LoongArch64: Fix dsymv and ssymv LASX version #5070
Merged
+4
−4
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
"fmov.d $f2, $f4" leaves all the bits higher than the 63-th bit unpredictable but it's obvious that the following code uses the value of those high bits. We actually want to replicate the lower 64 bits here, so we should use xvreplve0.d instead. LA464 (Loongson 3[A-Z]-5000) happens to replicate them for us due to some uarch internal details so the issue was not detected, but for LA664 (Loongson 3[A-Z]-6000) and future uarch we need to do things correctly or we end up getting a lot of test failures. Closes: https://bbs.aosc.io/t/topic/302 Signed-off-by: Xi Ruoyao <[email protected]>
|
Yes, I have introduced a bug. We should broadcast the accumulated result instead of simply moving it. |
|
I confirm that your changes do fix the problem. The compilation error disappears. |
|
Thank you for the quick fix. |
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Outdated suggestions cannot be applied.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.
"fmov.d $f2, $f4" leaves all the bits higher than the 63-th bit unpredictable but it's obvious that the following code uses the value of those high bits. We actually want to replicate the lower 64 bits here, so we should use xvreplve0.d instead.
LA464 (Loongson 3[A-Z]-5000) happens to replicate them for us due to some uarch internal details so the issue was not detected, but for LA664 (Loongson 3[A-Z]-6000) and future uarch we need to do things correctly or we end up getting a lot of test failures.
Closes: https://bbs.aosc.io/t/topic/302