[RS4GC] Lower calls to @llvm.experimental.deoptimize
This changes RS4GC to lower calls to ``@llvm.experimental.deoptimize``
to gc.statepoints wrapping ``__llvm_deoptimize``, and changes
``callsGCLeafFunction`` to recognize ``@llvm.experimental.deoptimize``
as a non GC leaf function.
I've had to hard code the ``"__llvm_deoptimize"`` name in
RewriteStatepointsForGC; since ``TargetLibraryInfo`` is available only
during codegen. This isn't without precedent in the codebase, so I'm
not overtly concerned.
llvm-svn: 264456
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 0ca5a96..bd8b7c4 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1603,18 +1603,18 @@
}
bool llvm::callsGCLeafFunction(ImmutableCallSite CS) {
- if (isa<IntrinsicInst>(CS.getInstruction()))
- // Most LLVM intrinsics are things which can never take a safepoint.
- // As a result, we don't need to have the stack parsable at the
- // callsite. This is a highly useful optimization since intrinsic
- // calls are fairly prevalent, particularly in debug builds.
- return true;
-
// Check if the function is specifically marked as a gc leaf function.
if (CS.hasFnAttr("gc-leaf-function"))
return true;
- if (const Function *F = CS.getCalledFunction())
- return F->hasFnAttribute("gc-leaf-function");
+ if (const Function *F = CS.getCalledFunction()) {
+ if (F->hasFnAttribute("gc-leaf-function"))
+ return true;
+
+ if (auto IID = F->getIntrinsicID())
+ // Most LLVM intrinsics do not take safepoints.
+ return IID != Intrinsic::experimental_gc_statepoint &&
+ IID != Intrinsic::experimental_deoptimize;
+ }
return false;
}