Merged r12362 into 3.12 branch.

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 8869a3e98d1b9d9fe89836d731b6e59ac3b94af2..1ae34a25d5718dd8926201bfad3d47d53eb59a41 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -3674,7 +3674,27 @@ void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
 }
 
 
+void LCodeGen::DeoptIfTaggedButNotSmi(LEnvironment* environment,
+                                      HValue* value,
+                                      LOperand* operand) {
+  if (value->representation().IsTagged() && !value->type().IsSmi()) {
+    if (operand->IsRegister()) {
+      __ test(ToRegister(operand), Immediate(kSmiTagMask));
+    } else {
+      __ test(ToOperand(operand), Immediate(kSmiTagMask));
+    }
+    DeoptimizeIf(not_zero, environment);
+  }
+}
+
+
 void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
+  DeoptIfTaggedButNotSmi(instr->environment(),
+                         instr->hydrogen()->length(),
+                         instr->length());
+  DeoptIfTaggedButNotSmi(instr->environment(),
+                         instr->hydrogen()->index(),
+                         instr->index());
   if (instr->index()->IsConstantOperand()) {
     int constant_index =
         ToInteger32(LConstantOperand::cast(instr->index()));