Add flags to allow wasm SIMD instructions (#910)

Add `--enable-simd` flag to `clif-util wasm`

cranelift/src/clif-util.rs

@@ -104,7 +104,13 @@ fn add_print_flag<'a>() -> clap::Arg<'a, 'a> {
 fn add_debug_flag<'a>() -> clap::Arg<'a, 'a> {
     Arg::with_name("debug")
         .short("d")
-        .help("enable debug output on stderr/stdout")
+        .help("Enable debug output on stderr/stdout")
+}
+
+fn add_enable_simd_flag<'a>() -> clap::Arg<'a, 'a> {
+    Arg::with_name("enable-simd")
+        .long("enable-simd")
+        .help("Enable WASM's SIMD operations")
 }
 
 /// Returns a vector of clap value options and changes these options into a vector of strings
@@ -137,6 +143,7 @@ fn add_wasm_or_compile<'a>(cmd: &str) -> clap::App<'a, 'a> {
         .arg(add_target_flag())
         .arg(add_input_file_arg())
         .arg(add_debug_flag())
+        .arg(add_enable_simd_flag())
 }
 
 fn handle_debug_flag(debug: bool) {
@@ -296,6 +303,7 @@ fn main() {
                     rest_cmd.is_present("print-size"),
                     rest_cmd.is_present("time-passes"),
                     rest_cmd.is_present("value-ranges"),
+                    rest_cmd.is_present("enable-simd"),
                 )
             };
 

cranelift/src/wasm.rs

@@ -19,7 +19,7 @@ use cranelift_wasm::{translate_module, DummyEnvironment, FuncIndex, ReturnMode};
 use std::path::Path;
 use std::path::PathBuf;
 use term;
-use wabt::wat2wasm;
+use wabt::{wat2wasm_with_features, Features};
 
 macro_rules! vprintln {
     ($x: expr, $($tts:tt)*) => {
@@ -49,6 +49,7 @@ pub fn run(
     flag_print_size: bool,
     flag_report_times: bool,
     flag_calc_value_ranges: bool,
+    flag_enable_simd: bool,
 ) -> Result<(), String> {
     let parsed = parse_sets_and_triple(flag_set, flag_triple)?;
 
@@ -64,6 +65,7 @@ pub fn run(
             flag_print_disasm,
             flag_report_times,
             flag_calc_value_ranges,
+            flag_enable_simd,
             &path.to_path_buf(),
             &name,
             parsed.as_fisa(),
@@ -81,6 +83,7 @@ fn handle_module(
     flag_print_disasm: bool,
     flag_report_times: bool,
     flag_calc_value_ranges: bool,
+    flag_enable_simd: bool,
     path: &PathBuf,
     name: &str,
     fisa: FlagsOrIsa,
@@ -97,7 +100,11 @@ fn handle_module(
     let mut module_binary = read_to_end(path.clone()).map_err(|err| err.to_string())?;
 
     if !module_binary.starts_with(&[b'\0', b'a', b's', b'm']) {
-        module_binary = match wat2wasm(&module_binary) {
+        let mut features = Features::new();
+        if flag_enable_simd {
+            features.enable_simd();
+        }
+        module_binary = match wat2wasm_with_features(&module_binary, features) {
             Ok(data) => data,
             Err(e) => return Err(e.to_string()),
         };