ZJIT: constant fold bitwise XOR (^) operations (ruby#16225)

Author: tomascco

zjit/src/hir.rs

@@ -4550,6 +4550,12 @@ impl Function {
                             _ => None,
                         })
                     }
+                    Insn::FixnumXor { left, right, .. } => {
+                        self.fold_fixnum_bop(insn_id, left, right, |l, r| match (l, r) {
+                            (Some(l), Some(r)) => Some(l ^ r),
+                            _ => None,
+                        })
+                    }
                     Insn::FixnumEq { left, right, .. } => {
                         self.fold_fixnum_pred(insn_id, left, right, |l, r| match (l, r) {
                             (Some(l), Some(r)) => Some(l == r),

zjit/src/hir/opt_tests.rs

@@ -450,6 +450,64 @@ mod hir_opt_tests {
         ");
     }
 
+    #[test]
+    fn test_fold_fixnum_xor() {
+        eval("
+            def test
+              2 ^ 5
+            end
+        ");
+
+        assert_snapshot!(hir_string("test"), @"
+        fn test@<compiled>:3:
+        bb1():
+          EntryPoint interpreter
+          v1:BasicObject = LoadSelf
+          Jump bb3(v1)
+        bb2():
+          EntryPoint JIT(0)
+          v4:BasicObject = LoadArg :self@0
+          Jump bb3(v4)
+        bb3(v6:BasicObject):
+          v10:Fixnum[2] = Const Value(2)
+          v12:Fixnum[5] = Const Value(5)
+          PatchPoint MethodRedefined(Integer@0x1000, ^@0x1008, cme:0x1010)
+          v24:Fixnum[7] = Const Value(7)
+          IncrCounter inline_cfunc_optimized_send_count
+          CheckInterrupts
+          Return v24
+        ");
+    }
+
+    #[test]
+    fn test_fold_fixnum_xor_same_negative_number() {
+        eval("
+            def test
+              123 ^ -123
+            end
+        ");
+
+        assert_snapshot!(hir_string("test"), @"
+        fn test@<compiled>:3:
+        bb1():
+          EntryPoint interpreter
+          v1:BasicObject = LoadSelf
+          Jump bb3(v1)
+        bb2():
+          EntryPoint JIT(0)
+          v4:BasicObject = LoadArg :self@0
+          Jump bb3(v4)
+        bb3(v6:BasicObject):
+          v10:Fixnum[123] = Const Value(123)
+          v12:Fixnum[-123] = Const Value(-123)
+          PatchPoint MethodRedefined(Integer@0x1000, ^@0x1008, cme:0x1010)
+          v24:Fixnum[-2] = Const Value(-2)
+          IncrCounter inline_cfunc_optimized_send_count
+          CheckInterrupts
+          Return v24
+        ");
+    }
+
     #[test]
     fn test_fold_fixnum_less() {
         eval("