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//! This module contains constants that are shared between the codegen and the meta crate, so they
//! are kept in sync.

// Numbering scheme for value types:
//
// 0: Void
// 0x01-0x6f: Special types
// 0x70-0x7d: Lane types
// 0x7e-0x7f: Reference types
// 0x80-0xff: Vector types
//
// Vector types are encoded with the lane type in the low 4 bits and log2(lanes)
// in the high 4 bits, giving a range of 2-256 lanes.

/// Start of the lane types.
pub const LANE_BASE: u8 = 0x70;

/// Base for reference types.
pub const REFERENCE_BASE: u8 = 0x7E;

/// Start of the 2-lane vector types.
pub const VECTOR_BASE: u8 = 0x80;

// Some constants about register classes and types.

/// Guaranteed maximum number of top-level register classes with pressure tracking in any ISA.
pub const MAX_TRACKED_TOP_RCS: usize = 4;

/// Guaranteed maximum number of register classes in any ISA.
pub const MAX_NUM_REG_CLASSES: usize = 32;