From 367ff5c2665933673a53bee3fa85a99e66998828 Mon Sep 17 00:00:00 2001
From: Jim Blandy <jimb@mozilla.com>
Date: Thu, 30 Sep 2010 10:57:58 -0700
Subject: [PATCH] Bug 514570: Simplify code generated for tests against 'null',
 in cases where we might as well test the whole value. r=dvander

---
 js/src/methodjit/PunboxAssembler.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/js/src/methodjit/PunboxAssembler.h b/js/src/methodjit/PunboxAssembler.h
index a23e47ec4d07..bde46d72a306 100644
--- a/js/src/methodjit/PunboxAssembler.h
+++ b/js/src/methodjit/PunboxAssembler.h
@@ -228,8 +228,7 @@ class Assembler : public BaseAssembler
 
     Jump testNull(Assembler::Condition cond, Address address) {
         loadValue(address, Registers::ValueReg);
-        convertValueToType(Registers::ValueReg);
-        return branchPtr(cond, Registers::ValueReg, ImmShiftedTag(JSVAL_SHIFTED_TAG_NULL));
+        return branchPtr(cond, Registers::ValueReg, Imm64(JSVAL_BITS(JSVAL_NULL)));
     }
 
     Jump testInt32(Assembler::Condition cond, RegisterID reg) {