diff --git a/benches/fibonacci.rs b/benches/fibonacci.rs
deleted file mode 100644
index 9a68a69e800f..000000000000
--- a/benches/fibonacci.rs
+++ /dev/null
@@ -1,26 +0,0 @@
-#![feature(test, rustc_private)]
-
-extern crate test;
-use crate::test::Bencher;
-mod helpers;
-use crate::helpers::*;
-
-#[bench]
-fn fib(bencher: &mut Bencher) {
-    bencher.iter(fibonacci_helper::main)
-}
-
-#[bench]
-fn fib_miri(bencher: &mut Bencher) {
-    miri_helper::run("fibonacci_helper", bencher);
-}
-
-#[bench]
-fn fib_iter(bencher: &mut Bencher) {
-    bencher.iter(fibonacci_helper_iterative::main)
-}
-
-#[bench]
-fn fib_iter_miri(bencher: &mut Bencher) {
-    miri_helper::run("fibonacci_helper_iterative", bencher);
-}
diff --git a/benches/helpers/fibonacci_helper.rs b/benches/helpers/fibonacci_helper.rs
deleted file mode 100644
index 586f1ce7da4d..000000000000
--- a/benches/helpers/fibonacci_helper.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-#[inline(never)]
-pub fn main() {
-    assert_eq!(fib(10), 55);
-}
-
-fn fib(n: usize) -> usize {
-    if n <= 2 { 1 } else { fib(n - 1) + fib(n - 2) }
-}
diff --git a/benches/helpers/fibonacci_helper_iterative.rs b/benches/helpers/fibonacci_helper_iterative.rs
deleted file mode 100644
index 0c2732828966..000000000000
--- a/benches/helpers/fibonacci_helper_iterative.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-#[inline(never)]
-pub fn main() {
-    assert_eq!(fib(10), 55);
-}
-
-fn fib(n: usize) -> usize {
-    let mut a = 0;
-    let mut b = 1;
-    for _ in 0..n {
-        let c = a;
-        a = b;
-        b += c;
-    }
-    a
-}
diff --git a/benches/helpers/miri_helper.rs b/benches/helpers/miri_helper.rs
deleted file mode 100644
index be542c2bc0a6..000000000000
--- a/benches/helpers/miri_helper.rs
+++ /dev/null
@@ -1,59 +0,0 @@
-extern crate rustc_driver;
-extern crate rustc_hir;
-extern crate rustc_interface;
-
-use rustc_driver::Compilation;
-use rustc_interface::{interface, Queries};
-
-use crate::test::Bencher;
-
-struct MiriCompilerCalls<'a> {
-    bencher: &'a mut Bencher,
-}
-
-impl rustc_driver::Callbacks for MiriCompilerCalls<'_> {
-    fn after_analysis<'tcx>(
-        &mut self,
-        compiler: &interface::Compiler,
-        queries: &'tcx Queries<'tcx>,
-    ) -> Compilation {
-        compiler.session().abort_if_errors();
-
-        queries.global_ctxt().unwrap().peek_mut().enter(|tcx| {
-            let (entry_def_id, entry_type) =
-                tcx.entry_fn(()).expect("no main or start function found");
-
-            self.bencher.iter(|| {
-                let config = miri::MiriConfig::default();
-                miri::eval_entry(tcx, entry_def_id, entry_type, config);
-            });
-        });
-
-        compiler.session().abort_if_errors();
-
-        Compilation::Stop
-    }
-}
-
-fn find_sysroot() -> String {
-    // Taken from https://github.com/Manishearth/rust-clippy/pull/911.
