User Guide

Contents

Top-down Tree Comparison

To understand how your application call tree has changed after your optimization and see the difference in performance metrics per function and its callees, click the
Top-down Tree
sub-tab and explore the
Top-down Tree
window.
In the compare mode, the
Top-down Tree
window shows the data columns of the two results and a new column showing the difference between the two results for each program unit. The difference is calculated as <Result 1 Value> - <Result 2 Value>.
The
Top-down Tree
window in the compare mode supports two types of grouping levels:
  • Function Stack
    granularity groups the data by function instances. Use the
    Start Address
    column to identify different instances of the same source function or same loop.
  • Source Function Stack
    granularity groups the data by source functions. In this mode, all instances of the same source function are aggregated into one function.
Example: Comparison for Hotspots Analysis Results
The function
foo()
is called from two places in your application,
bar1()
and
bar2()
. If you see that foo() became slower in result 2, use the
Top-down Tree
window (compare mode) to check whether it became slower when being called by
bar1()
, by
bar2()
, or both.
To compare results with stacks and without stacks, switch the Call Stack Mode filterbar option to
User/System functions
to attribute performance data to functions where samples occurred.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804