Make cast_(un)signed and wrapping_add be rustc_early_inline (rather than always)

scottmcm · scottmcm · commit 096c41f53d0e · 2025-08-05T20:45:19.000-07:00
Obviously there's way more that could do this, but I don't to do *all* of them at once.
diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs
@@ -225,7 +225,7 @@ macro_rules! int_impl {
         #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
-        #[inline(always)]
+        #[rustc_early_inline]
         pub const fn cast_unsigned(self) -> $UnsignedT {
             self as $UnsignedT
         }
@@ -1915,7 +1915,7 @@ macro_rules! int_impl {
         #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
-        #[inline(always)]
+        #[rustc_early_inline]
         pub const fn wrapping_add(self, rhs: Self) -> Self {
             intrinsics::wrapping_add(self, rhs)
         }
diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
@@ -277,7 +277,7 @@ macro_rules! uint_impl {
         #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
-        #[inline(always)]
+        #[rustc_early_inline]
         pub const fn cast_signed(self) -> $SignedT {
             self as $SignedT
         }
@@ -2070,7 +2070,7 @@ macro_rules! uint_impl {
         #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
-        #[inline(always)]
+        #[rustc_early_inline]
         pub const fn wrapping_add(self, rhs: Self) -> Self {
             intrinsics::wrapping_add(self, rhs)
         }
diff --git a/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-abort.mir
@@ -8,29 +8,29 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
         let mut _8: u16;
         scope 2 {
         }
-        scope 3 (inlined <u16 as Step>::forward_checked) {
-            scope 4 {
-                scope 6 (inlined core::num::<impl u16>::checked_add) {
+        scope 3 (inlined core::num::<impl u16>::wrapping_add) {
+        }
+        scope 4 (inlined <u16 as Step>::forward_checked) {
+            scope 5 {
+                scope 7 (inlined core::num::<impl u16>::checked_add) {
                     let mut _5: (u16, bool);
                     let mut _6: bool;
-                    scope 7 (inlined std::intrinsics::unlikely) {
+                    scope 8 (inlined std::intrinsics::unlikely) {
                         let _7: ();
                     }
                 }
             }
-            scope 5 (inlined convert::num::ptr_try_from_impls::<impl TryFrom<usize> for u16>::try_from) {
+            scope 6 (inlined convert::num::ptr_try_from_impls::<impl TryFrom<usize> for u16>::try_from) {
                 let mut _3: bool;
                 let mut _4: u16;
             }
         }
-        scope 8 (inlined Option::<u16>::is_none) {
-            scope 9 (inlined Option::<u16>::is_some) {
-                scope 10 {
+        scope 9 (inlined Option::<u16>::is_none) {
+            scope 10 (inlined Option::<u16>::is_some) {
+                scope 11 {
                 }
             }
         }
-        scope 11 (inlined core::num::<impl u16>::wrapping_add) {
-        }
     }
 
     bb0: {
diff --git a/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-unwind.mir
@@ -8,29 +8,29 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
         let mut _8: u16;
         scope 2 {
         }
-        scope 3 (inlined <u16 as Step>::forward_checked) {
-            scope 4 {
-                scope 6 (inlined core::num::<impl u16>::checked_add) {
+        scope 3 (inlined core::num::<impl u16>::wrapping_add) {
+        }
+        scope 4 (inlined <u16 as Step>::forward_checked) {
+            scope 5 {
+                scope 7 (inlined core::num::<impl u16>::checked_add) {
                     let mut _5: (u16, bool);
                     let mut _6: bool;
-                    scope 7 (inlined std::intrinsics::unlikely) {
+                    scope 8 (inlined std::intrinsics::unlikely) {
                         let _7: ();
                     }
                 }
             }
-            scope 5 (inlined convert::num::ptr_try_from_impls::<impl TryFrom<usize> for u16>::try_from) {
+            scope 6 (inlined convert::num::ptr_try_from_impls::<impl TryFrom<usize> for u16>::try_from) {
                 let mut _3: bool;
                 let mut _4: u16;
             }
         }
-        scope 8 (inlined Option::<u16>::is_none) {
-            scope 9 (inlined Option::<u16>::is_some) {
-                scope 10 {
+        scope 9 (inlined Option::<u16>::is_none) {
+            scope 10 (inlined Option::<u16>::is_some) {
+                scope 11 {
                 }
             }
         }
-        scope 11 (inlined core::num::<impl u16>::wrapping_add) {
-        }
     }
 
     bb0: {
diff --git a/tests/mir-opt/pre-codegen/integer_methods_debug.cast_and_add.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/integer_methods_debug.cast_and_add.PreCodegen.after.panic-abort.mir
@@ -4,16 +4,14 @@ fn cast_and_add(_1: i32) -> u32 {
     debug x => _1;
     let mut _0: u32;
     let mut _2: u32;
-
-    bb0: {
-        _2 = core::num::<impl i32>::cast_unsigned(copy _1) -> [return: bb1, unwind unreachable];
+    scope 1 (inlined core::num::<impl i32>::cast_unsigned) {
     }
-
-    bb1: {
-        _0 = core::num::<impl u32>::wrapping_add(move _2, const 42_u32) -> [return: bb2, unwind unreachable];
+    scope 2 (inlined core::num::<impl u32>::wrapping_add) {
     }
 
