Common: CallLambdaTrampoline can return a value #2697
Merged
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
endrift
force-pushed
the
fix-jit-trampoline
branch
from
57cb4db
to
157157c
Compare
endrift
changed the title
| @@ -971,10 +971,10 @@ class XEmitter | |||
| // (this method might be a thunk in the case of multi-inheritance) so we | |||
| // have to go through a trampoline function. | |||
| template <typename T, typename... Args> | |||
| static void CallLambdaTrampoline(const std::function<T(Args...)>* f, | |||
| static T CallLambdaTrampoline(const std::function<T(Args...)>* f, | |||
| Args... args) | |||
This comment was marked as off-topic.
This comment was marked as off-topic.
Sorry, something went wrong.
As it is currently written, CallLambdaTrampoline does not return a value. However, some of the functions that are being wrapped may return a value that the JIT is expected to understand. A compiler *cough cough clang* may opt to alter %rax after the wrapped lambda returns, e.g. popping a previous value, which can clobber the return value. If we actually have a return value, then the compiler must not clobber it.
endrift
force-pushed
the
fix-jit-trampoline
branch
from
157157c
to
c9a25f9
Compare
|
LGTM, however, I have no clue about Jit64... |
|
CC stable @Armada651 |
|
lgtm The place where the return value is used is here. |
Tilka
added a commit
that referenced
this pull request
Jul 4, 2015
Common: CallLambdaTrampoline can return a value
|
Has been cherry-picked into stable. |
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Outdated suggestions cannot be applied.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.
As it is currently written, CallLambdaTrampoline does not return a value. However, some of the functions that are being wrapped may return a value that the JIT is expected to understand. A compiler _cough cough clang_ may opt to alter
%raxafter the wrapped lambda returns, e.g. popping a previous value, which can clobber the return value. If we actually have a return value, then the compiler must not clobber it.