... here is some generally useful information I should have cc'd to llvmdev in the first place ...
-Chris
Chris,
I've now figured out how to track and single out specific instructions, which was ridiculously easy. Thanks!
I'm now on to trying to find more detail about those instructions, such as the values and addresses of the operands in memory (or, in the case of operands which are pointers, trying to get the pointer values, addresses, and values stored at location specified by the pointer values, etc..).
Would you suggest having LLVM add code after each instruction to get this, or is there another way to do this? I've tried writing some code, as follows (where i is an inst_iterator, but the results are not what I would have expected:
for (User::op_iterator j = i->op_begin(), f = i->op_end(); j != f; ++j) {
std::cerr << "Operand: " << (j->getUser())->getOperand(0) << "\n";
}
or
for (User::op_iterator j = i->op_begin(), f = i->op_end(); j != f; ++j) {
std::cerr << "Operand: " << j << "\n";
}
Thanks,
Sean
Chris,
Hi Sean, sorry for the delay, this got buried in my mail.
I've now figured out how to track and single out specific instructions, which was ridiculously easy. Thanks!
I'm now on to trying to find more detail about those instructions, such as the values and addresses of the operands in memory (or, in the case of operands which are pointers, trying to get the pointer values, addresses, and values stored at location specified by the pointer values, etc..).
Would you suggest having LLVM add code after each instruction to get this, or is there another way to do this? I've tried writing some code, as follows (where i is an inst_iterator, but the results are not what I would have expected:
for (User::op_iterator j = i->op_begin(), f = i->op_end(); j != f; ++j) {
std::cerr << "Operand: " << (j->getUser())->getOperand(0) << "\n";
}
or
for (User::op_iterator j = i->op_begin(), f = i->op_end(); j != f; ++j) {
std::cerr << "Operand: " << j << "\n";
}
This sort of thing isn't really what you want to do. Consider an instruction like this:
%X = load int* %P
This will iterate over the operands of the instructions (in this case, only %P), and print out the address of the IR node for that operand. From what I understand, you want a dynamic trace of the values as the program executes. In this case, I would suggest adding some instrumentation like this:
%X = load int* %P ; original instruction
call %mytracefn(int* %P) ; Do something to trace the value being loaded
... then run the program.
-Chris