-    let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));
-    let toolchain = option_env!("RUSTUP_TOOLCHAIN").or(option_env!("MULTIRUST_TOOLCHAIN"));
-    match (home, toolchain) {
-        (Some(home), Some(toolchain)) => format!("{}/toolchains/{}", home, toolchain),
-        _ =>
-            option_env!("RUST_SYSROOT")
-                .expect("need to specify RUST_SYSROOT env var or use rustup or multirust")
-                .to_owned(),
-    }
-}
-
-pub fn run(filename: &str, bencher: &mut Bencher) {
-    let args = &[
-        "miri".to_string(),
-        format!("benches/helpers/{}.rs", filename),
-        "--sysroot".to_string(),
-        find_sysroot(),
-    ];
-    rustc_driver::RunCompiler::new(args, &mut MiriCompilerCalls { bencher }).run().unwrap()
-}
diff --git a/benches/helpers/mod.rs b/benches/helpers/mod.rs
deleted file mode 100644
index 27504a2cc034..000000000000
--- a/benches/helpers/mod.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-// This module gets included in multiple crates, and they each only use part of it.
-#![allow(dead_code)]
-
-pub mod fibonacci_helper;
-pub mod fibonacci_helper_iterative;
-pub mod miri_helper;
-pub mod smoke_helper;
diff --git a/benches/helpers/repeat.rs b/benches/helpers/repeat.rs
deleted file mode 100644
index 0e8c5980b82b..000000000000
--- a/benches/helpers/repeat.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    let data: [u8; 1024] = [42; 1024];
-    assert_eq!(data.len(), 1024);
-}
diff --git a/benches/helpers/repeat_manual.rs b/benches/helpers/repeat_manual.rs
deleted file mode 100644
index bd5d6b1e1264..000000000000
--- a/benches/helpers/repeat_manual.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn main() {
-    let mut data: [u8; 1024] = unsafe { std::mem::uninitialized() };
-    for i in 0..data.len() {
-        unsafe {
-            std::ptr::write(&mut data[i], 0);
-        }
-    }
-    assert_eq!(data.len(), 1024);
-}
diff --git a/benches/helpers/smoke_helper.rs b/benches/helpers/smoke_helper.rs
deleted file mode 100644
index e81db817aeac..000000000000
--- a/benches/helpers/smoke_helper.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-#[inline(never)]
-pub fn main() {}
diff --git a/benches/repeat.rs b/benches/repeat.rs
deleted file mode 100644
index 0369b1f74cf5..000000000000
--- a/benches/repeat.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-#![feature(test, rustc_private)]
-
-extern crate test;
-use crate::test::Bencher;
-mod helpers;
-use crate::helpers::*;
-
-#[bench]
-fn repeat(bencher: &mut Bencher) {
-    miri_helper::run("repeat", bencher);
-}
-
-#[bench]
-fn repeat_manual(bencher: &mut Bencher) {
-    miri_helper::run("repeat_manual", bencher);
-}
diff --git a/benches/smoke.rs b/benches/smoke.rs
deleted file mode 100644
index 372cd0b22b7a..000000000000
--- a/benches/smoke.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-#![feature(test, rustc_private)]
-
-extern crate test;
-use crate::test::Bencher;
-mod helpers;
-use crate::helpers::*;
-
-#[bench]
-fn noop(bencher: &mut Bencher) {
-    bencher.iter(smoke_helper::main)
-}
-
-/*
-// really slow
-#[bench]
-fn noop_miri_full(bencher: &mut Bencher) {
-    let path = std::env::var("RUST_SYSROOT").expect("env variable `RUST_SYSROOT` not set");
-    bencher.iter(|| {
-        let mut process = std::process::Command::new("target/release/miri");
-        process.arg("benches/smoke_helper.rs")
-               .arg("--sysroot").arg(&path);
-        let output = process.output().unwrap();
-        if !output.status.success() {
-            println!("{}", String::from_utf8(output.stdout).unwrap());
-            println!("{}", String::from_utf8(output.stderr).unwrap());
-            panic!("failed to run miri");
-        }
-    })
-}
-*/
-
-#[bench]
-fn noop_miri_interpreter(bencher: &mut Bencher) {
-    miri_helper::run("smoke_helper", bencher);
-}