diff --git a/src/xenia/cpu/backend/x64/x64_sequences.cc b/src/xenia/cpu/backend/x64/x64_sequences.cc
index dc642603d..6a5880d5f 100644
--- a/src/xenia/cpu/backend/x64/x64_sequences.cc
+++ b/src/xenia/cpu/backend/x64/x64_sequences.cc
@@ -1453,12 +1453,32 @@ struct CONVERT_I32_F64
 struct CONVERT_I64_F64
     : Sequence<CONVERT_I64_F64, I<OPCODE_CONVERT, I64Op, F64Op>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    // Copy src1.
+    e.movq(e.rcx, i.src1);
+
     // TODO(benvanik): saturation check? cvtt* (trunc?)
     if (i.instr->flags == ROUND_TO_ZERO) {
       e.vcvttsd2si(i.dest, i.src1);
     } else {
       e.vcvtsd2si(i.dest, i.src1);
     }
+
+    // 0x8000000000000000
+    e.mov(e.rax, 0x1);
+    e.shl(e.rax, 63);
+
+    // Saturate positive overflow
+    // TODO(DrChat): Find a shorter equivalent sequence.
+    // if (result ind. && src1 >= 0)
+    //   result = 0x7FFFFFFFFFFFFFFF;
+    e.cmp(e.rax, i.dest);
+    e.sete(e.al);
+    e.movzx(e.rax, e.al);
+    e.shr(e.rcx, 63);
+    e.xor_(e.rcx, 0x01);
+    e.and_(e.rax, e.rcx);
+
+    e.sub(i.dest, e.rax);
   }
 };
 struct CONVERT_F32_I32
diff --git a/src/xenia/cpu/ppc/testing/instr_fcti.s b/src/xenia/cpu/ppc/testing/instr_fctixz.s
similarity index 50%
rename from src/xenia/cpu/ppc/testing/instr_fcti.s
rename to src/xenia/cpu/ppc/testing/instr_fctixz.s
index 3ea41eeec..c2df12eaf 100644
--- a/src/xenia/cpu/ppc/testing/instr_fcti.s
+++ b/src/xenia/cpu/ppc/testing/instr_fctixz.s
@@ -95,3 +95,100 @@ test_fctiwz_10:
 #   blr
 #   #_ REGISTER_OUT f0 0xfff4000000000000
 #   #_ REGISTER_OUT f1 0x0000000080000000
+
+# +0
+test_fctidz_1:
+  #_ REGISTER_IN f0 0x0000000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x0000000000000000
+  #_ REGISTER_OUT f1 0x0000000000000000
+
+# -0
+test_fctidz_2:
+  #_ REGISTER_IN f0 0x8000000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x8000000000000000
+  #_ REGISTER_OUT f1 0x0000000000000000
+
+# smallest positive subnormal
+test_fctidz_3:
+  #_ REGISTER_IN f0 0x0000000000000001
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x0000000000000001
+  #_ REGISTER_OUT f1 0x0000000000000000
+
+# largest subnormal
+test_fctidz_4:
+  #_ REGISTER_IN f0 0x000fffffffffffff
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x000fffffffffffff
+  #_ REGISTER_OUT f1 0x0000000000000000
+
+# +1
+test_fctidz_5:
+  #_ REGISTER_IN f0 0x3ff0000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x3ff0000000000000
+  #_ REGISTER_OUT f1 0x0000000000000001
+
+# -1
+test_fctidz_6:
+  #_ REGISTER_IN f0 0xbff0000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0xbff0000000000000
+  #_ REGISTER_OUT f1 0xffffffffffffffff
+
+# -(2^31)
+test_fctidz_7:
+  #_ REGISTER_IN f0 0xc1e0000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0xc1e0000000000000
+  #_ REGISTER_OUT f1 0xffffffff80000000
+
+# 2^31 - 1
+test_fctidz_8:
+  #_ REGISTER_IN f0 0x41dfffffffc00000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x41dfffffffc00000
+  #_ REGISTER_OUT f1 0x000000007fffffff
+
+# +infinity
+test_fctidz_9:
+  #_ REGISTER_IN f0 0x7ff0000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0x7ff0000000000000
+  #_ REGISTER_OUT f1 0x7fffffffffffffff
+
+# -infinity
+test_fctidz_10:
+  #_ REGISTER_IN f0 0xfff0000000000000
+  fctidz f1, f0
+  blr
+  #_ REGISTER_OUT f0 0xfff0000000000000
+  #_ REGISTER_OUT f1 0x8000000000000000
+
+# TODO(DrChat): Xenia doesn't handle NaNs yet.
+# # QNaN
+# test_fctidz_11:
+#   #_ REGISTER_IN f0 0xfff8000000000000
+#   fctidz f1, f0
+#   blr
+#   #_ REGISTER_OUT f0 0xfff8000000000000
+#   #_ REGISTER_OUT f1 0x8000000000000000
+# 
+# # SNaN
+# test_fctidz_12:
+#   #_ REGISTER_IN f0 0xfff4000000000000
+#   fctidz f1, f0
+#   blr
+#   #_ REGISTER_OUT f0 0xfff4000000000000
+#   #_ REGISTER_OUT f1 0x8000000000000000