[RS4GC] Handle call/invoke instructions as base defining values of vectors

Summary:
 There's an asymmetry in the definitions of findBaseDefiningValueOfVector() and
findBaseDefiningValue() of RS4GC. The later handles call and invoke instructions,
and the former does not. This appears to be simple oversight. This patch remedies
the oversight by adding the call and invoke cases to findBaseDefiningValueOfVector().

Reviewers: DaniilSuchkov, anna

Reviewed By: anna

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42653

llvm-svn: 323764

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
index c7acdef2713..99073ae527b 100644
--- a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
+++ b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
@@ -476,6 +476,12 @@ findBaseDefiningValueOfVector(Value *I) {
   if (auto *BC = dyn_cast<BitCastInst>(I))
     return findBaseDefiningValue(BC->getOperand(0));
 
+  // We assume that functions in the source language only return base
+  // pointers.  This should probably be generalized via attributes to support
+  // both source language and internal functions.
+  if (isa<CallInst>(I) || isa<InvokeInst>(I))
+    return BaseDefiningValueResult(I, true);
+
   // A PHI or Select is a base defining value.  The outer findBasePointer
   // algorithm is responsible for constructing a base value for this BDV.
   assert((isa<SelectInst>(I) || isa<PHINode>(I)) &&