Is a question about compiling with TASM/TASM32
AsmGuru62 or any other tasm(an),
please take a look here :

http://www.programmersheaven.com/c/MsgBoard/read.asp?Board=1&MsgID=226380&Setting=A9996F1301

: Is a question about compiling with TASM/TASM32
: AsmGuru62 or any other tasm(an),
: please take a look here :
: 
: http://www.programmersheaven.com/c/MsgBoard/read.asp?Board=1&MsgID=226380&Setting=A9996F1301
: 

void foo ()
{
  // COPY/PASTE here your code from ASM function
  // and then try to compile it and resolve all issues...
}

i try that you said, take a look here :

 #include "stdio.h"

 int main(int argc,char *argv[]){
   asm{
      mov dx,934h
      in eax,dx
      }
   }

the disassembler says :
+++++++++++++++++++ ASSEMBLY CODE LISTING ++++++++++++++++++
//********************** Start of Code in Object .text **************
Program Entry Point = 0040100C (ASMTEST.EXE File Offset:0000960C)
:00401000 55                      push ebp
:00401001 8BEC                    mov ebp, esp
:00401003 66BA3409                mov dx, 0934
:00401007 ED                      in ax, dx
:00401008 33C0                    xor eax, eax
:0040100A 5D                      pop ebp
:0040100B C3                      ret

don't accept EAX , i'm using BCC32 version 5.5 tlink v5 or ilink32 v7
and link as win32 console

in your opinion is safe to create a dll for direct I/O using C++,
or i must use ASM code instead ?
and last is this correct ?

  in eax,dx =?= in ax,dx
                in ax,dx  ; do i read i long in this way ?

: i try that you said, take a look here :
: 
:  #include "stdio.h"
: 
:  int main(int argc,char *argv[]){
:    asm{
:       mov dx,934h
:       in eax,dx
:       }
:    }
: 
: the disassembler says :
: +++++++++++++++++++ ASSEMBLY CODE LISTING ++++++++++++++++++
: //********************** Start of Code in Object .text **************
: Program Entry Point = 0040100C (ASMTEST.EXE File Offset:0000960C)
: :00401000 55                      push ebp
: :00401001 8BEC                    mov ebp, esp
: :00401003 66BA3409                mov dx, 0934
: :00401007 ED                      in ax, dx
: :00401008 33C0                    xor eax, eax
: :0040100A 5D                      pop ebp
: :0040100B C3                      ret
: 
: don't accept EAX , i'm using BCC32 version 5.5 tlink v5 or ilink32 v7
: and link as win32 console
: 
: in your opinion is safe to create a dll for direct I/O using C++,
: or i must use ASM code instead ?
: and last is this correct ?
: 
:   in eax,dx =?= in ax,dx
:                 in ax,dx  ; do i read i long in this way ?
: 
: 

66BA3409  MOV DX, 0934h
ED        IN  EAX, DX

__emit__ (0x66, 0xBA, 0x34, 0x09, 0xED);

i try that too,
the problem is the disassembler's output
i have W32Dasm v8.93

:00407F09 ED                      in ax, dx
:00407EBF 66ED                    in ax, dx

different opcodes but same commands

: i try that too,
: the problem is the disassembler's output
: i have W32Dasm v8.93
: 
: :00407F09 ED                      in ax, dx
: :00407EBF 66ED                    in ax, dx
: 
: different opcodes but same commands
: 
: 

PUSH EAX
PUSH AX