src/share/vm/c1/c1_LIRGenerator.cpp

rev 9031 : 8138892: C1: Improve counter overflow checking
Reviewed-by:

*** 3416,3433 ****
    LIR_Opr result = new_register(T_INT);
    __ load(counter, result);
    __ add(result, LIR_OprFact::intConst(InvocationCounter::count_increment), result);
    __ store(result, counter);
    if (notify) {
!     LIR_Opr mask = load_immediate(frequency << InvocationCounter::count_shift, T_INT);
!     LIR_Opr meth = new_register(T_METADATA);
!     __ metadata2reg(method->constant_encoding(), meth);
!     __ logical_and(result, mask, result);
!     __ cmp(lir_cond_equal, result, LIR_OprFact::intConst(0));
      // The bci for info can point to cmp for if's we want the if bci
      CodeStub* overflow = new CounterOverflowStub(info, bci, meth);
      __ branch(lir_cond_equal, T_INT, overflow);
      __ branch_destination(overflow->continuation());
    }
  }
  
  void LIRGenerator::do_RuntimeCall(RuntimeCall* x) {
--- 3416,3437 ----
    LIR_Opr result = new_register(T_INT);
    __ load(counter, result);
    __ add(result, LIR_OprFact::intConst(InvocationCounter::count_increment), result);
    __ store(result, counter);
    if (notify) {
!     LIR_Opr meth = LIR_OprFact::metadataConst(method->constant_encoding());
      // The bci for info can point to cmp for if's we want the if bci
      CodeStub* overflow = new CounterOverflowStub(info, bci, meth);
+     int freq = frequency << InvocationCounter::count_shift;
+     if (freq == 0) {
+       __ branch(lir_cond_always, T_ILLEGAL, overflow);
+     } else {
+       LIR_Opr mask = load_immediate(freq, T_INT);
+       __ logical_and(result, mask, result);
+       __ cmp(lir_cond_equal, result, LIR_OprFact::intConst(0));
        __ branch(lir_cond_equal, T_INT, overflow);
+     }
      __ branch_destination(overflow->continuation());
    }
  }
  
  void LIRGenerator::do_RuntimeCall(RuntimeCall* x) {