Share constants between codegen and the meta crate;

cranelift/codegen/meta/src/cdsl/regs.rs

@@ -1,3 +1,4 @@
+use cranelift_codegen_shared::constants;
 use cranelift_entity::{entity_impl, EntityRef, PrimaryMap};
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -364,19 +365,21 @@ impl IsaRegsBuilder {
             }
         }
 
-        // This limit should be coordinated with the `RegClassMask` and `RegClassIndex` types in
-        // isa/registers.rs of the non-meta code.
-        assert!(self.classes.len() <= 32, "Too many register classes");
+        assert!(
+            self.classes.len() <= constants::MAX_NUM_REG_CLASSES,
+            "Too many register classes"
+        );
 
-        // The maximum number of top-level register classes which have pressure tracking should be
-        // kept in sync with the MAX_TRACKED_TOPRCS constant in isa/registers.rs of the non-meta
-        // code.
         let num_toplevel = self
             .classes
             .values()
             .filter(|x| x.toprc == x.index && self.banks.get(x.bank).unwrap().pressure_tracking)
             .count();
-        assert!(num_toplevel <= 4, "Too many top-level register classes");
+
+        assert!(
+            num_toplevel <= constants::MAX_TRACKED_TOP_RCS,
+            "Too many top-level register classes"
+        );
 
         IsaRegs::new(self.banks, self.classes)
     }

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

@@ -1,24 +1,9 @@
 //! Cranelift ValueType hierarchy
 
-// Temporary disabled: Unused at the moment.
-// use std::collections::HashMap;
-
 use std::fmt;
 
 use crate::shared::types as shared_types;
-
-// 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.
-static LANE_BASE: u8 = 0x70;
-static REFERENCE_BASE: u8 = 0x7E;
+use cranelift_codegen_shared::constants;
 
 // Rust name prefix used for the `rust_name` method.
 static _RUST_NAME_PREFIX: &'static str = "ir::types::";
@@ -208,7 +193,7 @@ impl LaneType {
 
     /// Find the unique number associated with this lane type.
     pub fn number(self) -> u8 {
-        LANE_BASE
+        constants::LANE_BASE
             + match self {
                 LaneType::BoolType(shared_types::Bool::B1) => 0,
                 LaneType::BoolType(shared_types::Bool::B8) => 1,
@@ -579,7 +564,7 @@ impl ReferenceType {
 
     /// Find the unique number associated with this reference type.
     pub fn number(self) -> u8 {
-        REFERENCE_BASE
+        constants::REFERENCE_BASE
             + match self {
                 ReferenceType(shared_types::Reference::R32) => 0,
                 ReferenceType(shared_types::Reference::R64) => 1,