[builtins] Make Math.max and Math.min fast by default.

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index b12de805e2c958913cb3badf3f032a3b8d7abf62..4043ea207126a3494720ba845c1de860ac57b4f0 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -1416,6 +1416,122 @@ void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
 
 
 // static
+void Builtins::Generate_MathMaxMin(MacroAssembler* masm, MathMaxMinKind kind) {
+  // ----------- S t a t e -------------
+  //  -- eax                 : number of arguments
+  //  -- esp[0]              : return address
+  //  -- esp[(argc - n) * 8] : arg[n] (zero-based)
+  //  -- esp[(argc + 1) * 8] : receiver
+  // -----------------------------------
+  Condition const cc = (kind == MathMaxMinKind::kMin) ? below : above;
+  Heap::RootListIndex const root_index =
+      (kind == MathMaxMinKind::kMin) ? Heap::kInfinityValueRootIndex
+                                     : Heap::kMinusInfinityValueRootIndex;
+  XMMRegister const reg = (kind == MathMaxMinKind::kMin) ? xmm1 : xmm0;
+
+  // Load the accumulator with the default return value (either -Infinity or
+  // +Infinity), with the tagged value in edx and the double value in xmm0.
+  __ LoadRoot(edx, root_index);
+  __ movsd(xmm0, FieldOperand(edx, HeapNumber::kValueOffset));
+  __ Move(ecx, eax);
+
+  Label done_loop, loop;
+  __ bind(&loop);
+  {
+    // Check if all parameters done.
+    __ test(ecx, ecx);
+    __ j(zero, &done_loop);
+
+    // Load the next parameter tagged value into ebx.
+    __ mov(ebx, Operand(esp, ecx, times_pointer_size, 0));
+
+    // Load the double value of the parameter into xmm1, maybe converting the
+    // parameter to a number first using the ToNumberStub if necessary.
+    Label convert, convert_smi, convert_number, done_convert;
+    __ bind(&convert);
+    __ JumpIfSmi(ebx, &convert_smi);
+    __ JumpIfRoot(FieldOperand(ebx, HeapObject::kMapOffset),
+                  Heap::kHeapNumberMapRootIndex, &convert_number);
+    {
+      // Parameter is not a Number, use the ToNumberStub to convert it.
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ SmiTag(eax);
+      __ SmiTag(ecx);
+      __ Push(eax);
+      __ Push(ecx);
+      __ Push(edx);
+      __ mov(eax, ebx);
+      ToNumberStub stub(masm->isolate());
+      __ CallStub(&stub);
+      __ mov(ebx, eax);
+      __ Pop(edx);
+      __ Pop(ecx);
+      __ Pop(eax);
+      {
+        // Restore the double accumulator value (xmm0).
+        Label restore_smi, done_restore;
+        __ JumpIfSmi(edx, &restore_smi, Label::kNear);
+        __ movsd(xmm0, FieldOperand(edx, HeapNumber::kValueOffset));
+        __ jmp(&done_restore, Label::kNear);
+        __ bind(&restore_smi);
+        __ SmiUntag(edx);
+        __ Cvtsi2sd(xmm0, edx);
+        __ SmiTag(edx);
+        __ bind(&done_restore);
+      }
+      __ SmiUntag(ecx);
+      __ SmiUntag(eax);
+    }
+    __ jmp(&convert);
+    __ bind(&convert_number);
+    __ movsd(xmm1, FieldOperand(ebx, HeapNumber::kValueOffset));
+    __ jmp(&done_convert, Label::kNear);
+    __ bind(&convert_smi);
+    __ SmiUntag(ebx);
+    __ Cvtsi2sd(xmm1, ebx);
+    __ SmiTag(ebx);
+    __ bind(&done_convert);
+
+    // Perform the actual comparison with the accumulator value on the left hand
+    // side (xmm0) and the next parameter value on the right hand side (xmm1).
+    Label compare_equal, compare_nan, compare_swap, done_compare;
+    __ ucomisd(xmm0, xmm1);
+    __ j(parity_even, &compare_nan, Label::kNear);
+    __ j(cc, &done_compare, Label::kNear);
+    __ j(equal, &compare_equal, Label::kNear);
+
+    // Result is on the right hand side.
+    __ bind(&compare_swap);
+    __ movaps(xmm0, xmm1);
+    __ mov(edx, ebx);
+    __ jmp(&done_compare, Label::kNear);
+
+    // At least one side is NaN, which means that the result will be NaN too.
+    __ bind(&compare_nan);
+    __ LoadRoot(edx, Heap::kNanValueRootIndex);
+    __ movsd(xmm0, FieldOperand(edx, HeapNumber::kValueOffset));
+    __ jmp(&done_compare, Label::kNear);
+
+    // Left and right hand side are equal, check for -0 vs. +0.
+    __ bind(&compare_equal);
+    __ movmskpd(edi, reg);
+    __ test(edi, Immediate(1));
+    __ j(not_zero, &compare_swap);
+
+    __ bind(&done_compare);
+    __ dec(ecx);
+    __ jmp(&loop);
+  }
+
+  __ bind(&done_loop);
+  __ PopReturnAddressTo(ecx);
+  __ lea(esp, Operand(esp, eax, times_pointer_size, kPointerSize));
+  __ PushReturnAddressFrom(ecx);
+  __ mov(eax, edx);
+  __ Ret();
+}
+
+// static
 void Builtins::Generate_NumberConstructor(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax                 : number of arguments