Question about .IF .ENDIF

[Tight_Coder_Ex]

Is it possible to use .IF to test the contion of a flag

As an example

Code Select Expand


    bt    eax, 8

.if  CF
    ; my code if bit 8 is on
.endif

[thomas_remkus]

I don't think you can do that. You might need to do a "test" then "jmp".

[sinsi]

Code Select Expand

.IF (CARRY?)
Also ZERO? OVERFLOW? SIGN? and PARITY? Not sure if the brackets are required.

[jj2007]

Code Select Expand

.IF (CARRY?)
Also ZERO? OVERFLOW? SIGN? and PARITY? Not sure if the brackets are required.

Not required. I use .If Zero? etc all the time.

Be very careful with constructs like .If eax && Zero?  because the flag you are testing might be gone when you arrive at "Zero?". Check with Olly what goes and what not.

[dedndave]

.If eax && Zero?

wouldn't that be the case where you would use parens ?
i.e.
.If (eax && Zero?)
doesn't that cause it to completely evaluate the expression before testing ?

[Ficko]

.If (eax && Zero?)
doesn't that cause it to completely evaluate the expression before testing ?

Looks like not:

Code Select Expand


.if (eax && CARRY?)
.endif
;OR EAX,EAX
;JE SHORT
;JNB SHORT
.if (CARRY? && eax)
.endif
;JNB SHORT
;OR EAX,EAX
;JE SHORT
.if (CARRY? && ZERO?)
.endif
;JNB SHORT
;JNE SHORT


Just wondering do someone has macros for
.if (CARRY? || ZERO?)  etc. structures to emit "jbe" "jae" etc. ?
::)

[Tight_Coder_Ex]

Thank-you, works as expected and brackets are not required in version 6.14

[jj2007]

Just for fun.

include \masm32\include\masm32rt.inc

.code
start:

   xor edx, edx
   mov eax, 123
   sub edx, 1            ; dec edx does not change the carry flag!
   .if eax && Carry?
      MsgBox 0, "Would love to see that", "Hi", MB_OK
   .else
      MsgBox 0, "Failed miserably, sorry", "Hi", MB_OK
   .endif

   xor edx, edx
   mov eax, 123
   sub edx, 1
   .if Carry? && eax
      MsgBox 0, "Would love to see that", "Hi", MB_OK
   .else
      MsgBox 0, "Failed miserably, sorry", "Hi", MB_OK
   .endif

   exit
end start