diff --git a/src/mono/mono/mini/genmdesc.py b/src/mono/mono/mini/genmdesc.py
index 305bee2e1cc2e..58b25e0cb9407 100755
--- a/src/mono/mono/mini/genmdesc.py
+++ b/src/mono/mono/mini/genmdesc.py
@@ -91,8 +91,12 @@ def parse_mini_ops (target_define):
                     if m != None:
                         opcodes [m.group (1)] = OpDef(opcode_id, m.group (1), m.group (2), m.group (3), m.group (4))
                     else:
-                        print ("Unable to parse line: '{0}'".format (line))
-                        exit (1)
+                        m = re.search (r"MINI_OP4\(\w+\s*\,\s*\"([^\"]+)\", (\w+), (\w+), (\w+), (\w+), (\w+)\)", line)
+                        if m != None:
+                            opcodes [m.group (1)] = OpDef(opcode_id, m.group (1), m.group (2), m.group (3), m.group (4))
+                        else:
+                            print ("Unable to parse line: '{0}'".format (line))
+                            exit (1)
                 opcode_id += 1
     opcode_file.close ()
     return opcodes
diff --git a/src/mono/mono/mini/helpers.c b/src/mono/mono/mini/helpers.c
index 0a7b0d9b43373..fd3cf33b5a134 100644
--- a/src/mono/mono/mini/helpers.c
+++ b/src/mono/mono/mini/helpers.c
@@ -25,6 +25,9 @@
 #ifdef MINI_OP3
 #undef MINI_OP3
 #endif
+#ifdef MINI_OP4
+#undef MINI_OP4
+#endif
 
 // This, instead of an array of pointers, to optimize away a pointer and a relocation per string.
 #define MSGSTRFIELD(line) MSGSTRFIELD1(line)
@@ -32,22 +35,28 @@
 static const struct msgstr_t {
 #define MINI_OP(a,b,dest,src1,src2) char MSGSTRFIELD(__LINE__) [sizeof (b)];
 #define MINI_OP3(a,b,dest,src1,src2,src3) char MSGSTRFIELD(__LINE__) [sizeof (b)];
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) char MSGSTRFIELD(__LINE__) [sizeof (b)];
 #include "mini-ops.h"
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 } opstr = {
 #define MINI_OP(a,b,dest,src1,src2) b,
 #define MINI_OP3(a,b,dest,src1,src2,src3) b,
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) b,
 #include "mini-ops.h"
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 };
 static const gint16 opidx [] = {
 #define MINI_OP(a,b,dest,src1,src2)       offsetof (struct msgstr_t, MSGSTRFIELD(__LINE__)),
 #define MINI_OP3(a,b,dest,src1,src2,src3) offsetof (struct msgstr_t, MSGSTRFIELD(__LINE__)),
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) offsetof (struct msgstr_t, MSGSTRFIELD(__LINE__)),
 #include "mini-ops.h"
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 };
 
