[turbofan] Remove the function reload hack for OSR.

Initially we were unable to address certain stack slots in the callee
part of the frame, including the function marker, therefore we had to
hack a reload of the function register into the OSR prologue. Now that
we are able to address all stack slots, we no longer need this hack.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1666073002

Cr-Commit-Position: refs/heads/master@{#33974}

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

@@ -1138,8 +1138,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ ldr(r1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }
 

src/compiler/arm64/code-generator-arm64.cc

@@ -1448,8 +1448,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ ldr(x1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }
 

src/compiler/code-generator.cc

@@ -239,6 +239,12 @@ void CodeGenerator::RecordSafepoint(ReferenceMap* references,
       // Safepoint table indices are 0-based from the beginning of the spill
       // slot area, adjust appropriately.
       index -= stackSlotToSpillSlotDelta;
+      // We might index values in the fixed part of the frame (i.e. the
+      // closure pointer or the context pointer); these are not spill slots
+      // and therefore don't work with the SafepointTable currently, but
+      // we also don't need to worry about them, since the GC has special
+      // knowledge about those fields anyway.
+      if (index < 0) continue;
       safepoint.DefinePointerSlot(index, zone());
     } else if (operand.IsRegister() && (kind & Safepoint::kWithRegisters)) {
       Register reg = LocationOperand::cast(operand).GetRegister();

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

@@ -1478,8 +1478,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }
 

src/compiler/linkage.cc

@@ -345,10 +345,10 @@ CallDescriptor* Linkage::GetJSCallDescriptor(Zone* zone, bool is_osr,
 
   // The target for JS function calls is the JSFunction object.
   MachineType target_type = MachineType::AnyTagged();
-  // TODO(titzer): When entering into an OSR function from unoptimized code,
-  // the JSFunction is not in a register, but it is on the stack in an
-  // unaddressable spill slot. We hack this in the OSR prologue. Fix.
-  LinkageLocation target_loc = regloc(kJSFunctionRegister);
+  // When entering into an OSR function from unoptimized code the JSFunction
+  // is not in a register, but it is on the stack in the marker spill slot.
+  LinkageLocation target_loc = is_osr ? LinkageLocation::ForSavedCallerMarker()
+                                      : regloc(kJSFunctionRegister);
   return new (zone) CallDescriptor(     // --
       CallDescriptor::kCallJSFunction,  // kind
       target_type,                      // target MachineType

src/compiler/linkage.h

@@ -76,6 +76,12 @@ class LinkageLocation {
                               kPointerSize);
   }
 
+  static LinkageLocation ForSavedCallerMarker() {
+    return ForCalleeFrameSlot((StandardFrameConstants::kCallerPCOffset -
+                               StandardFrameConstants::kMarkerOffset) /
+                              kPointerSize);
+  }
+
   static LinkageLocation ConvertToTailCallerLocation(
       LinkageLocation caller_location, int stack_param_delta) {
     if (!caller_location.IsRegister()) {

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

@@ -1527,8 +1527,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ lw(a1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }
 

src/compiler/mips64/code-generator-mips64.cc

@@ -1836,8 +1836,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ ld(a1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }
 

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

@@ -1577,8 +1577,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ LoadP(r4, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }
 

src/compiler/x64/code-generator-x64.cc

@@ -1871,8 +1871,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ movq(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -=
         static_cast<int>(OsrHelper(info()).UnoptimizedFrameSlots());
   }

src/compiler/x87/code-generator-x87.cc

@@ -1942,8 +1942,6 @@ void CodeGenerator::AssemblePrologue() {
     // remaining stack slots.
     if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
-    // TODO(titzer): cannot address target function == local #-1
-    __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
     stack_shrink_slots -= OsrHelper(info()).UnoptimizedFrameSlots();
   }