[turbofan] Unify referencing of stack slots

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index 27033d66e051e899022baa6ba02fcb30fa7f8d8a..4241a5e9824c35c341241975b3feb585df099030 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -7,6 +7,7 @@
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
+#include "src/compiler/osr.h"
 #include "src/ia32/assembler-ia32.h"
 #include "src/ia32/frames-ia32.h"
 #include "src/ia32/macro-assembler-ia32.h"
@@ -1260,34 +1261,22 @@ void CodeGenerator::AssembleDeoptimizerCall(
 
 void CodeGenerator::AssemblePrologue() {
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
-  int stack_slots = frame()->GetSpillSlotCount();
   if (descriptor->kind() == CallDescriptor::kCallAddress) {
     // Assemble a prologue similar the to cdecl calling convention.
     __ push(ebp);
     __ mov(ebp, esp);
-    const RegList saves = descriptor->CalleeSavedRegisters();
-    if (saves != 0) {  // Save callee-saved registers.
-      int register_save_area_size = 0;
-      for (int i = Register::kNumRegisters - 1; i >= 0; i--) {
-        if (!((1 << i) & saves)) continue;
-        __ push(Register::from_code(i));
-        register_save_area_size += kPointerSize;
-      }
-      frame()->SetRegisterSaveAreaSize(register_save_area_size);
-    }
   } else if (descriptor->IsJSFunctionCall()) {
     // TODO(turbofan): this prologue is redundant with OSR, but needed for
     // code aging.
     CompilationInfo* info = this->info();
     __ Prologue(info->IsCodePreAgingActive());
-    frame()->SetRegisterSaveAreaSize(
-        StandardFrameConstants::kFixedFrameSizeFromFp);
   } else if (needs_frame_) {
     __ StubPrologue();
-    frame()->SetRegisterSaveAreaSize(
-        StandardFrameConstants::kFixedFrameSizeFromFp);
+  } else {
+    frame()->SetElidedFrameSizeInSlots(kPCOnStackSize / kPointerSize);
   }
 
+  int stack_shrink_slots = frame()->GetSpillSlotCount();
   if (info()->is_osr()) {
     // TurboFan OSR-compiled functions cannot be entered directly.
     __ Abort(kShouldNotDirectlyEnterOsrFunction);
@@ -1300,40 +1289,42 @@ void CodeGenerator::AssemblePrologue() {
     osr_pc_offset_ = __ pc_offset();
     // TODO(titzer): cannot address target function == local #-1
     __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
-    DCHECK(stack_slots >= frame()->GetOsrStackSlotCount());
-    stack_slots -= frame()->GetOsrStackSlotCount();
+    stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
+  }
+
+  const RegList saves = descriptor->CalleeSavedRegisters();
+  if (stack_shrink_slots > 0) {
+    __ sub(esp, Immediate(stack_shrink_slots * kPointerSize));
   }
 
-  if (stack_slots > 0) {
-    // Allocate the stack slots used by this frame.
-    __ sub(esp, Immediate(stack_slots * kPointerSize));
+  if (saves != 0) {  // Save callee-saved registers.
+    DCHECK(!info()->is_osr());
+    int pushed = 0;
+    for (int i = Register::kNumRegisters - 1; i >= 0; i--) {
+      if (!((1 << i) & saves)) continue;
+      __ push(Register::from_code(i));
+      ++pushed;
+    }
+    frame()->AllocateSavedCalleeRegisterSlots(pushed);
   }
 }
 
 
 void CodeGenerator::AssembleReturn() {
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
-  int stack_slots = frame()->GetSpillSlotCount();
-  if (descriptor->kind() == CallDescriptor::kCallAddress) {
-    const RegList saves = descriptor->CalleeSavedRegisters();
-    if (frame()->GetRegisterSaveAreaSize() > 0) {
-      // Remove this frame's spill slots first.
-      if (stack_slots > 0) {
-        __ add(esp, Immediate(stack_slots * kPointerSize));
-      }
-      // Restore registers.
-      if (saves != 0) {
-        for (int i = 0; i < Register::kNumRegisters; i++) {
-          if (!((1 << i) & saves)) continue;
-          __ pop(Register::from_code(i));
-        }
-      }
-      __ pop(ebp);  // Pop caller's frame pointer.
-    } else {
-      // No saved registers.
-      __ mov(esp, ebp);  // Move stack pointer back to frame pointer.
-      __ pop(ebp);       // Pop caller's frame pointer.
+
+  const RegList saves = descriptor->CalleeSavedRegisters();
+  // Restore registers.
+  if (saves != 0) {
+    for (int i = 0; i < Register::kNumRegisters; i++) {
+      if (!((1 << i) & saves)) continue;
+      __ pop(Register::from_code(i));
     }
+  }
+
+  if (descriptor->kind() == CallDescriptor::kCallAddress) {
+    __ mov(esp, ebp);  // Move stack pointer back to frame pointer.
+    __ pop(ebp);       // Pop caller's frame pointer.
   } else if (descriptor->IsJSFunctionCall() || needs_frame_) {
     // Canonicalize JSFunction return sites for now.
     if (return_label_.is_bound()) {