insns.def: add opt path for Hash#[] and Hash#[]= used with str literal keys

* insns.def (opt_aref_with): new instruction to optimize Hash#[],
  removing any allocation overhead when used with a string literal
  key. Patch by normalperson (Eric Wong). [ruby-core:59640] [Bug #9382]
* insns.def (opt_aset_with): new instruction to optimize Hash#[]=
* compile.c (iseq_compile_each): compiler shortcuts for new
  instructions
* hash.c (static VALUE rb_hash_compare_by_id_p): fix documentation for
  Hash#compare_by_identity to reflect frozen string sharing
* test/ruby/test_hash.rb (class TestHash): test for new behavior

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44551 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 39 insertions, 0 deletions

diff --git a/compile.c b/compile.c
index 5b28401f7d..849d4a5a5e 100644
--- a/compile.c
+++ b/compile.c
@@ -4319,6 +4319,9 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	break;
       }
       case NODE_CALL:
+	/* optimization shortcut
+	 *   "literal".freeze -> opt_str_freeze("literal")
+	 */
 	if (node->nd_recv && nd_type(node->nd_recv) == NODE_STR &&
 	    node->nd_mid == idFreeze && node->nd_args == NULL)
 	{
@@ -4330,6 +4333,23 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	    }
 	    break;
 	}
+	/* optimization shortcut
+	 *   obj["literal"] -> opt_aref_with(obj, "literal")
+	 */
+	if (node->nd_mid == idAREF && node->nd_recv != (NODE *)1 && node->nd_args &&
+	    nd_type(node->nd_args) == NODE_ARRAY && node->nd_args->nd_alen == 1 &&
+	    nd_type(node->nd_args->nd_head) == NODE_STR)
+	{
+	    VALUE str = rb_fstring(node->nd_args->nd_head->nd_lit);
+	    node->nd_args->nd_head->nd_lit = str;
+	    COMPILE(ret, "recv", node->nd_recv);
+	    ADD_INSN2(ret, line, opt_aref_with,
+		      new_callinfo(iseq, idAREF, 1, 0, 0), str);
+	    if (poped) {
+		ADD_INSN(ret, line, pop);
+	    }
+	    break;
+	}
       case NODE_FCALL:
       case NODE_VCALL:{		/* VCALL: variable or call */
 	/*
@@ -5300,6 +5320,25 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	VALUE flag = 0;
 	VALUE argc;
 
+	/* optimization shortcut
+	 *   obj["literal"] = value -> opt_aset_with(obj, "literal", value)
+	 */
+	if (node->nd_mid == idASET && node->nd_recv != (NODE *)1 && node->nd_args &&
+	    nd_type(node->nd_args) == NODE_ARRAY && node->nd_args->nd_alen == 2 &&
+	    nd_type(node->nd_args->nd_head) == NODE_STR)
+	{
+	    VALUE str = rb_fstring(node->nd_args->nd_head->nd_lit);
+	    node->nd_args->nd_head->nd_lit = str;
+	    COMPILE(ret, "recv", node->nd_recv);
+	    COMPILE(ret, "value", node->nd_args->nd_next->nd_head);
+	    ADD_INSN2(ret, line, opt_aset_with,
+		      new_callinfo(iseq, idASET, 2, 0, 0), str);
+	    if (poped) {
+		ADD_INSN(ret, line, pop);
+	    }
+	    break;
+	}
+
 	INIT_ANCHOR(recv);
 	INIT_ANCHOR(args);
 	argc = setup_args(iseq, args, node->nd_args, &flag);