HP Fortran Programmer Guide (766160-001, March 2014)

profiler Programming tools that determine where a program spends its execution
time. Profilers that come with HP Fortran 90 include prof, gprof, and
CXperf.
R-S
roundoff error The loss of precision that can occur as a result of floating-point arithmetic.
Different orders of evaluating a floating-point expression can produce
different accumulations of roundoff errors, which in turn can sometimes
cause the expression to yield significantly different results.
row-major order The method of storing C-language arrays in memory. (Fortran arrays are
stored in column-major order.) Row-major order requires the rows of a
two-dimensional array to be in contiguous memory locations. For example,
given the array a[3][4], element a[0][0]would be stored in the first
location, a[0][1]in the second, a[0][2]in the third, and so on.
segmentation
violation
A type of exception that occurs when an executing program attempts to
access memory outside of its allocated memory segment; also called a
memory fault
serial execution Program execution on only one processor at a time. See alsoparallel
execution..
shared executable An executable program whose text segment (that is, its code) can be shared
by multiple processes.
shared library A library of routines that can be linked to an executable program at runtime
and shared by several programs simultaneously. The names of shared
libraries have the .sl extension. See also archive library..
side effects A condition that prevents the optimizer from parallelizing a loop. A
procedure that is called within a loop has side effects if it communicates
with the outside world other than through a return value.
signal See trap.
stack overflow An error condition that occurs when the runtime system attempts to allocate
more memory from the stack than is available. This condition can occur
when attempting to allocate very large arrays or when a recursive program
is out of control.
static variable Variables that are allocated from static storage (sometimes referred to as
the heap). Static variables have two characteristics of note:
• They preserve their value for the lifetime of the program.
• They are initialized when they are allocated.
By default, program variables in HP Fortran 90 are automatic
stream I/O A type of I/O that is based on the concept of a stream—a flow of data to
or from a file or I/O device. Streams are managed by the HP-UX operating
system. Access to a stream is provided by a stream pointer, which is the
address of a C-like structure that contains information about a stream.
When the Fortran 90 intrinsic FSTREAMis given a logical unit number, it
returns a stream pointer, providing Fortran programs with access to
stream-based system routines.
symbol table A table of names of procedures and data, including their offset addresses.
The compiler inserts a symbol table in the object file for use by the debugger
and profiler.
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