 = direct call from JS, 0 = from runtime)    kDirectCall
- *  - fp[-16] stack_base         (Top of backtracking stack).                   kStackHighEnd
- *  - fp[-24] capture array size (may fit multiple sets of matches)             kNumOutputRegisters
- *  - fp[-32] int* capture_array (int[num_saved_registers_], for output).       kRegisterOutput
- *  - fp[-40] end of input       (address of end of string).                    kInputEnd
- *  - fp[-48] start of input     (address of first character in string).        kInputStart
- *  - fp[-56] start index        (character index of start).                    kStartIndex
- *  - fp[-64] void* input_string (location of a handle containing the string).  kInputString
- *  - fp[-72] success counter    (only for global regexps to count matches).    kSuccessfulCaptures
- *  - fp[-80] Offset of location before start of input (effectively character   kStringStartMinusOne
+ *  - fp[-16] capture array size (may fit multiple sets of matches)             kNumOutputRegisters
+ *  - fp[-24] int* capture_array (int[num_saved_registers_], for output).       kRegisterOutput
+ *  - fp[-32] end of input       (address of end of string).                    kInputEnd
+ *  - fp[-40] start of input     (address of first character in string).        kInputStart
+ *  - fp[-48] start index        (character index of start).                    kStartIndex
+ *  - fp[-56] void* input_string (location of a handle containing the string).  kInputString
+ *  - fp[-64] success counter    (only for global regexps to count matches).    kSuccessfulCaptures
+ *  - fp[-72] Offset of location before start of input (effectively character   kStringStartMinusOne
  *            position -1). Used to initialize capture registers to a
  *            non-position.
  *  --------- The following output registers are 32-bit values. ---------
- *  - fp[-88] register 0         (Only positions must be stored in the first    kRegisterZero
+ *  - fp[-80] register 0         (Only positions must be stored in the first    kRegisterZero
  *  -         register 1          num_saved_registers_ registers)
  *  -         ...
  *  -         register num_registers-1
@@ -114,7 +112,6 @@ namespace internal {
  *              Address end,
  *              int* capture_output_array,
  *              int num_capture_registers,
- *              byte* stack_area_base,
  *              bool direct_call = false,
  *              Isolate* isolate);
  * The call is performed by NativeRegExpMacroAssembler::Execute()
@@ -131,8 +128,10 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
                                                    Mode mode,
                                                    int registers_to_save)
     : NativeRegExpMacroAssembler(isolate, zone),
-      masm_(new MacroAssembler(isolate, CodeObjectRequired::kYes,
-                               NewAssemblerBuffer(kRegExpCodeSize))),
+      masm_(std::make_unique<MacroAssembler>(
+          isolate, CodeObjectRequired::kYes,
+          NewAssemblerBuffer(kRegExpCodeSize))),
+      no_root_array_scope_(masm_.get()),
       mode_(mode),
       num_registers_(registers_to_save),
       num_saved_registers_(registers_to_save),
@@ -142,8 +141,6 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
-  masm_->set_root_array_available(false);
-
   DCHECK_EQ(0, registers_to_save % 2);
   __ jmp(&entry_label_);   // We'll write the entry code later.
   // If the code gets too big or corrupted, an internal exception will be
@@ -155,7 +152,6 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
 }
 
 RegExpMacroAssemblerMIPS::~RegExpMacroAssemblerMIPS() {
-  delete masm_;
   // Unuse labels in case we throw away the assembler without calling GetCode.
   entry_label_.Unuse();
   start_label_.Unuse();
@@ -378,7 +374,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
     __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
 
     {
-      AllowExternalCallThatCantCauseGC scope(masm_);
+      AllowExternalCallThatCantCauseGC scope(masm_.get());
       ExternalReference function =
           unicode ? ExternalReference::re_case_insensitive_compare_unicode(
                         isolate())
@@ -637,6 +633,42 @@ void RegExpMacroAssemblerMIPS::Fail() {
   __ jmp(&exit_label_);
 }
 
