Add minimal support for missing instructions

[programa-stic]

Add minimal support for missing instructions

[neuromancer]

An informal survey on missing instructions (made using a large number of x86 binaries from Debian) is available here:

fstp   :3268  
fld    :2729  
movsx  :1276  
fmul   :1009  
fild   : 860  
lock   : 677  
fxch   : 579  
fldcw  : 486  
faddp  : 451  
fadd   : 426  
fst    : 398  
fnstsw : 365  
sahf   : 365  
fistp  : 248  
fldz   : 246  
fdiv   : 190  
fnstcw : 188  
fsub   : 174  
fucom  : 166  
fmulp  : 143  
fld1   : 108  
fucompp: 102  
fucomp :  97  
idiv   :  97  
fdivp  :  83  
fsubr  :  69  
fchs   :  66  
fsubp  :  65  
fdivrp :  46  
fsubrp :  46  
cwde   :  39  
setle  :  29  
fdivr  :  25  
fsqrt  :  23  
jnp    :  20  
setge  :  15  
setl   :  12  
bswap  :   9  
fabs   :   8  
frndint:   7  
cdq    :   6  
fist   :   4  
setnp  :   4  
bsr    :   3  
cli    :   1  
das    :   1  
in     :   1  
insb   :   1  
int    :   1  

[zachriggle]

I'm surprised to see movsx on this list

[cnheitman]

Hi! That list should be updated. movsx is currently supported along with setcc and jnp. Regarding FPU instructions, there's no plan to support them in the near future.

[neuromancer]

idiv seems to be a very useful instruction to support, since it is used to check some overflow constrains that we want to verify..

[cnheitman]

The most frequently used instructions has been implemented (FPU instructions are not included, there is no plan to implement them in the near future), so I'm closing this issue.