MIPS64: [turbofan] Implemented the TruncateFloat32ToUint64 TurboFan operator.

src/mips64/macro-assembler-mips64.cc

Index: src/mips64/macro-assembler-mips64.cc
diff --git a/src/mips64/macro-assembler-mips64.cc b/src/mips64/macro-assembler-mips64.cc
index dff40e5e74eabbd031c6c82241c3eb963b35de41..92c5d5becf07008ed62e426cd190bc95c7d3d071 100644
--- a/src/mips64/macro-assembler-mips64.cc
+++ b/src/mips64/macro-assembler-mips64.cc
@@ -1628,6 +1628,13 @@ void MacroAssembler::Trunc_ul_d(FPURegister fd, FPURegister fs,
 }
 
 
+void MacroAssembler::Trunc_ul_s(FPURegister fd, FPURegister fs,
+                                FPURegister scratch) {
+  Trunc_ul_s(fs, t8, scratch);
+  dmtc1(t8, fd);
+}
+
+
 void MacroAssembler::Trunc_w_d(FPURegister fd, FPURegister fs) {
   trunc_w_d(fd, fs);
 }
@@ -1686,7 +1693,7 @@ void MacroAssembler::Trunc_ul_d(FPURegister fd, Register rs,
   DCHECK(!fd.is(scratch));
   DCHECK(!rs.is(at));
 
-  // Load 2^63 into scratch as its float representation.
+  // Load 2^63 into scratch as its double representation.
   li(at, 0x43e0000000000000);
   dmtc1(at, scratch);
 
@@ -1712,6 +1719,37 @@ void MacroAssembler::Trunc_ul_d(FPURegister fd, Register rs,
 }
 
 
+void MacroAssembler::Trunc_ul_s(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, 0x5f000000);
+  dmtc1(at, scratch);
+
+  // Test if scratch > fd.
+  // If fd < 2^63 we can convert it normally.
+  Label simple_convert, done;
+  BranchF32(&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_s(scratch, fd, scratch);
+  trunc_l_s(scratch, scratch);
+  dmfc1(rs, scratch);
+  Or(rs, rs, Operand(1UL << 63));
+  Branch(&done);
+
+  // Simple conversion.
+  bind(&simple_convert);
+  trunc_l_s(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.