Displaying 2 results from an estimated 2 matches for "quantum_sigma_x".
2014 Jan 16
3
[LLVMdev] Loop unrolling opportunity in SPEC's libquantum with profile info
On Wed, Jan 15, 2014 at 5:30 PM, Nadav Rotem <nrotem at apple.com> wrote:
> Was the vectorizer successful in unrolling the loop in quantum_sigma_x? I
> wonder if 'size’ is typically high or low.
No. The vectorizer stated that it wasn't going to bother with the loop
because it wasn't profitable. Specifically:
LV: Checking a loop in "quantum_sigma_x"
LV: Found a loop: for.body
LV: Found an induction variable.
LV: Fou...
2014 Jan 16
11
[LLVMdev] Loop unrolling opportunity in SPEC's libquantum with profile info
I am starting to use the sample profiler to analyze new performance
opportunities. The loop unroller has popped up in several of the
benchmarks I'm running. In particular, libquantum. There is a ~12%
opportunity when the runtime unroller is triggered.
This helps functions like quantum_sigma_x
(http://sourcecodebrowser.com/libquantum/0.2.4/gates_8c_source.html#l00149).
The function accounts for ~20% of total runtime. By allowing the
runtime unroller, we can speedup the program by about 12%.
I have been poking at the unroller a little bit. Currently, the
runtime unroller is only triggere...