MIPS: Move stack unwinding logic into the runtime.

Port 4acbc93d

BUG=

Review URL: https://codereview.chromium.org/974873002

Cr-Commit-Position: refs/heads/master@{#26967}

src/mips/code-stubs-mips.cc

@@ -1036,6 +1036,59 @@ void CEntryStub::GenerateAheadOfTime(Isolate* isolate) {
 }
 
 
+static void ThrowPendingException(MacroAssembler* masm) {
+  Isolate* isolate = masm->isolate();
+
+  ExternalReference pending_handler_context_address(
+      Isolate::kPendingHandlerContextAddress, isolate);
+  ExternalReference pending_handler_code_address(
+      Isolate::kPendingHandlerCodeAddress, isolate);
+  ExternalReference pending_handler_offset_address(
+      Isolate::kPendingHandlerOffsetAddress, isolate);
+  ExternalReference pending_handler_fp_address(
+      Isolate::kPendingHandlerFPAddress, isolate);
+  ExternalReference pending_handler_sp_address(
+      Isolate::kPendingHandlerSPAddress, isolate);
+
+  // Ask the runtime for help to determine the handler. This will set v0 to
+  // contain the current pending exception, don't clobber it.
+  ExternalReference find_handler(Runtime::kFindExceptionHandler, isolate);
+  {
+    FrameScope scope(masm, StackFrame::MANUAL);
+    __ PrepareCallCFunction(3, 0, a0);
+    __ mov(a0, zero_reg);
+    __ mov(a1, zero_reg);
+    __ li(a2, Operand(ExternalReference::isolate_address(isolate)));
+    __ CallCFunction(find_handler, 3);
+  }
+
+  // Retrieve the handler context, SP and FP.
+  __ li(cp, Operand(pending_handler_context_address));
+  __ lw(cp, MemOperand(cp));
+  __ li(sp, Operand(pending_handler_sp_address));
+  __ lw(sp, MemOperand(sp));
+  __ li(fp, Operand(pending_handler_fp_address));
+  __ lw(fp, MemOperand(fp));
+
+  // If the handler is a JS frame, restore the context to the frame.
+  // (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
+  // or cp.
+  Label zero;
+  __ Branch(&zero, eq, cp, Operand(zero_reg));
+  __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  __ bind(&zero);
+
+  // Compute the handler entry address and jump to it.
+  __ li(a1, Operand(pending_handler_code_address));
+  __ lw(a1, MemOperand(a1));
+  __ li(a2, Operand(pending_handler_offset_address));
+  __ lw(a2, MemOperand(a2));
+  __ Addu(a1, a1, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ Addu(t9, a1, a2);
+  __ Jump(t9);
+}
+
+
 void CEntryStub::Generate(MacroAssembler* masm) {
   // Called from JavaScript; parameters are on stack as if calling JS function
   // a0: number of arguments including receiver
@@ -1121,13 +1174,12 @@ void CEntryStub::Generate(MacroAssembler* masm) {
   __ LoadRoot(t0, Heap::kExceptionRootIndex);
   __ Branch(&exception_returned, eq, t0, Operand(v0));
 
-  ExternalReference pending_exception_address(
-      Isolate::kPendingExceptionAddress, isolate());
-
   // Check that there is no pending exception, otherwise we
   // should have returned the exception sentinel.
   if (FLAG_debug_code) {
     Label okay;
+    ExternalReference pending_exception_address(
+        Isolate::kPendingExceptionAddress, isolate());
     __ li(a2, Operand(pending_exception_address));
     __ lw(a2, MemOperand(a2));
     __ LoadRoot(t0, Heap::kTheHoleValueRootIndex);
@@ -1146,26 +1198,7 @@ void CEntryStub::Generate(MacroAssembler* masm) {
 
