From 39e3eedde9cea5b1e31cb7dae09dd1f66f73a706 Mon Sep 17 00:00:00 2001
From: CAD97 <cad97@cad97.com>
Date: Mon, 3 Feb 2020 14:54:02 -0500
Subject: [PATCH] Add inherent impls for unchecked math intrinsics

---
 src/libcore/num/mod.rs | 102 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 39c7d6d24ed04..4ec68b4ab0063 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -710,6 +710,23 @@ $EndFeature, "
             }
         }
 
+        doc_comment! {
+            concat!("Unchecked integer addition. Computes `self + rhs, assuming overflow
+cannot occur. This results in undefined behavior when `self + rhs > ", stringify!($SelfT),
+"::max_value()` or `self + rhs < ", stringify!($SelfT), "::min_value()`."),
+            #[unstable(
+                feature = "unchecked_math",
+                reason = "niche optimization path",
+                issue = "none",
+            )]
+            #[must_use = "this returns the result of the operation, \
+                          without modifying the original"]
+            #[inline]
+            pub unsafe fn unchecked_add(self, rhs: Self) -> Self {
+                intrinsics::unchecked_add(self, rhs)
+            }
+        }
+
         doc_comment! {
             concat!("Checked integer subtraction. Computes `self - rhs`, returning `None` if
 overflow occurred.
@@ -734,6 +751,23 @@ $EndFeature, "
             }
         }
 
+        doc_comment! {
+            concat!("Unchecked integer subtraction. Computes `self - rhs, assuming overflow
+cannot occur. This results in undefined behavior when `self - rhs > ", stringify!($SelfT),
+"::max_value()` or `self - rhs < ", stringify!($SelfT), "::min_value()`."),
+            #[unstable(
+                feature = "unchecked_math",
+                reason = "niche optimization path",
+                issue = "none",
+            )]
+            #[must_use = "this returns the result of the operation, \
+                          without modifying the original"]
+            #[inline]
+            pub unsafe fn unchecked_sub(self, rhs: Self) -> Self {
+                intrinsics::unchecked_sub(self, rhs)
+            }
+        }
+
         doc_comment! {
             concat!("Checked integer multiplication. Computes `self * rhs`, returning `None` if
 overflow occurred.
@@ -758,6 +792,23 @@ $EndFeature, "
             }
         }
 
+        doc_comment! {
+            concat!("Unchecked integer multiplication. Computes `self * rhs, assuming overflow
+cannot occur. This results in undefined behavior when `self * rhs > ", stringify!($SelfT),
+"::max_value()` or `self * rhs < ", stringify!($SelfT), "::min_value()`."),
+            #[unstable(
+                feature = "unchecked_math",
+                reason = "niche optimization path",
+                issue = "none",
+            )]
+            #[must_use = "this returns the result of the operation, \
+                          without modifying the original"]
+            #[inline]
+            pub unsafe fn unchecked_mul(self, rhs: Self) -> Self {
+                intrinsics::unchecked_mul(self, rhs)
+            }
+        }
+
         doc_comment! {
             concat!("Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0`
 or the division results in overflow.
@@ -2856,6 +2907,23 @@ assert_eq!((", stringify!($SelfT), "::max_value() - 2).checked_add(3), None);",
             }
         }
 
+        doc_comment! {
+            concat!("Unchecked integer addition. Computes `self + rhs, assuming overflow
+cannot occur. This results in undefined behavior when `self + rhs > ", stringify!($SelfT),
+"::max_value()` or `self + rhs < ", stringify!($SelfT), "::min_value()`."),
+            #[unstable(
+                feature = "unchecked_math",
+                reason = "niche optimization path",
+                issue = "none",
+            )]
+            #[must_use = "this returns the result of the operation, \
+                          without modifying the original"]
+            #[inline]
+            pub unsafe fn unchecked_add(self, rhs: Self) -> Self {
+                intrinsics::unchecked_add(self, rhs)
+            }
+        }
+
         doc_comment! {
             concat!("Checked integer subtraction. Computes `self - rhs`, returning
 `None` if overflow occurred.
@@ -2878,6 +2946,23 @@ assert_eq!(0", stringify!($SelfT), ".checked_sub(1), None);", $EndFeature, "
             }
         }
 
+        doc_comment! {
+            concat!("Unchecked integer subtraction. Computes `self - rhs, assuming overflow
+cannot occur. This results in undefined behavior when `self - rhs > ", stringify!($SelfT),
+"::max_value()` or `self - rhs < ", stringify!($SelfT), "::min_value()`."),
+            #[unstable(
+                feature = "unchecked_math",
+                reason = "niche optimization path",
+                issue = "none",
+            )]
+            #[must_use = "this returns the result of the operation, \
+                          without modifying the original"]
+            #[inline]
+            pub unsafe fn unchecked_sub(self, rhs: Self) -> Self {
+                intrinsics::unchecked_sub(self, rhs)
+            }
+        }
+
         doc_comment! {
             concat!("Checked integer multiplication. Computes `self * rhs`, returning
 `None` if overflow occurred.
@@ -2900,6 +2985,23 @@ assert_eq!(", stringify!($SelfT), "::max_value().checked_mul(2), None);", $EndFe
             }
         }
 
+        doc_comment! {
+            concat!("Unchecked integer multiplication. Computes `self * rhs, assuming overflow
+cannot occur. This results in undefined behavior when `self * rhs > ", stringify!($SelfT),
+"::max_value()` or `self * rhs < ", stringify!($SelfT), "::min_value()`."),
+            #[unstable(
+                feature = "unchecked_math",
+                reason = "niche optimization path",
+                issue = "none",
+            )]
+            #[must_use = "this returns the result of the operation, \
+                          without modifying the original"]
+            #[inline]
+            pub unsafe fn unchecked_mul(self, rhs: Self) -> Self {
+                intrinsics::unchecked_mul(self, rhs)
+            }
+        }
+
         doc_comment! {
             concat!("Checked integer division. Computes `self / rhs`, returning `None`
 if `rhs == 0`.