[meta] Rename base/ to shared/ in the Rust meta crate;

cranelift/codegen/meta/src/shared/mod.rs

@@ -0,0 +1,4 @@
+//! Shared definitions for the Cranelift intermediate language.
+
+pub mod settings;
+pub mod types;

cranelift/codegen/meta/src/shared/settings.rs

@@ -0,0 +1,164 @@
+use crate::cdsl::settings::{SettingGroup, SettingGroupBuilder};
+
+pub fn generate() -> SettingGroup {
+    let mut settings = SettingGroupBuilder::new("shared");
+
+    settings.add_enum(
+        "opt_level",
+        r#"
+        Optimization level:
+
+        - default: Very profitable optimizations enabled, none slow.
+        - best: Enable all optimizations
+        - fastest: Optimize for compile time by disabling most optimizations.
+        "#,
+        vec!["default", "best", "fastest"],
+    );
+
+    settings.add_bool(
+        "enable_verifier",
+        r#"
+        Run the Cranelift IR verifier at strategic times during compilation.
+
+        This makes compilation slower but catches many bugs. The verifier is
+        disabled by default, except when reading Cranelift IR from a text file.
+        "#,
+        true,
+    );
+
+    // Note that Cranelift doesn't currently need an is_pie flag, because PIE is
+    // just PIC where symbols can't be pre-empted, which can be expressed with the
+    // `colocated` flag on external functions and global values.
+    settings.add_bool(
+        "is_pic",
+        "Enable Position-Independent Code generation",
+        false,
+    );
+
+    settings.add_bool(
+        "colocated_libcalls",
+        r#"
+            Use colocated libcalls.
+
+            Generate code that assumes that libcalls can be declared "colocated",
+            meaning they will be defined along with the current function, such that
+            they can use more efficient addressing.
+            "#,
+        false,
+    );
+
+    settings.add_bool(
+        "avoid_div_traps",
+        r#"
+            Generate explicit checks around native division instructions to avoid
+            their trapping.
+
+            This is primarily used by SpiderMonkey which doesn't install a signal
+            handler for SIGFPE, but expects a SIGILL trap for division by zero.
+
+            On ISAs like ARM where the native division instructions don't trap,
+            this setting has no effect - explicit checks are always inserted.
+            "#,
+        false,
+    );
+
+    settings.add_bool(
+        "enable_float",
+        r#"
+            Enable the use of floating-point instructions
+
+            Disabling use of floating-point instructions is not yet implemented.
+            "#,
+        true,
+    );
+
+    settings.add_bool(
+        "enable_nan_canonicalization",
+        r#"
+            Enable NaN canonicalization
+
+            This replaces NaNs with a single canonical value, for users requiring
+            entirely deterministic WebAssembly computation. This is not required
+            by the WebAssembly spec, so it is not enabled by default.
+            "#,
+        false,
+    );
+
+    settings.add_bool("enable_simd", "Enable the use of SIMD instructions.", true);
+
+    settings.add_bool(
+        "enable_atomics",
+        "Enable the use of atomic instructions",
+        true,
+    );
+
+    // Settings specific to the `baldrdash` calling convention.
+
+    settings.add_num(
+        "baldrdash_prologue_words",
+        r#"
+            Number of pointer-sized words pushed by the baldrdash prologue.
+
+            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,
+    );
+
+    // BaldrMonkey requires that not-yet-relocated function addresses be encoded
+    // as all-ones bitpatterns.
+    settings.add_bool(
+        "allones_funcaddrs",
+        "Emit not-yet-relocated function addresses as all-ones bit patterns.",
+        false,
+    );
+
+    // Stack probing options.
+
+    settings.add_bool(
+        "probestack_enabled",
+        r#"
+            Enable the use of stack probes, for calling conventions which support this
+            functionality.
+            "#,
+        true,
+    );
+
+    settings.add_bool(
+        "probestack_func_adjusts_sp",
+        r#"
+            Set this to true of the stack probe function modifies the stack pointer
+            itself.
+            "#,
+        false,
+    );
+
+    settings.add_num(
+        "probestack_size_log2",
+        r#"
+            The log2 of the size of the stack guard region.
+
+            Stack frames larger than this size will have stack overflow checked
+            by calling the probestack function.
+
+            The default is 12, which translates to a size of 4096.
+            "#,
+        12,
+    );
+
+    // Jump table options.
+
+    settings.add_bool(
+        "jump_tables_enabled",
+        "Enable the use of jump tables in generated machine code.",
+        true,
+    );
+
+    settings.finish()
+}

