diff --git a/src/libcore/clone.rs b/src/libcore/clone.rs
index 97b9525da6715..d6d3bf9950528 100644
--- a/src/libcore/clone.rs
+++ b/src/libcore/clone.rs
@@ -106,7 +106,7 @@ pub trait Clone : Sized {
     /// `a.clone_from(&b)` is equivalent to `a = b.clone()` in functionality,
     /// but can be overridden to reuse the resources of `a` to avoid unnecessary
     /// allocations.
-    #[inline(always)]
+    #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn clone_from(&mut self, source: &Self) {
         *self = source.clone()
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index f133bd93c9178..a9f55dc27880b 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -168,7 +168,7 @@ pub trait Eq: PartialEq<Self> {
     //
     // This should never be implemented by hand.
     #[doc(hidden)]
-    #[inline(always)]
+    #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn assert_receiver_is_total_eq(&self) {}
 }
diff --git a/src/libcore/hash/sip.rs b/src/libcore/hash/sip.rs
index db12496b6f320..91fd01b36d495 100644
--- a/src/libcore/hash/sip.rs
+++ b/src/libcore/hash/sip.rs
@@ -239,7 +239,7 @@ impl<S: Sip> Hasher<S> {
     // except for composite types (that includes slices and str hashing because of delimiter).
     // Without this extra push the compiler is very reluctant to inline delimiter writes,
     // degrading performance substantially for the most common use cases.
-    #[inline(always)]
+    #[inline]
     fn short_write(&mut self, msg: &[u8]) {
         debug_assert!(msg.len() <= 8);
         let length = msg.len();
diff --git a/src/libcore/nonzero.rs b/src/libcore/nonzero.rs
index d93085e96dbb2..977438051d93b 100644
--- a/src/libcore/nonzero.rs
+++ b/src/libcore/nonzero.rs
@@ -42,7 +42,7 @@ pub struct NonZero<T: Zeroable>(T);
 impl<T: Zeroable> NonZero<T> {
     /// Creates an instance of NonZero with the provided value.
     /// You must indeed ensure that the value is actually "non-zero".
-    #[inline(always)]
+    #[inline]
     pub const unsafe fn new(inner: T) -> NonZero<T> {
         NonZero(inner)
     }
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index cbd59ed371377..a8094ab932bf6 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -695,7 +695,7 @@ macro_rules! int_impl {
         /// assert_eq!((-128i8).wrapping_div(-1), -128);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_div(self, rhs: Self) -> Self {
             self.overflowing_div(rhs).0
         }
@@ -721,7 +721,7 @@ macro_rules! int_impl {
         /// assert_eq!((-128i8).wrapping_rem(-1), 0);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_rem(self, rhs: Self) -> Self {
             self.overflowing_rem(rhs).0
         }
@@ -744,7 +744,7 @@ macro_rules! int_impl {
         /// assert_eq!((-128i8).wrapping_neg(), -128);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_neg(self) -> Self {
             self.overflowing_neg().0
         }
@@ -769,7 +769,7 @@ macro_rules! int_impl {
         /// assert_eq!((-1i8).wrapping_shl(8), -1);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_shl(self, rhs: u32) -> Self {
             unsafe {
                 intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT)
@@ -796,7 +796,7 @@ macro_rules! int_impl {
         /// assert_eq!((-128i8).wrapping_shr(8), -128);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_shr(self, rhs: u32) -> Self {
             unsafe {
                 intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT)
@@ -822,7 +822,7 @@ macro_rules! int_impl {
         /// assert_eq!((-128i8).wrapping_abs() as u8, 128);
         /// ```
         #[stable(feature = "no_panic_abs", since = "1.13.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_abs(self) -> Self {
             if self.is_negative() {
                 self.wrapping_neg()
@@ -1831,7 +1831,7 @@ macro_rules! uint_impl {
         /// assert_eq!(100u8.wrapping_div(10), 10);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_div(self, rhs: Self) -> Self {
             self / rhs
         }
@@ -1851,7 +1851,7 @@ macro_rules! uint_impl {
         /// assert_eq!(100u8.wrapping_rem(10), 0);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_rem(self, rhs: Self) -> Self {
             self % rhs
         }
@@ -1877,7 +1877,7 @@ macro_rules! uint_impl {
         /// assert_eq!(180u8.wrapping_neg(), (127 + 1) - (180u8 - (127 + 1)));
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_neg(self) -> Self {
             self.overflowing_neg().0
         }
@@ -1902,7 +1902,7 @@ macro_rules! uint_impl {
         /// assert_eq!(1u8.wrapping_shl(8), 1);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_shl(self, rhs: u32) -> Self {
             unsafe {
                 intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT)
@@ -1929,7 +1929,7 @@ macro_rules! uint_impl {
         /// assert_eq!(128u8.wrapping_shr(8), 128);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[inline(always)]
+        #[inline]
         pub fn wrapping_shr(self, rhs: u32) -> Self {
