Hi,
One more question.
On 10.04.2015 23:39, Jan Hubicka wrote:
I must say I did not even try running AutoFDO myself (so I am happy to hear
it works).
I tried to use executable create_gcov built from AutoFDO repository at
github.
The problem is that the data generated by this program has size 1600
bytes not depending on the profile data given to it.
Steps to reproduce the issue:
1. Build AutoFDO under x86_64
2. Build, for example, the benchmark ytest.c (see attachment):
g++ -O2 -o ytest ytest.c -g2
(I used g++ that was built just now from gcc-5-branch branch from
git://gcc.gnu.org/git/gcc.git)
3. Run it under perf to collect the profile data:
sudo perf record ./ytest
The perf reports no error and says that
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.125 MB perf.data (~5442 samples) ]
Perf generates perf.data.
4. Run create_gcov on the obtained data:
create_gcov --binary ytest --profile perf.data --gcov ytest.gcov
--debug_dump
It creates 2 files:
* ytest.gcov which is 1600 bytes of size
* ytest.gcov.imports which is empty
Also there is no debug output from the program.
If I run create_llvm_prof on the data
create_llvm_prof --binary ytest --profile perf.data --out ytest.out
--debug_dump
It reports the following log:
Length of symbol map: 1
Number of functions: 0
and creates an empty file ytest.out.
Which is not true: all functions in the benchmark are marked with
__attribute__((noinline)) and readelf says that they stay in the binary:
readelf -s ytest | grep px_cycle
56: 0000000000400640 111 FUNC GLOBAL DEFAULT 12 _Z8px_cyclei
readelf -s ytest | grep py_cycle
60: 00000000004006b0 36 FUNC GLOBAL DEFAULT 12 _Z8py_cyclev
The size of resulting gcov data is the same (1600 bytes) for different
levels of debug information (-g0, -g1, -g2) and for different input
sources files.
What am I doing wrong?
--
Best regards,
Ilya Palachev
#define DX (480*4)
#define DY (640*4)
int* src = new int[DX*DY];
int* dst = new int[DX*DY];
int pxm = DX;
int pym = DY;
void px_cycle(int py) __attribute__((noinline));
void px_cycle(int py) {
int *p1 = dst + (py*pxm);
int *p2 = src + (pym - py - 1);
for (int px = 0; px < pxm; px++) {
if (px < pym && py < pxm) {
*p1 = *p2;
}
p1++;
p2 += pym;
}
}
void py_cycle() __attribute__((noinline));
void py_cycle() {
for (int py = 0; py < pym; py++) {
px_cycle(py);
}
}
int main() {
int i;
for (i = 0; i < 100; i++) {
py_cycle();
}
return 0;
}
