[runtime] Unify and simplify how frames are marked

src/arm/macro-assembler-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 737 matching lines @@
   push(lr);
   StoreBufferOverflowStub store_buffer_overflow(isolate(), fp_mode);
   CallStub(&store_buffer_overflow);
   pop(lr);
   bind(&done);
   if (and_then == kReturnAtEnd) {
     Ret();
   }
 }
 
+void MacroAssembler::PushCommonFrame(Register marker_reg) {
+  if (marker_reg.is_valid()) {
+    if (FLAG_enable_embedded_constant_pool) {
+      if (marker_reg.code() > pp.code()) {
+        stm(db_w, sp, pp.bit() | fp.bit() | lr.bit());
+        add(fp, sp, Operand(kPointerSize));
+        Push(marker_reg);
+      } else {
+        stm(db_w, sp, marker_reg.bit() | pp.bit() | fp.bit() | lr.bit());
+        add(fp, sp, Operand(2 * kPointerSize));
+      }
+    } else {
+      if (marker_reg.code() > fp.code()) {
+        stm(db_w, sp, fp.bit() | lr.bit());
+        mov(fp, Operand(sp));
+        Push(marker_reg);
+      } else {
+        stm(db_w, sp, marker_reg.bit() | fp.bit() | lr.bit());
+        add(fp, sp, Operand(kPointerSize));
+      }
+    }
+  } else {
+    stm(db_w, sp, (FLAG_enable_embedded_constant_pool ? pp.bit() : 0) |
+                      fp.bit() | lr.bit());
+    add(fp, sp, Operand(FLAG_enable_embedded_constant_pool ? kPointerSize : 0));
+  }
+}
 
-void MacroAssembler::PushFixedFrame(Register marker_reg) {
-  DCHECK(!marker_reg.is_valid() || marker_reg.code() < cp.code());
-  stm(db_w, sp, (marker_reg.is_valid() ? marker_reg.bit() : 0) | cp.bit() |
+void MacroAssembler::PopCommonFrame(Register marker_reg) {
+  if (marker_reg.is_valid()) {
+    if (FLAG_enable_embedded_constant_pool) {
+      if (marker_reg.code() > pp.code()) {
+        pop(marker_reg);
+        ldm(ia_w, sp, pp.bit() | fp.bit() | lr.bit());
+      } else {
+        ldm(ia_w, sp, marker_reg.bit() | pp.bit() | fp.bit() | lr.bit());
+      }
+    } else {
+      if (marker_reg.code() > fp.code()) {
+        pop(marker_reg);
+        ldm(ia_w, sp, fp.bit() | lr.bit());
+      } else {
+        ldm(ia_w, sp, marker_reg.bit() | fp.bit() | lr.bit());
+      }
+    }
+  } else {
+    ldm(ia_w, sp, (FLAG_enable_embedded_constant_pool ? pp.bit() : 0) |
+                      fp.bit() | lr.bit());
+  }
+}
+
+void MacroAssembler::PushStandardFrame(Register function_reg) {
+  DCHECK(!function_reg.is_valid() || function_reg.code() < cp.code());
+  stm(db_w, sp, (function_reg.is_valid() ? function_reg.bit() : 0) | cp.bit() |
                     (FLAG_enable_embedded_constant_pool ? pp.bit() : 0) |
                     fp.bit() | lr.bit());
+  int offset = -StandardFrameConstants::kContextOffset;
+  offset += function_reg.is_valid() ? kPointerSize : 0;
+  add(fp, sp, Operand(offset));
 }
 