-    bb2: {
+    bb0: {
+        _2 = copy _1 as u32 (IntToInt);
+        _0 = Add(copy _2, const 42_u32);
         return;
     }
 }
diff --git a/tests/mir-opt/pre-codegen/integer_methods_debug.cast_and_add.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/integer_methods_debug.cast_and_add.PreCodegen.after.panic-unwind.mir
@@ -4,16 +4,14 @@ fn cast_and_add(_1: i32) -> u32 {
     debug x => _1;
     let mut _0: u32;
     let mut _2: u32;
-
-    bb0: {
-        _2 = core::num::<impl i32>::cast_unsigned(copy _1) -> [return: bb1, unwind continue];
+    scope 1 (inlined core::num::<impl i32>::cast_unsigned) {
     }
-
-    bb1: {
-        _0 = core::num::<impl u32>::wrapping_add(move _2, const 42_u32) -> [return: bb2, unwind continue];
+    scope 2 (inlined core::num::<impl u32>::wrapping_add) {
     }
 
-    bb2: {
+    bb0: {
+        _2 = copy _1 as u32 (IntToInt);
+        _0 = Add(copy _2, const 42_u32);
         return;
     }
 }
diff --git a/tests/mir-opt/pre-codegen/integer_methods_debug.rs b/tests/mir-opt/pre-codegen/integer_methods_debug.rs
@@ -6,7 +6,9 @@
 // EMIT_MIR integer_methods_debug.cast_and_add.PreCodegen.after.mir
 pub fn cast_and_add(x: i32) -> u32 {
     // CHECK-LABEL: fn cast_and_add(_1: i32) -> u32
-    // CHECK: _2 = {{.+}}<impl i32>::cast_unsigned(copy _1)
-    // CHECK: _0 = {{.+}}<impl u32>::wrapping_add(move _2, const 42_u32) ->
+    // CHECK: (inlined {{.+}}<impl i32>::cast_unsigned)
+    // CHECK: (inlined {{.+}}<impl u32>::wrapping_add)
+    // CHECK: _2 = copy _1 as u32 (IntToInt);
+    // CHECK: _0 = Add(copy _2, const 42_u32);
     x.cast_unsigned().wrapping_add(42)
 }

Original file line number	Diff line number	Diff line change
`@@ -8,29 +8,29 @@ fn step_forward(_1: u16, _2: usize) -> u16 {`
`8`	`8`	`let mut _8: u16;`
`9`	`9`	`scope 2 {`
`10`	`10`	`}`
`11`		`- scope 3 (inlined <u16 as Step>::forward_checked) {`
`12`		`- scope 4 {`
`13`		`- scope 6 (inlined core::num::<impl u16>::checked_add) {`
	`11`	`+ scope 3 (inlined core::num::<impl u16>::wrapping_add) {`
	`12`	`+ }`
	`13`	`+ scope 4 (inlined <u16 as Step>::forward_checked) {`
	`14`	`+ scope 5 {`
	`15`	`+ scope 7 (inlined core::num::<impl u16>::checked_add) {`
`14`	`16`	`let mut _5: (u16, bool);`
`15`	`17`	`let mut _6: bool;`
`16`		`- scope 7 (inlined std::intrinsics::unlikely) {`
	`18`	`+ scope 8 (inlined std::intrinsics::unlikely) {`
`17`	`19`	`let _7: ();`
`18`	`20`	`}`
`19`	`21`	`}`
`20`	`22`	`}`
`21`		`- scope 5 (inlined convert::num::ptr_try_from_impls::<impl TryFrom<usize> for u16>::try_from) {`
	`23`	`+ scope 6 (inlined convert::num::ptr_try_from_impls::<impl TryFrom<usize> for u16>::try_from) {`
`22`	`24`	`let mut _3: bool;`
`23`	`25`	`let mut _4: u16;`
`24`	`26`	`}`
`25`	`27`	`}`
`26`		`- scope 8 (inlined Option::<u16>::is_none) {`
`27`		`- scope 9 (inlined Option::<u16>::is_some) {`
`28`		`- scope 10 {`
	`28`	`+ scope 9 (inlined Option::<u16>::is_none) {`
	`29`	`+ scope 10 (inlined Option::<u16>::is_some) {`
	`30`	`+ scope 11 {`
`29`	`31`	`}`
`30`	`32`	`}`
`31`	`33`	`}`
`32`		`- scope 11 (inlined core::num::<impl u16>::wrapping_add) {`
`33`		`- }`
`34`	`34`	`}`
`35`	`35`
`36`	`36`	`bb0: {`
Original file line number	Diff line number	Diff line change
`@@ -4,16 +4,14 @@ fn cast_and_add(_1: i32) -> u32 {`
`4`	`4`	`debug x => _1;`
`5`	`5`	`let mut _0: u32;`
`6`	`6`	`let mut _2: u32;`
`7`		`-`
`8`		`- bb0: {`
`9`		`- _2 = core::num::<impl i32>::cast_unsigned(copy _1) -> [return: bb1, unwind unreachable];`
	`7`	`+ scope 1 (inlined core::num::<impl i32>::cast_unsigned) {`
`10`	`8`	`}`
`11`		`-`
`12`		`- bb1: {`
`13`		`- _0 = core::num::<impl u32>::wrapping_add(move _2, const 42_u32) -> [return: bb2, unwind unreachable];`
	`9`	`+ scope 2 (inlined core::num::<impl u32>::wrapping_add) {`
`14`	`10`	`}`
`15`	`11`
`16`		`- bb2: {`
	`12`	`+ bb0: {`
	`13`	`+ _2 = copy _1 as u32 (IntToInt);`
	`14`	`+ _0 = Add(copy _2, const 42_u32);`
`17`	`15`	`return;`
`18`	`16`	`}`
`19`	`17`	`}`