[gcc r12-6789] tree-optimization/104152 - add missing check for SLP constant build

[gcc r12-6789] tree-optimization/104152 - add missing check for SLP constant build

[Richard Biener]

https://gcc.gnu.org/g:1ad72811242eb84dde1bb2e97d0804d6eabeac8a

commit r12-6789-g1ad72811242eb84dde1bb2e97d0804d6eabeac8a
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jan 21 09:48:33 2022 +0100

    tree-optimization/104152 - add missing check for SLP constant build
    
    This adds a missing check to verify we can actually build an
    invariant vector from components when SLP vectorizing an associatable
    chain.
    
    2022-01-21  Richard Biener  <rguenther@suse.de>
    
            PR tree-optimization/104152
            * tree-vect-slp.cc (vect_build_slp_tree_2): Add missing
            can_duplicate_and_interleave_p check.
    
            * gcc.dg/vect/pr104152.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/vect/pr104152.c | 40 ++++++++++++++++++++++++++++++++++++
 gcc/tree-vect-slp.cc                 | 13 ++++++++++--
 2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/vect/pr104152.c b/gcc/testsuite/gcc.dg/vect/pr104152.c
new file mode 100644
index 00000000000..3a313c32dc3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr104152.c
@@ -0,0 +1,40 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-Ofast" } */
+/* { dg-additional-options "-march=armv8.2-a+sve" { target aarch64-*-* } } */
+
+#define M_PI 3.14f
+#define NK 24
+#define DIM 3
+
+typedef float rvec_ [3];
+
+static rvec_ v0[NK] = {
+      { 1, 0, 0 },  { 0, 1, 0 },  { 0, 0, 1 },  { 1, 1, 0 },  { 1, -1, 0 },
+      { 1, 0, 1 },  { 1, 0, -1 }, { 0, 1, 1 },  { 0, 1, -1 }, { 1, 1, 1 },
+      { 1, 1, -1 }, { 1, -1, 1 }, { -1, 1, 1 }, { 2, 0, 0 },  { 0, 2, 0 },
+      { 0, 0, 2 },  { 3, 0, 0 },  { 0, 3, 0 },  { 0, 0, 3 },  { 4, 0, 0 },
+      { 0, 4, 0 },  { 0, 0, 4 } };
+
+static inline float iprod__(const rvec_ a, const rvec_ b)
+{
+  return (a[0] * b[0] + a[1] * b[1] + a[2] * b[2]);
+}
+
+int badaboum(rvec_ cm_mol, float **tc)
+{
+  float              sx;
+  int                k, d;
+  rvec_              kfac[3];
+
+  for (k = 0; k < DIM; k++)
+    for (d = 0; d < DIM; d++)
+      kfac[k][d] = M_PI * v0[k][d] / v0[d][d];
+
+  for (k = 0; k < DIM; k++)
+    {
+      sx = __builtin_sinf(iprod__(kfac[k], cm_mol));
+      tc[k][0] += sx * iprod__(v0[k], cm_mol);
+    }
+
+  return 0;
+}
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index c3a1681d7c6..5ffb63689f2 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -1926,8 +1926,17 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
 	      if (dt == vect_constant_def
 		  || dt == vect_external_def)
 		{
-		  /* We can always build those.  Might want to sort last
-		     or defer building.  */
+		  /* Check whether we can build the invariant.  If we can't
+		     we never will be able to.  */
+		  tree type = TREE_TYPE (chains[0][n].op);
+		  if (!GET_MODE_SIZE (vinfo->vector_mode).is_constant ()
+		      && (TREE_CODE (type) == BOOLEAN_TYPE
+			  || !can_duplicate_and_interleave_p (vinfo, group_size,
+							      type)))
+		    {
+		      matches[0] = false;
+		      goto out;
+		    }
 		  vec<tree> ops;
 		  ops.create (group_size);
 		  for (lane = 0; lane < group_size; ++lane)