PPC: [runtime] Unify and simplify how frames are marked

src/ppc/macro-assembler-ppc.cc

Index: src/ppc/macro-assembler-ppc.cc
diff --git a/src/ppc/macro-assembler-ppc.cc b/src/ppc/macro-assembler-ppc.cc
index 2e3fafa09df51a87bc6cb251d92e96a972082abc..40a4524824be06e7b575016e5cd367096f8a566c 100644
--- a/src/ppc/macro-assembler-ppc.cc
+++ b/src/ppc/macro-assembler-ppc.cc
@@ -591,42 +591,69 @@ void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
   }
 }
 
-
-void MacroAssembler::PushFixedFrame(Register marker_reg) {
+void MacroAssembler::PushCommonFrame(Register marker_reg) {
+  int fp_delta = 0;
   mflr(r0);
   if (FLAG_enable_embedded_constant_pool) {
     if (marker_reg.is_valid()) {
-      Push(r0, fp, kConstantPoolRegister, cp, marker_reg);
+      Push(r0, fp, kConstantPoolRegister, marker_reg);
+      fp_delta = 2;
     } else {
-      Push(r0, fp, kConstantPoolRegister, cp);
+      Push(r0, fp, kConstantPoolRegister);
+      fp_delta = 1;
     }
   } else {
     if (marker_reg.is_valid()) {
-      Push(r0, fp, cp, marker_reg);
+      Push(r0, fp, marker_reg);
+      fp_delta = 1;
     } else {
-      Push(r0, fp, cp);
+      Push(r0, fp);
+      fp_delta = 0;
     }
   }
+  addi(fp, sp, Operand(fp_delta * kPointerSize));
 }
 
-
-void MacroAssembler::PopFixedFrame(Register marker_reg) {
+void MacroAssembler::PopCommonFrame(Register marker_reg) {
   if (FLAG_enable_embedded_constant_pool) {
     if (marker_reg.is_valid()) {
-      Pop(r0, fp, kConstantPoolRegister, cp, marker_reg);
+      Pop(r0, fp, kConstantPoolRegister, marker_reg);
     } else {
-      Pop(r0, fp, kConstantPoolRegister, cp);
+      Pop(r0, fp, kConstantPoolRegister);
     }
   } else {
     if (marker_reg.is_valid()) {
-      Pop(r0, fp, cp, marker_reg);
+      Pop(r0, fp, marker_reg);
     } else {
-      Pop(r0, fp, cp);
+      Pop(r0, fp);
     }
   }
   mtlr(r0);
 }
 
+void MacroAssembler::PushStandardFrame(Register function_reg) {
+  int fp_delta = 0;
+  mflr(r0);
+  if (FLAG_enable_embedded_constant_pool) {
+    if (function_reg.is_valid()) {
+      Push(r0, fp, kConstantPoolRegister, cp, function_reg);
+      fp_delta = 3;
+    } else {
+      Push(r0, fp, kConstantPoolRegister, cp);
+      fp_delta = 2;
+    }
+  } else {
+    if (function_reg.is_valid()) {
+      Push(r0, fp, cp, function_reg);
+      fp_delta = 2;
+    } else {
+      Push(r0, fp, cp);
+      fp_delta = 1;
+    }
+  }
+  addi(fp, sp, Operand(fp_delta * kPointerSize));
+}
+
 void MacroAssembler::RestoreFrameStateForTailCall() {
   if (FLAG_enable_embedded_constant_pool) {
     LoadP(kConstantPoolRegister,
@@ -870,12 +897,10 @@ void MacroAssembler::LoadConstantPoolPointerRegister() {
   mov_label_addr(kConstantPoolRegister, ConstantPoolPosition());
 }
 
