Parallel For

Dependence Analysis
The parallel for system creates an intermediate data dependence analysis in order to generate parallel source code for different programming models.

A simplified translation of the following example parallel-for loop is given below.


Grid1 *g = new Grid1(0, n+1);
 
Grid1IteratorSub it(1, n, g);
 
DistArray x(g), y(g);
 
float e = 0;
 
ForEach(int i, it,
 
  	x(i) += ( y(i+1) + y(i-1) )*.5;
 
  	e    += sqr( y(i) ); )

dependence analysis:


1 begin:

1 iter: ` load [#,#] store [#,#]' `x' `class `DistArray1''

1 iter: ` load [#-1,#+1]' `y' class `DistArray1''

1 reduce: `add' `e' `float'

1 load: `it' `class `Grid1IteratorSub''

1 wend: