PPC: [runtime] Remove weird pushing of something on StackOverflow.

src/ppc/builtins-ppc.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 678 matching lines @@
   __ add(sp, sp, r4);
   __ addi(sp, sp, Operand(kPointerSize));
   __ blr();
 }
 
 
 enum IsTagged { kArgcIsSmiTagged, kArgcIsUntaggedInt };
 
 
 // Clobbers r5; preserves all other registers.
-static void Generate_CheckStackOverflow(MacroAssembler* masm,
-                                        const int calleeOffset, Register argc,
+static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
                                         IsTagged argc_is_tagged) {
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
   __ LoadRoot(r5, Heap::kRealStackLimitRootIndex);
   // Make r5 the space we have left. The stack might already be overflowed
   // here which will cause r5 to become negative.
   __ sub(r5, sp, r5);
   // Check if the arguments will overflow the stack.
   if (argc_is_tagged == kArgcIsSmiTagged) {
     __ SmiToPtrArrayOffset(r0, argc);
   } else {
     DCHECK(argc_is_tagged == kArgcIsUntaggedInt);
     __ ShiftLeftImm(r0, argc, Operand(kPointerSizeLog2));
   }
   __ cmp(r5, r0);
   __ bgt(&okay);  // Signed comparison.
 
   // Out of stack space.
-  __ LoadP(r4, MemOperand(fp, calleeOffset));
-  if (argc_is_tagged == kArgcIsUntaggedInt) {
-    __ SmiTag(argc);
-  }
-  __ Push(r4, argc);
   __ CallRuntime(Runtime::kThrowStackOverflow, 0);
 
   __ bind(&okay);
 }
 
 
 static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                              bool is_construct) {
   // Called from Generate_JS_Entry
   // r3: new.target
@@ skipping 16 matching lines @@
                                       masm->isolate());
     __ mov(cp, Operand(context_address));
     __ LoadP(cp, MemOperand(cp));
 
     __ InitializeRootRegister();
 
     // Push the function and the receiver onto the stack.
     __ Push(r4, r5);
 
     // Check if we have enough stack space to push all arguments.
-    // The function is the first thing that was pushed above after entering
-    // the internal frame.
-    const int kFunctionOffset =
-        InternalFrameConstants::kCodeOffset - kPointerSize;
     // Clobbers r5.
-    Generate_CheckStackOverflow(masm, kFunctionOffset, r6, kArgcIsUntaggedInt);
+    Generate_CheckStackOverflow(masm, r6, kArgcIsUntaggedInt);
 
     // Copy arguments to the stack in a loop.
     // r4: function
     // r6: argc
     // r7: argv, i.e. points to first arg
     Label loop, entry;
     __ ShiftLeftImm(r0, r6, Operand(kPointerSizeLog2));
     __ add(r5, r7, r0);
     // r5 points past last arg.
     __ b(&entry);
@@ skipping 564 matching lines @@
     __ LoadP(r3, MemOperand(fp, kFunctionOffset));  // get the function
     __ LoadP(r4, MemOperand(fp, kArgumentsOffset));  // get the args array
     __ Push(r3, r4);
     if (targetIsArgument) {
       __ InvokeBuiltin(Context::REFLECT_APPLY_PREPARE_BUILTIN_INDEX,
                        CALL_FUNCTION);
     } else {
       __ InvokeBuiltin(Context::APPLY_PREPARE_BUILTIN_INDEX, CALL_FUNCTION);
     }
 
-    Generate_CheckStackOverflow(masm, kFunctionOffset, r3, kArgcIsSmiTagged);
+    Generate_CheckStackOverflow(masm, r3, kArgcIsSmiTagged);
 
     // Push current limit and index.
     const int kIndexOffset = kVectorOffset - (2 * kPointerSize);
     const int kLimitOffset = kVectorOffset - (1 * kPointerSize);
     __ li(r4, Operand::Zero());
     __ LoadP(r5, MemOperand(fp, kReceiverOffset));
     __ Push(r3, r4, r5);  // limit, initial index and receiver.
 
     // Copy all arguments from the array to the stack.
     Generate_PushAppliedArguments(masm, kVectorOffset, kArgumentsOffset,
@@ skipping 41 matching lines @@
     __ bind(&validate_arguments);
     __ LoadP(r3, MemOperand(fp, kFunctionOffset));  // get the function
     __ push(r3);
     __ LoadP(r3, MemOperand(fp, kArgumentsOffset));  // get the args array
     __ push(r3);
     __ LoadP(r3, MemOperand(fp, kNewTargetOffset));  // get the new.target
     __ push(r3);
     __ InvokeBuiltin(Context::REFLECT_CONSTRUCT_PREPARE_BUILTIN_INDEX,
                      CALL_FUNCTION);
 
-    Generate_CheckStackOverflow(masm, kFunctionOffset, r3, kArgcIsSmiTagged);
+    Generate_CheckStackOverflow(masm, r3, kArgcIsSmiTagged);
 
     // Push current limit and index.
     const int kIndexOffset = kVectorOffset - (2 * kPointerSize);
     const int kLimitOffset = kVectorOffset - (1 * kPointerSize);
     __ li(r4, Operand::Zero());
     __ Push(r3, r4);  // limit and initial index.
     // Push the constructor function as callee
     __ LoadP(r3, MemOperand(fp, kFunctionOffset));
     __ push(r3);
 
@@ skipping 467 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC