Inlining NumberIfFinite (ia32).

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
===================================================================
--- src/ia32/codegen-ia32.cc	(revision 4033)
+++ src/ia32/codegen-ia32.cc	(working copy)
@@ -6057,7 +6057,38 @@
   frame_->Push(&result);
 }
 
+void CodeGenerator::GenerateNumberIsFinite(ZoneList<Expression*>* args) {
+  ASSERT_EQ(args->length(), 1);
+  Load(args->at(0));
+  Result num = frame_->Pop();
+  num.ToRegister();
+  Result result = allocator_->Allocate();
 
+  Label done;
+  __ mov(result.reg(), Factory::true_value());
+  __ test(num.reg(), Immediate(kSmiTagMask));
+  ASSERT(kSmiTag == 0);
+  __ j(zero, &done);
+
+  // The number is finite if it is not a NaN or Infinite. Both values have
+  // exponent 11111111111b.
+  __ mov(num.reg(), FieldOperand(num.reg(), HeapNumber::kExponentOffset));
+  __ add(num.reg(), Operand(num.reg()));  // Move exponent to the high bits.
+  __ cmp(num.reg(), HeapNumber::kExponentMask << 1);
+
+  if (CpuFeatures::IsSupported(CMOV)) {
+    CpuFeatures::Scope use_cmov(CMOV);

[Søren Thygesen Gjesse, 2010/03/08 12:00:48]

If it makes sense to use cmov here then please implement the missing variant
taking a handle to avoid the additional move.

+    __ mov(num.reg(), Factory::false_value());
+    __ cmov(above_equal, result.reg(), Operand(num.reg()));
+  } else {
+    __ j(below, &done);
+    __ mov(result.reg(), Factory::false_value());
+  }
+
+  __ bind(&done);
+  frame_->Push(&result);
+}
+
 void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
   if (CheckForInlineRuntimeCall(node)) {
     return;