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changeset

#4459: Performance of long integer division for intepreter is 13% up.

Thu, 25 Aug 2016 23:57:31 +0800

author

chenhaoxuan

date

Thu, 25 Aug 2016 23:57:31 +0800

changeset 87

3a1f2830f10d

parent 86

15380261070f

child 88

02ae7081a1a7

#4459: Performance of long integer division for intepreter is 13% up.
Use gsddiv to improve the performance of long integer division.

This is the test program:

public class GsddivTest{
public static void main(String[] args){
int count = 10000000;
long a=1234,b=1234000000,c;
long startTime = System.currentTimeMillis();
for (int i=0;i<count;i++){
b++;
c=b/a;
System.out.println(c);
}
long endTime = System.currentTimeMillis();
System.out.println("time:" + (endTime - startTime) + "ms");
}
}

     1.1 --- a/src/cpu/mips/vm/templateTable_mips_64.cpp	Thu Aug 25 17:34:45 2016 +0800
     1.2 +++ b/src/cpu/mips/vm/templateTable_mips_64.cpp	Thu Aug 25 23:57:31 2016 +0800
     1.3 @@ -1349,9 +1349,13 @@
     1.4    __ delayed()->nop();
     1.5  
     1.6    __ bind(normal);
     1.7 -  __ move(A1, FSR);
     1.8 -  __ pop_l(A2, A3); 
     1.9 -  __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::ldiv), A1, A2);
    1.10 +  __ pop_l(A2, A3);
    1.11 +  if (UseLoongsonISA) {
    1.12 +    __ gsddiv(FSR, A2, FSR);	
    1.13 +  } else {
    1.14 +    __ ddiv(A2, FSR);
    1.15 +    __ mflo(FSR);
    1.16 +  }
    1.17  }
    1.18  
    1.19  // NOTE: i DONT use the Interpreter::_throw_ArithmeticException_entry