MIPS: Handle holes in smi-untag from LoadKeyed requiring hole handling.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index ae0d6283f44c1a483964506e5644fbabccbf5ea8..49743fd5218bf86c78e825d67c2ccf1bf9064c38 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4610,6 +4610,22 @@ void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
     __ And(scratch, input, Operand(kHeapObjectTag));
     __ SmiUntag(result, input);
     DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
+  } else if (instr->hydrogen()->value()->IsLoadKeyed()) {
+    HLoadKeyed* load = HLoadKeyed::cast(instr->hydrogen()->value());
+    if (load->UsesMustHandleHole()) {
+      __ And(scratch, input, Operand(kHeapObjectTag));
+      __ SmiUntag(result, input);
+      if (load->hole_mode() == ALLOW_RETURN_HOLE) {
+        Label done;
+        __ Branch(&done, eq, scratch, Operand(zero_reg));
+        __ li(result, Operand(Smi::FromInt(0)));
+        __ bind(&done);
+      } else {
+        DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
+      }
+    } else {
+      __ SmiUntag(result, input);
+    }
   } else {
     __ SmiUntag(result, input);
   }