MIPS: Remove frame pointer from StackHandler.

src/mips/macro-assembler-mips.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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS
 
@@ skipping 3220 matching lines @@
   Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
 }
 
 
 // ---------------------------------------------------------------------------
 // Exception handling.
 
 void MacroAssembler::PushTryHandler(StackHandler::Kind kind,
                                     int handler_index) {
   // Adjust this code if not the case.
-  STATIC_ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kSize == 3 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kContextOffset == 2 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 3 * kPointerSize);
 
   // For the JSEntry handler, we must preserve a0-a3 and s0.
   // t1-t3 are available. We will build up the handler from the bottom by
   // pushing on the stack.
   // Set up the the state (t2) for pushing.
   unsigned state =
       StackHandler::IndexField::encode(handler_index) |
       StackHandler::KindField::encode(kind);
   li(t2, Operand(state));
 
-  // Push the frame pointer, context, and state.
+  // Push the context and state.
   if (kind == StackHandler::JS_ENTRY) {
-    DCHECK_EQ(static_cast<Smi*>(0), Smi::FromInt(0));
-    // The second zero_reg indicates no context.
-    // The first zero_reg is the NULL frame pointer.
+    DCHECK(Smi::FromInt(0) == 0);
+    // The zero_reg indicates no context.
     // The operands are reversed to match the order of MultiPush/Pop.
-    Push(zero_reg, zero_reg, t2);
+    Push(zero_reg, t2);
   } else {
-    MultiPush(t2.bit() | cp.bit() | fp.bit());
+    MultiPush(t2.bit() | cp.bit());
   }
 
   // Link the current handler as the next handler.
   li(t2, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
   lw(t1, MemOperand(t2));
   push(t1);
   // Set this new handler as the current one.
   sw(sp, MemOperand(t2));
 }
 
@@ skipping 2813 matching lines @@
   }
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS