diff --git a/gen/Makefile b/gen/Makefile
index 70d5191..53d1a94 100644
--- a/gen/Makefile
+++ b/gen/Makefile
@@ -1,5 +1,5 @@
 TARGET=../xbyak/xbyak_mnemonic.h
-BIN=sortline gen_code gen_avx512 gen_vnni
+BIN=sortline gen_code gen_avx512
 CFLAGS=-I../ -O2 -DXBYAK_NO_OP_NAMES -Wall -Wextra -Wno-missing-field-initializers
 all: $(TARGET)
 sortline: sortline.cpp
@@ -8,8 +8,6 @@
 	$(CXX) $(CFLAGS) $< -o $@
 gen_avx512: gen_avx512.cpp ../xbyak/xbyak.h avx_type.hpp
 	$(CXX) $(CFLAGS) $< -o $@
-gen_vnni: gen_vnni.cpp ../xbyak/xbyak.h avx_type.hpp
-	$(CXX) $(CFLAGS) $< -o $@
 
 $(TARGET): $(BIN)
 	./gen_code | ./sortline > $@
@@ -23,11 +21,6 @@
 	./gen_avx512 64 | ./sortline >> $@
 	echo "#endif" >> $@
 	echo "#endif" >> $@
-	echo "#ifdef XBYAK_DISABLE_AVX512" >> $@
-	./gen_vnni vexOnly | ./sortline >> $@
-	echo "#else" >> $@
-	./gen_vnni | ./sortline >> $@
-	echo "#endif" >> $@
 
 clean:
 	$(RM) $(BIN) $(TARGET)
diff --git a/gen/gen_code.cpp b/gen/gen_code.cpp
index ba7dbf6..90f2967 100644
--- a/gen/gen_code.cpp
+++ b/gen/gen_code.cpp
@@ -1729,6 +1729,24 @@
 			printf("void %s(const Xmm& x1, const Address& addr, const Xmm& x2) { opGather(x1, addr, x2, T_0F38 | T_66 | T_YMM | T_VSIB | T_W%d, 0x%x, %d); }\n", p.name, p.w, p.code, p.mode);
 		}
 	}
+	// vnni
+	{
+		const struct Tbl {
+			uint8_t code;
+			const char *name;
+			int type;
+		} tbl[] = {
+			{ 0x50, "vpdpbusd", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
+			{ 0x51, "vpdpbusds", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
+			{ 0x52, "vpdpwssd", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
+			{ 0x53, "vpdpwssds", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
+		};
+		for (size_t i = 0; i < NUM_OF_ARRAY(tbl); i++) {
+			const Tbl *p = &tbl[i];
+			std::string type = type2String(p->type);
+			printf("void %s(const Xmm& x1, const Xmm& x2, const Operand& op, PreferredEncoding encoding = DefaultEncoding) { opVnni(x1, x2, op, %s, 0x%02X, encoding); }\n", p->name, type.c_str(), p->code);
+		}
+	}
 }
 
 void put32()
diff --git a/gen/gen_vnni.cpp b/gen/gen_vnni.cpp
deleted file mode 100644
index 79564aa..0000000
--- a/gen/gen_vnni.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-#define XBYAK_DONT_READ_LIST
-#include <stdio.h>
-#include <string.h>
-#include "../xbyak/xbyak.h"
-#define NUM_OF_ARRAY(x) (sizeof(x) / sizeof(x[0]))
-
-using namespace Xbyak;
-#ifdef _MSC_VER
-	#pragma warning(disable : 4996) // scanf
-	#define snprintf _snprintf_s
-#endif
-
-#include "avx_type.hpp"
-
-void putVNNI(bool vexEncodingOnly)
-{
-	const struct Tbl {
-		uint8_t code;
-		const char *name;
-		int type;
-	} tbl[] = {
-		{ 0x50, "vpdpbusd", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
-		{ 0x51, "vpdpbusds", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
-
-		{ 0x52, "vpdpwssd", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
-		{ 0x53, "vpdpwssds", T_66 | T_0F38 | T_YMM | T_EW0 | T_SAE_Z | T_B32},
-	};
-	for (size_t i = 0; i < NUM_OF_ARRAY(tbl); i++) {
-		const Tbl *p = &tbl[i];
-		std::string type = type2String(p->type);
-		printf("void %s(const Xmm& x1, const Xmm& x2, const Operand& op%s) { opAVX_X_X_XM(x1, x2, op, %s%s, 0x%02X, NONE%s); }\n"
