ZJIT: Support inference of ModuleExact type

Author: st0012

zjit/src/cruby.rs

@@ -158,6 +158,7 @@ unsafe extern "C" {
     pub fn rb_vm_ic_hit_p(ic: IC, reg_ep: *const VALUE) -> bool;
     pub fn rb_vm_stack_canary() -> VALUE;
     pub fn rb_vm_push_cfunc_frame(cme: *const rb_callable_method_entry_t, recv_idx: c_int);
+    pub fn rb_obj_class(klass: VALUE) -> VALUE;
 }
 
 // Renames

zjit/src/hir.rs

@@ -5921,7 +5921,7 @@ mod opt_tests {
     }
 
     #[test]
-    fn module_instances_not_class_exact() {
+    fn module_instances_are_module_exact() {
         eval("
             def test = [Enumerable, Kernel]
             test # Warm the constant cache
@@ -5931,15 +5931,33 @@ mod opt_tests {
             bb0(v0:BasicObject):
               PatchPoint SingleRactorMode
               PatchPoint StableConstantNames(0x1000, Enumerable)
-              v11:BasicObject[VALUE(0x1008)] = Const Value(VALUE(0x1008))
+              v11:ModuleExact[VALUE(0x1008)] = Const Value(VALUE(0x1008))
               PatchPoint SingleRactorMode
               PatchPoint StableConstantNames(0x1010, Kernel)
-              v14:BasicObject[VALUE(0x1018)] = Const Value(VALUE(0x1018))
+              v14:ModuleExact[VALUE(0x1018)] = Const Value(VALUE(0x1018))
               v7:ArrayExact = NewArray v11, v14
               Return v7
         "#]]);
     }
 
+    #[test]
+    fn module_subclasses_are_not_module_exact() {
+        eval("
+            class ModuleSubclass < Module; end
+            MY_MODULE = ModuleSubclass.new
+            def test = MY_MODULE
+            test # Warm the constant cache
+        ");
+        assert_optimized_method_hir("test", expect![[r#"
+            fn test:
+            bb0(v0:BasicObject):
+              PatchPoint SingleRactorMode
+              PatchPoint StableConstantNames(0x1000, MY_MODULE)
+              v7:BasicObject[VALUE(0x1008)] = Const Value(VALUE(0x1008))
+              Return v7
+        "#]]);
+    }
+
     #[test]
     fn eliminate_array_size() {
         eval("
@@ -6067,7 +6085,7 @@ mod opt_tests {
             bb0(v0:BasicObject):
               PatchPoint SingleRactorMode
               PatchPoint StableConstantNames(0x1000, Kernel)
-              v7:BasicObject[VALUE(0x1008)] = Const Value(VALUE(0x1008))
+              v7:ModuleExact[VALUE(0x1008)] = Const Value(VALUE(0x1008))
               Return v7
         "#]]);
     }

zjit/src/hir_type/gen_hir_type.rb

@@ -75,6 +75,7 @@ def base_type name
 base_type "Set"
 base_type "Regexp"
 base_type "Class"
+base_type "Module"
 
 (integer, integer_exact) = base_type "Integer"
 # CRuby partitions Integer into immediate and non-immediate variants.

zjit/src/hir_type/hir_type.inc.rs

@@ -1,10 +1,11 @@
 #![allow(non_upper_case_globals)]
-use crate::cruby::{Qfalse, Qnil, Qtrue, VALUE, RUBY_T_ARRAY, RUBY_T_STRING, RUBY_T_HASH, RUBY_T_CLASS};
+use crate::cruby::{Qfalse, Qnil, Qtrue, VALUE, RUBY_T_ARRAY, RUBY_T_STRING, RUBY_T_HASH, RUBY_T_CLASS, RUBY_T_MODULE};
 use crate::cruby::{rb_cInteger, rb_cFloat, rb_cArray, rb_cHash, rb_cString, rb_cSymbol, rb_cObject, rb_cTrueClass, rb_cFalseClass, rb_cNilClass, rb_cRange, rb_cSet, rb_cRegexp, rb_cClass, rb_cModule};
 use crate::cruby::ClassRelationship;
 use crate::cruby::get_class_name;
 use crate::cruby::ruby_sym_to_rust_string;
 use crate::cruby::rb_mRubyVMFrozenCore;
+use crate::cruby::rb_obj_class;
 use crate::hir::PtrPrintMap;
 
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -145,9 +146,16 @@ fn is_range_exact(val: VALUE) -> bool {
     val.class_of() == unsafe { rb_cRange }
 }
 
-fn is_class_exact(val: VALUE) -> bool {
-    // Objects with RUBY_T_CLASS type and not instances of Module
-    val.builtin_type() == RUBY_T_CLASS && val.class_of() != unsafe { rb_cModule }
+fn is_module_exact(val: VALUE) -> bool {
+    if val.builtin_type() != RUBY_T_MODULE {
+        return false;
+    }
+
+    // For Class and Module instances, `class_of` will return the singleton class of the object.
+    // Using `rb_obj_class` will give us the actual class of the module so we can check if the
+    // object is an instance of Module, or an instance of Module subclass.
+    let klass = unsafe { rb_obj_class(val) };
+    klass == unsafe { rb_cModule }
 }
 
 impl Type {
@@ -202,7 +210,10 @@ impl Type {
         else if is_string_exact(val) {
             Type { bits: bits::StringExact, spec: Specialization::Object(val) }
         }
-        else if is_class_exact(val) {
+        else if is_module_exact(val) {
+            Type { bits: bits::ModuleExact, spec: Specialization::Object(val) }
+        }
+        else if val.builtin_type() == RUBY_T_CLASS {
             Type { bits: bits::ClassExact, spec: Specialization::Object(val) }
         }
         else if val.class_of() == unsafe { rb_cRegexp } {
@@ -301,6 +312,7 @@ impl Type {
         if class == unsafe { rb_cFloat } { return true; }
         if class == unsafe { rb_cHash } { return true; }
         if class == unsafe { rb_cInteger } { return true; }
+        if class == unsafe { rb_cModule } { return true; }
         if class == unsafe { rb_cNilClass } { return true; }
         if class == unsafe { rb_cObject } { return true; }
         if class == unsafe { rb_cRange } { return true; }
@@ -410,6 +422,7 @@ impl Type {
         if self.is_subtype(types::FloatExact) { return Some(unsafe { rb_cFloat }); }
         if self.is_subtype(types::HashExact) { return Some(unsafe { rb_cHash }); }
         if self.is_subtype(types::IntegerExact) { return Some(unsafe { rb_cInteger }); }
+        if self.is_subtype(types::ModuleExact) { return Some(unsafe { rb_cModule }); }
         if self.is_subtype(types::NilClassExact) { return Some(unsafe { rb_cNilClass }); }
         if self.is_subtype(types::ObjectExact) { return Some(unsafe { rb_cObject }); }
         if self.is_subtype(types::RangeExact) { return Some(unsafe { rb_cRange }); }