Eric at 15:07, 12 January 2015

2015-01-12T15:07:16Z

← Older revision		Revision as of 17:07, 12 January 2015
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			Automatic Locality-Friendly Interface Extension of Numerical Functions

	Raising the level of abstraction is a key concern of software engineering,		Raising the level of abstraction is a key concern of software engineering,
	and libraries (either used directly or as a target of a program		and libraries (either used directly or as a target of a program

Eric: Created page with "Raising the level of abstraction is a key concern of software engineering, and libraries (either used directly or as a target of a program generation system) are a successful tec..."

2015-01-12T15:06:45Z

Created page with "Raising the level of abstraction is a key concern of software engineering, and libraries (either used directly or as a target of a program generation system) are a successful tec..."

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Raising the level of abstraction is a key concern of software engineering,
and libraries (either used directly or as a target of a program
generation system) are a successful technique to raise programmer
productivity and to improve software quality. Unfortunately
successful libraries may contain functions that may not be
general enough. For example, many numeric performance libraries
contain functions that work on one- or higher-dimensional arrays.
A problem arises if a program wants to invoke such a function on
a non-contiguous subarray (e.g., in C the column of a matrix or a
subarray of an image). If the library developer did not foresee this
scenario, the client program must include explicit copy steps before
and after the library function call, incurring a possibly high
performance penalty. A better solution would be an enhanced library
function that allows for the desired access pattern. Exposing
the access pattern allows the compiler to optimize for the intended
usage scenario(s). As we do not want the library developer to generate
all interesting versions manually, we present a tool that takes
a library function written in C and generates such a customized
function for typical accesses. We describe the approach, discuss
limitations, and report on the performance. As example access patterns
we consider those most common in numerical applications:
striding and block striding, general permutations, as well as scaling.
We evaluate the tool on various library functions including
filters, scans, reductions, sorting, FFTs, and linear algebra operations.
The automatically generated custom version is in most cases
significantly faster than using individual steps, offering speed-ups
that are typically in the range of 1.2–1.8x

Joint work with Benjamin Hess and Thomas R. Gross

WG211/M14Puschel - Revision history

Eric at 15:07, 12 January 2015

Eric: Created page with "Raising the level of abstraction is a key concern of software engineering, and libraries (either used directly or as a target of a program generation system) are a successful tec..."