 
-void MacroAssembler::PopFixedFrame(Register marker_reg) {
-  DCHECK(!marker_reg.is_valid() || marker_reg.code() < cp.code());
-  ldm(ia_w, sp, (marker_reg.is_valid() ? marker_reg.bit() : 0) | cp.bit() |
-                    (FLAG_enable_embedded_constant_pool ? pp.bit() : 0) |
-                    fp.bit() | lr.bit());
-}
-
-
 // Push and pop all registers that can hold pointers.
 void MacroAssembler::PushSafepointRegisters() {
   // Safepoints expect a block of contiguous register values starting with r0.
   // except when FLAG_enable_embedded_constant_pool, which omits pp.
   DCHECK(kSafepointSavedRegisters ==
          (FLAG_enable_embedded_constant_pool
               ? ((1 << (kNumSafepointSavedRegisters + 1)) - 1) & ~pp.bit()
               : (1 << kNumSafepointSavedRegisters) - 1));
   // Safepoints expect a block of kNumSafepointRegisters values on the
   // stack, so adjust the stack for unsaved registers.
@@ skipping 282 matching lines @@
 }
 
 
 void MacroAssembler::LoadConstantPoolPointerRegister() {
   DCHECK(FLAG_enable_embedded_constant_pool);
   int entry_offset = pc_offset() + Instruction::kPCReadOffset;
   sub(ip, pc, Operand(entry_offset));
   LoadConstantPoolPointerRegisterFromCodeTargetAddress(ip);
 }
 
-
-void MacroAssembler::StubPrologue() {
-  PushFixedFrame();
-  Push(Smi::FromInt(StackFrame::STUB));
-  // Adjust FP to point to saved FP.
-  add(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
+void MacroAssembler::StubPrologue(StackFrame::Type type) {
+  mov(ip, Operand(Smi::FromInt(type)));
+  PushCommonFrame(ip);
   if (FLAG_enable_embedded_constant_pool) {
     LoadConstantPoolPointerRegister();
     set_constant_pool_available(true);
   }
 }
 
-
 void MacroAssembler::Prologue(bool code_pre_aging) {
   { PredictableCodeSizeScope predictible_code_size_scope(
         this, kNoCodeAgeSequenceLength);
     // The following three instructions must remain together and unmodified
     // for code aging to work properly.
     if (code_pre_aging) {
       // Pre-age the code.
       Code* stub = Code::GetPreAgedCodeAgeStub(isolate());
       add(r0, pc, Operand(-8));
       ldr(pc, MemOperand(pc, -4));
       emit_code_stub_address(stub);
     } else {
-      PushFixedFrame(r1);
+      PushStandardFrame(r1);
       nop(ip.code());
-      // Adjust FP to point to saved FP.
-      add(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
     }
   }
   if (FLAG_enable_embedded_constant_pool) {
     LoadConstantPoolPointerRegister();
     set_constant_pool_available(true);
   }
 }
 
 
 void MacroAssembler::EmitLoadTypeFeedbackVector(Register vector) {
   ldr(vector, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   ldr(vector, FieldMemOperand(vector, JSFunction::kSharedFunctionInfoOffset));
   ldr(vector,
       FieldMemOperand(vector, SharedFunctionInfo::kFeedbackVectorOffset));
 }
 
 
 void MacroAssembler::EnterFrame(StackFrame::Type type,
                                 bool load_constant_pool_pointer_reg) {
   // r0-r3: preserved
-  PushFixedFrame();
+  mov(ip, Operand(Smi::FromInt(type)));
+  PushCommonFrame(ip);
   if (FLAG_enable_embedded_constant_pool && load_constant_pool_pointer_reg) {
     LoadConstantPoolPointerRegister();
   }
-  mov(ip, Operand(Smi::FromInt(type)));
-  push(ip);
-  mov(ip, Operand(CodeObject()));
-  push(ip);
-  // Adjust FP to point to saved FP.
-  add(fp, sp,
-      Operand(StandardFrameConstants::kFixedFrameSizeFromFp + kPointerSize));
+  if (type == StackFrame::INTERNAL) {
+    mov(ip, Operand(CodeObject()));
+    push(ip);
+  }
 }
 
 
 int MacroAssembler::LeaveFrame(StackFrame::Type type) {
   // r0: preserved
   // r1: preserved
   // r2: preserved
 
