Implement type representation in Rust.

Start the Cretonne library as a Rust crate.

cranelift/.gitignore

@@ -1 +1,3 @@
 *.pyc
+Cargo.lock
+target

cranelift/src/libcretonne/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+authors = ["The cwCretonneRust Project Developers"]
+name = "cretonne"
+version = "0.0.0"
+
+[lib]
+name = "cretonne"
+path = "lib.rs"
+
+[dependencies]

cranelift/src/libcretonne/lib.rs

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+
+//====--------------------------------------------------------------------------------------====//
+//
+// Cretonne code generation library.
+//
+//====--------------------------------------------------------------------------------------====//
+
+mod types;

cranelift/src/libcretonne/types.rs

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+
+//! Common types for the Cretonne code generator.
+
+use std::fmt::{self, Display, Formatter, Write};
+
+/// The type of an SSA value.
+///
+/// The VOID type is only used for instructions that produce no value. It can't be part of a SIMD
+/// vector.
+///
+/// Basic integer types: `I8`, `I16`, `I32`, and `I64`. These types are sign-agnostic.
+///
+/// Basic floating point types: `F32` and `F64`. IEEE single and double precision.
+///
+/// Boolean types: `B1`, `B8`, `B16`, `B32`, and `B64`. These all encode 'true' or 'false'. The
+/// larger types use redundant bits.
+///
+/// SIMD vector types have power-of-two lanes, up to 256. Lanes can be any int/float/bool type.
+///
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct Type(u8);
+
+pub const VOID: Type = Type(0);
+
+pub const I8: Type = Type(1);
+pub const I16: Type = Type(2);
+pub const I32: Type = Type(3);
+pub const I64: Type = Type(4);
+
+pub const F32: Type = Type(5);
+pub const F64: Type = Type(6);
+
+pub const B1: Type = Type(7);
+pub const B8: Type = Type(8);
+pub const B16: Type = Type(9);
+pub const B32: Type = Type(10);
+pub const B64: Type = Type(11);
+
+impl Type {
+    /// Get the lane type of this SIMD vector type.
+    /// 
+    /// A scalar type is the same as a SIMD vector type with one lane, so it returns itself.
+    pub fn lane_type(self) -> Type {
+        Type(self.0 & 0x0f)
+    }
+
+    /// Get the number of bits in a lane.
+    pub fn lane_bits(self) -> u8 {
+        match self.lane_type() {
+            B1 => 1,
+            B8 | I8 => 8,
+            B16 | I16 => 16,
+            B32 | I32 | F32 => 32,
+            B64 | I64 | F64 => 64,
+            _ => 0,
+        }
+    }
+
+    /// Is this the VOID type?
+    pub fn is_void(self) -> bool {
+        self == VOID
+    }
+
+    /// Is this a scalar boolean type?
+    pub fn is_bool(self) -> bool {
+        match self {
+            B1 | B8 | B16 | B32 | B64 => true,
+            _ => false,
+        }
+    }
+
+    /// Is this a scalar integer type?
+    pub fn is_int(self) -> bool {
+        match self {
+            I8 | I16 | I32 | I64 => true,
+            _ => false,
+        }
+    }
+
+    /// Is this a scalar floating point type?
+    pub fn is_float(self) -> bool {
+        match self {
+            F32 | F64 => true,
+            _ => false,
+        }
+    }
+
+    /// Get log2 of the number of lanes in this SIMD vector type.
+    ///
+    /// All SIMD types have a lane count that is a power of two and no larger than 256, so this
+    /// will be a number in the range 0-8.
+    ///
+    /// A scalar type is the same as a SIMD vector type with one lane, so it return 0.
+    pub fn log2_lane_count(self) -> u8 {
+        self.0 >> 4
+    }
+
+    /// Is this a scalar type? (That is, not a SIMD vector type).
+    ///
+    /// A scalar type is the same as a SIMD vector type with one lane.
+    pub fn is_scalar(self) -> bool {
+        self.log2_lane_count() == 0
+    }
+
+    /// Get the number of lanes in this SIMD vector type.
+    ///
+    /// A scalar type is the same as a SIMD vector type with one lane, so it returns 1.
+    pub fn lane_count(self) -> u16 {
+        1 << self.log2_lane_count()
+    }
+
+    /// Get the total number of bits used to represent this type.
+    pub fn bits(self) -> u16 {
+        self.lane_bits() as u16 * self.lane_count()
