_mjit_compile_send.erb: retry inlining attr_reader

This reverts r63249 (revert r63212) and fixes a bug in it. The test to
prevent the bug is added as well.

vm_insnhelper.c: add `index` argument to vm_getivar. The argument is
created so that MJIT can pass the value of `cc->aux.index` on compilation
time.  The cache invalidation in _mjit_compile_send_guard.erb is only
working for the cache value on compilation time.
Note: As `index` is always passed as constant and it's force-inlined,
the performance of `vm_getivar` won't be degraded in VM.

_mjit_compile_send_guard.erb: New. Used to invalidate inlined values of cc.
common.mk: update dependencies for _mjit_compile_send_guard.erb

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63333 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 76 insertions, 15 deletions

diff --git a/common.mk b/common.mk
index 84ebfbd303..acb3d7ff4d 100644
--- a/common.mk
+++ b/common.mk
@@ -930,6 +930,7 @@ $(srcs_vpath)vm.inc: $(srcdir)/tool/ruby_vm/views/vm.inc.erb $(inc_common_header
   $(srcdir)/tool/ruby_vm/views/_insn_entry.erb $(srcdir)/tool/ruby_vm/views/_trace_instruction.erb
 $(srcs_vpath)mjit_compile.inc: $(srcdir)/tool/ruby_vm/views/mjit_compile.inc.erb $(inc_common_headers) \
   $(srcdir)/tool/ruby_vm/views/_mjit_compile_insn.erb $(srcdir)/tool/ruby_vm/views/_mjit_compile_send.erb \
+  $(srcdir)/tool/ruby_vm/views/_mjit_compile_send_guard.erb \
   $(srcdir)/tool/ruby_vm/views/_mjit_compile_insn_body.erb $(srcdir)/tool/ruby_vm/views/_mjit_compile_pc_and_sp.erb
 
 common-srcs: $(srcs_vpath)parse.c $(srcs_vpath)lex.c $(srcs_vpath)enc/trans/newline.c $(srcs_vpath)id.c \
diff --git a/test/ruby/test_jit.rb b/test/ruby/test_jit.rb
index 4699de7d2a..891b7f496f 100644
--- a/test/ruby/test_jit.rb
+++ b/test/ruby/test_jit.rb
@@ -612,6 +612,37 @@ class TestJIT < Test::Unit::TestCase
 
       print(2 * a.test)
     end;
+
+    assert_eval_with_jit("#{<<~"begin;"}\n#{<<~"end;"}", stdout: "true", success_count: 1, min_calls: 2)
+    begin;
+      class Hoge
+        attr_reader :foo
+
+        def initialize
+          @foo = []
+          @bar = nil
+        end
+      end
+
+      class Fuga < Hoge
+        def initialize
+          @bar = nil
+          @foo = []
+        end
+      end
+
+      def test(recv)
+        recv.foo.empty?
+      end
+
+      hoge = Hoge.new
+      fuga = Fuga.new
+
+      test(hoge) # VM: cc set index=1
+      test(hoge) # JIT: compile with index=1
+      test(fuga) # JIT -> VM: cc set index=2
+      print test(hoge) # JIT: should use index=1, not index=2 in cc
+    end;
   end
 
   def test_clean_so
diff --git a/tool/ruby_vm/views/_mjit_compile_send.erb b/tool/ruby_vm/views/_mjit_compile_send.erb
index 9b8225c8c5..cb7c1f40f8 100644
--- a/tool/ruby_vm/views/_mjit_compile_send.erb
+++ b/tool/ruby_vm/views/_mjit_compile_send.erb
@@ -20,7 +20,7 @@
         argc += ((ci->flag & VM_CALL_ARGS_BLOCKARG) ? 1 : 0);
 % end
 
-        if (cc->me->def->type == VM_METHOD_TYPE_ISEQ && inlinable_iseq_p(ci, cc, iseq = rb_iseq_check(cc->me->def->body.iseq.iseqptr))) {
+        if (cc->me->def->type == VM_METHOD_TYPE_ISEQ && inlinable_iseq_p(ci, cc, iseq = rb_iseq_check(cc->me->def->body.iseq.iseqptr))) { /* CI_SET_FASTPATH in vm_callee_setup_arg */
             int param_size = iseq->body->param.size; /* TODO: check calling->argc for argument_arity_error */
 
             fprintf(f, "{\n");
@@ -29,16 +29,12 @@
                 fprintf(f, "    MAYBE_UNUSED(unsigned int) stack_size = %u;\n", b->stack_size);
             }
 
+% # JIT: Invalidate call cache if it requires vm_search_method. This allows to inline some of following things.
+<%= render 'mjit_compile_send_guard' -%>
+
 % # JIT: move sp and pc if necessary
 <%= render 'mjit_compile_pc_and_sp', locals: { insn: insn } -%>
 
