libraries/SPI: abs -> std::abs and cast fixes#7362
Merged
earlephilhower merged 6 commits intoesp8266:masterfrom Jun 13, 2020
Merged
libraries/SPI: abs -> std::abs and cast fixes#7362earlephilhower merged 6 commits intoesp8266:masterfrom
earlephilhower merged 6 commits intoesp8266:masterfrom
Conversation
SPI library code erroneously assumed that: - abs() is a C function, so include stdlib.h is required. what happens instead is Arduino.h shadows `abs()` with it's own macro - uint32_t() - int32_t() promotes to int32_t, thus needing abs() Fix both issues, leaving existing calculations as-is.
devyte
requested changes
Jun 8, 2020
- restore abs call, cast freq to correctly display the intent - update magic numbers comments - move some spiclk_t magic numbers to func consts
mcspr
changed the title
devyte
approved these changes
Jun 9, 2020
earlephilhower
approved these changes
Jun 9, 2020
Collaborator
earlephilhower
left a comment
earlephilhower
left a comment
There was a problem hiding this comment.
I'm a little on the fence about converting 0x1fff->(1<<13)-1 on asthetic grounds (1fff is easier to grok for me when I think of HW register bitmasks), but generally LGTM. Thx.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Not to complicate comment chain in #6294 further
SPI library code erroneously assumed that
abs() is a C function, so include stdlib.h is required.what happens instead is Arduino.h shadows
abs()with it's own macrofreq - calFreqorfreq - bestFreqmay produce negative results and requireabs()In the referenced PR, when adding
using std::abs;it confuses GCC by introducing multiple functions named abs(), neither of which have uint32_t argument. As it turns out,uint32_t() - int32_t()promotes touint32_t, where old libc abs() silently converted it back tointFixing casts for
freqto explicitly make it a signed int when comparing with generated values, both of which are signed.edit: noting that abs() isn't a macro and we actually want signedness