MIPS: Critical fix for label binding in RegExp engine when trampoline is emitted.

src/mips/assembler-mips.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 472 matching lines @@
 
 const int kEndOfChain = -4;
 // Determines the end of the Jump chain (a subset of the label link chain).
 const int kEndOfJumpChain = 0;
 
 
 bool Assembler::IsBranch(Instr instr) {
   uint32_t opcode   = GetOpcodeField(instr);
   uint32_t rt_field = GetRtField(instr);
   uint32_t rs_field = GetRsField(instr);
-  uint32_t label_constant = GetLabelConst(instr);
   // Checks if the instruction is a branch.
   return opcode == BEQ ||
       opcode == BNE ||
       opcode == BLEZ ||
       opcode == BGTZ ||
       opcode == BEQL ||
       opcode == BNEL ||
       opcode == BLEZL ||
       opcode == BGTZL ||
       (opcode == REGIMM && (rt_field == BLTZ || rt_field == BGEZ ||
                             rt_field == BLTZAL || rt_field == BGEZAL)) ||
-      (opcode == COP1 && rs_field == BC1) ||  // Coprocessor branch.
-      label_constant == 0;  // Emitted label const in reg-exp engine.
+      (opcode == COP1 && rs_field == BC1);  // Coprocessor branch.
 }
 
+bool Assembler::IsEmittedConstant(Instr instr) {
+  uint32_t label_constant = GetLabelConst(instr);
+  return label_constant == 0;  // Emitted label const in reg-exp engine.
+}
 
 bool Assembler::IsBeq(Instr instr) {
   return GetOpcodeField(instr) == BEQ;
 }
 
 
 bool Assembler::IsBne(Instr instr) {
   return GetOpcodeField(instr) == BNE;
 }
 
@@ skipping 270 matching lines @@
           trampoline_pos = get_trampoline_entry(fixup_pos);
           CHECK(trampoline_pos != kInvalidSlotPos);
         }
         ASSERT((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
         target_at_put(fixup_pos, trampoline_pos);
         fixup_pos = trampoline_pos;
         dist = pos - fixup_pos;
       }
       target_at_put(fixup_pos, pos);
     } else {
-      ASSERT(IsJ(instr) || IsLui(instr));
+      ASSERT(IsJ(instr) || IsLui(instr) || IsEmittedConstant(instr));
       target_at_put(fixup_pos, pos);
     }
   }
   L->bind_to(pos);
 
   // Keep track of the last bound label so we don't eliminate any instructions
   // before a bound label.
   if (pos > last_bound_pos_)
     last_bound_pos_ = pos;
 }
@@ skipping 1486 matching lines @@
   }
 
   if (patched) {
       CPU::FlushICache(pc+2, sizeof(Address));
   }
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS