diff --git a/Cargo.lock b/Cargo.lock
index 9b920dfae2..52c8ef1b89 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -536,6 +536,7 @@ dependencies = [
  "cranelift-faerie",
  "cranelift-filetests",
  "cranelift-frontend",
+ "cranelift-interpreter",
  "cranelift-module",
  "cranelift-native",
  "cranelift-object",
@@ -547,10 +548,12 @@ dependencies = [
  "file-per-thread-logger",
  "filecheck",
  "indicatif",
+ "log",
  "pretty_env_logger",
  "serde",
  "target-lexicon",
  "term",
+ "thiserror",
  "walkdir",
  "wat",
 ]
diff --git a/cranelift/Cargo.toml b/cranelift/Cargo.toml
index fef8b439cb..f2e4ea9607 100644
--- a/cranelift/Cargo.toml
+++ b/cranelift/Cargo.toml
@@ -17,6 +17,7 @@ path = "src/clif-util.rs"
 cfg-if = "0.1"
 cranelift-codegen = { path = "codegen", version = "0.63.0" }
 cranelift-entity = { path = "entity", version = "0.63.0" }
+cranelift-interpreter = { path = "interpreter", version = "*" }
 cranelift-reader = { path = "reader", version = "0.63.0" }
 cranelift-frontend = { path = "frontend", version = "0.63.0" }
 cranelift-serde = { path = "serde", version = "0.63.0", optional = true }
@@ -31,6 +32,7 @@ cranelift-preopt = { path = "preopt", version = "0.63.0" }
 cranelift = { path = "umbrella", version = "0.63.0" }
 filecheck = "0.5.0"
 clap = "2.32.0"
+log = "0.4.8"
 serde = "1.0.8"
 term = "0.6.1"
 capstone = { version = "0.6.0", optional = true }
@@ -39,6 +41,7 @@ target-lexicon = "0.10"
 pretty_env_logger = "0.4.0"
 file-per-thread-logger = "0.1.2"
 indicatif = "0.13.0"
+thiserror = "1.0.15"
 walkdir = "2.2"
 
 [features]
diff --git a/cranelift/src/clif-util.rs b/cranelift/src/clif-util.rs
index 4066ef0fda..2a8f37664b 100755
--- a/cranelift/src/clif-util.rs
+++ b/cranelift/src/clif-util.rs
@@ -24,6 +24,7 @@ mod bugpoint;
 mod cat;
 mod compile;
 mod disasm;
+mod interpret;
 mod print_cfg;
 mod run;
 mod utils;
@@ -179,6 +180,13 @@ fn main() {
                 .arg(add_input_file_arg())
                 .arg(add_debug_flag()),
         )
+        .subcommand(
+            SubCommand::with_name("interpret")
+                .about("Interpret CLIF code")
+                .arg(add_verbose_flag())
+                .arg(add_input_file_arg())
+                .arg(add_debug_flag()),
+        )
         .subcommand(
             SubCommand::with_name("cat")
                 .about("Outputs .clif file")
@@ -239,6 +247,14 @@ fn main() {
             )
             .map(|_time| ())
         }
+        ("interpret", Some(rest_cmd)) => {
+            handle_debug_flag(rest_cmd.is_present("debug"));
+            interpret::run(
+                get_vec(rest_cmd.values_of("file")),
+                rest_cmd.is_present("verbose"),
+            )
+            .map(|_time| ())
+        }
         ("pass", Some(rest_cmd)) => {
             handle_debug_flag(rest_cmd.is_present("debug"));
 
diff --git a/cranelift/src/interpret.rs b/cranelift/src/interpret.rs
new file mode 100644
index 0000000000..efd0b22a6d
--- /dev/null
+++ b/cranelift/src/interpret.rs
@@ -0,0 +1,163 @@
+//! CLI tool to interpret Cranelift IR files.
+
+use crate::utils::iterate_files;
+use cranelift_interpreter::environment::Environment;
+use cranelift_interpreter::interpreter::{ControlFlow, Interpreter};
+use cranelift_reader::{parse_run_command, parse_test, ParseError, ParseOptions};
+use log::debug;
+use std::path::PathBuf;
+use std::{fs, io};
+use thiserror::Error;
+
+/// Run files through the Cranelift interpreter, interpreting any functions with annotations.
