MIPS64: Implemented the RoundUint64ToFloat64 TurboFan operator for x64 and arm64.

src/mips64/macro-assembler-mips64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
@@ skipping 1524 matching lines @@
   li(at, 0x41E00000);
   mtc1(zero_reg, scratch);
   mthc1(at, scratch);
   // Add it to fd.
   add_d(fd, fd, scratch);
 
   bind(&conversion_done);
 }
 
 
+void MacroAssembler::Cvt_d_ul(FPURegister fd, FPURegister fs) {
+  // Move the data from fs to t8.
+  dmfc1(t8, fs);
+  Cvt_d_ul(fd, t8);
+}
+
+
+void MacroAssembler::Cvt_d_ul(FPURegister fd, Register rs) {
+  // Convert rs to a FP value in fd.
+
+  DCHECK(!rs.is(t9));
+  DCHECK(!rs.is(at));
+
+  Label positive, conversion_done;
+
+  Branch(&positive, ge, rs, Operand(zero_reg));
+
+  // Rs >= 2^31.
+  andi(t9, rs, 1);
+  dsrl(rs, rs, 1);
+  or_(t9, t9, rs);
+  dmtc1(t9, fd);
+  cvt_d_l(fd, fd);
+  Branch(USE_DELAY_SLOT, &conversion_done);
+  add_d(fd, fd, fd);  // In delay slot.
+
+  bind(&positive);
+  // Rs < 2^31, we can do simple conversion.
+  dmtc1(rs, fd);
+  cvt_d_l(fd, fd);
+
+  bind(&conversion_done);
+}
+
+
 void MacroAssembler::Round_l_d(FPURegister fd, FPURegister fs) {
   round_l_d(fd, fs);
 }
 
 
 void MacroAssembler::Floor_l_d(FPURegister fd, FPURegister fs) {
   floor_l_d(fd, fs);
 }
 
 
@@ skipping 4641 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64