Programming Forums > Application Development > Assembly

MrSmiley · Jul 9th, 2005, 12:27 PM

Ok, so I am getting off of Visual Studios 6 and moving to Dev-C++(Which uses GCC). Well I'm currently writing an app that taps your Hardware information to get CPUID. It compiles fine in VS6 but since GCC uses AT&T asm, I'm stuck doing something completly different. So, I was wondering if anyone could tell me the proper way to translate this...

(Toggle Plain Text)

_asm{ 
xor eax, eax 
cpuid 
mov cpumax, eax 
// put vendor string in cpusignature 
mov edi, t 
mov dword ptr [edi], ebx 
mov dword ptr [edi+4], edx 
mov dword ptr [edi+8], ecx 
mov byte ptr [edi+12], 0 
}

Also if anyone knows how to get either the FSB or Multi from CPUID that information would be greatly appreciated.

DaWei · Jul 9th, 2005, 3:03 PM

Generally speaking, to translate to ATT syntax, do the following:

Add a suffix to the instruction indicating the operand size (even though it's usually implicit in the register operands), prepend the register name with a '%', and reverse the source and destination operands.

Example: mov bl, al ==> movb %al, %bl.

Immediate values are indicated by a '$':
movl $0xffff, %eax

Indirect memory references use parentheses:
mov dword ptr [edi+4], edx ==> movl %edx, (%edi+4)

That's sort of from the seat of my pants, might have something wrong. GCC also has another mechanism using an instruction template with register constraints, but it seems unnecessarily complicated to me.

lostcauz · Jul 9th, 2005, 3:39 PM

There is a compiler switch you can use to avoid the at&t mess. "-masm=intel" There is an example here. The formatting was buggered when the forum switched but it's readable. Also I wonder if this Dev-C++ everyone uses has a full installation of gcc or just enough to get by? I'll check it out for myself. Personally I'm more of a notepad/command-line kiddie.

Jul 9th, 2005, 12:27 PM	#1
MrSmiley Programmer Join Date: May 2005 Posts: 41 Rep Power: 0	INLINE conversions Ok, so I am getting off of Visual Studios 6 and moving to Dev-C++(Which uses GCC). Well I'm currently writing an app that taps your Hardware information to get CPUID. It compiles fine in VS6 but since GCC uses AT&T asm, I'm stuck doing something completly different. So, I was wondering if anyone could tell me the proper way to translate this... (Toggle Plain Text) _asm{ xor eax, eax cpuid mov cpumax, eax // put vendor string in cpusignature mov edi, t mov dword ptr [edi], ebx mov dword ptr [edi+4], edx mov dword ptr [edi+8], ecx mov byte ptr [edi+12], 0 } _asm{ xor eax, eax cpuid mov cpumax, eax // put vendor string in cpusignature mov edi, t mov dword ptr [edi], ebx mov dword ptr [edi+4], edx mov dword ptr [edi+8], ecx mov byte ptr [edi+12], 0 } Also if anyone knows how to get either the FSB or Multi from CPUID that information would be greatly appreciated.

Jul 9th, 2005, 3:03 PM	#2
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Generally speaking, to translate to ATT syntax, do the following: Add a suffix to the instruction indicating the operand size (even though it's usually implicit in the register operands), prepend the register name with a '%', and reverse the source and destination operands. Example: mov bl, al ==> movb %al, %bl. Immediate values are indicated by a '$': movl $0xffff, %eax Indirect memory references use parentheses: mov dword ptr [edi+4], edx ==> movl %edx, (%edi+4) That's sort of from the seat of my pants, might have something wrong. GCC also has another mechanism using an instruction template with register constraints, but it seems unnecessarily complicated to me. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Jul 9th, 2005, 3:39 PM	#3
lostcauz Hobbyist Programmer Join Date: Nov 2004 Location: 1691 miles East of L.A. Posts: 159 Rep Power: 4	There is a compiler switch you can use to avoid the at&t mess. "-masm=intel" There is an example here. The formatting was buggered when the forum switched but it's readable. Also I wonder if this Dev-C++ everyone uses has a full installation of gcc or just enough to get by? I'll check it out for myself. Personally I'm more of a notepad/command-line kiddie. __________________ -- lostcauz Stepped in what?... Behind whose barn?... I didn't even know they had a cow!

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Programming Forums > Application Development > Assembly

INLINE conversions