bytecodealliance · cfallin · Aug 2, 2022 · Jul 31, 2022 · Aug 1, 2022 · Aug 2, 2022
@@ -95,14 +95,16 @@ Planned uses
 
 Cranelift is designed to be a code generator for WebAssembly, but it is
 general enough to be useful elsewhere too. The initial planned uses that
-affected its design are:
-
- - [WebAssembly compiler for the SpiderMonkey engine in
-    Firefox](spidermonkey.md#phase-1-webassembly).
- - [Backend for the IonMonkey JavaScript JIT compiler in
-    Firefox](spidermonkey.md#phase-2-ionmonkey).
- - [Debug build backend for the Rust compiler](rustc.md).
- - [Wasmtime non-Web wasm engine](https://github.com/bytecodealliance/wasmtime).
+affected its design were:
+
+- [Wasmtime non-Web wasm engine](https://github.com/bytecodealliance/wasmtime).
+- [Debug build backend for the Rust compiler](rustc.md).
+- WebAssembly compiler for the SpiderMonkey engine in Firefox
+  (currently not planned anymore; SpiderMonkey team may re-assess in
+  the future).
+- Backend for the IonMonkey JavaScript JIT compiler in Firefox
+  (currently not planned anymore; SpiderMonkey team may re-assess in
+  the future).
 
 Building Cranelift
 ------------------

@@ -170,17 +170,8 @@ fn define_settings(shared: &SettingGroup) -> SettingGroup {
     // back in the shared SettingGroup, and use it in x86 instruction predicates.
 
     let is_pic = shared.get_bool("is_pic");
-    let emit_all_ones_funcaddrs = shared.get_bool("emit_all_ones_funcaddrs");
     settings.add_predicate("is_pic", predicate!(is_pic));
     settings.add_predicate("not_is_pic", predicate!(!is_pic));
-    settings.add_predicate(
-        "all_ones_funcaddrs_and_not_is_pic",
-        predicate!(emit_all_ones_funcaddrs && !is_pic),
-    );
-    settings.add_predicate(
-        "not_all_ones_funcaddrs_and_not_is_pic",
-        predicate!(!emit_all_ones_funcaddrs && !is_pic),
-    );
 
     // Presets corresponding to x86 CPUs.
 

@@ -332,24 +332,6 @@ fn define_control_flow(
         .is_terminator(true),
     );
 
-    let rvals = &Operand::new("rvals", &entities.varargs).with_doc("return values");
-    ig.push(
-        Inst::new(
-            "fallthrough_return",
-            r#"
-        Return from the function by fallthrough.
-
-        This is a specialized instruction for use where one wants to append
-        a custom epilogue, which will then perform the real return. This
-        instruction has no encoding.
-        "#,
-            &formats.multiary,
-        )
-        .operands_in(vec![rvals])
-        .is_return(true)
-        .is_terminator(true),
-    );
-
     let FN = &Operand::new("FN", &entities.func_ref)
         .with_doc("function to call, declared by `function`");
     let args = &Operand::new("args", &entities.varargs).with_doc("call arguments");

@@ -88,8 +88,8 @@ pub(crate) fn define() -> SettingGroup {
         "avoid_div_traps",
         "Generate explicit checks around native division instructions to avoid their trapping.",
         r#"
-            This is primarily used by SpiderMonkey which doesn't install a signal
-            handler for SIGFPE, but expects a SIGILL trap for division by zero.
+            Generate explicit checks around native division instructions to
+            avoid their trapping.
 
             On ISAs like ARM where the native division instructions don't trap,
             this setting has no effect - explicit checks are always inserted.
@@ -175,8 +175,6 @@ pub(crate) fn define() -> SettingGroup {
         vec!["none", "elf_gd", "macho", "coff"],
     );
 
-    // Settings specific to the `baldrdash` calling convention.
-
     settings.add_enum(
         "libcall_call_conv",
         "Defines the calling convention to use for LibCalls call expansion.",
@@ -196,29 +194,10 @@ pub(crate) fn define() -> SettingGroup {
             "system_v",
             "windows_fastcall",
             "apple_aarch64",
-            "baldrdash_system_v",
-            "baldrdash_windows",
-            "baldrdash_2020",
             "probestack",
         ],
     );
 
