Harmony: optimize Math.clz32.

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 62a3b76cf2db79f18f76d58bc8205be2d6bf80fa..f3500c77870423402e18e5fb46eb27fb3f77e9d8 100644
--- a/src/a64/lithium-codegen-a64.cc
+++ b/src/a64/lithium-codegen-a64.cc
@@ -3852,6 +3852,13 @@ void LCodeGen::DoMathLog(LMathLog* instr) {
 }
 
 
+void LCodeGen::DoMathClz32(LMathClz32* instr) {
+  Register input = ToRegister(instr->value());
+  Register result = ToRegister(instr->result());

[m.m.capewell, 2014/02/19 12:24:25]

The input and result should use ToRegister32, otherwise the number of leading
zeroes may be 32 more than expected.

+  __ Clz(result, input);
+}
+
+
 void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
   DoubleRegister input = ToDoubleRegister(instr->value());
   DoubleRegister result = ToDoubleRegister(instr->result());