[Core] Simplify audio_duration_to_ms() and audio_ms_to_duration(), reduce firmware size by a few bytes. #21427
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This commit simplifies `audio_duration_to_ms()` and `audio_ms_to_duration()` to reduce firmware size. The revised implementation is a shared integer implementation for both ARM and AVR. It has the same accuracy and supported numerical range as before, verified by new unit tests added with this commit. It costs a few bytes less in firware size: Checked with `qmk compile` before vs. after: keyboard before after delta ARV rhino 23374 23370 4 bytes smaller Moonlander (ARM) 69106 69098 8 bytes smaller Checked with godbolt.org Compiler Explorer (AVR results compiled with AVR gcc 13.1.0 -Os, ARM results with ARM 32-bit gcc 13.1 -Os): function before after delta AVR audio_duration_to_ms 24 19 5 instructions fewer AVR audio_ms_to_duration 24 21 3 instructions fewer ARM audio_duration_to_ms 16 9 7 instructions fewer ARM audio_ms_to_duration 17 8 9 instructions fewer
drashna
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Jul 3, 2023
tzarc
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Jul 7, 2023
jesperhellberg
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Sep 9, 2023
…duce firmware size by a few bytes. (qmk#21427)
thismarvin
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Sep 27, 2023
…duce firmware size by a few bytes. (qmk#21427)
akeep
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Oct 2, 2023
…duce firmware size by a few bytes. (qmk#21427)
autoferrit
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Dec 8, 2023
…duce firmware size by a few bytes. (qmk#21427)
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This commit simplifies
audio_duration_to_ms()andaudio_ms_to_duration()and reduces firmware size by a few bytes.Description
This commit simplifies the audio duration unit conversion functions
audio_duration_to_ms()andaudio_ms_to_duration()to reduce firmware size. While the existing code has separate implementations for AVR vs. ARM, this revision is a single shared integer implementation for both.This revision has the same accuracy and supported numerical range as before. This is verified by new unit tests added with this commit. I've also added comments with a brief math analysis to clarify when these conversions are sure to work without overflow.
This revision costs a few bytes less in firmware size.
Checked firmware size with
qmk compilebefore vs. after:Checked number of instructions with godbolt (AVR results compiled with AVR gcc 13.1.0 -Os, ARM results with ARM 32-bit gcc 13.1 -Os):
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