On Fri, Dec 4, 2015 at 8:51 PM, Bill Schmidt
<wschm...@linux.vnet.ibm.com> wrote:
> Since r226675, we have been seeing these failures:
>
> FAIL: gcc.dg/vect/vect-widen-mult-const-s16.c -flto -ffat-lto-objects
> scan-tree-dump-times vect "pattern recognized" 2
> FAIL: gcc.dg/vect/vect-widen-mult-const-s16.c scan-tree-dump-times vect
> "pattern recognized" 2
> FAIL: gcc.dg/vect/vect-widen-mult-const-u16.c -flto -ffat-lto-objects
> scan-tree-dump-times vect "pattern recognized" 2
> FAIL: gcc.dg/vect/vect-widen-mult-const-u16.c scan-tree-dump-times vect
> "pattern recognized" 2
>
> Comparing the vect-details dumps from r226674 to r226675, I see these as
> the reason:
>
> 63a64,66
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
>> note: vect_recog_mult_pattern: detected:
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
>> note: patt_47 = _6 << 2;
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
>> note: pattern recognized: patt_47 = _6 << 2;
> 70a74,76
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
>> note: vect_recog_mult_pattern: detected:
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
>> note: patt_40 = _6 << 1;
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
>> note: pattern recognized: patt_40 = _6 << 1;
>
> 747a754,756
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
>> note: vect_recog_mult_pattern: detected:
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
>> note: patt_47 = _6 << 2;
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
>> note: pattern recognized: patt_47 = _6 << 2;
> 754a764,766
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
>> note: vect_recog_mult_pattern: detected:
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
>> note: patt_40 = _6 << 1;
>> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
>> note: pattern recognized: patt_40 = _6 << 1;
>
> These seems precisely what's expected, given the nature of the patch,
> which is looking for these opportunities. So it's likely that we should
> just change
>
> /* { dg-final { scan-tree-dump-times "pattern recognized" 2
> "vect" { target vect_widen_mult_hi_to_si_pattern } } } */
>
> to
>
> /* { dg-final { scan-tree-dump-times "pattern recognized" 6
> "vect" { target vect_widen_mult_hi_to_si_pattern } } } */
>
> and similarly for the unsigned case. The following patch does this.
> However, I wanted to run this by Venkat since this was apparently not
> detected when his patch went in. This doesn't appear to be a
> target-specific issue, and most targets support
> vect_widen_mult_hi_to_si_pattern, so I'm not sure why this wasn't fixed
> with the original patch. Will this change break on any other targets
> for some reason?
>
> Tested on powerpc64le-unknown-linux-gnu. Ok for trunk?
Hmm. That will FAIL on x86_64 though because it can handle multiplication
natively. I think the pattern recognition is simply bogus as it fails to detect
the stmt is already part of the widen-mult pattern? In fact, pattern
recognition
looping over all pattern functions even if one already matched on the very
same stmt looks bogus to me.
