From c034cd54eda57829608e8ec09a71cf35256e1966 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Thu, 3 Dec 2015 11:00:39 -0800
Subject: [PATCH 1/2] add PIC

---
 vm_core.h       |  6 ++++++
 vm_insnhelper.c | 36 ++++++++++++++++++++++++++++++++++++
 vm_opts.h       |  2 ++
 3 files changed, 44 insertions(+)

diff --git a/vm_core.h b/vm_core.h
index 2343e11..01023a9 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -241,6 +241,12 @@ struct rb_call_cache {
 
     vm_call_handler call;
 
+#if OPT_POLYMORPHIC_INLINE_METHOD_CACHE
+    rb_serial_t class_serials[POLYMORPHIC_CACHE_SIZE];
+    const rb_callable_method_entry_t *mes[POLYMORPHIC_CACHE_SIZE];
+    vm_call_handler calls[POLYMORPHIC_CACHE_SIZE];
+#endif
+
     union {
 	unsigned int index; /* used by ivar */
 	enum method_missing_reason method_missing_reason; /* used by method_missing */
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 033edea..8692b7a 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -1123,9 +1123,32 @@ vm_search_method(const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE
     VALUE klass = CLASS_OF(recv);
 
 #if OPT_INLINE_METHOD_CACHE
+    int i;
     if (LIKELY(GET_GLOBAL_METHOD_STATE() == cc->method_state && RCLASS_SERIAL(klass) == cc->class_serial)) {
 	/* cache hit! */
 	return;
+#   if OPT_POLYMORPHIC_INLINE_METHOD_CACHE
+    } else {
+	if (LIKELY(GET_GLOBAL_METHOD_STATE() == cc->method_state)) {
+	    /* i = 0 will always be the same as the above branch, so we should
+	       skip checking it here. */
+	    for(i = 1; i < POLYMORPHIC_CACHE_SIZE; i++) {
+		if (RCLASS_SERIAL(klass) == cc->class_serials[i]) {
+		    cc->me = cc->mes[i];
+		    cc->class_serial = cc->class_serials[i];
+		    cc->call = cc->calls[i];
+		    /* cache hit! */
+		    return;
+		}
+	    }
+	} else {
+	    for(i = 0; i < POLYMORPHIC_CACHE_SIZE; i++) {
+		cc->mes[i] = 0;
+		cc->class_serials[i] = 0;
+		cc->calls[i] = 0;
+	    }
+	}
+#   endif
     }
 #endif
 
@@ -1135,6 +1158,19 @@ vm_search_method(const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE
 #if OPT_INLINE_METHOD_CACHE
     cc->method_state = GET_GLOBAL_METHOD_STATE();
     cc->class_serial = RCLASS_SERIAL(klass);
+
+#   if OPT_POLYMORPHIC_INLINE_METHOD_CACHE
+    for(i = POLYMORPHIC_CACHE_SIZE - 1; i > 0; i--) {
+	cc->mes[i] = cc->mes[i - 1];
+	cc->class_serials[i] = cc->class_serials[i - 1];
+	cc->calls[i] = cc->calls[i - 1];
+    }
+
+    cc->mes[0] = cc->me;
+    cc->class_serials[0] = cc->class_serial;
+    cc->calls[0] = cc->call;
+#   endif
+
 #endif
 }
 
diff --git a/vm_opts.h b/vm_opts.h
index 3fedf1d..8ef387c 100644
--- a/vm_opts.h
+++ b/vm_opts.h
@@ -38,6 +38,8 @@
 /* VM running option */
 #define OPT_CHECKED_RUN              1
 #define OPT_INLINE_METHOD_CACHE      1
+#define OPT_POLYMORPHIC_INLINE_METHOD_CACHE      1
+#define POLYMORPHIC_CACHE_SIZE       6
 #define OPT_GLOBAL_METHOD_CACHE      1
 #define OPT_BLOCKINLINING            0
 
-- 
2.2.1