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02f7806ecd
Stop `llvm.expect`ing assert terminators We're putting `llvm.expect` calls before the <https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/enum.TerminatorKind.html#variant.Assert> terminators. But we don't need them. One of the arms is always to a panic function that's marked `#[cold]`, which is `cold` <https://llvm.org/docs/LangRef.html#function-attributes> in LLVM, which > When computing edge weights, basic blocks post-dominated by a cold function call are also considered to be cold; and, thus, given low weight. So even without us emitting the extra intrinsic call, LLVM knows what to expect for the `br`. Thus we can save the (small) effort of emitting it and then LLVM optimizing it out. r? compiler
Please read the rustc-dev-guide chapter on Backend Agnostic Codegen.