Support WebAssembly SIMD instructions

Author: CryZe

.cargo/config.toml

@@ -0,0 +1,2 @@
+[target.wasm32-wasi]
+runner = "wasmtime run --wasm-features all --dir ."

.github/workflows/main.yml

@@ -53,3 +53,36 @@ jobs:
       env:
         RUSTFLAGS: -Ctarget-feature=+avx2
       run: cargo test --verbose --all-features
+
+  wasm:
+    runs-on: ubuntu-18.04
+    strategy:
+      matrix:
+        rust:
+          - stable
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Install toolchain
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: ${{ matrix.rust }}
+        override: true
+        target: wasm32-wasi
+
+    - name: Install wasmtime
+      run: |
+        curl https://wasmtime.dev/install.sh -sSf | bash
+        echo "$HOME/.wasmtime/bin" >> $GITHUB_PATH
+
+    - name: Build with minimal features (no_std)
+      run: cargo build --target wasm32-wasi --verbose --no-default-features --features libm
+
+    - name: Run tests without SIMD
+      run: cargo test --target wasm32-wasi --verbose --no-default-features --features png-format
+
+    - name: Run tests with SIMD128
+      env:
+        RUSTFLAGS: -Ctarget-feature=+simd128,+bulk-memory,+nontrapping-fptoint,+sign-ext
+      run: cargo test --target wasm32-wasi --verbose --all-features

src/wide/f32x4_t.rs

@@ -14,6 +14,25 @@ cfg_if::cfg_if! {
         #[derive(Default, Clone, Copy, PartialEq, Debug)]
         #[repr(C, align(16))]
         pub struct f32x4(m128);
+    } else if #[cfg(all(feature = "simd", target_feature = "simd128"))] {
+        use core::arch::wasm32::*;
+
+        // repr(transparent) allows for directly passing the v128 on the WASM stack.
+        #[derive(Clone, Copy, Debug)]
+        #[repr(transparent)]
+        pub struct f32x4(v128);
+
+        impl Default for f32x4 {
+            fn default() -> Self {
+                Self::splat(0.0)
+            }
+        }
+
+        impl PartialEq for f32x4 {
+            fn eq(&self, other: &Self) -> bool {
+                u32x4_all_true(f32x4_eq(self.0, other.0))
+            }
+        }
     } else {
         #[derive(Default, Clone, Copy, PartialEq, Debug)]
         #[repr(C, align(16))]
@@ -33,6 +52,8 @@ impl f32x4 {
         cfg_if::cfg_if! {
             if #[cfg(all(feature = "simd", target_feature = "sse"))] {
                 Self(max_m128(self.0, rhs.0))
+            } else if #[cfg(all(feature = "simd", target_feature = "simd128"))] {
+                Self(f32x4_max(self.0, rhs.0))
             } else {
                 Self([
                     self.0[0].max(rhs.0[0]),
@@ -48,6 +69,8 @@ impl f32x4 {
         cfg_if::cfg_if! {
             if #[cfg(all(feature = "simd", target_feature = "sse"))] {
                 Self(min_m128(self.0, rhs.0))
+            } else if #[cfg(all(feature = "simd", target_feature = "simd128"))] {
+                Self(f32x4_min(self.0, rhs.0))
             } else {
                 Self([
                     self.0[0].min(rhs.0[0]),
@@ -79,6 +102,8 @@ impl core::ops::Add for f32x4 {
         cfg_if::cfg_if! {
             if #[cfg(all(feature = "simd", target_feature = "sse"))] {
                 Self(add_m128(self.0, rhs.0))
+            } else if #[cfg(all(feature = "simd", target_feature = "simd128"))] {
+                Self(f32x4_add(self.0, rhs.0))
             } else {
                 Self([
                     self.0[0] + rhs.0[0],
@@ -104,6 +129,8 @@ impl core::ops::Sub for f32x4 {
         cfg_if::cfg_if! {
             if #[cfg(all(feature = "simd", target_feature = "sse"))] {
                 Self(sub_m128(self.0, rhs.0))
+            } else if #[cfg(all(feature = "simd", target_feature = "simd128"))] {
+                Self(f32x4_sub(self.0, rhs.0))
             } else {
                 Self([
                     self.0[0] - rhs.0[0],
@@ -123,6 +150,8 @@ impl core::ops::Mul for f32x4 {
         cfg_if::cfg_if! {
             if #[cfg(all(feature = "simd", target_feature = "sse"))] {
                 Self(mul_m128(self.0, rhs.0))
+            } else if #[cfg(all(feature = "simd", target_feature = "simd128"))] {
+                Self(f32x4_mul(self.0, rhs.0))
             } else {
                 Self([
                     self.0[0] * rhs.0[0],