MIPS: Orthogonalize Lithium binary op instructions.

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 6659b6c73dacf1b1861dd60cdab12a55e73301b0..3518f137a638ce6d7be42fce23f956999f118ccd 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4944,14 +4944,18 @@ void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
 
   Register input_reg = ToRegister(input);
 
-  DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
+  if (instr->hydrogen()->value()->representation().IsSmi()) {
+    __ SmiUntag(input_reg);
+  } else {
+    DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
 
-  // Let the deferred code handle the HeapObject case.
-  __ JumpIfNotSmi(input_reg, deferred->entry());
+    // Let the deferred code handle the HeapObject case.
+    __ JumpIfNotSmi(input_reg, deferred->entry());
 
-  // Smi to int32 conversion.
-  __ SmiUntag(input_reg);
-  __ bind(deferred->exit());
+    // Smi to int32 conversion.
+    __ SmiUntag(input_reg);
+    __ bind(deferred->exit());
+  }
 }