https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111156
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rsandifo at gcc dot gnu.org
--- Comment #23 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #18)
> diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
> index 7cf9504398c..8deeecfd4aa 100644
> --- a/gcc/tree-vect-slp.cc
> +++ b/gcc/tree-vect-slp.cc
> @@ -1280,8 +1280,11 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char
> *swap,
> && rhs_code.is_tree_code ()
> && (TREE_CODE_CLASS (tree_code (first_stmt_code))
> == tcc_comparison)
> - && (swap_tree_comparison (tree_code (first_stmt_code))
> - == tree_code (rhs_code)))
> + && ((swap_tree_comparison (tree_code (first_stmt_code))
> + == tree_code (rhs_code))
> + || ((TREE_CODE_CLASS (tree_code (alt_stmt_code))
> + == tcc_comparison)
> + && rhs_code == alt_stmt_code)))
> && !(STMT_VINFO_GROUPED_ACCESS (stmt_info)
> && (first_stmt_code == ARRAY_REF
> || first_stmt_code == BIT_FIELD_REF
>
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 7cf9504398c..e35eeeea3fa 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -1519,7 +1522,9 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char
*swap,
if (alt_stmt_code != ERROR_MARK
&& (!alt_stmt_code.is_tree_code ()
|| (TREE_CODE_CLASS (tree_code (alt_stmt_code)) != tcc_reference
- && TREE_CODE_CLASS (tree_code (alt_stmt_code)) !=
tcc_comparison)))
+ && (TREE_CODE_CLASS (tree_code (alt_stmt_code)) != tcc_comparison
+ || (swap_tree_comparison (tree_code (first_stmt_code))
+ != tree_code (alt_stmt_code))))))
{
*two_operators = true;
}
is also needed btw. to avoid wrong-code. I see
t.c:8:26: note: ==> examining statement: pretmp_29 = *_28;
t.c:8:26: missed: unsupported load permutation
t.c:10:30: missed: not vectorized: relevant stmt not supported: pretmp_29 =
*_28;
t.c:8:26: note: removing SLP instance operations starting from: .MASK_STORE
(_5, 8B, patt_12, pretmp_29);
using -O3 -march=armv8.3-a+sve - it then does
t.c:8:26: missed: unsupported SLP instances
t.c:8:26: note: re-trying with SLP disabled
and _that_ fails then with
t.c:8:26: missed: Not using elementwise accesses due to variable
vectorization factor.
t.c:6:1: missed: not vectorized: relevant stmt not supported: .MASK_STORE
(_5, 8B, patt_12, pretmp_29);
but the interesting bit is why it fails to handle the SLP case.
That's possibly because the load isn't a grouped access, we get
dr_group_size == 1 and group_size == 2 and nunits is {16, 16}
(!repeating_p) and so
/* We need to construct a separate mask for each vector statement. */
unsigned HOST_WIDE_INT const_nunits, const_vf;
if (!nunits.is_constant (&const_nunits)
|| !vf.is_constant (&const_vf))
return false;
I'm not sure what that comment means, but supposedly we simply fail to handle
another special case that we could here? Possibly dr_group_size == 1?
