Rollup merge of rust-lang#133674 - scottmcm:chain-carrying-add, r=Amanieu

matthiaskrgr · web-flow · commit 3f3377037179 · 2024-12-01T14:30:11.000+01:00
Fix chaining `carrying_add`s Something about the MIR lowering for `||` ended up breaking this, but it's fixed by changing the code to use `|` instead. I also added an assembly test to ensure it *keeps* being [`adc`](https://www.felixcloutier.com/x86/adc). cc rust-lang#85532 (comment), which noticed this.
diff --git a/core/src/num/uint_macros.rs b/core/src/num/uint_macros.rs
@@ -2354,7 +2354,7 @@ macro_rules! uint_impl {
             //   to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
             let (a, b) = self.overflowing_add(rhs);
             let (c, d) = a.overflowing_add(carry as $SelfT);
-            (c, b || d)
+            (c, b | d)
         }
 
         /// Calculates `self` + `rhs` with a signed `rhs`.

Original file line number	Diff line number	Diff line change
`@@ -2354,7 +2354,7 @@ macro_rules! uint_impl {`
`2354`	`2354`	`// to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic`
`2355`	`2355`	`let (a, b) = self.overflowing_add(rhs);`
`2356`	`2356`	`let (c, d) = a.overflowing_add(carry as $SelfT);`
`2357`		`- (c, b \|\| d)`
	`2357`	`+ (c, b \| d)`
`2358`	`2358`	`}`
`2359`	`2359`
`2360`	`2360`	/// Calculates `self` + `rhs` with a signed `rhs`.