[CallGraph] Teach the CallGraph about non-leaf intrinsics.

Summary:
Currently intrinsics don't affect the creation of the call graph.
This is not accurate with respect to statepoint and patchpoint
intrinsics -- these do call (or invoke) LLVM level functions.

This change fixes this inconsistency by adding a call to the external
node for call sites that call these non-leaf intrinsics.  This coupled
with the fact that these intrinsics also escape the function pointer
they call gives us a conservatively correct call graph.

Reviewers: reames, chandlerc, atrick, pgavlin

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10526

llvm-svn: 240039

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp b/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp
index 65ba1c7c6c4..6b3e0634626 100644
--- a/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp
+++ b/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp
@@ -217,8 +217,10 @@ bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC,
           // another value. This can happen when constant folding happens
           // of well known functions etc.
           !CallSite(I->first) ||
-           (CallSite(I->first).getCalledFunction() &&
-            CallSite(I->first).getCalledFunction()->isIntrinsic())) {
+          (CallSite(I->first).getCalledFunction() &&
+           CallSite(I->first).getCalledFunction()->isIntrinsic() &&
+           Intrinsic::isLeaf(
+               CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
         assert(!CheckingMode &&
                "CallGraphSCCPass did not update the CallGraph correctly!");