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rust-embedded / svd2rust

Generate Rust register maps (`struct`s) from SVD files
Apache License 2.0
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writer offset as a struct field #751

Closed burrbull closed 7 months ago

burrbull commented 8 months ago

This is retry of one of my old experiments.

It does 2 things:

  1. Moves offset from field writer generic to struct field.
  2. Always index field array from 0 (slightly confusing but much easier to work).

Generated code is much simpler.

The main advantage is you can now simply use .write(|w| w.fname(3).set_bit() for write/modify field arrays (previously only reading was accepted) same as .write(|w| w.fname3().set_bit().

The main disadvantage is bigger firmware size in debug mode.

cc @kossnikita, @therealprof and anyone who want to help.

I tried several examples from stm32f4xx-hal:

                   before PR vs after PR
blinky-timer-irq  41984/1172 vs 42628/1172
pwm-sinus         49672/8628 vs 50608/8632
rtc-alarm         63704/4680 vs 65648/4680
rtic-usart-shell 88024/17548 vs 88904/17548

So it is 2-3% bigger on debug mode for me.

cargo build --release -j1 --timings. time of stm32f4(f411) compilation on my machine, dependencies not included and peak memory usage during rtic-usart-shell compilation:

0.14.0    4.73s   758860k
0.15.1    3.00s   530916k
before PR 2.67s   476400k
after PR  2.47s   450996k
kossnikita commented 8 months ago

My crate is very similar to yours, and the PAC is also similar. So I don't think there will be a big difference. I don't understand how I can measure the compile time. Just the example build or HAL and PAС?

                   before PR vs after PR
qei               29656/9504 vs 30268/9504
pwm               35004/9524 vs 35612/9524

Sorry, I haven't finished the more complex examples yet.

burrbull commented 8 months ago

I don't understand how I can measure the compile time

You just need to cargo clean and then

cargo build --timings

(+ --release). After finish cargo generates html report and prints a link to it. Doesn't matter what you are building example or HAL. It show compilation time of each dependency.

kossnikita commented 8 months ago

Got it. I mean what time do you need? HAL compile or PAC + HAL?

burrbull commented 8 months ago

I've measured just a PAC compilation time. Sure a full time is also interesting, as this PR may also affect on linking time. But I don't see good way to estimate difference.

kossnikita commented 8 months ago 
cargo build --release -j1 --timings --example qei --features at32f415

PAC compile time:

6.7±0.15s vs 6.5±0.05s