================
@@ -2350,6 +2343,52 @@ are listed below.
pure ThinLTO, as all split regular LTO modules are merged and LTO linked
with regular LTO.
+.. option:: -fdevirtualize-speculatively
+
+ Enable speculative devirtualization optimization where a virtual call
+ can be transformed into a direct call under the assumption that its
+ object is of a particular type. A runtime check is inserted to validate
+ the assumption before making the direct call, and if the check fails,
+ the original virtual call is made instead. This optimization can enable
+ more inlining opportunities and better optimization of the direct call.
+ This is different from other whole program devirtualization optimizations
+ that rely on global analysis and hidden visibility of the objects to prove
+ that the object is always of a particular type at a virtual call site.
+ This optimization doesn't require global analysis or hidden visibility.
+ This optimization doesn't devirtualize all virtual calls, but only
+ when there's a single implementation of the virtual function.
+ There could be a single implementaiton of the virtual function
+ either because the function is not overridden in any derived class,
+ or because there is a sinlge instantiated object that is using the funciton.
----------------
teresajohnson wrote:
typos "sinlge" and "funciton". Also, I don't understand the second case here
after the "or" - why does it matter if there is a single instantiated object?
https://github.com/llvm/llvm-project/pull/159685
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