+pub fn run(files: Vec<String>, flag_print: bool) -> Result<(), String> {
+    let mut total = 0;
+    let mut errors = 0;
+    for file in iterate_files(files) {
+        total += 1;
+        let runner = FileInterpreter::from_path(file).map_err(|e| e.to_string())?;
+        match runner.run() {
+            Ok(_) => {
+                if flag_print {
+                    println!("{}", runner.path());
+                }
+            }
+            Err(e) => {
+                if flag_print {
+                    println!("{}: {}", runner.path(), e.to_string());
+                }
+                errors += 1;
+            }
+        }
+    }
+
+    if flag_print {
+        match total {
+            0 => println!("0 files"),
+            1 => println!("1 file"),
+            n => println!("{} files", n),
+        }
+    }
+
+    match errors {
+        0 => Ok(()),
+        1 => Err(String::from("1 failure")),
+        n => Err(format!("{} failures", n)),
+    }
+}
+
+/// Contains CLIF code that can be executed with [FileInterpreter::run].
+pub struct FileInterpreter {
+    path: Option<PathBuf>,
+    contents: String,
+}
+
+impl FileInterpreter {
+    /// Construct a file runner from a CLIF file path.
+    pub fn from_path(path: impl Into<PathBuf>) -> Result<Self, io::Error> {
+        let path = path.into();
+        debug!("New file runner from path: {}:", path.to_string_lossy());
+        let contents = fs::read_to_string(&path)?;
+        Ok(Self {
+            path: Some(path),
+            contents,
+        })
+    }
+
+    /// Construct a file runner from a CLIF code string. Currently only used for testing.
+    #[cfg(test)]
+    pub fn from_inline_code(contents: String) -> Self {
+        debug!("New file runner from inline code: {}:", &contents[..20]);
+        Self {
+            path: None,
+            contents,
+        }
+    }
+
+    /// Return the path of the file runner or `[inline code]`.
+    pub fn path(&self) -> String {
+        match self.path {
+            None => "[inline code]".to_string(),
+            Some(ref p) => p.to_string_lossy().to_string(),
+        }
+    }
+
+    /// Run the file; this searches for annotations like `; run: %fn0(42)` or
+    /// `; test: %fn0(42) == 2` and executes them, performing any test comparisons if necessary.
+    pub fn run(&self) -> Result<(), FileInterpreterFailure> {
+        // parse file
+        let test = parse_test(&self.contents, ParseOptions::default())
+            .map_err(|e| FileInterpreterFailure::ParsingClif(self.path(), e))?;
+
+        // collect functions
+        let mut env = Environment::default();
+        let mut commands = vec![];
+        for (func, details) in test.functions.into_iter() {
+            for comment in details.comments {
+                if let Some(command) = parse_run_command(comment.text, &func.signature)
+                    .map_err(|e| FileInterpreterFailure::ParsingClif(self.path(), e))?
+                {
+                    commands.push(command);
+                }
+            }
+            // Note: func.name may truncate the function name
+            env.add(func.name.to_string(), func);
+        }
+
+        // Run assertion commands
+        let interpreter = Interpreter::new(env);
+        for command in commands {
+            command
+                .run(|func_name, args| {
+                    // Because we have stored function names with a leading %, we need to re-add it.
+                    let func_name = &format!("%{}", func_name);
+                    match interpreter.call_by_name(func_name, args) {
+                        Ok(ControlFlow::Return(results)) => Ok(results),
+                        Ok(_) => panic!("Unexpected returned control flow--this is likely a bug."),
+                        Err(t) => Err(t.to_string()),
+                    }
+                })
+                .map_err(|s| FileInterpreterFailure::FailedExecution(s))?;
+        }
+
+        Ok(())
+    }
+}
+
+/// Possible sources of failure in this file.
+#[derive(Error, Debug)]
+pub enum FileInterpreterFailure {
+    #[error("failure reading file")]
+    Io(#[from] io::Error),
+    #[error("failure parsing file {0}: {1}")]
+    ParsingClif(String, ParseError),
+    #[error("failed to run function: {0}")]
+    FailedExecution(String),
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn nop() {
+        let code = String::from(
+            "
+            function %test() -> b8 {
+            block0:
+                nop
+                v1 = bconst.b8 true
+                v2 = iconst.i8 42
+                return v1
+            }
+            ; run: %test() == true
+            ",
+        );
+        FileInterpreter::from_inline_code(code).run().unwrap()
+    }
+
+    #[test]
+    fn filetests() {
+        run(vec!["../filetests/filetests/interpreter".to_string()], true).unwrap()
+    }
+}