Namelist input problem

John S. Tse MLK at vm.nrc.ca
Wed Mar 6 02:12:01 AEST 1991


There may be a bug with the MIPS f77 compiler on handling namelist
input.   When the following program was compiled with -O1 optimization
it gave the correct result.  However, when compiled under -O2, the
variable x(i) becomes ZERO !!  More interestingly, if one inserted
a write statement after the READ, it gave the correct results even
under -O2 .  Apparently, the value in variable a was not loaded into x(i)
in the DO loop when compiled under -O2.
    Any idea ??
	program test
	namelist /idata/ j,a
	dimension x(100)
	do 100 i = 1, 5
		read(5,nml=idata)
		x(j) = a
100	continue
	write(6,10) (x(i),i=1,5)
10	format(e12.5)
	stop
	end
 $idata j=5, a = 5.0 $end
 $idata j=3, a = 3.0 $end
 $idata j=2, a = 2.0 $end
 $idata j=4, a = 4.0 $end
 $idata j=1, a = 1.0 $end
  John S. Tse
 Steacie Institute for Molecular Science
 National Research Council of Canada
 MLK @ NRCVM01.BITNET



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