[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 Jakub Jelinek jakub at gcc dot gnu.org changed: What|Removed |Added Target Milestone|4.9.1 |4.9.2 --- Comment #16 from Jakub Jelinek jakub at gcc dot gnu.org --- GCC 4.9.1 has been released.
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #15 from Marc Glisse glisse at gcc dot gnu.org --- Seems related to PR 57328.
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #6 from Richard Biener rguenth at gcc dot gnu.org --- Created attachment 32803 -- https://gcc.gnu.org/bugzilla/attachment.cgi?id=32803action=edit patch Like this.
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194
--- Comment #7 from vincenzo Innocente vincenzo.innocente at cern dot ch ---
great!
the original version (that vectorized in 4.8.1)
void barX() {
for (int i=0; i1024; ++i) {
k[i] = (x[i]0) (w[i]y[i]);
z[i] = (k[i]) ? z[i] : y[i];
}
}
does not vectorize yet.
On the other hand I am very happy to see
void bar() {
for (int i=0; i1024; ++i) {
auto c = ( (x[i]0) (w[i]y[i])) | (y[i]0.5f);
z[i] = c ? y[i] : z[i];
}
}
vectorized
if (c) z[i] = y[i];
does not even with -ftree-loop-if-convert-stores
not a real issue at least for what I am concerned
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194
--- Comment #8 from rguenther at suse dot de rguenther at suse dot de ---
On Fri, 16 May 2014, vincenzo.innocente at cern dot ch wrote:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194
--- Comment #7 from vincenzo Innocente vincenzo.innocente at cern dot ch ---
great!
the original version (that vectorized in 4.8.1)
void barX() {
for (int i=0; i1024; ++i) {
k[i] = (x[i]0) (w[i]y[i]);
z[i] = (k[i]) ? z[i] : y[i];
}
}
does not vectorize yet.
That's because we hit
check_bool_pattern (var=ssa_name 0x76c36e10, loop_vinfo=0x1f3e900,
bb_vinfo=0x0)
at /space/rguenther/src/svn/trunk/gcc/tree-vect-patterns.c:2596
2596 dt))
...
2605 if (!has_single_use (def))
2606return false;
because
_5 = x[i_18];
_6 = _5 0.0;
_7 = w[i_18];
_8 = y[i_18];
_9 = _7 _8;
_10 = _9 _6;
_11 = (int) _10;
k[i_18] = _11;
iftmp.0_13 = z[i_18];
iftmp.0_2 = _10 ? iftmp.0_13 : _8;
thus we have CSEd the load from k and propagated from the
conversion. VRP does this:
_11 = (int) _10;
- k[i_1] = _11;
- if (_11 != 0)
+ k[i_18] = _11;
+ if (_10 != 0)
and -fno-tree-vrp fixes the regression. If k were of type
_Bool then it likely wouldn't vectorize with 4.8 either.
The vectorizer cannot handle multi-uses of a pattern part
(in this case it's the start which would be doable, but it's
far from trivial ...). That said,
static float x[1024];
static float y[1024];
static float z[1024];
static float w[1024];
static _Bool k[1024];
void __attribute__((noinline,noclone)) barX()
{
int i;
for (i=0; i1024; ++i) {
k[i] = (x[i]0) (w[i]y[i]);
z[i] = (k[i]) ? z[i] : y[i];
}
}
is not vectorized even in 4.8 for the cited reason.
On the other hand I am very happy to see
void bar() {
for (int i=0; i1024; ++i) {
auto c = ( (x[i]0) (w[i]y[i])) | (y[i]0.5f);
z[i] = c ? y[i] : z[i];
}
}
vectorized
if (c) z[i] = y[i];
does not even with -ftree-loop-if-convert-stores
not a real issue at least for what I am concerned
I think it doesn't introduce data races unless you
also specify --param allow-store-data-races=1.
I also don't see the testcases vectorized when using
instead of .
If not already there, these warrant (different) bugreports.
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #9 from Richard Biener rguenth at gcc dot gnu.org --- Author: rguenth Date: Fri May 16 11:21:11 2014 New Revision: 210514 URL: http://gcc.gnu.org/viewcvs?rev=210514root=gccview=rev Log: 2014-05-16 Richard Biener rguent...@suse.de PR tree-optimization/61194 * tree-vect-patterns.c (adjust_bool_pattern): Also handle bool patterns ending in a COND_EXPR. * gcc.dg/vect/pr61194.c: New testcase. Added: trunk/gcc/testsuite/gcc.dg/vect/pr61194.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vect-patterns.c
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #10 from Richard Biener rguenth at gcc dot gnu.org --- Created attachment 32805 -- https://gcc.gnu.org/bugzilla/attachment.cgi?id=32805action=edit patch fixing the regression This would fix the regression (also without the previous patch?)