   // Handling of exception.
   __ bind(&exception_returned);
-
-  // Retrieve the pending exception.
-  __ li(a2, Operand(pending_exception_address));
-  __ lw(v0, MemOperand(a2));
-
-  // Clear the pending exception.
-  __ li(a3, Operand(isolate()->factory()->the_hole_value()));
-  __ sw(a3, MemOperand(a2));
-
-  // Special handling of termination exceptions which are uncatchable
-  // by javascript code.
-  Label throw_termination_exception;
-  __ LoadRoot(t0, Heap::kTerminationExceptionRootIndex);
-  __ Branch(&throw_termination_exception, eq, v0, Operand(t0));
-
-  // Handle normal exception.
-  __ Throw(v0);
-
-  __ bind(&throw_termination_exception);
-  __ ThrowUncatchable(v0);
+  ThrowPendingException(masm);
 }
 
 
@@ -2338,17 +2371,9 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   __ lw(v0, MemOperand(a2, 0));
   __ Branch(&runtime, eq, v0, Operand(a1));
 
-  __ sw(a1, MemOperand(a2, 0));  // Clear pending exception.
-
-  // Check if the exception is a termination. If so, throw as uncatchable.
-  __ LoadRoot(a0, Heap::kTerminationExceptionRootIndex);
-  Label termination_exception;
-  __ Branch(&termination_exception, eq, v0, Operand(a0));
-
-  __ Throw(v0);
-
-  __ bind(&termination_exception);
-  __ ThrowUncatchable(v0);
+  // For exception, throw the exception again.
+  __ EnterExitFrame(false);
+  ThrowPendingException(masm);
 
   __ bind(&failure);
   // For failure and exception return null.

src/mips/macro-assembler-mips.cc

@@ -3270,101 +3270,6 @@ void MacroAssembler::PopTryHandler() {
 }
 
 
-void MacroAssembler::JumpToHandlerEntry() {
-  // Compute the handler entry address and jump to it.  The handler table is
-  // a fixed array of (smi-tagged) code offsets.
-  // v0 = exception, a1 = code object, a2 = state.
-  lw(a3, FieldMemOperand(a1, Code::kHandlerTableOffset));  // Handler table.
-  Addu(a3, a3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  srl(a2, a2, StackHandler::kKindWidth);  // Handler index.
-  sll(a2, a2, kPointerSizeLog2);
-  Addu(a2, a3, a2);
-  lw(a2, MemOperand(a2));  // Smi-tagged offset.
-  Addu(a1, a1, Operand(Code::kHeaderSize - kHeapObjectTag));  // Code start.
-  sra(t9, a2, kSmiTagSize);
-  Addu(t9, t9, a1);
-  Jump(t9);  // Jump.
-}
-
-
-void MacroAssembler::Throw(Register value) {
-  // Adjust this code if not the case.
-  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
-  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
-
-  // The exception is expected in v0.
-  Move(v0, value);
-
-  // Drop the stack pointer to the top of the top handler.
-  li(a3, Operand(ExternalReference(Isolate::kHandlerAddress,
-                                   isolate())));
-  lw(sp, MemOperand(a3));
-
-  // Restore the next handler.
-  pop(a2);
-  sw(a2, MemOperand(a3));
-
-  // Get the code object (a1) and state (a2).  Restore the context and frame
-  // pointer.
-  MultiPop(a1.bit() | a2.bit() | cp.bit() | fp.bit());
-
-  // If the handler is a JS frame, restore the context to the frame.
-  // (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
-  // or cp.
-  Label done;
-  Branch(&done, eq, cp, Operand(zero_reg));
-  sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
-  bind(&done);
-
-  JumpToHandlerEntry();
-}
-
-
-void MacroAssembler::ThrowUncatchable(Register value) {
-  // Adjust this code if not the case.
-  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
-
-  // The exception is expected in v0.
-  if (!value.is(v0)) {
-    mov(v0, value);
-  }
-  // Drop the stack pointer to the top of the top stack handler.
-  li(a3, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
-  lw(sp, MemOperand(a3));
-
-  // Unwind the handlers until the ENTRY handler is found.
-  Label fetch_next, check_kind;
-  jmp(&check_kind);
-  bind(&fetch_next);
-  lw(sp, MemOperand(sp, StackHandlerConstants::kNextOffset));
-
-  bind(&check_kind);
-  STATIC_ASSERT(StackHandler::JS_ENTRY == 0);
-  lw(a2, MemOperand(sp, StackHandlerConstants::kStateOffset));
-  And(a2, a2, Operand(StackHandler::KindField::kMask));
-  Branch(&fetch_next, ne, a2, Operand(zero_reg));
-
-  // Set the top handler address to next handler past the top ENTRY handler.
-  pop(a2);
-  sw(a2, MemOperand(a3));
-
-  // Get the code object (a1) and state (a2).  Clear the context and frame
-  // pointer (0 was saved in the handler).
-  MultiPop(a1.bit() | a2.bit() | cp.bit() | fp.bit());
-
-  JumpToHandlerEntry();
-}
-
-
 void MacroAssembler::Allocate(int object_size,
                               Register result,
                               Register scratch1,

