Find Source of Code Size Increase

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Problem Statement

You are compiling your code with two different options sets, or two different compiler versions, and you want to find the functions which have the largest code size increase between the builds.

Presumptions

The number and name of all the functions in the two builds is exactly the same
All function names are unique
- Though you can probably deal with this if you really want to
You have some experience with Excel. You know how to sort data, enter basic formulas, etc.

Collect Code Size Data

Collect code size data by using the --func_info option of the Object File Display (OFD) utility. OFD is described in the Assembly Language Tools Guide for your device family. The executable is named something like ofd6x, ofd55, or ofd470. Only fairly recent versions of OFD support the --func_info option.

Target	Version
C6000	v6.1.0
ARM	v4.5.0
C5500	v4.2.0
MSP430	v3.0.0
C2000	v5.1.0

Note, however, that since OFD is a purely diagnostic tool, it is OK to use a newer OFD on code built with an older compiler. The topic Compiler Releases tells you where to get compiler updates.

So, to collect code size data on your two builds ...

% ofd55 --func_info file1.out > size_data1.csv
% ofd55 --func_info file2.out > size_data2.csv

View Code Size Data with Excel

The output from using --func_info is in CSV format. CSV stands for comma separated values. It is a very simple format. For example ...

C:\dir>ofd6x --func_info file.out | more
"HOSTclose","SHARED/trgdrv.c",0x00004ee0,0x00004f7c,156
"HOSTlseek","SHARED/trgdrv.c",0x000042a0,0x00004374,212
...

Each row represents data for one function. The data is separated by commas. The data on one row is: function name, file name, starting address, ending address, size.

The details of the format don't matter much in this article. Just let Excel deal with that. On a typically configured Windows system, you can "execute" a .csv file to bring it up in Excel ...

% size_data1.csv

Compare Code Size Data with Excel

Bring up both .csv files in Excel
Delete the file name, starting address, and ending address columns
Sort both files by function name
Copy the columns from one file into the other
Put the name columns next to each other and visually inspect one last time to make sure they are exactly the same
Delete one name column
Add a formula to subtract the two size columns, called the delta
Sort by the delta

The functions with the largest delta are now at the top of the spreadsheet. Here is an example, with column headings added for clarity.

For technical support please post your questions at http://e2e.ti.com. Please post only comments about the article Find Source of Code Size Increase here.