Wrapper generates more instructions for simple integer operations #119520
Description
Code
I tried this code (godbolt):
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)] pub struct Int(u32); const A: Int = Int(201); const B: Int = Int(270); const C: Int = Int(153); #[inline(never)] #[rustfmt::skip] pub fn wrapped(x: Int) -> bool { (x >= A && x <= B) || x == C } #[inline(never)] #[rustfmt::skip] pub fn primitive(x: Int) -> bool { (x.0 >= A.0 && x.0 <= B.0) || x.0 == C.0 }I expected to see this happen: both functions compile to identical assembly
Instead, this happened: wrapped contains way more instructions:
example::wrapped: cmp edi, 201 jb .LBB0_3 xor eax, eax cmp edi, 270 mov ecx, 255 setne al cmovae ecx, eax mov al, 1 test cl, cl je .LBB0_4 movzx ecx, cl cmp ecx, 255 jne .LBB0_3 .LBB0_4: ret .LBB0_3: cmp edi, 153 sete al ret example::primitive: lea eax, [rdi - 201] cmp eax, 70 setb cl cmp edi, 153 sete al or al, cl retVersion it worked on
It most recently worked on: 1.64
Version with regression
rustc --version --verbose:
rustc 1.77.0-nightly (e51e98dde 2023-12-31) binary: rustc commit-hash: e51e98dde6a60637b6a71b8105245b629ac3fe77 commit-date: 2023-12-31 host: x86_64-unknown-linux-gnu release: 1.77.0-nightly LLVM version: 17.0.6 I have bisected it to between 1.64 and 1.65 on Godbolt, and then further with cargo bisect-rustc which points to nightly-2022-08-17 (4033686...86c6ebe):
Regression in nightly-2022-08-17 ... looking for regression commit between 2022-08-16 and 2022-08-17 ... found 8 bors merge commits in the specified range commit[0] 2022-08-15: Auto merge of #100595 - matthiaskrgr:rollup-f1zur58, r=matthiaskrgr commit[1] 2022-08-15: Auto merge of #100007 - ChrisDenton:dtor-inline-never, r=michaelwoerister commit[2] 2022-08-16: Auto merge of #100237 - cjgillot:no-special-hash-hir, r=nagisa commit[3] 2022-08-16: Auto merge of #100611 - matthiaskrgr:rollup-rxj10ur, r=matthiaskrgr commit[4] 2022-08-16: Auto merge of #100441 - nnethercote:shrink-ast-Attribute, r=petrochenkov commit[5] 2022-08-16: Auto merge of #99612 - yanchen4791:issue-95079-fix, r=compiler-errors commit[6] 2022-08-16: Auto merge of #100626 - Dylan-DPC:rollup-mwbm7kj, r=Dylan-DPC commit[7] 2022-08-16: Auto merge of #100644 - TaKO8Ki:rollup-n0o6a1t, r=TaKO8Ki Backtrace
Backtrace
<backtrace> @rustbot modify labels: +I-slow +regression-from-stable-to-stable -regression-untriaged