Fix a DCHECK failure in Arm64RelativePatcher with read barrier.

We could encounter an add immediate with
LinkerPatch::Type::kDexCacheArray for the
HLoadString::LoadKind::kDexCachePcRelative case of VisitLoadString if
the non-baker read barrier is enabled.

Bug: 28249352
Bug: 12687968
Change-Id: I226bea26f6a614cfabb0307805de7cedb3b54a7f

1 files changed, 8 insertions, 1 deletions

diff --git a/compiler/linker/arm64/relative_patcher_arm64.cc b/compiler/linker/arm64/relative_patcher_arm64.cc
index b4ecbd8c50..72771079be 100644
--- a/compiler/linker/arm64/relative_patcher_arm64.cc
+++ b/compiler/linker/arm64/relative_patcher_arm64.cc
@@ -210,7 +210,14 @@ void Arm64RelativePatcher::PatchPcRelativeReference(std::vector<uint8_t>* code,
   } else {
     if ((insn & 0xfffffc00) == 0x91000000) {
       // ADD immediate, 64-bit with imm12 == 0 (unset).
-      DCHECK(patch.GetType() == LinkerPatch::Type::kStringRelative) << patch.GetType();
+      if (!kEmitCompilerReadBarrier) {
+        DCHECK(patch.GetType() == LinkerPatch::Type::kStringRelative) << patch.GetType();
+      } else {
+        // With the read barrier (non-baker) enabled, it could be kDexCacheArray in the
+        // HLoadString::LoadKind::kDexCachePcRelative case of VisitLoadString().
+        DCHECK(patch.GetType() == LinkerPatch::Type::kStringRelative ||
+               patch.GetType() == LinkerPatch::Type::kDexCacheArray) << patch.GetType();
+      }
       shift = 0u;  // No shift for ADD.
     } else {
       // LDR 32-bit or 64-bit with imm12 == 0 (unset).