Let NaN flow as double into HBranch

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 ec87a9c72ed88b442efa294297e25d551426a076..dd28de87be2eec915a4f558b778e5b692200d209 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2134,6 +2134,16 @@ void LCodeGen::DoBranch(LBranch* instr) {
       ASSERT(!info()->IsStub());
       __ test(reg, Operand(reg));
       EmitBranch(true_block, false_block, not_equal);
+    } else if (type.IsJSArray()) {
+      EmitBranch(true_block, false_block, no_condition);
+    } else if (type.IsHeapNumber()) {

[Toon Verwaest, 2013/06/18 17:01:52]

ASSERT(!info()->IsStub());
XMM is not available for stubs.

+        CpuFeatureScope scope(masm(), SSE2);
+        __ xorps(xmm0, xmm0);
+        __ ucomisd(xmm0, FieldOperand(reg, HeapNumber::kValueOffset));
+        EmitBranch(true_block, false_block, not_equal);
+    } else if (type.IsString()) {
+        __ cmp(FieldOperand(reg, String::kLengthOffset), Immediate(0));
+        EmitBranch(true_block, false_block, not_equal);
     } else {
       Label* true_label = chunk_->GetAssemblyLabel(true_block);
       Label* false_label = chunk_->GetAssemblyLabel(false_block);
@@ -2229,8 +2239,10 @@ void LCodeGen::DoBranch(LBranch* instr) {
         __ bind(&not_heap_number);
       }
 
-      // We've seen something for the first time -> deopt.
-      DeoptimizeIf(no_condition, instr->environment());
+      if (expected != ToBooleanStub::all_types()) {
+        // We've seen something for the first time -> deopt.
+        DeoptimizeIf(no_condition, instr->environment());
+      }
     }
   }
 }