https://gcc.gnu.org/g:94c3508c5a14d1948fe3bffa9e16c6f3d9c2836a
commit r14-9533-g94c3508c5a14d1948fe3bffa9e16c6f3d9c2836a
Author: Richard Biener <rguent...@suse.de>
Date: Mon Mar 18 12:39:03 2024 +0100
tree-optimization/114375 - disallow SLP discovery of permuted mask loads
We cannot currently handle permutations of mask loads in code generation
or permute optimization. But we simply drop any permutation on the
floor, so the following instead rejects the SLP build rather than
producing wrong-code. I've also made sure to reject them in
vectorizable_load for completeness.
PR tree-optimization/114375
* tree-vect-slp.cc (vect_build_slp_tree_2): Compute the
load permutation for masked loads but reject it when any
such is necessary.
* tree-vect-stmts.cc (vectorizable_load): Reject masked
VMAT_ELEMENTWISE and VMAT_STRIDED_SLP as those are not
supported.
* gcc.dg/vect/vect-pr114375.c: New testcase.
Diff:
---
gcc/testsuite/gcc.dg/vect/vect-pr114375.c | 44 +++++++++++++++++++++++++++++++
gcc/tree-vect-slp.cc | 39 ++++++++++++++++++++-------
gcc/tree-vect-stmts.cc | 8 ++++++
3 files changed, 81 insertions(+), 10 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/vect/vect-pr114375.c
b/gcc/testsuite/gcc.dg/vect/vect-pr114375.c
new file mode 100644
index 00000000000..1e1cb0123d0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-pr114375.c
@@ -0,0 +1,44 @@
+/* { dg-additional-options "-mavx2" { target avx2_runtime } } */
+
+#include "tree-vect.h"
+
+int a[512];
+int b[512];
+int c[512];
+
+void __attribute__((noipa))
+foo(int * __restrict p)
+{
+ for (int i = 0; i < 64; ++i)
+ {
+ int tem = 2, tem2 = 2;
+ if (a[4*i + 1])
+ tem = p[4*i];
+ if (a[4*i])
+ tem2 = p[4*i + 2];
+ b[2*i] = tem2;
+ b[2*i+1] = tem;
+ if (a[4*i + 2])
+ tem = p[4*i + 1];
+ if (a[4*i + 3])
+ tem2 = p[4*i + 3];
+ c[2*i] = tem2;
+ c[2*i+1] = tem;
+ }
+}
+int main()
+{
+ check_vect ();
+
+ for (int i = 0; i < 512; ++i)
+ a[i] = (i >> 1) & 1;
+
+ foo (a);
+
+ if (c[0] != 1 || c[1] != 0 || c[2] != 1 || c[3] != 0
+ || b[0] != 2 || b[1] != 2 || b[2] != 2 || b[3] != 2)
+ abort ();
+
+ return 0;
+}
+
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 527b06c9f9c..23f9593191a 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -1921,12 +1921,7 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
if (STMT_VINFO_DATA_REF (stmt_info)
&& DR_IS_READ (STMT_VINFO_DATA_REF (stmt_info)))
{
- if (gcall *stmt = dyn_cast <gcall *> (stmt_info->stmt))
- gcc_assert (gimple_call_internal_p (stmt, IFN_MASK_LOAD)
- || gimple_call_internal_p (stmt, IFN_GATHER_LOAD)
- || gimple_call_internal_p (stmt, IFN_MASK_GATHER_LOAD)
- || gimple_call_internal_p (stmt, IFN_MASK_LEN_GATHER_LOAD));
- else if (STMT_VINFO_GATHER_SCATTER_P (stmt_info))
+ if (STMT_VINFO_GATHER_SCATTER_P (stmt_info))
gcc_assert (DR_IS_READ (STMT_VINFO_DATA_REF (stmt_info)));
else
{
@@ -1943,19 +1938,43 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
load_permutation.create (group_size);
stmt_vec_info first_stmt_info
= DR_GROUP_FIRST_ELEMENT (SLP_TREE_SCALAR_STMTS (node)[0]);
+ bool any_permute = false;
FOR_EACH_VEC_ELT (SLP_TREE_SCALAR_STMTS (node), j, load_info)
{
int load_place;
if (STMT_VINFO_GROUPED_ACCESS (stmt_info))
load_place = vect_get_place_in_interleaving_chain
- (load_info, first_stmt_info);
+ (load_info, first_stmt_info);
else
load_place = 0;
gcc_assert (load_place != -1);
- load_permutation.safe_push (load_place);
+ any_permute |= load_place != j;
+ load_permutation.quick_push (load_place);
+ }
+
+ if (gcall *stmt = dyn_cast <gcall *> (stmt_info->stmt))
+ {
+ gcc_assert (gimple_call_internal_p (stmt, IFN_MASK_LOAD)
+ || gimple_call_internal_p (stmt, IFN_GATHER_LOAD)
+ || gimple_call_internal_p (stmt, IFN_MASK_GATHER_LOAD)
+ || gimple_call_internal_p (stmt,
+ IFN_MASK_LEN_GATHER_LOAD));
+ load_permutation.release ();
+ /* We cannot handle permuted masked loads, see PR114375. */
+ if (any_permute
+ || (STMT_VINFO_GROUPED_ACCESS (stmt_info)
+ && DR_GROUP_SIZE (first_stmt_info) != group_size)
+ || STMT_VINFO_STRIDED_P (stmt_info))
+ {
+ matches[0] = false;
+ return NULL;
+ }
+ }
+ else
+ {
+ SLP_TREE_LOAD_PERMUTATION (node) = load_permutation;
+ return node;
}
- SLP_TREE_LOAD_PERMUTATION (node) = load_permutation;
- return node;
}
}
else if (gimple_assign_single_p (stmt_info->stmt)
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index e8617439a48..5a4eb136c6d 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -10080,6 +10080,14 @@ vectorizable_load (vec_info *vinfo,
"unsupported masked emulated gather.\n");
return false;
}
+ else if (memory_access_type == VMAT_ELEMENTWISE
+ || memory_access_type == VMAT_STRIDED_SLP)
+ {
+ if (dump_enabled_p ())
+ dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+ "unsupported masked strided access.\n");
+ return false;
+ }
}
bool costing_p = !vec_stmt;