 #endif /* DISABLE_LOGGING */
diff --git a/src/mono/mono/mini/method-to-ir.c b/src/mono/mono/mini/method-to-ir.c
index 1b900f43040c1..66208d256e256 100644
--- a/src/mono/mono/mini/method-to-ir.c
+++ b/src/mono/mono/mini/method-to-ir.c
@@ -201,8 +201,12 @@ static GENERATE_GET_CLASS_WITH_CACHE (geqcomparer, "System.Collections.Generic",
 #ifdef MINI_OP3
 #undef MINI_OP3
 #endif
-#define MINI_OP(a,b,dest,src1,src2) dest, src1, src2, ' ',
-#define MINI_OP3(a,b,dest,src1,src2,src3) dest, src1, src2, src3,
+#ifdef MINI_OP4
+#undef MINI_OP4
+#endif
+#define MINI_OP(a,b,dest,src1,src2) dest, src1, src2, ' ', ' ',
+#define MINI_OP3(a,b,dest,src1,src2,src3) dest, src1, src2, src3, ' ',
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) dest, src1, src2, src3, src4,
 #define NONE ' '
 #define IREG 'i'
 #define FREG 'f'
@@ -220,9 +224,11 @@ mini_ins_info[] = {
 };
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 
 #define MINI_OP(a,b,dest,src1,src2) ((src2) != NONE ? 2 : ((src1) != NONE ? 1 : 0)),
 #define MINI_OP3(a,b,dest,src1,src2,src3) ((src3) != NONE ? 3 : ((src2) != NONE ? 2 : ((src1) != NONE ? 1 : 0))),
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) ((src4) != NONE ? 4 : ((src3) != NONE ? 3 : ((src2) != NONE ? 2 : ((src1) != NONE ? 1 : 0)))),
 /* 
  * This should contain the index of the last sreg + 1. This is not the same
  * as the number of sregs for opcodes like IA64_CMP_EQ_IMM.
@@ -232,6 +238,7 @@ const gint8 mini_ins_sreg_counts[] = {
 };
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 
 guint32
 mono_alloc_ireg (MonoCompile *cfg)
diff --git a/src/mono/mono/mini/mini-llvm.c b/src/mono/mono/mini/mini-llvm.c
index 7dcc4b71a810d..7c2498b5942a5 100644
--- a/src/mono/mono/mini/mini-llvm.c
+++ b/src/mono/mono/mini/mini-llvm.c
@@ -210,8 +210,12 @@ typedef struct {
 #ifdef MINI_OP3
 #undef MINI_OP3
 #endif
-#define MINI_OP(a,b,dest,src1,src2) dest, src1, src2, ' ',
-#define MINI_OP3(a,b,dest,src1,src2,src3) dest, src1, src2, src3,
+#ifdef MINI_OP4
+#undef MINI_OP4
+#endif
+#define MINI_OP(a,b,dest,src1,src2) dest, src1, src2, ' ', ' ',
+#define MINI_OP3(a,b,dest,src1,src2,src3) dest, src1, src2, src3, ' ',
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) dest, src1, src2, src3, src4,
 #define NONE ' '
 #define IREG 'i'
 #define FREG 'f'
@@ -225,6 +229,7 @@ mini_llvm_ins_info[] = {
 };
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 
 #if TARGET_SIZEOF_VOID_P == 4
 #define GET_LONG_IMM(ins) ((ins)->inst_l)
diff --git a/src/mono/mono/mini/mini.h b/src/mono/mono/mini/mini.h
index ee3d184189a19..8c37552583eeb 100644
--- a/src/mono/mono/mini/mini.h
+++ b/src/mono/mono/mini/mini.h
@@ -717,7 +717,7 @@ typedef struct {
 	LLVMArgInfo args [1];
 } LLVMCallInfo;
 
-#define MONO_MAX_SRC_REGS	3
+#define MONO_MAX_SRC_REGS	4
 
 struct MonoInst {
  	guint16 opcode;
@@ -725,7 +725,7 @@ struct MonoInst {
 	guint8  flags;
 	
 	/* used by the register allocator */
-	gint32 dreg, sreg1, sreg2, sreg3;
+	gint32 dreg, sreg1, sreg2, sreg3, sreg4;
 
 	MonoInst *next, *prev;
 
@@ -1728,8 +1728,12 @@ extern MonoJitStats mono_jit_stats;
 #ifdef MINI_OP3
 #undef MINI_OP3
 #endif
+#ifdef MINI_OP4
+#undef MINI_OP4
+#endif
 #define MINI_OP(a,b,dest,src1,src2) a,
 #define MINI_OP3(a,b,dest,src1,src2,src3) a,
+#define MINI_OP4(a,b,dest,src1,src2,src3,src4) a,
 enum {
 	OP_START = MONO_CEE_LAST - 1,
 #include "mini-ops.h"
@@ -1737,6 +1741,7 @@ enum {
 };
 #undef MINI_OP
 #undef MINI_OP3
+#undef MINI_OP4
 
 #if TARGET_SIZEOF_VOID_P == 8
 #define OP_PCONST OP_I8CONST