Additional protection (macosx with gfortran)

[u/mrichter/AliRoot.git] / HIJING / hipyset1_35 / rlu_hijing.F

* $Id$
    
C*********************************************************************  
    
      FUNCTION RLU_HIJING(IDUM)    
    
C...Purpose: to generate random numbers uniformly distributed between   
C...0 and 1, excluding the endpoints.   
#include "ludatr_hijing.inc"
      EQUIVALENCE (MRLU1,MRLU(1)),(MRLU2,MRLU(2)),(MRLU3,MRLU(3)),  
     &(MRLU4,MRLU(4)),(MRLU5,MRLU(5)),(MRLU6,MRLU(6)),  
     &(RRLU98,RRLU(98)),(RRLU99,RRLU(99)),(RRLU00,RRLU(100))    
    
C...Initialize generation from given seed.  
      IF(MRLU2.EQ.0) THEN   
        IJ=MOD(MRLU1/30082,31329)   
        KL=MOD(MRLU1,30082) 
        I=MOD(IJ/177,177)+2 
        J=MOD(IJ,177)+2 
        K=MOD(KL/169,178)+1 
        L=MOD(KL,169)   
        DO 110 II=1,97  
        S=0.    
        T=0.5   
        DO 100 JJ=1,24  
        M=MOD(MOD(I*J,179)*K,179)   
        I=J 
        J=K 
        K=M 
        L=MOD(53*L+1,169)   
        IF(MOD(L*M,64).GE.32) S=S+T 
  100   T=0.5*T 
  110   RRLU(II)=S  
        TWOM24=1.   
        DO 120 I24=1,24 
  120   TWOM24=0.5*TWOM24   
        RRLU98=362436.*TWOM24   
        RRLU99=7654321.*TWOM24  
        RRLU00=16777213.*TWOM24 
        MRLU2=1 
        MRLU3=0 
        MRLU4=97    
        MRLU5=33    
      ENDIF 
    
C...Generate next random number.    
  130 RUNI=RRLU(MRLU4)-RRLU(MRLU5)  
      IF(RUNI.LT.0.) RUNI=RUNI+1.   
      RRLU(MRLU4)=RUNI  
      MRLU4=MRLU4-1 
      IF(MRLU4.EQ.0) MRLU4=97   
      MRLU5=MRLU5-1 
      IF(MRLU5.EQ.0) MRLU5=97   
      RRLU98=RRLU98-RRLU99  
      IF(RRLU98.LT.0.) RRLU98=RRLU98+RRLU00 
      RUNI=RUNI-RRLU98  
      IF(RUNI.LT.0.) RUNI=RUNI+1.   
      IF(RUNI.LE.0.OR.RUNI.GE.1.) GOTO 130  
    
C...Update counters. Random number to output.   
      MRLU3=MRLU3+1 
      IF(MRLU3.EQ.1000000000) THEN  
        MRLU2=MRLU2+1   
        MRLU3=0 
      ENDIF 
      RLU_HIJING=RUNI  
    
      RETURN    
      END