frame pointer register 'ebx' modified by inline assembly code - visual-studio-2010

Question

Unfortunately, I had to re-image my laptop to install Visual Studio 2012. My project build but with above warning. Previously I had Visual Studio 2010 and I never got the above warning. The code is as follows:
__asm
{
//Initialize pointers on matrices
mov eax, dword ptr [this]
mov ebx, dword ptr [eax+UPkk]
mov dword ptr [UPkk_ptr],ebx
mov ebx, dword ptr [eax+UPk1k]
mov dword ptr [UPk1k_ptr],ebx
mov ebx, dword ptr [eax+DPk1k]
mov dword ptr [DPk1k_ptr],ebx
mov ebx, dword ptr [eax+DPkk]
mov dword ptr [DPkk_ptr],ebx
mov ebx, dword ptr [eax+mat_A]
mov dword ptr [mat_A_ptr],ebx
mov ebx, dword ptr [eax+vec_a]
mov dword ptr [vec_a_ptr],ebx
mov ebx, dword ptr [eax+vec_b]
mov dword ptr [vec_b_ptr],ebx
}
Do I need to change any settings in the project?
Best Regards
Chintan
Edit: In the above code when I replace ebx with ecx, the warnings go away and the code works fine. However, there is another piece of code where I have used ebx and ecx and in that case my program crashes. Here is the code:
__asm
{
//Initialize UPk1k[idx_4] pointer
mov eax, dword ptr [UPk1k_ptr]
mov ebx, dword ptr [idx_4]
imul ebx,8
add eax,ebx
mov dword ptr [UPk1k_id4_ptr],eax
//Initialize UPkk[idx_4] pointer
mov eax, dword ptr [UPkk_ptr]
mov ebx, dword ptr [idx_4]
imul ebx,8
add eax,ebx
mov dword ptr [UPkk_id4_ptr],eax
//Initialize UPk1k[idx_4] pointer
mov eax, dword ptr [vec_b_ptr]
mov ebx, dword ptr [idx_1]
imul ebx,8
add eax,ebx
mov dword ptr [vec_b_id1_ptr],eax
mov edi, dword ptr [idx_1] //Load idx_1 in edi
mov esi, 0 //initialize loop counter
jmp start_proc11
start_for11:inc esi //idx_2++
start_proc11:cmp esi, edi //idx_2<idx_1 ?
jge end_for11 //If yes so end of the loop
mov eax, UPk1k_id4_ptr //load UPk1k[idx_4] adress
mov ebx, vec_b_ptr //load vec_b adress
mov ecx, esi
imul ecx,8
add eax, ecx //UPk1k[idx_4+idx_2] in eax
add ebx, ecx //vec_b[idx_2] in eax
fld qword ptr [eax]//push UPk1k[idx_4+idx_2]
fld qword ptr [ebx] //push vec_b[idx_2]
mov edx,dword ptr [Sd_ptr]
fmul qword ptr [edx] //vec_b[idx_2]*Sd
fadd //pop UPk1k[idx_4+idx_2]+vec_b[idx_2]*Sd
mov edx,dword ptr [UPkk_id4_ptr]
fstp qword ptr [edx+esi*8] //pop UPkk[idx_4+idx_2]=UPk1k[idx_4+idx_2]+vec_b[idx_2]*Sd
fld qword ptr [ebx] //push vec_b[idx_2]
mov edx,dword ptr [vec_b_id1_ptr]
fld qword ptr [edx] //push vec_b[idx_2]
fmul qword ptr [eax]
fadd
fstp qword ptr [ebx]
jmp start_for11 //end of the loop
end_for11:
}
Many Thanks
Best Regards
CS

Answer 1

See MSDN about registers and that warning. They explain why the warning is produced: it forces the compiler to preserve value of EBX, which might be counter-productive to performance, the usual reason inline asm is used. Relevant quote:
In addition, by using EBX, ESI or EDI in inline assembly code, you
force the compiler to save and restore those registers in the function
prologue and epilogue.
To disable the warning, I think the syntax is
#pragma warning( disable : 4731 )
However, I'd try to use some other register instead, because the warning is there for a good reason, really, like most warnings.
In fact, Looking at your asm code, simply replace ebx With ecx, that should solve the problem.