sw: Fix invalid inline assembly in snrt_dma_wait_channel
#180
Conversation
This file contains 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
The inline assembly uses `t1` both as input operand (via the `cfg` variable) and within the clobber list. This is illegal but due to a bug in clang 12 that has been fixed in clang 14 has gone unnoticed. Quoting from the GCC documentation (https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Clobbers-and-Scratch-Registers-1): > Clobber descriptions may not in any way overlap with an input or output operand. For example, you may not have an operand describing a register class with one member when listing that register in the clobber list. Variables declared to live in specific registers (see Variables in Specified Registers) and used as asm input or output operands must have no part mentioned in the clobber description. This correctly emits an error if using Clang 14 or any version of GCC: https://godbolt.org/z/17zrdK18e The fix is to simply remove the clobber of `t1` which is safe to do as it is only used as input.
fischeti
approved these changes
Aug 14, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
The inline assembly uses
t1both as input operand (via thecfgvariable) and within the clobber list. This is illegal but due to a bug in clang 12 that has been fixed in clang 14 has gone unnoticed. Quoting from the GCC documentation (https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Clobbers-and-Scratch-Registers-1):This correctly emits an error if using Clang 14 or any version of GCC: https://godbolt.org/z/17zrdK18e
The fix is to simply remove the clobber of
t1which is safe to do as it is only used as input.