TotalView Users Guide - CI Wiki

Examining and Analyzing Arrays
Displaying Array Slices
TotalView lets you display array subsections by editing the Slice field in an
array’s Variable Window. (An array subsection is called a slice.) The Slice field
contains placeholders for all array dimensions. For example, the following
is a C declaration for a three-dimensional array:
integer an_array[10][20][5]
Because this is a three-dimensional array, the initial slice definition is
[:][:][:]. This lets you know that the array has three dimensions and that
TotalView is displaying all array elements.
The following is a deferred shape array definition for a two-dimensional
array variable:
integer, dimension (:,:) :: another_array
The TotalView slice definition is (:,:).
TotalView displays as many colons (:) as there are array dimensions. For
example, the slice definition for a one-dimensional array (a vector) is [:] for
C arrays and (:) for Fortran arrays.
CLI: dprint -slice “\[n:m\]” an_array
Using Slices and Strides
A slice has the following form:
lower_bound:upper_bound[:stride]
The stride, which is optional, tells TotalView to skip over elements and not
display them. Adding a stride to a slice tells the debugger to display every
stride element of the array, starting at the lower_bound and continuing through
the upper_bound, inclusive.
For example, a slice of [0:9:9] used on a ten-element C array tells TotalView
to display the first element and last element, which is the ninth element
beyond the lower bound.
If the stride is negative and the lower bound is greater than the upper
bound, TotalView displays a dimension with its indices reversed. That is,
TotalView treats the slice as if it was defined as follows:
[upperbound : lowerbound : stride]
For example, the following definition tells TotalView to display an array
beginning at its last value and moving to its first:
[::-1]
dprint -slice “(n:m,p:q)” an_array
CLI: dprint an_array(n:m:p,q:r:s)
334 Chapter 15: Examining Arrays