Support conversion of clamped double values for pixel arrays in Crankshaft.

src/x64/macro-assembler-x64.cc

 // Copyright 2011 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 2552 matching lines @@
                               Label* fail,
                               bool is_heap_object) {
   if (!is_heap_object) {
     JumpIfSmi(obj, fail);
   }
   Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
   j(not_equal, fail);
 }
 
 
+void MacroAssembler::ClampUint8(Register reg) {
+  Label done;
+  testl(reg, Immediate(0xFFFFFF00));
+  j(zero, &done, Label::kNear);
+  setcc(negative, reg);  // 1 if negative, 0 if positive.
+  decb(reg);  // 0 if negative, 255 if positive.
+  bind(&done);
+}
+
+
+void MacroAssembler::ClampDoubleToUint8(XMMRegister input_reg,
+                                        XMMRegister temp_xmm_reg,
+                                        Register result_reg,
+                                        Register temp_reg) {
+  Label done;
+  Set(result_reg, 0);
+  xorps(temp_xmm_reg, temp_xmm_reg);
+  ucomisd(input_reg, temp_xmm_reg);
+  j(below, &done, Label::kNear);
+  uint64_t one_half = BitCast<uint64_t, double>(0.5);
+  Set(temp_reg, one_half);
+  movq(temp_xmm_reg, temp_reg);
+  addsd(temp_xmm_reg, input_reg);
+  cvttsd2si(result_reg, temp_xmm_reg);
+  testl(result_reg, Immediate(0xFFFFFF00));
+  j(zero, &done, Label::kNear);
+  Set(result_reg, 255);
+  bind(&done);
+}
+
+
 void MacroAssembler::AbortIfNotNumber(Register object) {
   Label ok;
   Condition is_smi = CheckSmi(object);
   j(is_smi, &ok, Label::kNear);
   Cmp(FieldOperand(object, HeapObject::kMapOffset),
       isolate()->factory()->heap_number_map());
   Assert(equal, "Operand not a number");
   bind(&ok);
 }
 
@@ skipping 1070 matching lines @@
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64