+void RegExpMacroAssemblerMIPS::LoadRegExpStackPointerFromMemory(Register dst) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_stack_pointer(isolate());
+  __ li(dst, Operand(ref));
+  __ Ld(dst, MemOperand(dst));
+}
+
+void RegExpMacroAssemblerMIPS::StoreRegExpStackPointerToMemory(
+    Register src, Register scratch) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_stack_pointer(isolate());
+  __ li(scratch, Operand(ref));
+  __ Sd(src, MemOperand(scratch));
+}
+
+void RegExpMacroAssemblerMIPS::PushRegExpBasePointer(Register scratch1,
+                                                     Register scratch2) {
+  LoadRegExpStackPointerFromMemory(scratch1);
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(scratch2, Operand(ref));
+  __ Ld(scratch2, MemOperand(scratch2));
+  __ Dsubu(scratch2, scratch1, scratch2);
+  __ Sd(scratch2, MemOperand(frame_pointer(), kRegExpStackBasePointer));
+}
+
+void RegExpMacroAssemblerMIPS::PopRegExpBasePointer(Register scratch1,
+                                                    Register scratch2) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ Ld(scratch1, MemOperand(frame_pointer(), kRegExpStackBasePointer));
+  __ li(scratch2, Operand(ref));
+  __ Ld(scratch2, MemOperand(scratch2));
+  __ Daddu(scratch1, scratch1, scratch2);
+  StoreRegExpStackPointerToMemory(scratch1, scratch2);
+}
 
 Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
   Label return_v0;
@@ -654,7 +686,7 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
 
     // Tell the system that we have a stack frame.  Because the type is MANUAL,
     // no is generated.
-    FrameScope scope(masm_, StackFrame::MANUAL);
+    FrameScope scope(masm_.get(), StackFrame::MANUAL);
 
     // Actually emit code to start a new stack frame.
     // Push arguments
@@ -683,6 +715,13 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     __ push(a0);  // Make room for "string start - 1" constant.
     STATIC_ASSERT(kBacktrackCount == kStringStartMinusOne - kSystemPointerSize);
     __ push(a0);  // The backtrack counter
+    STATIC_ASSERT(kRegExpStackBasePointer ==
+                  kBacktrackCount - kSystemPointerSize);
+    __ push(a0);  // The regexp stack base ptr.
+
+    // Store the regexp base pointer - we'll later restore it / write it to
+    // memory when returning from this irregexp code object.
+    PushRegExpBasePointer(a0, a1);
 
     // Check if we have space on the stack for registers.
     Label stack_limit_hit;
@@ -763,7 +802,7 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     }
 
     // Initialize backtrack stack pointer.
-    __ Ld(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
+    LoadRegExpStackPointerFromMemory(backtrack_stackpointer());
 
     __ jmp(&start_label_);
 
@@ -866,6 +905,10 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     }
 
     __ bind(&return_v0);
+    // Restore the original regexp stack pointer value (effectively, pop the
+    // stored base pointer).
+    PopRegExpBasePointer(a0, a1);
+
     // Skip sp past regexp registers and local variables..
     __ mov(sp, frame_pointer());
     // Restore registers s0..s7 and return (restoring ra to pc).
@@ -883,6 +926,8 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     // Preempt-code.
     if (check_preempt_label_.is_linked()) {
       SafeCallTarget(&check_preempt_label_);
+      StoreRegExpStackPointerToMemory(backtrack_stackpointer(), a0);
+
       // Put regexp engine registers on stack.
       RegList regexp_registers_to_retain = current_input_offset().bit() |
           current_character().bit() | backtrack_stackpointer().bit();
@@ -893,6 +938,8 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
       // result as return value.
       __ Branch(&return_v0, ne, v0, Operand(zero_reg));
 
+      LoadRegExpStackPointerFromMemory(backtrack_stackpointer());
+
       // String might have moved: Reload end of string from frame.
       __ Ld(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
       __ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
@@ -902,25 +949,24 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
     // Backtrack stack overflow code.
     if (stack_overflow_label_.is_linked()) {
       SafeCallTarget(&stack_overflow_label_);
+      StoreRegExpStackPointerToMemory(backtrack_stackpointer(), a0);
       // Reached if the backtrack-stack limit has been hit.
       // Put regexp engine registers on stack first.
       RegList regexp_registers = current_input_offset().bit() |
           current_character().bit();
       __ MultiPush(regexp_registers);
 
