From 0d0fc55122f7e64cf4d491c4a5f4bb941f29ec65 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 18 Jul 2014 02:10:37 +0000
Subject: [PATCH] enum.c: optimize any? object allocations for Array and Hash

* enum.c (enum_any): optimize object allocations for Array and
  Hash when `each` is not redefined, always false if empty and the
  case without a block.  [fix GH-617]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46859 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog |  6 ++++++
 common.mk |  2 +-
 enum.c    | 35 ++++++++++++++++++++++++++++++++++-
 vm.c      |  1 +
 vm_core.h |  1 +
 5 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ffd65a04e3..bbd7535bfc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Jul 18 11:10:53 2014  Scott Francis  <scott.francis@shopify.com>
+
+	* enum.c (enum_any): optimize object allocations for Array and
+	  Hash when `each` is not redefined, always false if empty and the
+	  case without a block.  [fix GH-617]
+
 Fri Jul 18 10:14:42 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* lib/fileutils.rb: added missing options of FileUtils.touch by @Domon.
diff --git a/common.mk b/common.mk
index 160df019af..ae3a151583 100644
--- a/common.mk
+++ b/common.mk
@@ -689,7 +689,7 @@ encoding.$(OBJEXT): {$(VPATH)}encoding.c $(RUBY_H_INCLUDES) \
   $(ENCODING_H_INCLUDES) {$(VPATH)}regenc.h {$(VPATH)}util.h \
   {$(VPATH)}internal.h
 enum.$(OBJEXT): {$(VPATH)}enum.c $(RUBY_H_INCLUDES) {$(VPATH)}node.h \
-  {$(VPATH)}util.h {$(VPATH)}id.h {$(VPATH)}internal.h
+  {$(VPATH)}util.h {$(VPATH)}id.h {$(VPATH)}internal.h $(VM_CORE_H_INCLUDES)
 enumerator.$(OBJEXT): {$(VPATH)}enumerator.c $(RUBY_H_INCLUDES) \
   {$(VPATH)}internal.h {$(VPATH)}node.h
 error.$(OBJEXT): {$(VPATH)}error.c {$(VPATH)}known_errors.inc \
diff --git a/enum.c b/enum.c
index 44a73d3543..1703003c7d 100644
--- a/enum.c
+++ b/enum.c
@@ -14,6 +14,7 @@
 #include "node.h"
 #include "id.h"
 #include "internal.h"
+#include "vm_core.h"
 
 VALUE rb_f_send(int argc, VALUE *argv, VALUE recv);
 
@@ -1023,6 +1024,11 @@ name##_iter_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, memo)) \
 static VALUE \
 enum_##name##_func(VALUE result, NODE *memo)
 
+#define ARY_OPTIMIZABLE_EACH(obj) \
+    (RBASIC_CLASS(obj) == rb_cArray && BASIC_OP_UNREDEFINED_P(BOP_EACH, ARRAY_REDEFINED_OP_FLAG))
+#define HASH_OPTIMIZABLE_EACH(obj) \
+    (RBASIC_CLASS(obj) == rb_cHash && BASIC_OP_UNREDEFINED_P(BOP_EACH, HASH_REDEFINED_OP_FLAG))
+
 DEFINE_ENUMFUNCS(all)
 {
     if (!RTEST(result)) {
@@ -1086,7 +1092,34 @@ DEFINE_ENUMFUNCS(any)
 static VALUE
 enum_any(VALUE obj)
 {
-    NODE *memo = NEW_MEMO(Qfalse, 0, 0);
+    NODE *memo;
+
+    if (!SPECIAL_CONST_P(obj)) {
+	switch (BUILTIN_TYPE(obj)) {
+	  case T_ARRAY:
+	    if (ARY_OPTIMIZABLE_EACH(obj)) {
+		long i, len = RARRAY_LEN(obj);
+		if (!len) return Qfalse;
+		if (!rb_block_given_p()) {
+		    const VALUE *ptr = RARRAY_CONST_PTR(obj);
+		    for (i = 0; i < len; ++i) if (RTEST(ptr[i])) return Qtrue;
+		    return Qfalse;
+		}
+	    }
+	    break;
+	  case T_HASH:
+	    if (HASH_OPTIMIZABLE_EACH(obj)) {
+		if (RHASH_EMPTY_P(obj)) return Qfalse;
+		if (!rb_block_given_p()) {
+		    /* yields pairs, never false */
+		    return Qtrue;
+		}
+	    }
+	    break;
+	}
+    }
+
+    memo = NEW_MEMO(Qfalse, 0, 0);
     rb_block_call(obj, id_each, 0, 0, ENUMFUNC(any), (VALUE)memo);
     return memo->u1.value;
 }
diff --git a/vm.c b/vm.c
index f9a2c3df5b..9630c31de6 100644
--- a/vm.c
+++ b/vm.c
@@ -1236,6 +1236,7 @@ vm_init_redefined_flag(void)
     OP(Succ, SUCC), (C(Fixnum), C(String), C(Time));
     OP(EqTilde, MATCH), (C(Regexp), C(String));
     OP(Freeze, FREEZE), (C(String));
+    OP(Each, EACH), (C(Array), C(Hash));
 #undef C
 #undef OP
 }
diff --git a/vm_core.h b/vm_core.h
index ff54c2928d..ca93e22722 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -341,6 +341,7 @@ enum ruby_basic_operators {
     BOP_NEQ,
     BOP_MATCH,
     BOP_FREEZE,
+    BOP_EACH,
 
     BOP_LAST_
 };