Implemented the RoundInt64ToFloat32 TurboFan operator for x64, arm64, and mips64.

src/x64/assembler-x64.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 "src/x64/assembler-x64.h"
 
 #include <cstring>
 
 #if V8_TARGET_ARCH_X64
 
@@ skipping 3147 matching lines @@
 void Assembler::cvtlsi2ss(XMMRegister dst, Register src) {
   EnsureSpace ensure_space(this);
   emit(0xF3);
   emit_optional_rex_32(dst, src);
   emit(0x0F);
   emit(0x2A);
   emit_sse_operand(dst, src);
 }
 
 
+void Assembler::cvtqsi2ss(XMMRegister dst, const Operand& src) {
+  DCHECK(!IsEnabled(AVX));
+  EnsureSpace ensure_space(this);
+  emit(0xF3);
+  emit_rex_64(dst, src);
+  emit(0x0F);
+  emit(0x2A);
+  emit_sse_operand(dst, src);
+}
+
+
+void Assembler::cvtqsi2ss(XMMRegister dst, Register src) {
+  DCHECK(!IsEnabled(AVX));
+  EnsureSpace ensure_space(this);
+  emit(0xF3);
+  emit_rex_64(dst, src);
+  emit(0x0F);
+  emit(0x2A);
+  emit_sse_operand(dst, src);
+}
+
+
 void Assembler::cvtqsi2sd(XMMRegister dst, const Operand& src) {
   DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF2);
   emit_rex_64(dst, src);
   emit(0x0F);
   emit(0x2A);
   emit_sse_operand(dst, src);
 }
 
@@ skipping 899 matching lines @@
 
 bool RelocInfo::IsInConstantPool() {
   return false;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64