-
-void MacroAssembler::StubPrologue(Register base, int prologue_offset) {
-  LoadSmiLiteral(r11, Smi::FromInt(StackFrame::STUB));
-  PushFixedFrame(r11);
-  // Adjust FP to point to saved FP.
-  addi(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
+void MacroAssembler::StubPrologue(StackFrame::Type type, Register base,
+                                  int prologue_offset) {
+  LoadSmiLiteral(r11, Smi::FromInt(type));
+  PushCommonFrame(r11);
   if (FLAG_enable_embedded_constant_pool) {
     if (!base.is(no_reg)) {
       // base contains prologue address
@@ -911,9 +936,7 @@ void MacroAssembler::Prologue(bool code_pre_aging, Register base,
       }
     } else {
       // This matches the code found in GetNoCodeAgeSequence()
-      PushFixedFrame(r4);
-      // Adjust fp to point to saved fp.
-      addi(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
+      PushStandardFrame(r4);
       for (int i = 0; i < kNoCodeAgeSequenceNops; i++) {
         nop();
       }
@@ -938,20 +961,20 @@ void MacroAssembler::EmitLoadTypeFeedbackVector(Register vector) {
 void MacroAssembler::EnterFrame(StackFrame::Type type,
                                 bool load_constant_pool_pointer_reg) {
   if (FLAG_enable_embedded_constant_pool && load_constant_pool_pointer_reg) {
-    PushFixedFrame();
-    // This path should not rely on ip containing code entry.
+    // Push type explicitly so we can leverage the constant pool.
+    // This path cannot rely on ip containing code entry.
+    PushCommonFrame();
     LoadConstantPoolPointerRegister();
     LoadSmiLiteral(ip, Smi::FromInt(type));
     push(ip);
   } else {
     LoadSmiLiteral(ip, Smi::FromInt(type));
-    PushFixedFrame(ip);
+    PushCommonFrame(ip);
+  }
+  if (type == StackFrame::INTERNAL) {
+    mov(r0, Operand(CodeObject()));
+    push(r0);
   }
-  // Adjust FP to point to saved FP.
-  addi(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
-
-  mov(r0, Operand(CodeObject()));
-  push(r0);
 }
 
 
@@ -967,11 +990,8 @@ int MacroAssembler::LeaveFrame(StackFrame::Type type, int stack_adjustment) {
   LoadP(r0, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
   LoadP(ip, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   if (FLAG_enable_embedded_constant_pool) {
-    const int exitOffset = ExitFrameConstants::kConstantPoolOffset;
-    const int standardOffset = StandardFrameConstants::kConstantPoolOffset;
-    const int offset =
-        ((type == StackFrame::EXIT) ? exitOffset : standardOffset);
-    LoadP(kConstantPoolRegister, MemOperand(fp, offset));
+    LoadP(kConstantPoolRegister,
+          MemOperand(fp, StandardFrameConstants::kConstantPoolOffset));
   }
   mtlr(r0);
   frame_ends = pc_offset();
@@ -1008,12 +1028,10 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space) {
   // all of the pushes that have happened inside of V8
   // since we were called from C code
 
-  // replicate ARM frame - TODO make this more closely follow PPC ABI
-  mflr(r0);
-  Push(r0, fp);
-  mr(fp, sp);
+  LoadSmiLiteral(ip, Smi::FromInt(StackFrame::EXIT));
+  PushCommonFrame(ip);
   // Reserve room for saved entry sp and code object.
-  subi(sp, sp, Operand(ExitFrameConstants::kFrameSize));
+  subi(sp, fp, Operand(ExitFrameConstants::kFixedFrameSizeFromFp));
 
   if (emit_debug_code()) {
     li(r8, Operand::Zero());
@@ -1098,7 +1116,7 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
     // Calculate the stack location of the saved doubles and restore them.
     const int kNumRegs = kNumCallerSavedDoubles;
     const int offset =
-        (ExitFrameConstants::kFrameSize + kNumRegs * kDoubleSize);
+        (ExitFrameConstants::kFixedFrameSizeFromFp + kNumRegs * kDoubleSize);
     addi(r6, fp, Operand(-offset));
     MultiPopDoubles(kCallerSavedDoubles, r6);
   }
@@ -1477,8 +1495,20 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
   DCHECK(!holder_reg.is(ip));
   DCHECK(!scratch.is(ip));
 
-  // Load current lexical context from the stack frame.
-  LoadP(scratch, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  // Load current lexical context from the active StandardFrame, which
+  // may require crawling past STUB frames.
+  Label load_context;
+  Label has_context;
+  DCHECK(!ip.is(scratch));
+  mr(ip, fp);
+  bind(&load_context);
+  LoadP(scratch,
+        MemOperand(ip, CommonFrameConstants::kContextOrFrameTypeOffset));
+  JumpIfNotSmi(scratch, &has_context);
+  LoadP(ip, MemOperand(ip, CommonFrameConstants::kCallerFPOffset));
+  b(&load_context);
+  bind(&has_context);
+
 // In debug mode, make sure the lexical context is set.
 #ifdef DEBUG
   cmpi(scratch, Operand::Zero());