Support GLSL450 and Simple memory models (#168)

* Support GLSL450 and Simple memory models

* Update spirv-builder/src/lib.rs

Co-authored-by: XAMPPRocky <[email protected]>

* Only emit SPV_KHR_vulkan_memory_model when needed

Co-authored-by: XAMPPRocky <[email protected]>

Author: khyperia

rustc_codegen_spirv/src/builder_spirv.rs

@@ -71,17 +71,26 @@ pub struct BuilderSpirv {
 }
 
 impl BuilderSpirv {
-    pub fn new(version: Option<(u8, u8)>, kernel_mode: bool) -> Self {
+    pub fn new(
+        version: Option<(u8, u8)>,
+        memory_model: Option<MemoryModel>,
+        kernel_mode: bool,
+    ) -> Self {
         let mut builder = Builder::new();
         // Default to spir-v 1.3
         let version = version.unwrap_or((1, 3));
         builder.set_version(version.0, version.1);
+        let memory_model = memory_model.unwrap_or(MemoryModel::Vulkan);
         if kernel_mode {
             builder.capability(Capability::Kernel);
         } else {
-            builder.extension("SPV_KHR_vulkan_memory_model");
             builder.capability(Capability::Shader);
-            builder.capability(Capability::VulkanMemoryModel);
+            if memory_model == MemoryModel::Vulkan {
+                if version < (1, 5) {
+                    builder.extension("SPV_KHR_vulkan_memory_model");
+                }
+                builder.capability(Capability::VulkanMemoryModel);
+            }
             builder.capability(Capability::VariablePointers);
             if version < (1, 3) {
                 builder.extension("SPV_KHR_variable_pointers");
@@ -98,7 +107,7 @@ impl BuilderSpirv {
             builder.capability(Capability::Addresses);
             builder.memory_model(AddressingModel::Physical32, MemoryModel::OpenCL);
         } else {
-            builder.memory_model(AddressingModel::Logical, MemoryModel::Vulkan);
+            builder.memory_model(AddressingModel::Logical, memory_model);
         }
         Self {
             builder: RefCell::new(builder),

rustc_codegen_spirv/src/codegen_cx/mod.rs

@@ -10,7 +10,7 @@ use crate::spirv_type::{SpirvType, SpirvTypePrinter, TypeCache};
 use crate::symbols::Symbols;
 use bimap::BiHashMap;
 use rspirv::dr::{Module, Operand};
-use rspirv::spirv::{Decoration, LinkageType, StorageClass, Word};
+use rspirv::spirv::{Decoration, LinkageType, MemoryModel, StorageClass, Word};
 use rustc_codegen_ssa::mir::debuginfo::{FunctionDebugContext, VariableKind};
 use rustc_codegen_ssa::traits::{
     AsmMethods, BackendTypes, CoverageInfoMethods, DebugInfoMethods, MiscMethods,
@@ -63,8 +63,9 @@ pub struct CodegenCx<'tcx> {
 impl<'tcx> CodegenCx<'tcx> {
     pub fn new(tcx: TyCtxt<'tcx>, codegen_unit: &'tcx CodegenUnit<'tcx>) -> Self {
         let sym = Box::new(Symbols::new());
-        let mut kernel_mode = false;
         let mut spirv_version = None;
+        let mut memory_model = None;
+        let mut kernel_mode = false;
         for &feature in &tcx.sess.target_features {
             if feature == sym.kernel {
                 kernel_mode = true;
@@ -80,12 +81,20 @@ impl<'tcx> CodegenCx<'tcx> {
                 spirv_version = Some((1, 4));
             } else if feature == sym.spirv15 {
                 spirv_version = Some((1, 5));
+            } else if feature == sym.simple {
+                memory_model = Some(MemoryModel::Simple);
+            } else if feature == sym.vulkan {
+                memory_model = Some(MemoryModel::Vulkan);
+            } else if feature == sym.glsl450 {
+                memory_model = Some(MemoryModel::GLSL450);
+            } else {
+                tcx.sess.err(&format!("Unknown feature {}", feature));
             }
         }
         Self {
             tcx,
             codegen_unit,
-            builder: BuilderSpirv::new(spirv_version, kernel_mode),
+            builder: BuilderSpirv::new(spirv_version, memory_model, kernel_mode),
             instances: Default::default(),
             function_parameter_values: Default::default(),
             type_cache: Default::default(),

rustc_codegen_spirv/src/symbols.rs

@@ -13,6 +13,9 @@ pub struct Symbols {
     pub spirv: Symbol,
     pub spirv_std: Symbol,
     pub kernel: Symbol,
+    pub simple: Symbol,
+    pub vulkan: Symbol,
+    pub glsl450: Symbol,
     pub spirv10: Symbol,
     pub spirv11: Symbol,
     pub spirv12: Symbol,
@@ -217,6 +220,9 @@ impl Symbols {
             spirv: Symbol::intern("spirv"),
             spirv_std: Symbol::intern("spirv_std"),
             kernel: Symbol::intern("kernel"),
+            simple: Symbol::intern("simple"),
+            vulkan: Symbol::intern("vulkan"),
+            glsl450: Symbol::intern("glsl450"),
             spirv10: Symbol::intern("spirv1.0"),
             spirv11: Symbol::intern("spirv1.1"),
             spirv12: Symbol::intern("spirv1.2"),

