GD32: Fast GPIO optimization#27845
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thinkyhead merged 2 commits intoMarlinFirmware:bugfix-2.1.xfrom May 8, 2025
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Adding FORCE_INLINE to the fast GPIO functions gives us a couple benefits. First, code folding will reducing these functions to their direct register accesses - which is ideal. Second, it allows us to optimize away the pin-port map - reducing code size (~250 bytes or so) as well as eliminating all overhead. This has been verified via decompilation. The only down side is that the EEPROM (software IIC) seems to rely on this overhead to meet timing requirements, and since we now have zero overhead, writing to the EEPROM is broken. I'll submit another PR with that fix.
EvilGremlin
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Description
Adding FORCE_INLINE to the fast GPIO functions gives us a couple benefits.
First, code folding will reduce these functions to their direct register accesses - which is ideal.
Second, it allows us to optimize away the pin-port map - reducing code size (~250 bytes or so) as well as eliminating all overhead.
This has been verified via decompilation.
The only down side is that the EEPROM (software IIC) seems to rely on this overhead to meet timing requirements, and since we now have zero overhead, writing to the EEPROM is broken.
I'll submit another PR with that fix.
Requirements
GD32 Board
Benefits
Zero overhead for IO and smaller code size.
Configurations
N/A
Related Issues
N/A