this is for holding javascript data
Camil Demetrescu edited approach.tex
over 8 years ago
Commit id: 2c2f9c098ce3e217015ffedc75a11c6600a4107a
deletions | additions
diff --git a/approach.tex b/approach.tex
index f802c3b..ee82d40 100644
--- a/approach.tex
+++ b/approach.tex
...
Classical OSR implementations adjust the stack so that execution can continue in \fvariant\ with the current frame \mynote{add citations}. This requires manipulating the program state at machine code level and is highly ABI- and compiler-dependent. A simpler approach, which we follow in this article, consists of creating a new frame every time an OSR is fired, essentially regarding an OSR transition as a function call \mynote{cite WebKit and McVM}.
Our implementation targets two general scenarios: 1) {\em resolved OSR}: \fvariant\ is known before executing \fbase\ as in the deoptimization example discussed above; 2) {\em open OSR}: \fvariant\ is generated when the OSR is fired, supporting deferred compilation strategies. In both cases, \fbase\ is instrumented before its execution to incorporate the OSR machinery. We call such OSR-instrumented version \fosrfrom. Instrumentation consists of adding a check of the OSR
condition. If condition and, if the condition is satisfied,
\fosrfrom\ a function call that fires the
OSR via OSR, followed by a
regular return statement. The assumption is that the called function
call. produces the same side-effects and return values that one would obtain by \fbase\ if no OSR were performed.
In the resolved OSR scenario (see Figure~\ref{fi:overview-osr-final}), the OSR invokes an instrumented version of \fvariant\ called \fosrto, passing to it {\em all variables that are live at the OSR point}. Notice that, differently from \fvariant, \fosrto\ takes as input the live variables of \fbase\ at \textsf{L}.
%and returns the same value when it has terminated.
The assumption is that the called function produces the same side-effects and return values that one would obtain by \textsf{f} if no OSR were performed.
%\ref{fi:overview-osr-final}
...