src/mips/macro-assembler-mips.h

@@ -970,13 +970,6 @@ class MacroAssembler: public Assembler {
   // Must preserve the result register.
   void PopTryHandler();
 
-  // Passes thrown value to the handler of top of the try handler chain.
-  void Throw(Register value);
-
-  // Propagates an uncatchable exception to the top of the current JS stack's
-  // handler chain.
-  void ThrowUncatchable(Register value);
-
   // Copies a fixed number of fields of heap objects from src to dst.
   void CopyFields(Register dst, Register src, RegList temps, int field_count);
 
@@ -1654,10 +1647,6 @@ const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
                           Register bitmap_reg,
                           Register mask_reg);
 
-  // Helper for throwing exceptions.  Compute a handler address and jump to
-  // it.  See the implementation for register usage.
-  void JumpToHandlerEntry();
-
   // Compute memory operands for safepoint stack slots.
   static int SafepointRegisterStackIndex(int reg_code);
   MemOperand SafepointRegisterSlot(Register reg);

src/mips64/code-stubs-mips64.cc

@@ -1032,6 +1032,59 @@ void CEntryStub::GenerateAheadOfTime(Isolate* isolate) {
 }
 
 
+static void ThrowPendingException(MacroAssembler* masm) {
+  Isolate* isolate = masm->isolate();
+
+  ExternalReference pending_handler_context_address(
+      Isolate::kPendingHandlerContextAddress, isolate);
+  ExternalReference pending_handler_code_address(
+      Isolate::kPendingHandlerCodeAddress, isolate);
+  ExternalReference pending_handler_offset_address(
+      Isolate::kPendingHandlerOffsetAddress, isolate);
+  ExternalReference pending_handler_fp_address(
+      Isolate::kPendingHandlerFPAddress, isolate);
+  ExternalReference pending_handler_sp_address(
+      Isolate::kPendingHandlerSPAddress, isolate);
+
+  // Ask the runtime for help to determine the handler. This will set v0 to
+  // contain the current pending exception, don't clobber it.
+  ExternalReference find_handler(Runtime::kFindExceptionHandler, isolate);
+  {
+    FrameScope scope(masm, StackFrame::MANUAL);
+    __ PrepareCallCFunction(3, 0, a0);
+    __ mov(a0, zero_reg);
+    __ mov(a1, zero_reg);
+    __ li(a2, Operand(ExternalReference::isolate_address(isolate)));
+    __ CallCFunction(find_handler, 3);
+  }
+
+  // Retrieve the handler context, SP and FP.
+  __ li(cp, Operand(pending_handler_context_address));
+  __ ld(cp, MemOperand(cp));
+  __ li(sp, Operand(pending_handler_sp_address));
+  __ ld(sp, MemOperand(sp));
+  __ li(fp, Operand(pending_handler_fp_address));
+  __ ld(fp, MemOperand(fp));
+
+  // If the handler is a JS frame, restore the context to the frame.
+  // (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
+  // or cp.
+  Label zero;
+  __ Branch(&zero, eq, cp, Operand(zero_reg));
+  __ sd(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  __ bind(&zero);
+
+  // Compute the handler entry address and jump to it.
+  __ li(a1, Operand(pending_handler_code_address));
+  __ ld(a1, MemOperand(a1));
+  __ li(a2, Operand(pending_handler_offset_address));
+  __ ld(a2, MemOperand(a2));
+  __ Daddu(a1, a1, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ Daddu(t9, a1, a2);
+  __ Jump(t9);
+}
+
+
 void CEntryStub::Generate(MacroAssembler* masm) {
   // Called from JavaScript; parameters are on stack as if calling JS function
   // a0: number of arguments including receiver
@@ -1116,13 +1169,12 @@ void CEntryStub::Generate(MacroAssembler* masm) {
   __ LoadRoot(a4, Heap::kExceptionRootIndex);
   __ Branch(&exception_returned, eq, a4, Operand(v0));
 