cranelift/codegen/meta/src/shared/types.rs

@@ -0,0 +1,188 @@
+//! This module predefines all the Cranelift scalar types.
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Bool {
+    /// 1-bit bool.
+    B1 = 1,
+    /// 8-bit bool.
+    B8 = 8,
+    /// 16-bit bool.
+    B16 = 16,
+    /// 32-bit bool.
+    B32 = 32,
+    /// 64-bit bool.
+    B64 = 64,
+}
+
+/// This provides an iterator through all of the supported bool variants.
+pub struct BoolIterator {
+    index: u8,
+}
+
+impl BoolIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+impl Iterator for BoolIterator {
+    type Item = Bool;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Bool::B1),
+            1 => Some(Bool::B8),
+            2 => Some(Bool::B16),
+            3 => Some(Bool::B32),
+            4 => Some(Bool::B64),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Int {
+    /// 8-bit int.
+    I8 = 8,
+    /// 16-bit int.
+    I16 = 16,
+    /// 32-bit int.
+    I32 = 32,
+    /// 64-bit int.
+    I64 = 64,
+}
+
+/// This provides an iterator through all of the supported int variants.
+pub struct IntIterator {
+    index: u8,
+}
+
+impl IntIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+impl Iterator for IntIterator {
+    type Item = Int;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Int::I8),
+            1 => Some(Int::I16),
+            2 => Some(Int::I32),
+            3 => Some(Int::I64),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Float {
+    F32 = 32,
+    F64 = 64,
+}
+
+/// Iterator through the variants of the Float enum.
+pub struct FloatIterator {
+    index: u8,
+}
+
+impl FloatIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+/// This provides an iterator through all of the supported float variants.
+impl Iterator for FloatIterator {
+    type Item = Float;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Float::F32),
+            1 => Some(Float::F64),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+/// A type representing CPU flags.
+///
+/// Flags can't be stored in memory.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Flag {
+    /// CPU flags from an integer comparison.
+    IFlags,
+    /// CPU flags from a floating point comparison.
+    FFlags,
+}
+
+/// Iterator through the variants of the Flag enum.
+pub struct FlagIterator {
+    index: u8,
+}
+
+impl FlagIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+impl Iterator for FlagIterator {
+    type Item = Flag;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Flag::IFlags),
+            1 => Some(Flag::FFlags),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+#[cfg(test)]
+mod iter_tests {
+    use super::*;
+
+    #[test]
+    fn bool_iter_works() {
+        let mut bool_iter = BoolIterator::new();
+        assert_eq!(bool_iter.next(), Some(Bool::B1));
+        assert_eq!(bool_iter.next(), Some(Bool::B8));
+        assert_eq!(bool_iter.next(), Some(Bool::B16));
+        assert_eq!(bool_iter.next(), Some(Bool::B32));
+        assert_eq!(bool_iter.next(), Some(Bool::B64));
+        assert_eq!(bool_iter.next(), None);
+    }
+
+    #[test]
+    fn int_iter_works() {
+        let mut int_iter = IntIterator::new();
+        assert_eq!(int_iter.next(), Some(Int::I8));
+        assert_eq!(int_iter.next(), Some(Int::I16));
+        assert_eq!(int_iter.next(), Some(Int::I32));
+        assert_eq!(int_iter.next(), Some(Int::I64));
+        assert_eq!(int_iter.next(), None);
+    }
+
+    #[test]
+    fn float_iter_works() {
+        let mut float_iter = FloatIterator::new();
+        assert_eq!(float_iter.next(), Some(Float::F32));
+        assert_eq!(float_iter.next(), Some(Float::F64));
+        assert_eq!(float_iter.next(), None);
+    }
+
+    #[test]
+    fn flag_iter_works() {
+        let mut flag_iter = FlagIterator::new();
+        assert_eq!(flag_iter.next(), Some(Flag::IFlags));
+        assert_eq!(flag_iter.next(), Some(Flag::FFlags));
+        assert_eq!(flag_iter.next(), None);
+    }
+}