A64: Use the result of compare IC in StringCompareAndBranch.

src/a64/lithium-codegen-a64.cc

Index: src/a64/lithium-codegen-a64.cc
diff --git a/src/a64/lithium-codegen-a64.cc b/src/a64/lithium-codegen-a64.cc
index 4282bc7b67b097fd777f8a328c94b7a3b935c3af..f3894d5445b7732972c6b5d325d444e79dee6c6b 100644
--- a/src/a64/lithium-codegen-a64.cc
+++ b/src/a64/lithium-codegen-a64.cc
@@ -5108,6 +5108,8 @@ void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
 
   Condition condition = TokenToCondition(op, false);
 
+  __ Tst(x0, x0);

[jbramley, 2014/02/05 13:01:41]

ARM (and AArch64) processors generally prefer "Cmp(x0, 0)". (I assume that the
condition can be either EQ or NE here.)

However, in this case, you're probably better off using EmitCompareAndBranch
because that will use Cbz or Cbnz if possible.

[ulan, 2014/02/05 13:09:21]

Done.

+
   EmitBranch(instr, condition);
 }