http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969
--- Comment #11 from vincenzo Innocente <vincenzo.innocente at cern dot ch>
2012-04-13 13:03:48 UTC ---
I do not have a clear case in hand with evidence of "double" compare
I will have a closer look to "real life" code.
btw
I just noticed that your test case does not vectorize even if
I rewrite as
for (; a ; ++j)
xsum[j] = (cluster[j] > 0.) ? 0. : cluster[j];
any idea why?
c++ -O3 -c ifconv.cc -ftree-loop-if-convert-stores -ftree-vectorizer-verbose=9
Analyzing loop at ifconv.cc:10
10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: control flow in loop.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
pb-d-128-141-131-26:bugs48 innocent$ c++ -O3 -c ifconv.cc
-ftree-loop-if-convert-stores -ftree-vectorizer-verbose=9
Analyzing loop at ifconv.cc:10
10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: control flow in loop.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
pb-d-128-141-131-26:bugs48 innocent$ c++ -Ofast -c ifconv.cc
-ftree-loop-if-convert-stores -ftree-vectorizer-verbose=9
Analyzing loop at ifconv.cc:10
10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: multiple exits.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
pb-d-128-141-131-26:bugs48 innocent$ c++ -Ofast -c ifconv.cc
-ftree-vectorizer-verbose=9
Analyzing loop at ifconv.cc:10
10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: multiple exits.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
