calminstruction clzero? dest*
        asmcmd  =x86.=parse_operand =@dest,dest
        check   @dest.type = 'reg' & @dest.rm = 0 & @dest.size <> 1
        jyes    _prefix
        asmcmd  =err 'operand must be rAX'
        exit
_prefix:
        asmcmd  =x86.=store_operand_prefix =@dest.=size
        asmcmd  =db 0Fh,1,0FCh
end calminstruction

macro mwaitx?
        db 0Fh,01h,0FBh
end macro

macro monitorx?
        db 0Fh,01h,0FAh
end macro

clzero rax
clzero eax
clzero ax    

; SSE4a

macro extrq? dest*,src*,sel
        SSE.parse_operand @dest,dest
        if @dest.type = 'mmreg' & @dest.size = 16
                match ,sel ; 66 0F 79 /r
                        SSE.parse_operand @src,src
                        if @src.type = 'mmreg' & @src.size = 16
                                @src.opcode_prefix = 66h
                                x86.store_instruction <0Fh,79h>,@src,@dest.rm
                        else
                                err 'invalid combination of operands'
                        end if
                else ; xmm,ib,ib ; 66 0F 78 /0 ib ib
                        x86.parse_operand @aux1,src
                        x86.parse_operand @aux2,sel
                        if @aux1.type <> 'imm' | @aux1.size and not 1 \
                        | @aux2.type <> 'imm' | @aux2.size and not 1
                                err 'invalid combination of operands'
                        else
                                @dest.opcode_prefix = 66h
                                x86.store_instruction <0Fh,78h>,@dest,0,2,(@aux2.imm shl 8) or @aux1.imm
                        end if
                end match
        else
                err 'invalid combination of operands'
        end if
end macro

macro insertq? dest*,src*,sel1,sel2
        SSE.parse_operand @dest,dest
        SSE.parse_operand @src,src
        if @dest.type = 'mmreg' & @src.type = 'mmreg'
                if (@dest.size or @src.size) <> 16
                        err 'invalid operand size'
                end if
                match ,sel1 sel2
                        @src.opcode_prefix = 0F2h
                        x86.store_instruction <0Fh,79h>,@src,@dest.rm
                else
                        x86.parse_operand @aux1,sel1
                        x86.parse_operand @aux2,sel2
                        if @aux1.type <> 'imm' | @aux1.size and not 1 \
                        | @aux2.type <> 'imm' | @aux2.size and not 1
                                err 'invalid combination of operands'
                        else
                                @src.opcode_prefix = 0F2h
                                x86.store_instruction <0Fh,78h>,@src,@dest.rm,2,(@aux2.imm shl 8) or @aux1.imm
                        end if
                end match
        else
                err 'invalid combination of operands'
        end if
end macro

iterate instr, movntss,movntsd
        macro instr? dest*,src*
                SSE.parse_operand @dest,dest
                SSE.parse_operand @src,src
                if @dest.type = 'mem' & @dest.size = 4*% \
                & @src.type = 'mmreg' & @src.size = 16
                        @dest.opcode_prefix = 0F4h - %
                        x86.store_instruction <0Fh,2Bh>,@dest,@src.rm
                else
                        err 'invalid combination of operands'
                end if
        end macro
end iterate    

x86.store_instruction <0Fh,78h>,@dest,@dest.rm,2,(@aux2.imm shl 8) or @aux1.imm