Refactor addsub.rs

Author: AaronKutch

src/int/addsub.rs

@@ -39,19 +39,9 @@ trait Addo: AddSub
 where
     <Self as Int>::UnsignedInt: UAddSub,
 {
-    fn addo(self, other: Self, overflow: &mut i32) -> Self {
-        *overflow = 0;
-        let result = AddSub::add(self, other);
-        if other >= Self::ZERO {
-            if result < self {
-                *overflow = 1;
-            }
-        } else {
-            if result >= self {
-                *overflow = 1;
-            }
-        }
-        result
+    fn addo(self, other: Self) -> (Self, bool) {
+        let sum = AddSub::add(self, other);
+        (sum, (other < Self::ZERO) != (sum < self))
     }
 }
 
@@ -62,19 +52,9 @@ trait Subo: AddSub
 where
     <Self as Int>::UnsignedInt: UAddSub,
 {
-    fn subo(self, other: Self, overflow: &mut i32) -> Self {
-        *overflow = 0;
-        let result = AddSub::sub(self, other);
-        if other >= Self::ZERO {
-            if result > self {
-                *overflow = 1;
-            }
-        } else {
-            if result <= self {
-                *overflow = 1;
-            }
-        }
-        result
+    fn subo(self, other: Self) -> (Self, bool) {
+        let sum = AddSub::sub(self, other);
+        (sum, (other < Self::ZERO) != (self < sum))
     }
 }
 
@@ -83,43 +63,34 @@ impl Subo for u128 {}
 
 intrinsics! {
     pub extern "C" fn __rust_i128_add(a: i128, b: i128) -> i128 {
-        __rust_u128_add(a as _, b as _) as _
+        AddSub::add(a,b)
     }
 
     pub extern "C" fn __rust_i128_addo(a: i128, b: i128) -> (i128, bool) {
-        let mut oflow = 0;
-        let r = a.addo(b, &mut oflow);
-        (r, oflow != 0)
+        a.addo(b)
     }
 
     pub extern "C" fn __rust_u128_add(a: u128, b: u128) -> u128 {
-        a.add(b)
+        AddSub::add(a,b)
     }
 
     pub extern "C" fn __rust_u128_addo(a: u128, b: u128) -> (u128, bool) {
-        let mut oflow = 0;
-        let r = a.addo(b, &mut oflow);
-        (r, oflow != 0)
+        a.addo(b)
     }
 
-
     pub extern "C" fn __rust_i128_sub(a: i128, b: i128) -> i128 {
-        __rust_u128_sub(a as _, b as _) as _
+        AddSub::sub(a,b)
     }
 
     pub extern "C" fn __rust_i128_subo(a: i128, b: i128) -> (i128, bool) {
-        let mut oflow = 0;
-        let r = a.subo(b, &mut oflow);
-        (r, oflow != 0)
+        a.subo(b)
     }
 
     pub extern "C" fn __rust_u128_sub(a: u128, b: u128) -> u128 {
-        a.sub(b)
+        AddSub::sub(a,b)
     }
 
     pub extern "C" fn __rust_u128_subo(a: u128, b: u128) -> (u128, bool) {
-        let mut oflow = 0;
-        let r = a.subo(b, &mut oflow);
-        (r, oflow != 0)
+        a.subo(b)
     }
 }