feat(Singlepass, Cranelift): add --enable-unaligned-memory-accesses (v2)

.gitignore

@@ -31,3 +31,4 @@ link.tar.gz
 .direnv
 .envrc
 /tests/tmp
+.codex

lib/cli/src/backend.rs

@@ -218,6 +218,12 @@ pub struct RuntimeOptions {
     #[clap(long = "enable-nan-canonicalization")]
     enable_nan_canonicalization: bool,
 
+    /// Allow unaligned memory accesses.
+    ///
+    /// Available for Cranelift and Singlepass (RISC-V).
+    #[clap(long = "enable-unaligned-memory-accesses")]
+    enable_unaligned_memory_accesses: bool,
+
     #[clap(flatten)]
     features: WasmFeatures,
 }
@@ -461,6 +467,9 @@ impl RuntimeOptions {
             #[cfg(feature = "singlepass")]
             BackendType::Singlepass => {
                 let mut config = wasmer_compiler_singlepass::Singlepass::new();
+                if self.enable_unaligned_memory_accesses {
+                    config.allow_unaligned_memory_accesses(true);
+                }
                 if self.enable_verifier {
                     config.enable_verifier();
                 }
@@ -486,6 +495,9 @@ impl RuntimeOptions {
             #[cfg(feature = "cranelift")]
             BackendType::Cranelift => {
                 let mut config = wasmer_compiler_cranelift::Cranelift::new();
+                if self.enable_unaligned_memory_accesses {
+                    config.allow_unaligned_memory_accesses(true);
+                }
                 if self.enable_verifier {
                     config.enable_verifier();
                 }
@@ -605,6 +617,9 @@ impl BackendType {
             #[cfg(feature = "singlepass")]
             Self::Singlepass => {
                 let mut config = wasmer_compiler_singlepass::Singlepass::new();
+                if runtime_opts.enable_unaligned_memory_accesses {
+                    config.allow_unaligned_memory_accesses(true);
+                }
                 let supported_features = config.supported_features_for_target(target);
                 if runtime_opts.enable_verifier {
                     config.enable_verifier();
@@ -636,6 +651,9 @@ impl BackendType {
             #[cfg(feature = "cranelift")]
             Self::Cranelift => {
                 let mut config = wasmer_compiler_cranelift::Cranelift::new();
+                if runtime_opts.enable_unaligned_memory_accesses {
+                    config.allow_unaligned_memory_accesses(true);
+                }
                 let supported_features = config.supported_features_for_target(target);
                 if runtime_opts.enable_verifier {
                     config.enable_verifier();

lib/compiler-cranelift/src/compiler.rs

@@ -321,7 +321,7 @@ impl CraneliftCompiler {
         let mut custom_sections = PrimaryMap::new();
 
         #[cfg(not(feature = "rayon"))]
-        let mut func_translator = FuncTranslator::new();
+        let mut func_translator = FuncTranslator::new(self.config.allow_unaligned_memory_accesses);
         #[cfg(not(feature = "rayon"))]
         let results = function_body_inputs
             .iter()
@@ -351,7 +351,7 @@ impl CraneliftCompiler {
 
             translate_function_buckets(
                 &pool,
-                FuncTranslator::new,
+                || FuncTranslator::new(self.config.allow_unaligned_memory_accesses),
                 |func_translator, i, input| compile_function(func_translator, i, input),
                 progress.clone(),
                 &buckets,

lib/compiler-cranelift/src/config.rs

@@ -106,6 +106,7 @@ pub enum CraneliftOptLevel {
 #[derive(Debug, Clone)]
 pub struct Cranelift {
     enable_nan_canonicalization: bool,
+    pub(crate) allow_unaligned_memory_accesses: bool,
     enable_verifier: bool,
     pub(crate) enable_perfmap: bool,
     enable_pic: bool,
@@ -123,6 +124,7 @@ impl Cranelift {
     pub fn new() -> Self {
         Self {
             enable_nan_canonicalization: false,
+            allow_unaligned_memory_accesses: false,
             enable_verifier: false,
             opt_level: CraneliftOptLevel::Speed,
             enable_pic: false,
@@ -142,6 +144,14 @@ impl Cranelift {
         self
     }
 
+    /// Enable run-time handling of potentially unaligned memory accesses.
+    /// Unaligned memory accesses occur when you try to read N bytes of data starting
+    /// from an address that is not evenly divisible by N.
+    pub fn allow_unaligned_memory_accesses(&mut self, enable: bool) -> &mut Self {
+        self.allow_unaligned_memory_accesses = enable;
+        self
+    }
+
     /// Set the number of threads to use for compilation.
     pub fn num_threads(&mut self, num_threads: NonZero<usize>) -> &mut Self {
         self.num_threads = num_threads;
@@ -286,6 +296,10 @@ impl CompilerConfig for Cranelift {
         self.enable_perfmap = true;
     }
 
+    fn enable_unaligned_memory_accesses(&mut self) {
+        self.allow_unaligned_memory_accesses = true;
+    }
+
     fn canonicalize_nans(&mut self, enable: bool) {
         self.enable_nan_canonicalization = enable;
     }