-      // Call GrowStack(backtrack_stackpointer(), &stack_base)
-      static const int num_arguments = 3;
-      __ PrepareCallCFunction(num_arguments, a0);
-      __ mov(a0, backtrack_stackpointer());
-      __ Daddu(a1, frame_pointer(), Operand(kStackHighEnd));
-      __ li(a2, Operand(ExternalReference::isolate_address(masm_->isolate())));
+      // Call GrowStack(isolate)
+      static constexpr int kNumArguments = 1;
+      __ PrepareCallCFunction(kNumArguments, a0);
+      __ li(a0, Operand(ExternalReference::isolate_address(masm_->isolate())));
       ExternalReference grow_stack =
           ExternalReference::re_grow_stack(masm_->isolate());
-      __ CallCFunction(grow_stack, num_arguments);
+      __ CallCFunction(grow_stack, kNumArguments);
       // Restore regexp registers.
       __ MultiPop(regexp_registers);
-      // If return nullptr, we have failed to grow the stack, and
-      // must exit with a stack-overflow exception.
+      // If nullptr is returned, we have failed to grow the stack, and must exit
+      // with a stack-overflow exception.
       __ Branch(&exit_with_exception, eq, v0, Operand(zero_reg));
       // Otherwise use return value as new stack pointer.
       __ mov(backtrack_stackpointer(), v0);
@@ -1012,7 +1058,7 @@ void RegExpMacroAssemblerMIPS::PushBacktrack(Label* label) {
     int target = label->pos();
     __ li(a0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
   } else {
-    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
+    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_.get());
     Label after_constant;
     __ Branch(&after_constant);
     int offset = masm_->pc_offset();
@@ -1049,14 +1095,24 @@ void RegExpMacroAssemblerMIPS::ReadCurrentPositionFromRegister(int reg) {
   __ Ld(current_input_offset(), register_location(reg));
 }
 
+void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(a0, Operand(ref));
+  __ Ld(a0, MemOperand(a0));
+  __ Dsubu(a0, backtrack_stackpointer(), a0);
+  __ Sd(a0, register_location(reg));
+}
 
 void RegExpMacroAssemblerMIPS::ReadStackPointerFromRegister(int reg) {
+  ExternalReference ref =
+      ExternalReference::address_of_regexp_stack_memory_top_address(isolate());
+  __ li(a0, Operand(ref));
+  __ Ld(a0, MemOperand(a0));
   __ Ld(backtrack_stackpointer(), register_location(reg));
-  __ Ld(a0, MemOperand(frame_pointer(), kStackHighEnd));
   __ Daddu(backtrack_stackpointer(), backtrack_stackpointer(), Operand(a0));
 }
 
-
 void RegExpMacroAssemblerMIPS::SetCurrentPositionFromEnd(int by) {
   Label after_position;
   __ Branch(&after_position,
@@ -1104,14 +1160,6 @@ void RegExpMacroAssemblerMIPS::ClearRegisters(int reg_from, int reg_to) {
   }
 }
 
-
-void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
-  __ Ld(a1, MemOperand(frame_pointer(), kStackHighEnd));
-  __ Dsubu(a0, backtrack_stackpointer(), a1);
-  __ Sd(a0, register_location(reg));
-}
-
-
 bool RegExpMacroAssemblerMIPS::CanReadUnaligned() {
   return false;
 }

src/regexp/mips64/regexp-macro-assembler-mips64.h

@@ -5,9 +5,7 @@
 #ifndef V8_REGEXP_MIPS64_REGEXP_MACRO_ASSEMBLER_MIPS64_H_
 #define V8_REGEXP_MIPS64_REGEXP_MACRO_ASSEMBLER_MIPS64_H_
 
-#include "src/base/strings.h"
 #include "src/codegen/macro-assembler.h"
-#include "src/codegen/mips64/assembler-mips64.h"
 #include "src/regexp/regexp-macro-assembler.h"
 
 namespace v8 {
@@ -96,35 +94,39 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   static const int kFramePointer = 0;
 
   // Above the frame pointer - Stored registers and stack passed parameters.
-  // Registers s0 to s7, fp, and ra.
   static const int kStoredRegisters = kFramePointer;
   // Return address (stored from link register, read into pc on return).
 
   // TODO(plind): This 9 - is 8 s-regs (s0..s7) plus fp.
 