+    }
+
+    /// Get a SIMD vector type with `n` times more lanes than this one.
+    ///
+    /// If this is a scalar type, this produces a SIMD type with this as a lane type and `n` lanes.
+    ///
+    /// If this is already a SIMD vector type, this produces a SIMD vector type with `n *
+    /// self.lane_count()` lanes.
+    pub fn by(self, n: u16) -> Type {
+        debug_assert!(self.lane_bits() > 0,
+                      "Can't make SIMD vectors with void lanes.");
+        debug_assert!(n.is_power_of_two(),
+                      "Number of SIMD lanes must be a power of two");
+        let log2_lanes: u32 = n.trailing_zeros();
+        let new_type = self.0 as u32 + (log2_lanes << 4);
+        assert!(new_type < 0x90, "No more than 256 SIMD lanes supported");
+        Type(new_type as u8)
+    }
+
+    /// Get a SIMD vector with half the number of lanes.
+    pub fn half_vector(self) -> Type {
+        assert!(!self.is_scalar(), "Expecting a proper SIMD vector type.");
+        Type(self.0 - 0x10)
+    }
+}
+
+impl Display for Type {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        if self.is_void() {
+            write!(f, "void")
+        } else if self.is_bool() {
+            write!(f, "b{}", self.lane_bits())
+        } else if self.is_int() {
+            write!(f, "i{}", self.lane_bits())
+        } else if self.is_float() {
+            write!(f, "f{}", self.lane_bits())
+        } else if !self.is_scalar() {
+            write!(f, "{}x{}", self.lane_type(), self.lane_count())
+        } else {
+            panic!("Invalid Type(0x{:x})", self.0)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn basic_scalars() {
+        assert_eq!(VOID, VOID.lane_type());
+        assert_eq!(0, VOID.bits());
+        assert_eq!(B1, B1.lane_type());
+        assert_eq!(B8, B8.lane_type());
+        assert_eq!(B16, B16.lane_type());
+        assert_eq!(B32, B32.lane_type());
+        assert_eq!(B64, B64.lane_type());
+        assert_eq!(I8, I8.lane_type());
+        assert_eq!(I16, I16.lane_type());
+        assert_eq!(I32, I32.lane_type());
+        assert_eq!(I64, I64.lane_type());
+        assert_eq!(F32, F32.lane_type());
+        assert_eq!(F64, F64.lane_type());
+
+        assert_eq!(VOID.lane_bits(), 0);
+        assert_eq!(B1.lane_bits(), 1);
+        assert_eq!(B8.lane_bits(), 8);
+        assert_eq!(B16.lane_bits(), 16);
+        assert_eq!(B32.lane_bits(), 32);
+        assert_eq!(B64.lane_bits(), 64);
+        assert_eq!(I8.lane_bits(), 8);
+        assert_eq!(I16.lane_bits(), 16);
+        assert_eq!(I32.lane_bits(), 32);
+        assert_eq!(I64.lane_bits(), 64);
+        assert_eq!(F32.lane_bits(), 32);
+        assert_eq!(F64.lane_bits(), 64);
+    }
+
+    #[test]
+    fn vectors() {
+        let big = F64.by(256);
+        assert_eq!(big.lane_bits(), 64);
+        assert_eq!(big.lane_count(), 256);
+        assert_eq!(big.bits(), 64 * 256);
+
+        assert_eq!(format!("{}", big.half_vector()), "f64x128");
+        assert_eq!(format!("{}", B1.by(2).half_vector()), "b1");
+    }
+
+    #[test]
+    fn format_scalars() {
+        assert_eq!(format!("{}", VOID), "void");
+        assert_eq!(format!("{}", B1), "b1");
+        assert_eq!(format!("{}", B8), "b8");
+        assert_eq!(format!("{}", B16), "b16");
+        assert_eq!(format!("{}", B32), "b32");
+        assert_eq!(format!("{}", B64), "b64");
+        assert_eq!(format!("{}", I8), "i8");
+        assert_eq!(format!("{}", I16), "i16");
+        assert_eq!(format!("{}", I32), "i32");
+        assert_eq!(format!("{}", I64), "i64");
+        assert_eq!(format!("{}", F32), "f32");
+        assert_eq!(format!("{}", F64), "f64");
+    }
+
+    #[test]
+    fn format_vectors() {
+        assert_eq!(format!("{}", B1.by(8)), "b1x8");
+        assert_eq!(format!("{}", B8.by(1)), "b8");
+        assert_eq!(format!("{}", B16.by(256)), "b16x256");
+        assert_eq!(format!("{}", B32.by(4).by(2)), "b32x8");
+        assert_eq!(format!("{}", B64.by(8)), "b64x8");
+        assert_eq!(format!("{}", I8.by(64)), "i8x64");
+        assert_eq!(format!("{}", F64.by(2)), "f64x2");
+    }
+}