-			, p->name, !vexEncodingOnly ? ", preferred_encoding_t encoding = DEFAULT" : "", type.c_str()
-			, !vexEncodingOnly ? " | T_PREF_EVEX" : "", p->code, !vexEncodingOnly ? ", encoding" : "");
-	}
-}
-
-int main(int argc, char *[])
-{
-	bool vexEncodingOnly = argc == 2;
-	putVNNI(vexEncodingOnly);
-}
diff --git a/gen/update.bat b/gen/update.bat
index c9e5537..161ed87 100644
--- a/gen/update.bat
+++ b/gen/update.bat
@@ -15,9 +15,3 @@
 gen_avx512 64 | %SORT% >> %TARGET%
 echo #endif>> %TARGET%
 echo #endif>> %TARGET%
-cl gen_vnni.cpp %OPT%
-echo #ifdef XBYAK_DISABLE_AVX512>> %TARGET%
-gen_vnni vexOnly | %SORT% >> %TARGET%
-echo #else>> %TARGET%
-gen_vnni | %SORT% >> %TARGET%
-echo #endif>> %TARGET%
diff --git a/test/misc.cpp b/test/misc.cpp
index 2a55ec2..0d79e64 100644
--- a/test/misc.cpp
+++ b/test/misc.cpp
@@ -815,4 +815,29 @@
 	CYBOZU_TEST_EXCEPTION(c.notSupported(), std::exception);
 	CYBOZU_TEST_EXCEPTION(c.notSupported2(), std::exception);
 }
+
+CYBOZU_TEST_AUTO(vnni)
+{
+	struct Code : Xbyak::CodeGenerator {
+		Code()
+		{
+			vpdpbusd(xm0, xm1, xm2); // EVEX
+			vpdpbusd(xm0, xm1, xm2, VexEncoding); // VEX
+		}
+		void badVex()
+		{
+			vpdpbusd(xm0, xm1, xm31, VexEncoding);
+		}
+	} c;
+	const uint8_t tbl[] = {
+		0x62, 0xF2, 0x75, 0x08, 0x50, 0xC2,
+		0xC4, 0xE2, 0x71, 0x50, 0xC2,
+	};
+	const size_t n = sizeof(tbl) / sizeof(tbl[0]);
+	CYBOZU_TEST_EQUAL(c.getSize(), n);
+	CYBOZU_TEST_EQUAL_ARRAY(c.getCode(), tbl, n);
+
+	CYBOZU_TEST_EXCEPTION(c.badVex(), std::exception);
+}
+
 #endif
diff --git a/xbyak/xbyak.h b/xbyak/xbyak.h
index 72b4710..d60ee8d 100644
--- a/xbyak/xbyak.h
+++ b/xbyak/xbyak.h
@@ -1543,7 +1543,11 @@
 	return mgr->getCode() + offset;
 }
 
-typedef enum preferred_encoding_t_ { VEX, DEFAULT } preferred_encoding_t;
+typedef enum {
+	DefaultEncoding,
+	VexEncoding,
+	EvexEncoding
+} PreferredEncoding;
 
 class CodeGenerator : public CodeArray {
 public:
@@ -1654,7 +1658,6 @@
 		T_M_K = 1 << 28, // mem{k}
 		T_VSIB = 1 << 29,
 		T_MEM_EVEX = 1 << 30, // use evex if mem
-		T_PREF_EVEX = 1 << 31, // generate EVEX if preferred_encoding = DEFAULT for AVX512
 		T_XXX
 	};
 	void vex(const Reg& reg, const Reg& base, const Operand *v, int type, int code, bool x = false)
@@ -1694,7 +1697,7 @@
 	}
 	int evex(const Reg& reg, const Reg& base, const Operand *v, int type, int code, bool x = false, bool b = false, int aaa = 0, uint32_t VL = 0, bool Hi16Vidx = false)
 	{
-		if (!(type & (T_EVEX | T_MUST_EVEX | T_PREF_EVEX))) XBYAK_THROW_RET(ERR_EVEX_IS_INVALID, 0)
+		if (!(type & (T_EVEX | T_MUST_EVEX))) XBYAK_THROW_RET(ERR_EVEX_IS_INVALID, 0)
 		int w = (type & T_EW1) ? 1 : 0;
 		uint32_t mm = (type & T_0F) ? 1 : (type & T_0F38) ? 2 : (type & T_0F3A) ? 3 : 0;
 		uint32_t pp = (type & T_66) ? 1 : (type & T_F3) ? 2 : (type & T_F2) ? 3 : 0;
@@ -2131,15 +2134,8 @@
 	{
 		db(code1); db(code2 | reg.getIdx());
 	}
-	void opVex(const Reg& r, const Operand *p1, const Operand& op2, int type, int code, int imm8 = NONE, preferred_encoding_t encoding_ = DEFAULT)
+	void opVex(const Reg& r, const Operand *p1, const Operand& op2, int type, int code, int imm8 = NONE)
 	{
-#ifdef XBYAK_DISABLE_AVX512
