Displaying 2 results from an estimated 2 matches for "2718_6".
2011 Aug 10
0
[LLVMdev] Handling of pointer difference in llvm-gcc and clang
...?
in llvm-gcc (and dragonegg) this is coming directly from GCC's gimple:
f (int * p, int * q)
{
long int D.2718;
long int D.2717;
long int p.1;
long int q.0;
int D.2714;
<bb 2>:
q.0_2 = (long int) q_1(D);
p.1_4 = (long int) p_3(D);
D.2717_5 = q.0_2 - p.1_4;
D.2718_6 = D.2717_5 /[ex] 4;
D.2714_7 = (int) D.2718_6;
return D.2714_7;
}
Signed overflow in the difference of two long int (ptrdiff_t) values results in
undefined behaviour according to the GCC type system, which is where the nsw
flag comes from.
The C front-end generates this gimple in the point...
2011 Aug 10
3
[LLVMdev] Handling of pointer difference in llvm-gcc and clang
Hi,
We are developing a bounded model checker for C/C++ programs
(http://baldur.iti.kit.edu/llbmc/) that operates on LLVM's intermediate
representation. While checking a C++ program that uses STL containers
we noticed that llvm-gcc and clang handle pointer differences in
disagreeing ways.
Consider the following C function:
int f(int *p, int *q)
{
return q - p;
}
Here's the