[PATCH] tree-optimization/110221 - SLP and loop mask/len

[Richard Biener <rguenther@suse.de>]

The following fixes the issue that when SLP stmts are internal defs
but appear invariant because they end up only using invariant defs
then they get scheduled outside of the loop.  This nice optimization
breaks down when loop masks or lens are applied since those are not
explicitly tracked as dependences.  The following makes sure to never
schedule internal defs outside of the vectorized loop when the
loop uses masks/lens.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	PR tree-optimization/110221
	* tree-vect-slp.cc (vect_schedule_slp_node): When loop
	masking / len is applied make sure to not schedule
	intenal defs outside of the loop.

	* gfortran.dg/pr110221.f: New testcase.
---
 gcc/testsuite/gfortran.dg/pr110221.f | 17 +++++++++++++++++
 gcc/tree-vect-slp.cc                 | 10 ++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 gcc/testsuite/gfortran.dg/pr110221.f

diff --git a/gcc/testsuite/gfortran.dg/pr110221.f b/gcc/testsuite/gfortran.dg/pr110221.f
new file mode 100644
index 00000000000..8b57384313a
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr110221.f
@@ -0,0 +1,17 @@
+C PR middle-end/68146
+C { dg-do compile }
+C { dg-options "-O2 -w" }
+C { dg-additional-options "-mavx512f --param vect-partial-vector-usage=2" { target avx512f } }
+      SUBROUTINE CJYVB(V,Z,V0,CBJ,CDJ,CBY,CYY)
+      IMPLICIT DOUBLE PRECISION (A,B,G,O-Y)
+      IMPLICIT COMPLEX*16 (C,Z)
+      DIMENSION CBJ(0:*),CDJ(0:*),CBY(0:*)
+      N=INT(V)
+      CALL GAMMA2(VG,GA)
+      DO 65 K=1,N
+        CBY(K)=CYY
+65    CONTINUE
+      CDJ(0)=V0/Z*CBJ(0)-CBJ(1)
+      DO 70 K=1,N
+70      CDJ(K)=-(K+V0)/Z*CBJ(K)+CBJ(K-1)
+      END
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 3e5814c3a31..80e279d8f50 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9081,6 +9081,16 @@ vect_schedule_slp_node (vec_info *vinfo,
       /* Emit other stmts after the children vectorized defs which is
 	 earliest possible.  */
       gimple *last_stmt = NULL;
+      if (auto loop_vinfo = dyn_cast <loop_vec_info> (vinfo))
+	if (LOOP_VINFO_FULLY_MASKED_P (loop_vinfo)
+	    || LOOP_VINFO_FULLY_WITH_LENGTH_P (loop_vinfo))
+	  {
+	    /* But avoid scheduling internal defs outside of the loop when
+	       we might have only implicitly tracked loop mask/len defs.  */
+	    gimple_stmt_iterator si
+	      = gsi_after_labels (LOOP_VINFO_LOOP (loop_vinfo)->header);
+	    last_stmt = *si;
+	  }
       bool seen_vector_def = false;
       FOR_EACH_VEC_ELT (SLP_TREE_CHILDREN (node), i, child)
 	if (SLP_TREE_DEF_TYPE (child) == vect_internal_def)
-- 
2.35.3