Intel: Branch reordering and port arm EmitNumberUntagD() Improvement

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5290 matching lines @@
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 Register temp_reg,
                                 XMMRegister result_reg,
                                 bool can_convert_undefined_to_nan,
                                 bool deoptimize_on_minus_zero,
                                 LEnvironment* env,
                                 NumberUntagDMode mode) {
-  Label load_smi, done;
+  Label convert, load_smi, done;
 
   if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
     // Smi check.
     __ JumpIfSmi(input_reg, &load_smi, Label::kNear);
 
     // Heap number map check.
     __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
            factory()->heap_number_map());
-    if (!can_convert_undefined_to_nan) {
+    if (can_convert_undefined_to_nan) {
+      __ j(not_equal, &convert, Label::kNear);
+    } else {
       DeoptimizeIf(not_equal, env);
-    } else {
-      Label heap_number, convert;
-      __ j(equal, &heap_number, Label::kNear);
+    }
 
-      // Convert undefined (and hole) to NaN.
-      __ cmp(input_reg, factory()->undefined_value());
-      DeoptimizeIf(not_equal, env);
-
-      __ bind(&convert);
-      ExternalReference nan =
-          ExternalReference::address_of_canonical_non_hole_nan();
-      __ movdbl(result_reg, Operand::StaticVariable(nan));
-      __ jmp(&done, Label::kNear);
-
-      __ bind(&heap_number);
-    }
     // Heap number to XMM conversion.
     __ movdbl(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
+
     if (deoptimize_on_minus_zero) {
       XMMRegister xmm_scratch = xmm0;
       __ xorps(xmm_scratch, xmm_scratch);
       __ ucomisd(result_reg, xmm_scratch);
       __ j(not_zero, &done, Label::kNear);
       __ movmskpd(temp_reg, result_reg);
       __ test_b(temp_reg, 1);
       DeoptimizeIf(not_zero, env);
     }
     __ jmp(&done, Label::kNear);
+
+    if (can_convert_undefined_to_nan) {
+      __ bind(&convert);
+
+      // Convert undefined (and hole) to NaN.
+      __ cmp(input_reg, factory()->undefined_value());
+      DeoptimizeIf(not_equal, env);
+
+      ExternalReference nan =
+          ExternalReference::address_of_canonical_non_hole_nan();
+      __ movdbl(result_reg, Operand::StaticVariable(nan));
+      __ jmp(&done, Label::kNear);
+    }
   } else {
     ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
   }
 
   __ bind(&load_smi);
   // Smi to XMM conversion. Clobbering a temp is faster than re-tagging the
   // input register since we avoid dependencies.
   __ mov(temp_reg, input_reg);
   __ SmiUntag(temp_reg);  // Untag smi before converting to float.
   __ Cvtsi2sd(result_reg, Operand(temp_reg));
@@ skipping 997 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32