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194
--- Comment #11 from Richard Biener rguenth at gcc dot gnu.org ---
(In reply to Richard Biener from comment #10)
Created attachment 32805 [details]
patch fixing the regression
This would fix the regression (also without the previous patch?)
It does, on the 4.9 branch at least, for
static float x[1024];
static float y[1024];
static float z[1024];
static float w[1024];
static int k[1024];
void __attribute__((noinline,noclone)) barX()
{
int i;
for (i=0; i1024; ++i)
{
k[i] = x[i]0;
k[i] = w[i]y[i];
z[i] = (k[i]) ? z[i] : y[i];
}
}
but it doesn't change the outcome of the big testcase in the original report.
It does together with the other patch though:
g++-4.9 t.C -Ofast -ftree-loop-if-convert-stores -fopt-info-vec -B. -fopenmp
t.C:11:5: note: loop vectorized
t.C:19:23: note: loop vectorized
t.C:24:5: note: loop vectorized
t.C:29:5: note: loop vectorized
t.C:35:5: note: loop vectorized
t.C:41:5: note: loop vectorized
t.C:47:5: note: loop vectorized
bar2 still not vectorized there.
But with 4.7 I see the same as with 4.8 and 4.9:
35: LOOP VECTORIZED.
41: LOOP VECTORIZED.
47: LOOP VECTORIZED.
so where exactly does the regression part appear for you? Is that only
for the code in comment#1?
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194
--- Comment #12 from Richard Biener rguenth at gcc dot gnu.org ---
void bar2() {
for (int i=0; i1024; ++i) {
k[i] = x[i]0; j[i] = w[i]0;
z[i] = ( k[i] j[i]) ? z[i] : y[i];
}
}
has similar issues (non-single-uses due to CSE and propagating from the
conversion sources):
_5 = x[i_20];
_6 = _5 0.0;
_7 = (int) _6;
k[i_20] = _7;
_9 = w[i_20];
_10 = _9 0.0;
_11 = (int) _10;
j[i_20] = _11;
_18 = _10 _6;
iftmp.0_14 = z[i_20];
iftmp.0_15 = y[i_20];
iftmp.0_2 = _18 ? iftmp.0_14 : iftmp.0_15;
z[i_20] = iftmp.0_2;
This is generally caused by optimizing code to use smaller precisions. So
I think we need a more general solution for this than just the 2nd patch
I attached (which I won't pursue - I figure the first one would be way
more useful as it results in the same result for your initial large testcase
where the 2nd patch doesn't make a difference).
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #13 from vincenzo Innocente vincenzo.innocente at cern dot ch --- I confirm that with last patch the regression is gone also in a more complex actual application I had. The regression concerns only comment 2 and 3. all the other cases in comment 1 were various attempt of mine to see if anything was changed that allowed vectorization using a different syntax. I am happy that now they all vectorize (but bar2...) when, in 2011, I wrote the original test case, I introduced the int vector to make it vectorize (most probably I also submitted a bug report on the subject)
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #14 from vincenzo Innocente vincenzo.innocente at cern dot ch --- provided that future patches will make the code in comment 1 and 2 (and bar) go vectorize is fine with me. if it ends up to vectorize also with bool instead of int even better. (I am not sure that bit/byte handling is really more efficient in sse and avx w.r.t plain 32bit int)
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Last reconfirmed||2014-05-15 Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org Summary|[4.9 Regression]|[4.9/4.10 Regression] |vectorization failed with |vectorization failed with |bit-precision arithmetic |bit-precision arithmetic |not supported even if |not supported even if |conversion to int is|conversion to int is |requested |requested Ever confirmed|0 |1 --- Comment #3 from Richard Biener rguenth at gcc dot gnu.org --- I see on trunk after if-conversion _6 = _5 0.0; _9 = _7 _8; _10 = _9 _6; _11 = (int) _10; k[i_18] = _11; iftmp.0_13 = z[i_18]; iftmp.0_2 = _10 ? iftmp.0_13 : _8; z[i_18] = iftmp.0_2; so what happens is that we do have bit-precision arithmetic with the bitwise and. This is a regression because of the way we lower comparisons now I guess. I will have a look.
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #4 from Richard Biener rguenth at gcc dot gnu.org --- Actually the vectorizer punts on the comparisons itself. The pattern recognizer handles some of them as patt_10 = _4 0.0 ? 1 : 0; but not those feeding the BIT expressions which would need to be widened then (though they are supported as bit-precision).
[Bug tree-optimization/61194] [4.9/4.10 Regression] vectorization failed with bit-precision arithmetic not supported even if conversion to int is requested
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194 --- Comment #5 from vincenzo Innocente vincenzo.innocente at cern dot ch --- of course if you can make z[i] = ( (x[i]0) (w[i]0)) ? z[i] : y[i]; to vectorize would be even better!
