Embedded development: Tools - optimizing firmware using DRT

　　 Not only from a business perspective , And from the perspective of microcontroller , Embedded development is usually carried out under severe resource constraints . Upgrading to a higher end processor may make the project economically infeasible , Especially for mass applications where every penny can play a role . A group called DRT Of GCC Firmware optimizer , It produces some very interesting optimization results .

　　 When optimizing embedded systems , Developers may want to optimize three main areas ： Code size 、 Speed and energy use . When optimizing , Often a trade-off must be made , For example, larger code size for faster processing .DRT What's interesting about , The tool is optimized in all three areas at the same time , To provide the best overall results .

　　

 

　　DRT Tools optimize the entire program , And perform an optimization called reordering optimization . Reordering optimization is performed after the program is compiled , And as a special linker . The reorder will be optimized by doing the following :

　　 Load relative instructions for loading relative addresses

　　 Branch target

　　 Keep sharing

　　 Data shuffling

　　 Exit truncation

　　 Function reordering

　　 Instruction scale

　　 Remove the extra nop

　　 Remove unused code / Data sequence

　　 Small constant load

　　 The reorder optimizer will adjust the code size 、 Energy use and processing speed have a significant impact . For applications between two different microcontroller sizes or device choices , Using such an optimizer alone is enough to use a cheaper microcontroller .

　　DRT Tools do 30 Days of usage , You can experience , See how much extra performance an application can get .30 After the trial period of days , The cost of this tool is about the same as that of high-end debugger probes . Not terrible price restraint , But it may be beyond the price range of most individual or small team Embedded developers . However , If appropriate trade studies are carried out , The price savings of microcontroller costs may greatly exceed the cost of tools .