> > It's https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119181
>
> Please mention that in the changelog. Also ...
Changed.
> Please put this condition in the set of conds we test in the else branch of
> ...
>
> > > /* Do not place the same access in the interleaving chain
> > > twice. */
> > > if (init_b == init_prev)
> > > {
>
> ... this if. There we have conditions grouped spltting groups.
>
Changed.
Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
Ready push to trunk.
The patch tries to solve miss vectorization for below case.
void
foo (int* a, int* restrict b)
{
b[0] = a[0] * a[64];
b[1] = a[65] * a[1];
b[2] = a[2] * a[66];
b[3] = a[67] * a[3];
b[4] = a[68] * a[4];
b[5] = a[69] * a[5];
b[6] = a[6] * a[70];
b[7] = a[7] * a[71];
}
In vect_analyze_data_ref_accesses, a[0], a[1], .. a[7], a[64], ...,
a[71] are in same group with size of 71. It caused vectorization
unprofitable.
gcc/ChangeLog:
PR tree-optimization/119181
* tree-vect-data-refs.cc (vect_analyze_data_ref_accesses):
Split datarefs when there's a gap bigger than
MAX_BITSIZE_MODE_ANY_MODE.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/bb-slp-pr119181.c: New test.
---
gcc/testsuite/gcc.dg/vect/bb-slp-pr119181.c | 15 +++++++++++++++
gcc/tree-vect-data-refs.cc | 7 +++++++
2 files changed, 22 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/vect/bb-slp-pr119181.c
diff --git a/gcc/testsuite/gcc.dg/vect/bb-slp-pr119181.c
b/gcc/testsuite/gcc.dg/vect/bb-slp-pr119181.c
new file mode 100644
index 00000000000..b0d3e5a3cb8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/bb-slp-pr119181.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+void
+foo (int* a, int* restrict b)
+{
+ b[0] = a[0] * a[64];
+ b[1] = a[65] * a[1];
+ b[2] = a[2] * a[66];
+ b[3] = a[67] * a[3];
+ b[4] = a[68] * a[4];
+ b[5] = a[69] * a[5];
+ b[6] = a[6] * a[70];
+ b[7] = a[7] * a[71];
+}
+
+/* { dg-final { scan-tree-dump-times "optimized: basic block" 1 "slp2" {
target vect_int_mult } } } */
diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
index 9fd1ef29650..f2deb751ed9 100644
--- a/gcc/tree-vect-data-refs.cc
+++ b/gcc/tree-vect-data-refs.cc
@@ -3682,6 +3682,13 @@ vect_analyze_data_ref_accesses (vec_info *vinfo,
!= type_size_a))
break;
+ /* For datarefs with big gap, it's better to split them into
different
+ groups.
+ .i.e a[0], a[1], a[2], .. a[7], a[100], a[101],..., a[107] */
+ if ((unsigned HOST_WIDE_INT)(init_b - init_prev) * tree_to_uhwi
(szb)
+ > MAX_BITSIZE_MODE_ANY_MODE / BITS_PER_UNIT)
+ break;
+
/* If the step (if not zero or non-constant) is smaller than the
difference between data-refs' inits this splits groups into
suitable sizes. */
--
2.34.1