-  ExternalReference pending_exception_address(
-      Isolate::kPendingExceptionAddress, isolate());
-
   // Check that there is no pending exception, otherwise we
   // should have returned the exception sentinel.
   if (FLAG_debug_code) {
     Label okay;
+    ExternalReference pending_exception_address(
+        Isolate::kPendingExceptionAddress, isolate());
     __ li(a2, Operand(pending_exception_address));
     __ ld(a2, MemOperand(a2));
     __ LoadRoot(a4, Heap::kTheHoleValueRootIndex);
@@ -1141,26 +1193,7 @@ void CEntryStub::Generate(MacroAssembler* masm) {
 
   // Handling of exception.
   __ bind(&exception_returned);
-
-  // Retrieve the pending exception.
-  __ li(a2, Operand(pending_exception_address));
-  __ ld(v0, MemOperand(a2));
-
-  // Clear the pending exception.
-  __ li(a3, Operand(isolate()->factory()->the_hole_value()));
-  __ sd(a3, MemOperand(a2));
-
-  // Special handling of termination exceptions which are uncatchable
-  // by javascript code.
-  Label throw_termination_exception;
-  __ LoadRoot(a4, Heap::kTerminationExceptionRootIndex);
-  __ Branch(&throw_termination_exception, eq, v0, Operand(a4));
-
-  // Handle normal exception.
-  __ Throw(v0);
-
-  __ bind(&throw_termination_exception);
-  __ ThrowUncatchable(v0);
+  ThrowPendingException(masm);
 }
 
 
@@ -2374,17 +2407,9 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   __ ld(v0, MemOperand(a2, 0));
   __ Branch(&runtime, eq, v0, Operand(a1));
 
-  __ sd(a1, MemOperand(a2, 0));  // Clear pending exception.
-
-  // Check if the exception is a termination. If so, throw as uncatchable.
-  __ LoadRoot(a0, Heap::kTerminationExceptionRootIndex);
-  Label termination_exception;
-  __ Branch(&termination_exception, eq, v0, Operand(a0));
-
-  __ Throw(v0);
-
-  __ bind(&termination_exception);
-  __ ThrowUncatchable(v0);
+  // For exception, throw the exception again.
+  __ EnterExitFrame(false);
+  ThrowPendingException(masm);
 