-% # JIT: Invalidate call cache if it requires vm_search_method. This allows to inline some of following things.
-            fprintf(f, "    if (UNLIKELY(GET_GLOBAL_METHOD_STATE() != %"PRI_SERIALT_PREFIX"u ||\n", cc->method_state);
-            fprintf(f, "        RCLASS_SERIAL(CLASS_OF(stack[%d])) != %"PRI_SERIALT_PREFIX"u)) {\n", b->stack_size - 1 - argc, cc->class_serial);
-            fprintf(f, "        reg_cfp->pc = original_body_iseq + %d;\n", pos);
-            fprintf(f, "        goto cancel;\n");
-            fprintf(f, "    }\n");
-
 % # JIT: Print insn body in insns.def
             fprintf(f, "    {\n");
             fprintf(f, "        struct rb_calling_info calling;\n");
@@ -88,5 +84,19 @@
             fprintf(f, "}\n");
             break;
         }
+% if insn.name == 'opt_send_without_block'
+        else if (cc->me->def->type == VM_METHOD_TYPE_IVAR && !(ci->flag & VM_CALL_ARGS_SPLAT)) { /* CI_SET_FASTPATH with vm_call_ivar */
+% # JIT: Invalidate call cache if it requires vm_search_method. This allows to inline some of following things.
+<%= render 'mjit_compile_send_guard' -%>
+
+% # JIT: vm_call_ivar without sp motion
+            fprintf(f, "    stack[%d] = vm_getivar(stack[%d], (ID)0x%"PRIxVALUE", NULL, (CALL_CACHE)0x%"PRIxVALUE", (st_index_t)%ld, 1);\n",
+                    b->stack_size - argc - 1, b->stack_size - argc - 1, cc->me->def->body.attr.id, (VALUE)cc, (long)cc->aux.index);
+
+% # compiler: Move JIT compiler's internal stack pointer
+            b->stack_size += <%= insn.call_attribute('sp_inc') %>;
+            break;
+        }
+% end
     }
 }
diff --git a/tool/ruby_vm/views/_mjit_compile_send_guard.erb b/tool/ruby_vm/views/_mjit_compile_send_guard.erb
new file mode 100644
index 0000000000..7bdb2a3ebf
--- /dev/null
+++ b/tool/ruby_vm/views/_mjit_compile_send_guard.erb
@@ -0,0 +1,14 @@
+% # Copyright (c) 2018 Takashi Kokubun.  All rights reserved.
+% #
+% # This file is a part of  the programming language Ruby.  Permission is hereby
+% # granted, to either  redistribute and/or modify this file,  provided that the
+% # conditions mentioned  in the  file COPYING  are met.   Consult the  file for
+% # details.
+%
+% # JIT: Invalidate call cache if it requires vm_search_method. This allows to inline some of following things.
+            fprintf(f, "    if (UNLIKELY(GET_GLOBAL_METHOD_STATE() != %"PRI_SERIALT_PREFIX"u ||\n", cc->method_state);
+            fprintf(f, "        RCLASS_SERIAL(CLASS_OF(stack[%d])) != %"PRI_SERIALT_PREFIX"u)) {\n", b->stack_size - 1 - argc, cc->class_serial);
+            fprintf(f, "        reg_cfp->pc = original_body_iseq + %d;\n", pos);
+            fprintf(f, "        reg_cfp->sp = (VALUE *)reg_cfp->bp + %d;\n", b->stack_size + 1);
+            fprintf(f, "        goto cancel;\n");
+            fprintf(f, "    }\n");
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 0f365db3f5..57e5499e4e 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -927,24 +927,29 @@ vm_search_const_defined_class(const VALUE cbase, ID id)
 #define USE_IC_FOR_IVAR 1
 #endif
 
-ALWAYS_INLINE(static VALUE vm_getivar(VALUE, ID, IC, struct rb_call_cache *, int));
+/* `index` argument is used in MJIT to inline index value of call cache */
+ALWAYS_INLINE(static VALUE vm_getivar(VALUE, ID, IC, struct rb_call_cache *, st_index_t, int));
 static inline VALUE
-vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, int is_attr)
+vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, st_index_t index, int is_attr)
 {
 #if USE_IC_FOR_IVAR
     if (LIKELY(RB_TYPE_P(obj, T_OBJECT))) {
 	VALUE val = Qundef;
-	if (LIKELY(is_attr ?
+        if (LIKELY(index > 0 || is_attr ?
 		   RB_DEBUG_COUNTER_INC_UNLESS(ivar_get_ic_miss_unset, cc->aux.index > 0) :
 		   RB_DEBUG_COUNTER_INC_UNLESS(ivar_get_ic_miss_serial,
 					       ic->ic_serial == RCLASS_SERIAL(RBASIC(obj)->klass)))) {
-	    st_index_t index = !is_attr ? ic->ic_value.index : (cc->aux.index - 1);
+            if (index == 0) {
+                index = !is_attr ? ic->ic_value.index : (cc->aux.index - 1);
+            }
+            else {
+                index--; /* MJIT passes `cc->aux.index` as `index`. This will be `cc->aux.index - 1` */
+            }
 	    if (LIKELY(index < ROBJECT_NUMIV(obj))) {
 		val = ROBJECT_IVPTR(obj)[index];
 	    }
 	}
 	else {
-	    st_data_t index;
 	    struct st_table *iv_index_tbl = ROBJECT_IV_INDEX_TBL(obj);
 
 	    if (iv_index_tbl) {
@@ -1032,7 +1037,7 @@ vm_setivar(VALUE obj, ID id, VALUE val, IC ic, struct rb_call_cache *cc, int is_
 static inline VALUE
 vm_getinstancevariable(VALUE obj, ID id, IC ic)
 {
-    return vm_getivar(obj, id, ic, 0, 0);
+    return vm_getivar(obj, id, ic, NULL, 0, FALSE);
 }
 
 static inline void
@@ -1944,7 +1949,7 @@ static VALUE
 vm_call_ivar(rb_execution_context_t *ec, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
 {
     cfp->sp -= 1;
-    return vm_getivar(calling->recv, cc->me->def->body.attr.id, NULL, cc, 1);
+    return vm_getivar(calling->recv, cc->me->def->body.attr.id, NULL, cc, 0, TRUE);
 }
 
 static VALUE