             unsafe {
                 intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT)
diff --git a/src/libcore/num/wrapping.rs b/src/libcore/num/wrapping.rs
index 6cc374b13b7b3..acdf685e850ab 100644
--- a/src/libcore/num/wrapping.rs
+++ b/src/libcore/num/wrapping.rs
@@ -19,7 +19,7 @@ macro_rules! sh_impl_signed {
         impl Shl<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn shl(self, other: $f) -> Wrapping<$t> {
                 if other < 0 {
                     Wrapping(self.0.wrapping_shr((-other & self::shift_max::$t as $f) as u32))
@@ -31,7 +31,7 @@ macro_rules! sh_impl_signed {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl ShlAssign<$f> for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn shl_assign(&mut self, other: $f) {
                 *self = *self << other;
             }
@@ -41,7 +41,7 @@ macro_rules! sh_impl_signed {
         impl Shr<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn shr(self, other: $f) -> Wrapping<$t> {
                 if other < 0 {
                     Wrapping(self.0.wrapping_shl((-other & self::shift_max::$t as $f) as u32))
@@ -53,7 +53,7 @@ macro_rules! sh_impl_signed {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl ShrAssign<$f> for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn shr_assign(&mut self, other: $f) {
                 *self = *self >> other;
             }
@@ -67,7 +67,7 @@ macro_rules! sh_impl_unsigned {
         impl Shl<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn shl(self, other: $f) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_shl((other & self::shift_max::$t as $f) as u32))
             }
@@ -75,7 +75,7 @@ macro_rules! sh_impl_unsigned {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl ShlAssign<$f> for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn shl_assign(&mut self, other: $f) {
                 *self = *self << other;
             }
@@ -85,7 +85,7 @@ macro_rules! sh_impl_unsigned {
         impl Shr<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn shr(self, other: $f) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_shr((other & self::shift_max::$t as $f) as u32))
             }
@@ -93,7 +93,7 @@ macro_rules! sh_impl_unsigned {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl ShrAssign<$f> for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn shr_assign(&mut self, other: $f) {
                 *self = *self >> other;
             }
@@ -127,7 +127,7 @@ macro_rules! wrapping_impl {
         impl Add for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn add(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_add(other.0))
             }
@@ -137,7 +137,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl AddAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn add_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self + other;
             }
@@ -147,7 +147,7 @@ macro_rules! wrapping_impl {
         impl Sub for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn sub(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_sub(other.0))
             }
@@ -157,7 +157,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl SubAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn sub_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self - other;
             }
@@ -167,7 +167,7 @@ macro_rules! wrapping_impl {
         impl Mul for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn mul(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_mul(other.0))
             }
@@ -177,7 +177,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl MulAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn mul_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self * other;
             }
@@ -187,7 +187,7 @@ macro_rules! wrapping_impl {
         impl Div for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn div(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_div(other.0))
             }
@@ -197,7 +197,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl DivAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn div_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self / other;
             }
@@ -207,7 +207,7 @@ macro_rules! wrapping_impl {
         impl Rem for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn rem(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0.wrapping_rem(other.0))
             }
@@ -217,7 +217,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl RemAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn rem_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self % other;
             }
@@ -227,7 +227,7 @@ macro_rules! wrapping_impl {
         impl Not for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn not(self) -> Wrapping<$t> {
                 Wrapping(!self.0)
             }
@@ -239,7 +239,7 @@ macro_rules! wrapping_impl {
         impl BitXor for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn bitxor(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0 ^ other.0)