   __ bind(&failure);
   // For failure and exception return null.

src/mips64/macro-assembler-mips64.cc

@@ -3261,101 +3261,6 @@ void MacroAssembler::PopTryHandler() {
 }
 
 
-void MacroAssembler::JumpToHandlerEntry() {
-  // Compute the handler entry address and jump to it.  The handler table is
-  // a fixed array of (smi-tagged) code offsets.
-  // v0 = exception, a1 = code object, a2 = state.
-  ld(a3, FieldMemOperand(a1, Code::kHandlerTableOffset));
-  Daddu(a3, a3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  dsrl(a2, a2, StackHandler::kKindWidth);  // Handler index.
-  dsll(a2, a2, kPointerSizeLog2);
-  Daddu(a2, a3, a2);
-  ld(a2, MemOperand(a2));  // Smi-tagged offset.
-  Daddu(a1, a1, Operand(Code::kHeaderSize - kHeapObjectTag));  // Code start.
-  dsra32(t9, a2, 0);
-  Daddu(t9, t9, a1);
-  Jump(t9);  // Jump.
-}
-
-
-void MacroAssembler::Throw(Register value) {
-  // Adjust this code if not the case.
-  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
-  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
-
-  // The exception is expected in v0.
-  Move(v0, value);
-
-  // Drop the stack pointer to the top of the top handler.
-  li(a3, Operand(ExternalReference(Isolate::kHandlerAddress,
-                                   isolate())));
-  ld(sp, MemOperand(a3));
-
-  // Restore the next handler.
-  pop(a2);
-  sd(a2, MemOperand(a3));
-
-  // Get the code object (a1) and state (a2).  Restore the context and frame
-  // pointer.
-  MultiPop(a1.bit() | a2.bit() | cp.bit() | fp.bit());
-
-  // If the handler is a JS frame, restore the context to the frame.
-  // (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
-  // or cp.
-  Label done;
-  Branch(&done, eq, cp, Operand(zero_reg));
-  sd(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
-  bind(&done);
-
-  JumpToHandlerEntry();
-}
-
-
-void MacroAssembler::ThrowUncatchable(Register value) {
-  // Adjust this code if not the case.
-  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
-
-  // The exception is expected in v0.
-  if (!value.is(v0)) {
-    mov(v0, value);
-  }
-  // Drop the stack pointer to the top of the top stack handler.
-  li(a3, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
-  ld(sp, MemOperand(a3));
-
-  // Unwind the handlers until the ENTRY handler is found.
-  Label fetch_next, check_kind;
-  jmp(&check_kind);
-  bind(&fetch_next);
-  ld(sp, MemOperand(sp, StackHandlerConstants::kNextOffset));
-
-  bind(&check_kind);
-  STATIC_ASSERT(StackHandler::JS_ENTRY == 0);
-  ld(a2, MemOperand(sp, StackHandlerConstants::kStateOffset));
-  And(a2, a2, Operand(StackHandler::KindField::kMask));
-  Branch(&fetch_next, ne, a2, Operand(zero_reg));
-
-  // Set the top handler address to next handler past the top ENTRY handler.
-  pop(a2);
-  sd(a2, MemOperand(a3));
-
-  // Get the code object (a1) and state (a2).  Clear the context and frame
-  // pointer (0 was saved in the handler).
-  MultiPop(a1.bit() | a2.bit() | cp.bit() | fp.bit());
-
-  JumpToHandlerEntry();
-}
-
-
 void MacroAssembler::Allocate(int object_size,
                               Register result,
                               Register scratch1,

src/mips64/macro-assembler-mips64.h

@@ -1000,13 +1000,6 @@ class MacroAssembler: public Assembler {
   // Must preserve the result register.
   void PopTryHandler();
 
-  // Passes thrown value to the handler of top of the try handler chain.
-  void Throw(Register value);
-
-  // Propagates an uncatchable exception to the top of the current JS stack's
-  // handler chain.
-  void ThrowUncatchable(Register value);
-
   // Copies a fixed number of fields of heap objects from src to dst.
   void CopyFields(Register dst, Register src, RegList temps, int field_count);
 
@@ -1723,10 +1716,6 @@ const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
                           Register bitmap_reg,
                           Register mask_reg);
 
-  // Helper for throwing exceptions.  Compute a handler address and jump to
-  // it.  See the implementation for register usage.
-  void JumpToHandlerEntry();
-
   // Compute memory operands for safepoint stack slots.
   static int SafepointRegisterStackIndex(int reg_code);
   MemOperand SafepointRegisterSlot(Register reg);