-		preferred_encoding_t encoding = VEX;
-#else
-		preferred_encoding_t encoding = encoding_;
-#endif
-		if ((encoding == VEX) && ((type & T_MUST_EVEX) || (r.hasEvex() || p1->hasEvex() || op2.hasEvex()))) XBYAK_THROW(ERR_BAD_COMBINATION);
-
 		if (op2.isMEM()) {
 			const Address& addr = op2.getAddress();
 			const RegExp& regExp = addr.getRegExp();
@@ -2148,7 +2144,7 @@
 			if (BIT == 64 && addr.is32bit()) db(0x67);
 			int disp8N = 0;
 			bool x = index.isExtIdx();
-			if ((encoding == DEFAULT) && ((type & (T_MUST_EVEX | T_PREF_EVEX | T_MEM_EVEX)) || r.hasEvex() || (p1 && p1->hasEvex()) || addr.isBroadcast() || addr.getOpmaskIdx())) {
+			if ((type & (T_MUST_EVEX|T_MEM_EVEX)) || r.hasEvex() || (p1 && p1->hasEvex()) || addr.isBroadcast() || addr.getOpmaskIdx()) {
 				int aaa = addr.getOpmaskIdx();
 				if (aaa && !(type & T_M_K)) XBYAK_THROW(ERR_INVALID_OPMASK_WITH_MEMORY)
 				bool b = false;
@@ -2164,7 +2160,7 @@
 			opAddr(addr, r.getIdx(), (imm8 != NONE) ? 1 : 0, disp8N, (type & T_VSIB) != 0);
 		} else {
 			const Reg& base = op2.getReg();
-			if ((encoding == DEFAULT) && ((type & (T_MUST_EVEX | T_PREF_EVEX)) || r.hasEvex() || (p1 && p1->hasEvex()) || base.hasEvex())) {
+			if ((type & T_MUST_EVEX) || r.hasEvex() || (p1 && p1->hasEvex()) || base.hasEvex()) {
 				evex(r, base, p1, type, code);
 			} else {
 				vex(r, base, p1, type, code);
@@ -2185,7 +2181,7 @@
 		type |= (bit == 64) ? T_W1 : T_W0;
 		opVex(r, p1, *p2, type, code, imm8);
 	}
-	void opAVX_X_X_XM(const Xmm& x1, const Operand& op1, const Operand& op2, int type, int code0, int imm8 = NONE, preferred_encoding_t encoding = DEFAULT)
+	void opAVX_X_X_XM(const Xmm& x1, const Operand& op1, const Operand& op2, int type, int code0, int imm8 = NONE)
 	{
 		const Xmm *x2 = static_cast<const Xmm*>(&op1);
 		const Operand *op = &op2;
@@ -2195,7 +2191,7 @@
 		}
 		// (x1, x2, op)
 		if (!((x1.isXMM() && x2->isXMM()) || ((type & T_YMM) && ((x1.isYMM() && x2->isYMM()) || (x1.isZMM() && x2->isZMM()))))) XBYAK_THROW(ERR_BAD_COMBINATION)
-		opVex(x1, x2, *op, type, code0, imm8, encoding);
+		opVex(x1, x2, *op, type, code0, imm8);
 	}
 	void opAVX_K_X_XM(const Opmask& k, const Xmm& x2, const Operand& op3, int type, int code0, int imm8 = NONE)
 	{
@@ -2307,6 +2303,21 @@
 		if (addr.getRegExp().getIndex().getKind() != kind) XBYAK_THROW(ERR_BAD_VSIB_ADDRESSING)
 		opVex(x, 0, addr, type, code);
 	}
+	void opVnni(const Xmm& x1, const Xmm& x2, const Operand& op, int type, int code0, PreferredEncoding encoding)
+	{
+		if (encoding == DefaultEncoding) {
+#ifdef XBYAK_DISABLE_AVX512
+			encoding = VexEncoding;
+#else
+			encoding = EvexEncoding;
+#endif
+		}
+		if (encoding == EvexEncoding) {
+			type |= T_MUST_EVEX;
+		}
+		opAVX_X_X_XM(x1, x2, op, type, code0);
+	}
+
 	void opInOut(const Reg& a, const Reg& d, uint8_t code)
 	{
 		if (a.getIdx() == Operand::AL && d.getIdx() == Operand::DX && d.getBit() == 16) {
diff --git a/xbyak/xbyak_mnemonic.h b/xbyak/xbyak_mnemonic.h
index 2e025a6..6aaa74e 100644
--- a/xbyak/xbyak_mnemonic.h
+++ b/xbyak/xbyak_mnemonic.h
@@ -1180,6 +1180,10 @@
 void vpcmpgtw(const Xmm& x1, const Xmm& x2, const Operand& op) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F | T_YMM, 0x65); }