-  static const int kReturnAddress = kStoredRegisters + 9 * kPointerSize;
+  static const int kReturnAddress = kStoredRegisters + 9 * kSystemPointerSize;
   // Stack frame header.
   static const int kStackFrameHeader = kReturnAddress;
-  // Stack parameters placed by caller.
-  static const int kIsolate = kStackFrameHeader + kPointerSize;
 
   // Below the frame pointer.
   // Register parameters stored by setup code.
-  static const int kDirectCall = kFramePointer - kPointerSize;
-  static const int kStackHighEnd = kDirectCall - kPointerSize;
-  static const int kNumOutputRegisters = kStackHighEnd - kPointerSize;
-  static const int kRegisterOutput = kNumOutputRegisters - kPointerSize;
-  static const int kInputEnd = kRegisterOutput - kPointerSize;
-  static const int kInputStart = kInputEnd - kPointerSize;
-  static const int kStartIndex = kInputStart - kPointerSize;
-  static const int kInputString = kStartIndex - kPointerSize;
+  static const int kIsolate = kFramePointer - kSystemPointerSize;
+  static const int kDirectCall = kIsolate - kSystemPointerSize;
+  static const int kNumOutputRegisters = kDirectCall - kSystemPointerSize;
+  static const int kRegisterOutput = kNumOutputRegisters - kSystemPointerSize;
+  static const int kInputEnd = kRegisterOutput - kSystemPointerSize;
+  static const int kInputStart = kInputEnd - kSystemPointerSize;
+  static const int kStartIndex = kInputStart - kSystemPointerSize;
+  static const int kInputString = kStartIndex - kSystemPointerSize;
   // When adding local variables remember to push space for them in
   // the frame in GetCode.
-  static const int kSuccessfulCaptures = kInputString - kPointerSize;
-  static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
+  static const int kSuccessfulCaptures = kInputString - kSystemPointerSize;
+  static const int kStringStartMinusOne =
+      kSuccessfulCaptures - kSystemPointerSize;
   static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
+  // Stores the initial value of the regexp stack pointer in a
+  // position-independent representation (in case the regexp stack grows and
+  // thus moves).
+  static const int kRegExpStackBasePointer =
+      kBacktrackCount - kSystemPointerSize;
+
   // First register address. Following registers are below it on the stack.
-  static const int kRegisterZero = kBacktrackCount - kSystemPointerSize;
+  static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
 
   // Initial size of code buffer.
   static const int kRegExpCodeSize = 1024;
@@ -144,27 +146,27 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
 
   // Register holding the current input position as negative offset from
   // the end of the string.
-  inline Register current_input_offset() { return a6; }
+  static constexpr Register current_input_offset() { return a6; }
 
   // The register containing the current character after LoadCurrentCharacter.
-  inline Register current_character() { return a7; }
+  static constexpr Register current_character() { return a7; }
 
   // Register holding address of the end of the input string.
-  inline Register end_of_input_address() { return t2; }
+  static constexpr Register end_of_input_address() { return t2; }
 
   // Register holding the frame address. Local variables, parameters and
   // regexp registers are addressed relative to this.
-  inline Register frame_pointer() { return fp; }
+  static constexpr Register frame_pointer() { return fp; }
 
   // The register containing the backtrack stack top. Provides a meaningful
   // name to the register.
-  inline Register backtrack_stackpointer() { return t0; }
+  static constexpr Register backtrack_stackpointer() { return t0; }
 
   // Register holding pointer to the current code object.
-  inline Register code_pointer() { return a5; }
+  static constexpr Register code_pointer() { return a5; }
 
   // Byte size of chars in the string to match (decided by the Mode argument).
-  inline int char_size() { return static_cast<int>(mode_); }
+  inline int char_size() const { return static_cast<int>(mode_); }
 
   // Equivalent to a conditional branch to the label, unless the label
   // is nullptr, in which case it is a conditional Backtrack.
@@ -190,19 +192,25 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   // and increments it by a word size.
   inline void Pop(Register target);
 
+  void LoadRegExpStackPointerFromMemory(Register dst);
+  void StoreRegExpStackPointerToMemory(Register src, Register scratch);
+  void PushRegExpBasePointer(Register scratch1, Register scratch2);
+  void PopRegExpBasePointer(Register scratch1, Register scratch2);
+
   Isolate* isolate() const { return masm_->isolate(); }
 
-  MacroAssembler* masm_;
+  const std::unique_ptr<MacroAssembler> masm_;
+  const NoRootArrayScope no_root_array_scope_;
 
   // Which mode to generate code for (Latin1 or UC16).
-  Mode mode_;
+  const Mode mode_;
 
   // One greater than maximal register index actually used.
   int num_registers_;
 
   // Number of registers to output at the end (the saved registers
   // are always 0..num_saved_registers_-1).
-  int num_saved_registers_;
+  const int num_saved_registers_;
 
   // Labels used internally.
   Label entry_label_;