[runtime] Fix get_virtual_stelemref_wrapper STELEMREF_CLASS case to actually do the...

The code was bailing straight to native which is significantly slower. This is the result of roslyn compiling corlib on my machine:

Before:
real	0m5.757s
user	0m22.059s
sys	0m1.736s

After:
real	0m5.816s
user	0m23.623s
sys	0m1.693s

diff --git a/mono/metadata/marshal.c b/mono/metadata/marshal.c
index 105655bd1b0b32840a17a5933e2a6a0b283dee87..1f4613fb540507ea684a0be13a5cb594a532de99 100644 (file)
--- a/mono/metadata/marshal.c
+++ b/mono/metadata/marshal.c
@@ -9163,7 +9163,7 @@ mono_marshal_isinst_with_cache (MonoObject *obj, MonoClass *klass, uintptr_t *ca
 
 /**
  * mono_marshal_get_isinst_with_cache:
- * This does the equivalent of \c mono_object_isinst_with_cache.
+ * This does the equivalent of \c mono_marshal_isinst_with_cache.
  */
 MonoMethod *
 mono_marshal_get_isinst_with_cache (void)
@@ -9933,8 +9933,6 @@ get_virtual_stelemref_wrapper (int kind)
                break;
 
        case STELEMREF_CLASS: {
-               int b_fast;
-
                /*
                the method:
                <ldelema (bound check)>
@@ -9975,17 +9973,6 @@ get_virtual_stelemref_wrapper (int kind)
                /* vklass = value->vtable->klass */
                load_value_class (mb, vklass);
 
-               /* fastpath */
-               mono_mb_emit_ldloc (mb, vklass);
-               mono_mb_emit_ldloc (mb, aklass);
-               b_fast = mono_mb_emit_branch (mb, CEE_BEQ);
-
-               /*if (mono_object_isinst (value, aklass)) */
-               mono_mb_emit_ldarg (mb, 2);
-               mono_mb_emit_ldloc (mb, aklass);
-               mono_mb_emit_icall (mb, mono_object_isinst_icall);
-               b2 = mono_mb_emit_branch (mb, CEE_BRFALSE);
-
                /* if (vklass->idepth < aklass->idepth) goto failue */
                mono_mb_emit_ldloc (mb, vklass);
                mono_mb_emit_ldflda (mb, MONO_STRUCT_OFFSET (MonoClass, idepth));
@@ -10017,14 +10004,12 @@ get_virtual_stelemref_wrapper (int kind)
 
                /* do_store: */
                mono_mb_patch_branch (mb, b1);
-               mono_mb_patch_branch (mb, b_fast);
                mono_mb_emit_ldloc (mb, array_slot_addr);
                mono_mb_emit_ldarg (mb, 2);
                mono_mb_emit_byte (mb, CEE_STIND_REF);
                mono_mb_emit_byte (mb, CEE_RET);
 
                /* do_exception: */
-               mono_mb_patch_branch (mb, b2);
                mono_mb_patch_branch (mb, b3);
                mono_mb_patch_branch (mb, b4);