Sort type bits at compile time for Display

Merged: https://github.com/ruby/ruby/pull/13131

zjit/src/gen_hir_type.rb

@@ -14,7 +14,7 @@ class Type
   end
 
   def all_subtypes
-    subtypes + subtypes.flat_map { |subtype| subtype.all_subtypes }
+    subtypes.flat_map { |subtype| subtype.all_subtypes } + subtypes
   end
 
   def subtype name
@@ -102,17 +102,25 @@ unsigned = primitive_int.subtype "CUnsigned"
 # Assign individual bits to type leaves and union bit patterns to nodes with subtypes
 num_bits = 0
 bits = {"Bottom" => ["0u64"]}
+numeric_bits = {"Bottom" => 0}
 Set[top, *top.all_subtypes].sort_by(&:name).each {|type|
   subtypes = type.subtypes
   if subtypes.empty?
     # Assign bits for leaves
     bits[type.name] = ["1u64 << #{num_bits}"]
+    numeric_bits[type.name] = 1 << num_bits
     num_bits += 1
   else
     # Assign bits for unions
     bits[type.name] = subtypes.map(&:name).sort
   end
 }
+[*top.all_subtypes, top].each {|type|
+  subtypes = type.subtypes
+  unless subtypes.empty?
+    numeric_bits[type.name] = subtypes.map {|ty| numeric_bits[ty.name]}.reduce(&:|)
+  end
+}
 
 # ===== Finished generating the DAG; write Rust code =====
 
@@ -123,7 +131,10 @@ bits.keys.sort.map {|type_name|
   puts "  pub const #{type_name}: u64 = #{subtypes};"
 }
 puts "  pub const AllBitPatterns: [(&'static str, u64); #{bits.size}] = ["
-bits.keys.sort.map {|type_name|
+# Sort the bit patterns by decreasing value so that we can print the densest
+# possible to-string representation of a Type. For example, CSigned instead of
+# CInt8|CInt16|...
+numeric_bits.sort_by {|key, val| -val}.each {|type_name, _|
   puts "    (\"#{type_name}\", #{type_name}),"
 }
 puts "  ];"