Does the (untested)
Index: gcc/tree-vect-patterns.c
===================================================================
--- gcc/tree-vect-patterns.c (revision 231357)
+++ gcc/tree-vect-patterns.c (working copy)
@@ -3791,7 +3791,7 @@ vect_mark_pattern_stmts (gimple *orig_st
This function also does some bookkeeping, as explained in the documentation
for vect_recog_pattern. */
-static void
+static bool
vect_pattern_recog_1 (vect_recog_func_ptr vect_recog_func,
gimple_stmt_iterator si,
vec<gimple *> *stmts_to_replace)
@@ -3809,7 +3809,7 @@ vect_pattern_recog_1 (vect_recog_func_pt
stmts_to_replace->quick_push (stmt);
pattern_stmt = (* vect_recog_func) (stmts_to_replace, &type_in, &type_out);
if (!pattern_stmt)
- return;
+ return false;
stmt = stmts_to_replace->last ();
stmt_info = vinfo_for_stmt (stmt);
@@ -3831,13 +3831,13 @@ vect_pattern_recog_1 (vect_recog_func_pt
/* Check target support */
type_in = get_vectype_for_scalar_type (type_in);
if (!type_in)
- return;
+ return false;
if (type_out)
type_out = get_vectype_for_scalar_type (type_out);
else
type_out = type_in;
if (!type_out)
- return;
+ return false;
pattern_vectype = type_out;
if (is_gimple_assign (pattern_stmt))
@@ -3853,7 +3853,7 @@ vect_pattern_recog_1 (vect_recog_func_pt
if (!optab
|| (icode = optab_handler (optab, vec_mode)) == CODE_FOR_nothing
|| (insn_data[icode].operand[0].mode != TYPE_MODE (type_out)))
- return;
+ return false;
}
/* Found a vectorizable pattern. */
@@ -3892,6 +3892,8 @@ vect_pattern_recog_1 (vect_recog_func_pt
vect_mark_pattern_stmts (stmt, pattern_stmt, NULL_TREE);
}
+
+ return true;
}
@@ -4005,8 +4007,9 @@ vect_pattern_recog (vec_info *vinfo)
for (j = 0; j < NUM_PATTERNS; j++)
{
vect_recog_func = vect_vect_recog_func_ptrs[j];
- vect_pattern_recog_1 (vect_recog_func, si,
- &stmts_to_replace);
+ if (vect_pattern_recog_1 (vect_recog_func, si,
+ &stmts_to_replace))
+ break;
}
}
}
@@ -4026,8 +4029,9 @@ vect_pattern_recog (vec_info *vinfo)
for (j = 0; j < NUM_PATTERNS; j++)
{
vect_recog_func = vect_vect_recog_func_ptrs[j];
- vect_pattern_recog_1 (vect_recog_func, si,
- &stmts_to_replace);
+ if (vect_pattern_recog_1 (vect_recog_func, si,
+ &stmts_to_replace))
+ break;
}
}
}
help?
Richard.
> Thanks,
> Bill
>
>
> [gcc/testsuite]
>
> 2015-12-04 Bill Schmidt <wschm...@linux.vnet.ibm.com>
>
> * gcc.dg/vect/vect-widen-mult-const-s16.c: Change number of
> occurrences of "pattern recognized" to 6.
> * gcc.dg/vect/vect-widen-mult-const-u16.c: Likewise.
>
>
> Index: gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c (revision
> 231278)
> +++ gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c (working copy)
> @@ -56,5 +56,5 @@ int main (void)
>
> /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" { target
> vect_widen_mult_hi_to_si } } } */
> /* { dg-final { scan-tree-dump-times "vect_recog_widen_mult_pattern:
> detected" 2 "vect" { target vect_widen_mult_hi_to_si_pattern } } } */
> -/* { dg-final { scan-tree-dump-times "pattern recognized" 2 "vect" { target
> vect_widen_mult_hi_to_si_pattern } } } */
> +/* { dg-final { scan-tree-dump-times "pattern recognized" 6 "vect" { target
> vect_widen_mult_hi_to_si_pattern } } } */
>
> Index: gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-u16.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-u16.c (revision
> 231278)
> +++ gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-u16.c (working copy)
> @@ -73,4 +73,4 @@ int main (void)
>
> /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 3 "vect" { target
> vect_widen_mult_hi_to_si } } } */
> /* { dg-final { scan-tree-dump-times "vect_recog_widen_mult_pattern:
> detected" 2 "vect" { target vect_widen_mult_hi_to_si_pattern } } } */
> -/* { dg-final { scan-tree-dump-times "pattern recognized" 2 "vect" { target
> vect_widen_mult_hi_to_si_pattern } } } */
> +/* { dg-final { scan-tree-dump-times "pattern recognized" 8 "vect" { target
> vect_widen_mult_hi_to_si_pattern } } } */
>
>
>
>
