Time measuring is wrong in LU

[CXianRen]

Hi,
seems there is a bug in LU.

I got a log like this:

 LU Benchmark Completed
 class_npb       =                        C
 Size            =            162x 162x 162
 Total threads   =                       16
 Iterations      =                      250
 Time in seconds =                    48.91
 Mop/s total     =                 41685.61
 Operation type  =           floating point
 Verification    =               SUCCESSFUL
 Version         =                      4.1
 Compile date    =              27 Jan 2026
 Compiler ver    =                   14.0.0
 OpenMP version  =                   201811

 Compile options:
    CC           = clang++ -std=c++14
    CLINK        = $(CC)
    C_LIB        = -lm
    C_INC        = -I../common 
    CFLAGS       = -O3 -fopenmp -mcmodel=medium
    CLINKFLAGS   = -O3 -fopenmp -mcmodel=medium
    RAND         = (none)


----------------------------------------------------------------------
    NPB-CPP is developed by: 
        Dalvan Griebler
        Gabriell Araujo (Sequential Porting)
        Júnior Löff (Parallel Implementation)

    In case of questions or problems, please send an e-mail to us:
        dalvan.griebler; gabriell.araujo; junior.loff@edu.pucrs.br
----------------------------------------------------------------------

  SECTION     Time (secs)
  total   :   48.914  (100.00%)
  rhsx    :   39.115  ( 79.97%)
  rhsy    :   69.802  (142.70%)
  rhsz    :   69.379  (141.84%)
  rhs     :   29.059  ( 59.41%)
     -->  sub-rhs:  178.296  (364.51%)
     --> rest-rhs: -149.236  (-305.10%)
  jacld   :    3.317  (  6.78%)
  blts    :   10.013  ( 20.47%)
  jacu    :    3.385  (  6.92%)
  buts    :   10.522  ( 21.51%)
  add     :    2.211  (  4.52%)
  l2norm  :    0.016  (  0.03%)

You can see the "rest-rhs" is negative.

[CXianRen]

fixed by fixing line: if(timeron){timer_start(T_RHS);}

NPB-CPP/NPB-OMP/LU/lu.cpp

Line 2207 in 5bc1e2c

if(timeron){timer_start(T_RHS);}