spirv-builder/src/lib.rs

@@ -27,17 +27,25 @@ impl fmt::Display for SpirvBuilderError {
 
 impl Error for SpirvBuilderError {}
 
+pub enum MemoryModel {
+    Simple,
+    Vulkan,
+    GLSL450,
+}
+
 pub struct SpirvBuilder {
     path_to_crate: PathBuf,
     print_metadata: bool,
     spirv_version: Option<(u8, u8)>,
+    memory_model: Option<MemoryModel>,
 }
 impl SpirvBuilder {
     pub fn new(path_to_crate: impl AsRef<Path>) -> Self {
         Self {
             path_to_crate: path_to_crate.as_ref().to_owned(),
             print_metadata: true,
             spirv_version: None,
+            memory_model: None,
         }
     }
 
@@ -47,20 +55,23 @@ impl SpirvBuilder {
         self
     }
 
+    /// Sets the SPIR-V binary version to use. Defaults to v1.3.
     pub fn spirv_version(mut self, major: u8, minor: u8) -> Self {
         self.spirv_version = Some((major, minor));
         self
     }
 
+    /// Sets the SPIR-V memory model. Defaults to Vulkan.
+    pub fn memory_model(mut self, memory_model: MemoryModel) -> Self {
+        self.memory_model = Some(memory_model);
+        self
+    }
+
     /// Builds the module. Returns the path to the built spir-v file. If print_metadata is true,
     /// you usually don't have to inspect the path, as the environment variable will already be
     /// set.
     pub fn build(self) -> Result<PathBuf, SpirvBuilderError> {
-        let spirv_module = invoke_rustc(
-            self.path_to_crate.as_ref(),
-            self.print_metadata,
-            self.spirv_version,
-        )?;
+        let spirv_module = invoke_rustc(&self)?;
         let env_var = spirv_module.file_name().unwrap().to_str().unwrap();
         if self.print_metadata {
             println!("cargo:rustc-env={}={}", env_var, spirv_module.display());
@@ -101,11 +112,7 @@ fn find_rustc_codegen_spirv() -> PathBuf {
     panic!("Could not find {} in library path", filename);
 }
 
-fn invoke_rustc(
-    path_to_crate: &Path,
-    print_metadata: bool,
-    spirv_version: Option<(u8, u8)>,
-) -> Result<PathBuf, SpirvBuilderError> {
+fn invoke_rustc(builder: &SpirvBuilder) -> Result<PathBuf, SpirvBuilderError> {
     // Okay, this is a little bonkers: in a normal world, we'd have the user clone
     // rustc_codegen_spirv and pass in the path to it, and then we'd invoke cargo to build it, grab
     // the resulting .so, and pass it into -Z codegen-backend. But that's really gross: the user
@@ -115,14 +122,30 @@ fn invoke_rustc(
     // rustc expects a full path, instead of a filename looked up via LD_LIBRARY_PATH, so we need
     // to copy cargo's understanding of library lookup and find the library and its full path.
     let rustc_codegen_spirv = find_rustc_codegen_spirv();
-    let spirv_version_feture = match spirv_version {
-        None => "".to_string(),
-        Some((major, minor)) => format!(" -C target-feature=+spirv{}.{}", major, minor),
+    let mut target_features = Vec::new();
+    // these must match codegen_cx/mod.rs
+    if let Some((major, minor)) = builder.spirv_version {
+        target_features.push(format!("+spirv{}.{}", major, minor));
+    }
+    if let Some(memory_model) = &builder.memory_model {
+        target_features.push(
+            match memory_model {
+                MemoryModel::Simple => "+simple",
+                MemoryModel::Vulkan => "+vulkan",
+                MemoryModel::GLSL450 => "+glsl450",
+            }
+            .to_string(),
+        );
+    }
+    let feature_flag = if target_features.is_empty() {
+        String::new()
+    } else {
+        format!(" -C target-feature={}", target_features.join(","))
     };
     let rustflags = format!(
         "-Z codegen-backend={}{}",
         rustc_codegen_spirv.display(),
-        spirv_version_feture
+        feature_flag,
     );
     let build = Command::new("cargo")
         .args(&[
@@ -135,14 +158,14 @@ fn invoke_rustc(
             "--release",
         ])
         .stderr(Stdio::inherit())
-        .current_dir(path_to_crate)
+        .current_dir(&builder.path_to_crate)
         .env("RUSTFLAGS", rustflags)
         .output()
         .expect("failed to execute cargo build");
     if build.status.success() {
         let stdout = String::from_utf8(build.stdout).unwrap();
         let artifact = get_last_artifact(&stdout);
-        if print_metadata {
+        if builder.print_metadata {
             print_deps_of(&artifact);
         }
         Ok(artifact)