zjit/src/hir_type.inc.rs

@@ -57,62 +57,62 @@ mod bits {
   pub const TrueClassUser: u64 = 1u64 << 33;
   pub const User: u64 = ArrayUser | FalseClassUser | FloatUser | HashUser | IntegerUser | NilClassUser | StringUser | SymbolUser | TrueClassUser;
   pub const AllBitPatterns: [(&'static str, u64); 56] = [
-    ("Array", Array),
-    ("ArrayExact", ArrayExact),
-    ("ArrayUser", ArrayUser),
-    ("Bignum", Bignum),
-    ("Bottom", Bottom),
+    ("Top", Top),
+    ("Object", Object),
+    ("ObjectUser", ObjectUser),
+    ("TrueClass", TrueClass),
+    ("User", User),
+    ("TrueClassUser", TrueClassUser),
     ("BuiltinExact", BuiltinExact),
-    ("CBool", CBool),
-    ("CDouble", CDouble),
-    ("CInt", CInt),
-    ("CInt16", CInt16),
-    ("CInt32", CInt32),
-    ("CInt64", CInt64),
-    ("CInt8", CInt8),
-    ("CNull", CNull),
-    ("CPtr", CPtr),
-    ("CSigned", CSigned),
-    ("CUInt16", CUInt16),
-    ("CUInt32", CUInt32),
-    ("CUInt64", CUInt64),
-    ("CUInt8", CUInt8),
-    ("CUnsigned", CUnsigned),
-    ("DynamicSymbol", DynamicSymbol),
-    ("FalseClass", FalseClass),
-    ("FalseClassExact", FalseClassExact),
-    ("FalseClassUser", FalseClassUser),
-    ("Fixnum", Fixnum),
+    ("TrueClassExact", TrueClassExact),
+    ("Symbol", Symbol),
+    ("SymbolUser", SymbolUser),
+    ("String", String),
+    ("StringUser", StringUser),
+    ("StringExact", StringExact),
+    ("SymbolExact", SymbolExact),
+    ("StaticSymbol", StaticSymbol),
+    ("ObjectExact", ObjectExact),
+    ("NilClass", NilClass),
+    ("NilClassUser", NilClassUser),
+    ("NilClassExact", NilClassExact),
+    ("Integer", Integer),
+    ("IntegerUser", IntegerUser),
     ("Float", Float),
     ("FloatExact", FloatExact),
-    ("FloatUser", FloatUser),
-    ("Flonum", Flonum),
-    ("Hash", Hash),
-    ("HashExact", HashExact),
-    ("HashUser", HashUser),
     ("HeapFloat", HeapFloat),
-    ("Integer", Integer),
+    ("Hash", Hash),
+    ("HashUser", HashUser),
+    ("HashExact", HashExact),
+    ("Flonum", Flonum),
+    ("FloatUser", FloatUser),
     ("IntegerExact", IntegerExact),
-    ("IntegerUser", IntegerUser),
-    ("NilClass", NilClass),
-    ("NilClassExact", NilClassExact),
-    ("NilClassUser", NilClassUser),
-    ("Object", Object),
-    ("ObjectExact", ObjectExact),
-    ("ObjectUser", ObjectUser),
+    ("Fixnum", Fixnum),
+    ("FalseClass", FalseClass),
+    ("FalseClassUser", FalseClassUser),
+    ("FalseClassExact", FalseClassExact),
+    ("DynamicSymbol", DynamicSymbol),
     ("Primitive", Primitive),
-    ("StaticSymbol", StaticSymbol),
-    ("String", String),
-    ("StringExact", StringExact),
-    ("StringUser", StringUser),
-    ("Symbol", Symbol),
-    ("SymbolExact", SymbolExact),
-    ("SymbolUser", SymbolUser),
-    ("Top", Top),
-    ("TrueClass", TrueClass),
-    ("TrueClassExact", TrueClassExact),
-    ("TrueClassUser", TrueClassUser),
-    ("User", User),
+    ("CInt", CInt),
+    ("CUnsigned", CUnsigned),
+    ("CUInt8", CUInt8),
+    ("CUInt64", CUInt64),
+    ("CUInt32", CUInt32),
+    ("CUInt16", CUInt16),
+    ("CPtr", CPtr),
+    ("CNull", CNull),
+    ("CSigned", CSigned),
+    ("CInt8", CInt8),
+    ("CInt64", CInt64),
+    ("CInt32", CInt32),
+    ("CInt16", CInt16),
+    ("CDouble", CDouble),
+    ("CBool", CBool),
+    ("Bignum", Bignum),
+    ("Array", Array),
+    ("ArrayUser", ArrayUser),
+    ("ArrayExact", ArrayExact),
+    ("Bottom", Bottom),
   ];
   pub const NumTypeBits: u64 = 34;
 }

zjit/src/hir_type.rs

@@ -102,13 +102,12 @@ impl std::fmt::Display for Type {
                 return write_spec(f, *self);
             }
         }
-        let mut bit_patterns = Vec::from_iter(bits::AllBitPatterns);
-        bit_patterns.sort_by(|(_, left), (_, right)| left.partial_cmp(right).unwrap());
+        assert!(bits::AllBitPatterns.is_sorted_by(|(_, left), (_, right)| left > right));
         let mut bits = self.bits;
         let mut sep = "";
-        for (name, pattern) in bit_patterns {
+        for (name, pattern) in bits::AllBitPatterns {
             if bits == 0 { break; }
-            if (bits & pattern) != 0 {
+            if (bits & pattern) == pattern {
                 write!(f, "{sep}{name}")?;
                 sep = "|";
                 bits &= !pattern;
@@ -475,7 +474,7 @@ mod tests {
     #[test]
     fn display_multiple_bits() {
         assert_eq!(format!("{}", types::CSigned), "CSigned");
-        assert_eq!(format!("{}", types::CUInt8.union(types::CInt32)), "CInt32|CUInt8");
+        assert_eq!(format!("{}", types::CUInt8.union(types::CInt32)), "CUInt8|CInt32");
         assert_eq!(format!("{}", types::HashExact.union(types::HashUser)), "Hash");
     }