   // Drop the execution stack down to the frame pointer and restore
   // the caller frame pointer, return address and constant pool pointer
@@ skipping 10 matching lines @@
   }
   return frame_ends;
 }
 
 
 void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space) {
   // Set up the frame structure on the stack.
   DCHECK_EQ(2 * kPointerSize, ExitFrameConstants::kCallerSPDisplacement);
   DCHECK_EQ(1 * kPointerSize, ExitFrameConstants::kCallerPCOffset);
   DCHECK_EQ(0 * kPointerSize, ExitFrameConstants::kCallerFPOffset);
-  Push(lr, fp);
-  mov(fp, Operand(sp));  // Set up new frame pointer.
+  mov(ip, Operand(Smi::FromInt(StackFrame::EXIT)));
+  PushCommonFrame(ip);
   // Reserve room for saved entry sp and code object.
-  sub(sp, sp, Operand(ExitFrameConstants::kFrameSize));
+  sub(sp, fp, Operand(ExitFrameConstants::kFixedFrameSizeFromFp));
   if (emit_debug_code()) {
     mov(ip, Operand::Zero());
     str(ip, MemOperand(fp, ExitFrameConstants::kSPOffset));
   }
   if (FLAG_enable_embedded_constant_pool) {
     str(pp, MemOperand(fp, ExitFrameConstants::kConstantPoolOffset));
   }
   mov(ip, Operand(CodeObject()));
   str(ip, MemOperand(fp, ExitFrameConstants::kCodeOffset));
 
@@ skipping 61 matching lines @@
 
 
 void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
                                     bool restore_context,
                                     bool argument_count_is_length) {
   ConstantPoolUnavailableScope constant_pool_unavailable(this);
 
   // Optionally restore all double registers.
   if (save_doubles) {
     // Calculate the stack location of the saved doubles and restore them.
-    const int offset = ExitFrameConstants::kFrameSize;
+    const int offset = ExitFrameConstants::kFixedFrameSizeFromFp;
     sub(r3, fp,
         Operand(offset + DwVfpRegister::kMaxNumRegisters * kDoubleSize));
     RestoreFPRegs(r3, ip);
   }
 
   // Clear top frame.
   mov(r3, Operand::Zero());
   mov(ip, Operand(ExternalReference(Isolate::kCEntryFPAddress, isolate())));
   str(r3, MemOperand(ip));
 
@@ skipping 308 matching lines @@
 
 void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
                                             Register scratch,
                                             Label* miss) {
   Label same_contexts;
 
   DCHECK(!holder_reg.is(scratch));
   DCHECK(!holder_reg.is(ip));
   DCHECK(!scratch.is(ip));
 
-  // Load current lexical context from the stack frame.
-  ldr(scratch, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  // Load current lexical context from the active StandardFrame, which
+  // my require crawling past STUB frames.

[titzer, 2016/03/07 10:48:43]

s/my/may

[danno, 2016/03/08 07:04:44]

Done.

+  Label load_context;
+  Label has_context;
+  DCHECK(!ip.is(scratch));
+  mov(ip, fp);
+  bind(&load_context);
+  ldr(scratch, MemOperand(ip, CommonFrameConstants::kContextOrFrameTypeOffset));
+  JumpIfNotSmi(scratch, &has_context);
+  ldr(ip, MemOperand(ip, CommonFrameConstants::kCallerFPOffset));
+  b(&load_context);
+  bind(&has_context);
+
   // In debug mode, make sure the lexical context is set.
 #ifdef DEBUG
   cmp(scratch, Operand::Zero());
   Check(ne, kWeShouldNotHaveAnEmptyLexicalContext);
 #endif
 
   // Load the native context of the current context.
   ldr(scratch, ContextMemOperand(scratch, Context::NATIVE_CONTEXT_INDEX));
 
   // Check the context is a native context.
@@ skipping 2095 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM