diff --git a/gen/gen_code.cpp b/gen/gen_code.cpp
index c1d6256..3749ba9 100644
--- a/gen/gen_code.cpp
+++ b/gen/gen_code.cpp
@@ -947,14 +947,19 @@ void put()
 		const struct Tbl {
 			const char *name;
 			uint8_t code;
+			uint8_t code2;
 		} tbl[] = {
-			{ "popcnt", 0xB8 },
-			{ "tzcnt", 0xBC },
-			{ "lzcnt", 0xBD },
+			{ "popcnt", 0xB8, 0 },
+			{ "tzcnt", 0xBC, 0xF4 },
+			{ "lzcnt", 0xBD, 0xF5 },
 		};
 		for (size_t i = 0; i < NUM_OF_ARRAY(tbl); i++) {
 			const Tbl *p = &tbl[i];
-			printf("void %s(const Reg&reg, const Operand& op) { opCnt(reg, op, 0x%02X); }\n", p->name, p->code);
+			if (p->code2) {
+				printf("void %s(const Reg&reg, const Operand& op) { if (opROO(Reg(), op, reg, T_VEX|T_NF, 0x%02X)) return; opCnt(reg, op, 0x%02X); }\n", p->name, p->code2, p->code);
+			} else {
+				printf("void %s(const Reg&reg, const Operand& op) { opCnt(reg, op, 0x%02X); }\n", p->name, p->code);
+			}
 		}
 	}
 	// SSSE3
diff --git a/xbyak/xbyak_mnemonic.h b/xbyak/xbyak_mnemonic.h
index ad09088..ebb1588 100644
--- a/xbyak/xbyak_mnemonic.h
+++ b/xbyak/xbyak_mnemonic.h
@@ -493,7 +493,7 @@ void loopne(const Label& label) { opJmp(label, T_SHORT, 0xE0, 0, 0); }
 void loopne(const char *label) { loopne(std::string(label)); }
 void loopne(std::string label) { opJmp(label, T_SHORT, 0xE0, 0, 0); }
 void lss(const Reg& reg, const Address& addr) { opLoadSeg(addr, reg, T_0F, 0xB2); }
-void lzcnt(const Reg&reg, const Operand& op) { opCnt(reg, op, 0xBD); }
+void lzcnt(const Reg&reg, const Operand& op) { if (opROO(Reg(), op, reg, T_VEX|T_NF, 0xF5)) return; opCnt(reg, op, 0xBD); }
 void maskmovdqu(const Xmm& reg1, const Xmm& reg2) { opRR(reg1, reg2, T_66|T_0F, 0xF7); }
 void maskmovq(const Mmx& reg1, const Mmx& reg2) { if (!reg1.isMMX() || !reg2.isMMX()) XBYAK_THROW(ERR_BAD_COMBINATION) opRR(reg1, reg2, T_0F, 0xF7); }
 void maxpd(const Xmm& xmm, const Operand& op) { opSSE(xmm, op, T_0F | T_66, 0x5F, isXMM_XMMorMEM); }
@@ -844,7 +844,7 @@ void subss(const Xmm& xmm, const Operand& op) { opSSE(xmm, op, T_0F | T_F3, 0x5C
 void sysenter() { db(0x0F); db(0x34); }
 void sysexit() { db(0x0F); db(0x35); }
 void tpause(const Reg32& r) { int idx = r.getIdx(); if (idx > 7) XBYAK_THROW(ERR_BAD_PARAMETER) db(0x66); db(0x0F); db(0xAE); setModRM(3, 6, idx); }
-void tzcnt(const Reg&reg, const Operand& op) { opCnt(reg, op, 0xBC); }
+void tzcnt(const Reg&reg, const Operand& op) { if (opROO(Reg(), op, reg, T_VEX|T_NF, 0xF4)) return; opCnt(reg, op, 0xBC); }
 void ucomisd(const Xmm& xmm, const Operand& op) { opSSE(xmm, op, T_66|T_0F, 0x2E, isXMM_XMMorMEM); }
 void ucomiss(const Xmm& xmm, const Operand& op) { opSSE(xmm, op, T_0F, 0x2E, isXMM_XMMorMEM); }
 void ud2() { db(0x0F); db(0x0B); }