             }
@@ -249,7 +249,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl BitXorAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn bitxor_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self ^ other;
             }
@@ -259,7 +259,7 @@ macro_rules! wrapping_impl {
         impl BitOr for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn bitor(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0 | other.0)
             }
@@ -269,7 +269,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl BitOrAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn bitor_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self | other;
             }
@@ -279,7 +279,7 @@ macro_rules! wrapping_impl {
         impl BitAnd for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
-            #[inline(always)]
+            #[inline]
             fn bitand(self, other: Wrapping<$t>) -> Wrapping<$t> {
                 Wrapping(self.0 & other.0)
             }
@@ -289,7 +289,7 @@ macro_rules! wrapping_impl {
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
         impl BitAndAssign for Wrapping<$t> {
-            #[inline(always)]
+            #[inline]
             fn bitand_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self & other;
             }
@@ -298,7 +298,7 @@ macro_rules! wrapping_impl {
         #[stable(feature = "wrapping_neg", since = "1.10.0")]
         impl Neg for Wrapping<$t> {
             type Output = Self;
-            #[inline(always)]
+            #[inline]
             fn neg(self) -> Self {
                 Wrapping(0) - self
             }
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 4f118f58441c4..b19e07b8578c0 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -244,7 +244,7 @@ pub unsafe fn replace<T>(dest: *mut T, mut src: T) -> T {
 ///     assert_eq!(std::ptr::read(y), 12);
 /// }
 /// ```
-#[inline(always)]
+#[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub unsafe fn read<T>(src: *const T) -> T {
     let mut tmp: T = mem::uninitialized();
@@ -278,7 +278,7 @@ pub unsafe fn read<T>(src: *const T) -> T {
 ///     assert_eq!(std::ptr::read_unaligned(y), 12);
 /// }
 /// ```
-#[inline(always)]
+#[inline]
 #[stable(feature = "ptr_unaligned", since = "1.17.0")]
 pub unsafe fn read_unaligned<T>(src: *const T) -> T {
     let mut tmp: T = mem::uninitialized();
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index 62c7e7aa1cce2..fa0c482e55c91 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -1105,7 +1105,7 @@ impl<'a, T> IntoIterator for &'a mut [T] {
     }
 }
 
-#[inline(always)]
+#[inline]
 fn size_from_ptr<T>(_: *const T) -> usize {
     mem::size_of::<T>()
 }
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 3862b4a2eb046..1df69a1b598e4 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -369,7 +369,7 @@ unsafe fn from_raw_parts_mut<'a>(p: *mut u8, len: usize) -> &'a mut str {
 ///
 /// assert_eq!("💖", sparkle_heart);
 /// ```
-#[inline(always)]
+#[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
     mem::transmute(v)
@@ -381,7 +381,7 @@ pub unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
 /// See the immutable version, [`from_utf8_unchecked()`][fromutf8], for more information.
 ///
 /// [fromutf8]: fn.from_utf8_unchecked.html
-#[inline(always)]
+#[inline]
 #[unstable(feature = "str_mut_extras", issue = "41119")]
 pub unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str {
     mem::transmute(v)
@@ -1380,7 +1380,7 @@ fn contains_nonascii(x: usize) -> bool {
 /// returning `true` in that case, or, if it is invalid, `false` with
 /// `iter` reset such that it is pointing at the first byte in the
 /// invalid sequence.
-#[inline(always)]
+#[inline]
 fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
     let mut index = 0;
     let len = v.len();
diff --git a/src/libcore/str/pattern.rs b/src/libcore/str/pattern.rs
index 5a007285e4873..3c9c1d6cab479 100644
--- a/src/libcore/str/pattern.rs
+++ b/src/libcore/str/pattern.rs
@@ -668,7 +668,7 @@ unsafe impl<'a, 'b> Searcher<'a> for StrSearcher<'a, 'b> {
         }
     }
 
-    #[inline(always)]
+    #[inline]
     fn next_match(&mut self) -> Option<(usize, usize)> {
         match self.searcher {
             StrSearcherImpl::Empty(..) => {
@@ -936,7 +936,7 @@ impl TwoWaySearcher {
         bytes.iter().fold(0, |a, &b| (1 << (b & 0x3f)) | a)
     }
 
-    #[inline(always)]
+    #[inline]
     fn byteset_contains(&self, byte: u8) -> bool {
         (self.byteset >> ((byte & 0x3f) as usize)) & 1 != 0
     }
@@ -946,7 +946,7 @@ impl TwoWaySearcher {
     // left to right. If v matches, we try to match u by scanning right to left.
     // How far we can jump when we encounter a mismatch is all based on the fact
     // that (u, v) is a critical factorization for the needle.
-    #[inline(always)]
+    #[inline]
     fn next<S>(&mut self, haystack: &[u8], needle: &[u8], long_period: bool)
         -> S::Output
         where S: TwoWayStrategy