MIPS64: [turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

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 1605 matching lines @@
 }
 
 
 void MacroAssembler::Trunc_uw_d(FPURegister fd,
                                 FPURegister fs,
                                 FPURegister scratch) {
   Trunc_uw_d(fs, t8, scratch);
   mtc1(t8, fd);
 }
 
+void MacroAssembler::Trunc_ul_d(FPURegister fd, FPURegister fs,
+                                FPURegister scratch) {
+  Trunc_ul_d(fs, t8, scratch);
+  dmtc1(t8, fd);
+}
+
 
 void MacroAssembler::Trunc_w_d(FPURegister fd, FPURegister fs) {
   trunc_w_d(fd, fs);
 }
 
 
 void MacroAssembler::Round_w_d(FPURegister fd, FPURegister fs) {
   round_w_d(fd, fs);
 }
 
@@ skipping 34 matching lines @@
   Branch(&done);
   // Simple conversion.
   bind(&simple_convert);
   trunc_w_d(scratch, fd);
   mfc1(rs, scratch);
 
   bind(&done);
 }
 
 
+void MacroAssembler::Trunc_ul_d(FPURegister fd, Register rs,
+                                FPURegister scratch) {
+  DCHECK(!fd.is(scratch));
+  DCHECK(!rs.is(at));
+
+  // Load 2^63 into scratch as its float representation.
+  li(at, 0x43e0000000000000);
+  dmtc1(at, scratch);
+
+  // Test if scratch > fd.
+  // If fd < 2^63 we can convert it normally.
+  Label simple_convert, done;
+  BranchF(&simple_convert, NULL, lt, fd, scratch);
+
+  // First we subtract 2^63 from fd, then trunc it to rs
+  // and add 2^63 to rs.
+  sub_d(scratch, fd, scratch);
+  trunc_l_d(scratch, scratch);
+  dmfc1(rs, scratch);
+  Or(rs, rs, Operand(1UL << 63));

[Alan Li, 2015/11/20 13:35:22]

maybe splitting the Or into LI and ORI, and put ORI in the delay slot is better?

+  Branch(&done);
+
+  // Simple conversion.
+  bind(&simple_convert);
+  trunc_l_d(scratch, fd);
+  dmfc1(rs, scratch);
+
+  bind(&done);
+}
+
+
 void MacroAssembler::Madd_d(FPURegister fd, FPURegister fr, FPURegister fs,
     FPURegister ft, FPURegister scratch) {
   if (0) {  // TODO(plind): find reasonable arch-variant symbol names.
     madd_d(fd, fr, fs, ft);
   } else {
     // Can not change source regs's value.
     DCHECK(!fr.is(scratch) && !fs.is(scratch) && !ft.is(scratch));
     mul_d(scratch, fs, ft);
     add_d(fd, fr, scratch);
   }
@@ skipping 4538 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