Revert "Add a level of indirection to exception handler addresses."

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index 2d4f4cdb2f551966f55b646299f27c3c014400c9..bb4f71b3893eafdd23b9ba9d43f5886379781b65 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -725,105 +725,84 @@ void MacroAssembler::LeaveApiExitFrame() {
 
 
 void MacroAssembler::PushTryHandler(CodeLocation try_location,
-                                    HandlerType type,
-                                    int handler_index) {
+                                    HandlerType type) {
   // 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);
-
-  // We will build up the handler from the bottom by pushing on the stack.
-  // First compute the state and push the frame pointer and context.
-  unsigned state = StackHandler::OffsetField::encode(handler_index);
+  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
+  // The pc (return address) is already on TOS.
   if (try_location == IN_JAVASCRIPT) {
+    if (type == TRY_CATCH_HANDLER) {
+      push(Immediate(StackHandler::TRY_CATCH));
+    } else {
+      push(Immediate(StackHandler::TRY_FINALLY));
+    }
     push(ebp);
     push(esi);
-    state |= (type == TRY_CATCH_HANDLER)
-        ? StackHandler::KindField::encode(StackHandler::TRY_CATCH)
-        : StackHandler::KindField::encode(StackHandler::TRY_FINALLY);
   } else {
     ASSERT(try_location == IN_JS_ENTRY);
-    // The frame pointer does not point to a JS frame so we save NULL for
-    // ebp. We expect the code throwing an exception to check ebp before
-    // dereferencing it to restore the context.
+    // The frame pointer does not point to a JS frame so we save NULL
+    // for ebp. We expect the code throwing an exception to check ebp
+    // before dereferencing it to restore the context.
+    push(Immediate(StackHandler::ENTRY));
     push(Immediate(0));  // NULL frame pointer.
     push(Immediate(Smi::FromInt(0)));  // No context.
-    state |= StackHandler::KindField::encode(StackHandler::ENTRY);
   }
-
-  // Push the state and the code object.
-  push(Immediate(state));
-  push(CodeObject());
-
-  // Link the current handler as the next handler.
-  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
-  push(Operand::StaticVariable(handler_address));
-  // Set this new handler as the current one.
-  mov(Operand::StaticVariable(handler_address), esp);
+  // Save the current handler as the next handler.
+  push(Operand::StaticVariable(ExternalReference(Isolate::kHandlerAddress,
+                                                 isolate())));
+  // Link this handler as the new current one.
+  mov(Operand::StaticVariable(ExternalReference(Isolate::kHandlerAddress,
+                                                isolate())),
+      esp);
 }
 
 
 void MacroAssembler::PopTryHandler() {
   STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
-  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
-  pop(Operand::StaticVariable(handler_address));
+  pop(Operand::StaticVariable(ExternalReference(Isolate::kHandlerAddress,
+                                                isolate())));
   add(esp, Immediate(StackHandlerConstants::kSize - kPointerSize));
 }
 
 
-void MacroAssembler::JumpToHandlerEntry() {
-  // Compute the handler entry address and jump to it.  The handler table is
-  // a fixed array of (smi-tagged) code offsets.
-  // eax = exception, edi = code object, edx = state.
-  mov(ebx, FieldOperand(edi, Code::kHandlerTableOffset));
-  shr(edx, StackHandler::kKindWidth);
-  mov(edx, FieldOperand(ebx, edx, times_4, FixedArray::kHeaderSize));
-  SmiUntag(edx);
-  lea(edi, FieldOperand(edi, edx, times_1, Code::kHeaderSize));
-  jmp(edi);
-}
-
-
 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 eax.
+  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
+  // eax must hold the exception.
   if (!value.is(eax)) {
     mov(eax, value);
   }
-  // Drop the stack pointer to the top of the top handler.
-  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
-  mov(esp, Operand::StaticVariable(handler_address));
-  // Restore the next handler.
-  pop(Operand::StaticVariable(handler_address));
 
-  // Remove the code object and state, compute the handler address in edi.
-  pop(edi);  // Code object.
-  pop(edx);  // Index and state.
+  // Drop the sp to the top of the handler.
+  ExternalReference handler_address(Isolate::kHandlerAddress,
+                                    isolate());
+  mov(esp, Operand::StaticVariable(handler_address));
 
-  // Restore the context and frame pointer.
+  // Restore next handler, context, and frame pointer; discard handler state.
+  pop(Operand::StaticVariable(handler_address));
   pop(esi);  // Context.
   pop(ebp);  // Frame pointer.
+  pop(edx);  // State.
 
   // If the handler is a JS frame, restore the context to the frame.
-  // (kind == ENTRY) == (ebp == 0) == (esi == 0), so we could test either
-  // ebp or esi.
+  // (edx == ENTRY) == (ebp == 0) == (esi == 0), so we could test any
+  // of them.
   Label skip;
-  test(esi, esi);
-  j(zero, &skip, Label::kNear);
+  cmp(edx, Immediate(StackHandler::ENTRY));
+  j(equal, &skip, Label::kNear);
   mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
   bind(&skip);
 
-  JumpToHandlerEntry();
+  ret(0);
 }
 
 
@@ -832,10 +811,10 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
   // 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);
+  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
 
   // The exception is expected in eax.
   if (type == OUT_OF_MEMORY) {
@@ -864,23 +843,20 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
   mov(esp, Operand(esp, StackHandlerConstants::kNextOffset));
 
   bind(&check_kind);
-  STATIC_ASSERT(StackHandler::ENTRY == 0);
-  test(Operand(esp, StackHandlerConstants::kStateOffset),
-       Immediate(StackHandler::KindField::kMask));
-  j(not_zero, &fetch_next);
+  cmp(Operand(esp, StackHandlerConstants::kStateOffset),
+      Immediate(StackHandler::ENTRY));
+  j(not_equal, &fetch_next);
 
   // Set the top handler address to next handler past the top ENTRY handler.
   pop(Operand::StaticVariable(handler_address));
 
-  // Remove the code object and state, compute the handler address in edi.
-  pop(edi);  // Code object.
-  pop(edx);  // Index and state.
-
-  // Clear the context pointer and frame pointer (0 was saved in the handler).
+  // Clear the context and frame pointer (0 was saved in the handler), and
+  // discard the state.
   pop(esi);
   pop(ebp);
+  pop(edx);  // State.
 
-  JumpToHandlerEntry();
+  ret(0);
 }