Fix String.equals() for moveable String.class.

If the String.class is moveable (i.e. running without boot
image), the instanceof check emitted by the JIT in the
String.equals() intrinsic would require read barriers.
As we do not really care about the performance of running
without the boot image, disable the intrinsic in this case.

Test: 669-moveable-string-class-equals (--jit)
Bug: 68181300
Change-Id: I39c9f9935e0482b3b30f1ae5cd23515cbda0603b

1 files changed, 7 insertions, 0 deletions

diff --git a/compiler/optimizing/intrinsics_mips.cc b/compiler/optimizing/intrinsics_mips.cc
index 4a8fbf26ce..140526a018 100644
--- a/compiler/optimizing/intrinsics_mips.cc
+++ b/compiler/optimizing/intrinsics_mips.cc
@@ -2062,6 +2062,13 @@ void IntrinsicCodeGeneratorMIPS::VisitStringCompareTo(HInvoke* invoke) {
 
 // boolean java.lang.String.equals(Object anObject)
 void IntrinsicLocationsBuilderMIPS::VisitStringEquals(HInvoke* invoke) {
+  if (kEmitCompilerReadBarrier &&
+      !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+      !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+    // No support for this odd case (String class is moveable, not in the boot image).
+    return;
+  }
+
   LocationSummary* locations =
       new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
   locations->SetInAt(0, Location::RequiresRegister());