make opt_str_freeze leaf

Simply use DISPATCH_ORIGINAL_INSN instead of rb_funcall.  This is,
when possible, overall performant because method dispatch results are
cached inside of CALL_CACHE.  Should also be good for JIT.

----

trunk: ruby 2.6.0dev (2018-09-12 trunk 64689) [x86_64-darwin15]
ours: ruby 2.6.0dev (2018-09-12 leaf-insn 64688) [x86_64-darwin15]
last_commit=make opt_str_freeze leaf
Calculating -------------------------------------
                          trunk        ours
    vm2_freezestring     5.440M     31.411M i/s -      6.000M times in 1.102968s 0.191017s

Comparison:
                 vm2_freezestring
                ours:  31410864.5 i/s
               trunk:   5439865.4 i/s - 5.77x  slower



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64690 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

benchmark/vm2_freezestring.yml

@@ -0,0 +1,10 @@
+prelude: |
+  class String
+    def freeze
+      -self
+    end
+  end
+benchmark:
+  vm2_freezestring: |
+    "tXnL1BP5T1WPXMjuFNLQtallEtRcay1t2lHtJSrlVsDgvunlbtfpr/DGdH0NGYE9".freeze
+loop_count: 6000000

compile.c

@@ -6384,10 +6384,14 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, in
 	    ISEQ_COMPILE_DATA(iseq)->option->specialized_instruction) {
 	    VALUE str = freeze_literal(iseq, node->nd_recv->nd_lit);
 	    if (node->nd_mid == idUMinus) {
-		ADD_INSN1(ret, line, opt_str_uminus, str);
+		ADD_INSN3(ret, line, opt_str_uminus, str,
+                          new_callinfo(iseq, idUMinus, 0, 0, NULL, FALSE),
+                          Qundef /* CALL_CACHE */);
 	    }
 	    else {
-		ADD_INSN1(ret, line, opt_str_freeze, str);
+		ADD_INSN3(ret, line, opt_str_freeze, str,
+                          new_callinfo(iseq, idFreeze, 0, 0, NULL, FALSE),
+                          Qundef /* CALL_CACHE */);
 	    }
 	    if (popped) {
 		ADD_INSN(ret, line, pop);

insns.def

@@ -753,22 +753,36 @@ send
 
 DEFINE_INSN
 opt_str_freeze
-(VALUE str)
+(VALUE str, CALL_INFO ci, CALL_CACHE cc)
 ()
 (VALUE val)
-// attr bool leaf = BASIC_OP_UNREDEFINED_P(BOP_FREEZE, STRING_REDEFINED_OP_FLAG);
 {
     val = vm_opt_str_freeze(str, BOP_FREEZE, idFreeze);
+
+    if (val == Qundef) {
+        PUSH(str);
+#ifndef MJIT_HEADER
+        ADD_PC(-WIDTH_OF_opt_send_without_block);
+#endif
+        DISPATCH_ORIGINAL_INSN(opt_send_without_block);
+    }
 }
 
 DEFINE_INSN
 opt_str_uminus
-(VALUE str)
+(VALUE str, CALL_INFO ci, CALL_CACHE cc)
 ()
 (VALUE val)
-// attr bool leaf = BASIC_OP_UNREDEFINED_P(BOP_UMINUS, STRING_REDEFINED_OP_FLAG);
 {
     val = vm_opt_str_freeze(str, BOP_UMINUS, idUMinus);
+
+    if (val == Qundef) {
+        PUSH(str);
+#ifndef MJIT_HEADER
+        ADD_PC(-WIDTH_OF_opt_send_without_block);
+#endif
+        DISPATCH_ORIGINAL_INSN(opt_send_without_block);
+    }
 }
 
 DEFINE_INSN

vm_insnhelper.c

@@ -3219,7 +3219,7 @@ vm_opt_str_freeze(VALUE str, int bop, ID id)
 	return str;
     }
     else {
-	return rb_funcall(rb_str_resurrect(str), id, 0);
+	return Qundef;
     }
 }