From feede2d46836f2739665e14f11725293cd6e43d4 Mon Sep 17 00:00:00 2001
From: ictrobot <ictrobot@outlook.com>
Date: Thu, 19 Sep 2024 12:09:29 +0200
Subject: [PATCH] Add simd128 implementation to wasm demo

---
 crates/aoc_wasm/web/index.html   |  2 +-
 crates/aoc_wasm/web/web.mjs      | 24 ++++++++++++++-
 crates/utils/src/multiversion.rs |  1 +
 crates/xtask/src/cmd/web.rs      | 51 +++++++++++++++++++-------------
 crates/xtask/src/common.rs       | 19 ++++++++++--
 5 files changed, 71 insertions(+), 26 deletions(-)
diff --git a/crates/aoc_wasm/web/index.html b/crates/aoc_wasm/web/index.html
index 843a92a..10c5ea7 100644
--- a/crates/aoc_wasm/web/index.html
+++ b/crates/aoc_wasm/web/index.html
@@ -71,7 +71,7 @@
     <script src="./web.mjs" type="module"></script>
     <link rel="modulepreload" href="./aoc.mjs" />
     <link rel="modulepreload" href="./worker.mjs" />
-    <link rel="preload" href="./aoc.wasm" as="fetch" crossorigin />
+    <link rel="preload" href="./aoc-simd128.wasm" as="fetch" crossorigin />
 </head>
 <body class="is-flex is-flex-direction-column">
     <nav class="navbar" role="navigation" aria-label="main navigation">
diff --git a/crates/aoc_wasm/web/web.mjs b/crates/aoc_wasm/web/web.mjs
index 2c44df6..298d6e5 100644
--- a/crates/aoc_wasm/web/web.mjs
+++ b/crates/aoc_wasm/web/web.mjs
@@ -1,6 +1,28 @@
 import {Aoc} from "./aoc.mjs";
 
-const module = await WebAssembly.compileStreaming(fetch("./aoc.wasm"));
+const MODULE_PATHS = [
+    "./aoc-simd128.wasm",
+    "./aoc.wasm",
+];
+
+let module;
+for (const path of MODULE_PATHS) {
+    try {
+        module = await WebAssembly.compileStreaming(fetch(path));
+        console.log("Using " + path);
+        break;
+    } catch (err) {
+        if (err instanceof WebAssembly.CompileError) {
+            console.warn("Compiling " + path + " failed: " + err);
+        } else {
+            throw err;
+        }
+    }
+}
+if (module === undefined) {
+    throw new Error("Failed to load WebAssembly module");
+}
+
 const worker = new Worker("./worker.mjs", {type: "module"});
 worker.postMessage(["init", module]);
 
diff --git a/crates/utils/src/multiversion.rs b/crates/utils/src/multiversion.rs
index c1505e9..c8e8de5 100644
--- a/crates/utils/src/multiversion.rs
+++ b/crates/utils/src/multiversion.rs
@@ -151,6 +151,7 @@ macro_rules! multiversion {
         ::std::sync::LazyLock::new(#[cfg_attr(target_family = "wasm", expect(unreachable_code))] || {
             use $crate::multiversion::Version::*;
 
+            // Instant::now() isn't implemented in WebAssembly, so hardcode implementations
             #[cfg(all(target_family = "wasm", target_feature = "simd128"))]
             return Array256;
             #[cfg(all(target_family = "wasm"))]
diff --git a/crates/xtask/src/cmd/web.rs b/crates/xtask/src/cmd/web.rs
index 1826ce5..0567835 100644
--- a/crates/xtask/src/cmd/web.rs
+++ b/crates/xtask/src/cmd/web.rs
@@ -18,31 +18,40 @@ pub fn main(args: impl Iterator<Item = String>) -> Result<(), Box<dyn Error>> {
         delete_dir(&output)?;
     }
 
-    run_cargo(&["clean", "--doc"])?;
-    run_cargo(&["doc", "--no-deps"])?;
-    run_cargo(&[
-        "build",
-        "-p",
-        "aoc_wasm",
-        "--lib",
-        "--target=wasm32-unknown-unknown",
-        "--release",
-    ])?;
-
     create_dir(&output)?;
 
-    let output_wasm = output.join("aoc.wasm");
-    copy_file(
-        repo_dir_path()
-            .join("target")
-            .join("wasm32-unknown-unknown")
-            .join("release")
-            .join("aoc_wasm.wasm"),
-        &output_wasm,
-    )?;
+    run_cargo(&["clean", "--doc"], &[])?;
+    run_cargo(&["doc", "--no-deps"], &[])?;
 
     let mut rewrites = vec![];
-    add_rewrite(&mut rewrites, &output_wasm)?;
+    for (features, name) in [
+        ("", "aoc.wasm"),
+        ("-C target_feature=+simd128", "aoc-simd128.wasm"),
+    ] {
+        run_cargo(
+            &[
+                "build",
+                "-p",
+                "aoc_wasm",
+                "--lib",
+                "--target=wasm32-unknown-unknown",
+                "--release",
+            ],
+            &[("RUSTFLAGS", features)],
+        )?;
+
+        let output_wasm = output.join(name);
+        copy_file(
+            repo_dir_path()
+                .join("target")
+                .join("wasm32-unknown-unknown")
+                .join("release")
+                .join("aoc_wasm.wasm"),
+            &output_wasm,
+        )?;
+
+        add_rewrite(&mut rewrites, &output_wasm)?;
+    }
 
     let web = repo_dir_path().join("crates").join("aoc_wasm").join("web");
     for file in ["aoc.mjs", "worker.mjs", "web.mjs", "index.html"] {
diff --git a/crates/xtask/src/common.rs b/crates/xtask/src/common.rs
index 7928f2e..2703dcb 100644
--- a/crates/xtask/src/common.rs
+++ b/crates/xtask/src/common.rs
@@ -1,4 +1,5 @@
 use std::error::Error;
+use std::fmt::Write;
 use std::fs::{create_dir_all, read_to_string, remove_dir_all, write};
 use std::path::{Path, PathBuf};
 use std::process::Command;
@@ -144,9 +145,21 @@ fn cargo_var(key: &str) -> String {
         .unwrap_or_else(|_| panic!("expected {key} environment variable to be set by cargo"))
 }
 
-pub fn run_cargo(args: &[&str]) -> Result<(), Box<dyn Error>> {
-    println!("running cargo with {args:?}");
-    let status = Command::new(cargo_var("CARGO")).args(args).status()?;
+pub fn run_cargo(args: &[&str], envs: &[(&str, &str)]) -> Result<(), Box<dyn Error>> {
+    println!(
+        "running \"{}cargo {}\"",
+        envs.iter().fold(String::new(), |mut acc, &(k, v)| {
+            write!(acc, "{k}='{v}' ").unwrap();
+            acc
+        }),
+        args.join(" "),
+    );
+
+    let status = Command::new(cargo_var("CARGO"))
+        .args(args)
+        .envs(envs.iter().copied())
+        .status()?;
+
     if status.success() {
         Ok(())
     } else {
