Optimizing: LoadString may not have any side effects.

LoadString does not have any side effects if the string is
known to be in the dex cache or it's a boot image string
referenced directly, as specified by the string load kind.
We need to clear the side effects for these cases to avoid
a DCHECK() failure when such LoadString instruction ends up
between a ClinitCheck and an instruction to which we want to
merge that ClinitCheck. This may happen as a consequence of
inlining, LICM and DCE as shown by a regression test.

Bug: 27929914
Change-Id: I7b3bddf7d8c79ce1828a4a751f1270cf2e3d61f0

1 files changed, 1 insertions, 0 deletions

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 8a2e83a9ef..bb28b84dab 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -5674,6 +5674,7 @@ class HLoadString : public HExpression<1> {
     SetPackedFlag<kFlagIsInDexCache>(true);
     DCHECK(!NeedsEnvironment());
     RemoveEnvironment();
+    SetSideEffects(SideEffects::None());
   }
 
   size_t InputCount() const OVERRIDE {