 void vpcmpistri(const Xmm& xm, const Operand& op, uint8_t imm) { opAVX_X_XM_IMM(xm, op, T_66 | T_0F3A, 0x63, imm); }
 void vpcmpistrm(const Xmm& xm, const Operand& op, uint8_t imm) { opAVX_X_XM_IMM(xm, op, T_66 | T_0F3A, 0x62, imm); }
+void vpdpbusd(const Xmm& x1, const Xmm& x2, const Operand& op, PreferredEncoding encoding = DefaultEncoding) { opVnni(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x50, encoding); }
+void vpdpbusds(const Xmm& x1, const Xmm& x2, const Operand& op, PreferredEncoding encoding = DefaultEncoding) { opVnni(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x51, encoding); }
+void vpdpwssd(const Xmm& x1, const Xmm& x2, const Operand& op, PreferredEncoding encoding = DefaultEncoding) { opVnni(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x52, encoding); }
+void vpdpwssds(const Xmm& x1, const Xmm& x2, const Operand& op, PreferredEncoding encoding = DefaultEncoding) { opVnni(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x53, encoding); }
 void vperm2f128(const Ymm& y1, const Ymm& y2, const Operand& op, uint8_t imm) { if (!(y1.isYMM() && y2.isYMM() && op.isYMEM())) XBYAK_THROW(ERR_BAD_COMBINATION) opVex(y1, &y2, op, T_0F3A | T_66 | T_W0 | T_YMM, 0x06, imm); }
 void vperm2i128(const Ymm& y1, const Ymm& y2, const Operand& op, uint8_t imm) { if (!(y1.isYMM() && y2.isYMM() && op.isYMEM())) XBYAK_THROW(ERR_BAD_COMBINATION) opVex(y1, &y2, op, T_0F3A | T_66 | T_W0 | T_YMM, 0x46, imm); }
 void vpermd(const Ymm& y1, const Ymm& y2, const Operand& op) { opAVX_X_X_XM(y1, y2, op, T_66 | T_0F38 | T_W0 | T_EW0 | T_YMM | T_EVEX | T_B32, 0x36); }
@@ -2044,14 +2048,3 @@
 void vpbroadcastq(const Xmm& x, const Reg64& r) { opVex(x, 0, r, T_66 | T_0F38 | T_EW1 | T_YMM | T_MUST_EVEX, 0x7C); }
 #endif
 #endif
-#ifdef XBYAK_DISABLE_AVX512
-void vpdpbusd(const Xmm& x1, const Xmm& x2, const Operand& op) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x50, NONE); }
-void vpdpbusds(const Xmm& x1, const Xmm& x2, const Operand& op) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x51, NONE); }
-void vpdpwssd(const Xmm& x1, const Xmm& x2, const Operand& op) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x52, NONE); }
-void vpdpwssds(const Xmm& x1, const Xmm& x2, const Operand& op) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32, 0x53, NONE); }
-#else
-void vpdpbusd(const Xmm& x1, const Xmm& x2, const Operand& op, preferred_encoding_t encoding = DEFAULT) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32 | T_PREF_EVEX, 0x50, NONE, encoding); }
-void vpdpbusds(const Xmm& x1, const Xmm& x2, const Operand& op, preferred_encoding_t encoding = DEFAULT) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32 | T_PREF_EVEX, 0x51, NONE, encoding); }
-void vpdpwssd(const Xmm& x1, const Xmm& x2, const Operand& op, preferred_encoding_t encoding = DEFAULT) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32 | T_PREF_EVEX, 0x52, NONE, encoding); }
-void vpdpwssds(const Xmm& x1, const Xmm& x2, const Operand& op, preferred_encoding_t encoding = DEFAULT) { opAVX_X_X_XM(x1, x2, op, T_66 | T_0F38 | T_EW0 | T_YMM | T_SAE_Z | T_B32 | T_PREF_EVEX, 0x53, NONE, encoding); }
-#endif