Improve constant element index access code generation

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 f3bcf1abc3fc1974af2b7bd55a8aeec35aec8269..0687e82550d37411f34fe2df806718bb84d1bfce 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -3681,8 +3681,14 @@ void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
 
 void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
   if (instr->index()->IsConstantOperand()) {
-    __ cmp(ToOperand(instr->length()),
-           Immediate(ToInteger32(LConstantOperand::cast(instr->index()))));
+    int constant_index =
+        ToInteger32(LConstantOperand::cast(instr->index()));
+    if (instr->hydrogen()->length()->representation().IsTagged()) {
+      __ cmp(ToOperand(instr->length()),
+             Immediate(Smi::FromInt(constant_index)));
+    } else {
+      __ cmp(ToOperand(instr->length()), Immediate(constant_index));
+    }
     DeoptimizeIf(below_equal, instr->environment());
   } else {
     __ cmp(ToRegister(instr->index()), ToOperand(instr->length()));