-    settings.add_num(
-        "baldrdash_prologue_words",
-        "Number of pointer-sized words pushed by the baldrdash prologue.",
-        r#"
-            Functions with the `baldrdash` calling convention don't generate their
-            own prologue and epilogue. They depend on externally generated code
-            that pushes a fixed number of words in the prologue and restores them
-            in the epilogue.
-
-            This setting configures the number of pointer-sized words pushed on the
-            stack when the Cranelift-generated code is entered. This includes the
-            pushed return address on x86.
-        "#,
-        0,
-    );
-
     settings.add_bool(
         "enable_llvm_abi_extensions",
         "Enable various ABI extensions defined by LLVM's behavior.",
@@ -277,15 +256,6 @@ pub(crate) fn define() -> SettingGroup {
         false,
     );
 
-    // BaldrMonkey requires that not-yet-relocated function addresses be encoded
-    // as all-ones bitpatterns.
-    settings.add_bool(
-        "emit_all_ones_funcaddrs",
-        "Emit not-yet-relocated function addresses as all-ones bit patterns.",
-        "",
-        false,
-    );
-
     // Stack probing options.
 
     settings.add_bool(

@@ -215,11 +215,6 @@ impl fmt::Display for AbiParam {
 /// particulars of the target's ABI, and the CLIF should be platform-independent, these attributes
 /// specify *how* to extend (according to the signedness of the original program) rather than
 /// *whether* to extend.
-///
-/// For example, on x86-64, the SystemV ABI does not require extensions of narrow values, so these
-/// `ArgumentExtension` attributes are ignored; but in the Baldrdash (SpiderMonkey) ABI on the same
-/// platform, all narrow values *are* extended, so these attributes may lead to extra
-/// zero/sign-extend instructions in the generated machine code.
 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
 #[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
 pub enum ArgumentExtension {
@@ -297,20 +292,6 @@ pub enum ArgumentPurpose {
     /// This is a pointer to a stack limit. It is used to check the current stack pointer
     /// against. Can only appear once in a signature.
     StackLimit,
-
-    /// A callee TLS value.
-    ///
-    /// In the Baldrdash-2020 calling convention, the stack upon entry to the callee contains the
-    /// TLS-register values for the caller and the callee. This argument is used to provide the
-    /// value for the callee.
-    CalleeTLS,
-
-    /// A caller TLS value.
-    ///
-    /// In the Baldrdash-2020 calling convention, the stack upon entry to the callee contains the
-    /// TLS-register values for the caller and the callee. This argument is used to provide the
-    /// value for the caller.
-    CallerTLS,
 }
 
 impl fmt::Display for ArgumentPurpose {
@@ -325,8 +306,6 @@ impl fmt::Display for ArgumentPurpose {
             Self::VMContext => "vmctx",
             Self::SignatureId => "sigid",
             Self::StackLimit => "stack_limit",
-            Self::CalleeTLS => "callee_tls",
-            Self::CallerTLS => "caller_tls",
         })
     }
 }
@@ -447,28 +426,22 @@ mod tests {
             CallConv::Cold,
             CallConv::SystemV,
             CallConv::WindowsFastcall,
-            CallConv::BaldrdashSystemV,
-            CallConv::BaldrdashWindows,
-            CallConv::Baldrdash2020,
         ] {
             assert_eq!(Ok(cc), cc.to_string().parse())
         }
     }
 
     #[test]
     fn signatures() {
-        let mut sig = Signature::new(CallConv::BaldrdashSystemV);
-        assert_eq!(sig.to_string(), "() baldrdash_system_v");
+        let mut sig = Signature::new(CallConv::WindowsFastcall);
+        assert_eq!(sig.to_string(), "() windows_fastcall");
         sig.params.push(AbiParam::new(I32));
-        assert_eq!(sig.to_string(), "(i32) baldrdash_system_v");
+        assert_eq!(sig.to_string(), "(i32) windows_fastcall");
         sig.returns.push(AbiParam::new(F32));
-        assert_eq!(sig.to_string(), "(i32) -> f32 baldrdash_system_v");
+        assert_eq!(sig.to_string(), "(i32) -> f32 windows_fastcall");
         sig.params.push(AbiParam::new(I32.by(4).unwrap()));
-        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32 baldrdash_system_v");
+        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32 windows_fastcall");
         sig.returns.push(AbiParam::new(B8));
-        assert_eq!(
-            sig.to_string(),
-            "(i32, i32x4) -> f32, b8 baldrdash_system_v"
-        );
+        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32, b8 windows_fastcall");
     }
 }