re PR tree-optimization/92324 (ICE in expand_direct_optab_fn, at internal-fn.c:2890)

2019-11-15  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92324
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Fix
	singedness of SLP reduction epilouge operations.  Also reduce
	the vector width for SLP reductions before doing elementwise
	operations if possible.

	* gcc.dg/vect/pr92324-4.c: New testcase.

From-SVN: r278289

4 files changed, 81 insertions, 30 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2f9325289a2..5eb21e7e4a8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2019-11-15  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/92324
+	* tree-vect-loop.c (vect_create_epilog_for_reduction): Fix
+	singedness of SLP reduction epilouge operations.  Also reduce
+	the vector width for SLP reductions before doing elementwise
+	operations if possible.
+
 2019-11-15  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* passes.c (skip_pass): Set epilogue_completed if skipping the
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6b123832d5d..4377c4c38c1 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-11-15  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/92324
+	* gcc.dg/vect/pr92324-4.c: New testcase.
+
 2019-11-15  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/69654
diff --git a/gcc/testsuite/gcc.dg/vect/pr92324-4.c b/gcc/testsuite/gcc.dg/vect/pr92324-4.c
new file mode 100644
index 00000000000..83479852233
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr92324-4.c
@@ -0,0 +1,30 @@
+#include "tree-vect.h"
+
+unsigned a[1024];
+int gres1, gres2;
+
+int __attribute__((noipa))
+foo (int n)
+{
+  int res1 = 0;
+  int res2 = 0;
+  for (int i = 0; i < n; ++i)
+    {
+      res1 = res1 > a[2*i] ? res1 : a[2*i];
+      res2 = res2 > a[2*i+1] ? res2 : a[2*i+1];
+    }
+  gres1 = res1;
+  gres2 = res2;
+}
+
+int main ()
+{
+  check_vect ();
+  a[30] = (unsigned)__INT_MAX__ + 1;
+  a[31] = (unsigned)__INT_MAX__ + 1;
+  foo (16);
+  if (gres1 != -__INT_MAX__ - 1
+      || gres2 != -__INT_MAX__ - 1)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 567fcc75e2b..389ef170607 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -4930,6 +4930,8 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
       bool reduce_with_shift;
       tree vec_temp;
 
+      gcc_assert (slp_reduc || new_phis.length () == 1);
+
       /* See if the target wants to do the final (shift) reduction
 	 in a vector mode of smaller size and first reduce upper/lower
 	 halves against each other.  */
@@ -4937,6 +4939,21 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
       tree stype = TREE_TYPE (vectype);
       unsigned nunits = TYPE_VECTOR_SUBPARTS (vectype).to_constant ();
       unsigned nunits1 = nunits;
+      if ((mode1 = targetm.vectorize.split_reduction (mode)) != mode
+	  && new_phis.length () == 1)
+	{
+	  nunits1 = GET_MODE_NUNITS (mode1).to_constant ();
+	  /* For SLP reductions we have to make sure lanes match up, but
+	     since we're doing individual element final reduction reducing
+	     vector width here is even more important.
+	     ???  We can also separate lanes with permutes, for the common
+	     case of power-of-two group-size odd/even extracts would work.  */
+	  if (slp_reduc && nunits != nunits1)
+	    {
+	      nunits1 = least_common_multiple (nunits1, group_size);
+	      gcc_assert (exact_log2 (nunits1) != -1 && nunits1 <= nunits);
+	    }
+	}
       if (!slp_reduc
 	  && (mode1 = targetm.vectorize.split_reduction (mode)) != mode)
 	nunits1 = GET_MODE_NUNITS (mode1).to_constant ();
@@ -4958,7 +4975,6 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
       new_temp = new_phi_result;
       while (nunits > nunits1)
 	{
-	  gcc_assert (!slp_reduc);
 	  nunits /= 2;
 	  vectype1 = get_related_vectype_for_scalar_type (TYPE_MODE (vectype),
 							  stype, nunits);
@@ -5113,6 +5129,8 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
 
 	  int vec_size_in_bits = tree_to_uhwi (TYPE_SIZE (vectype1));
 	  int element_bitsize = tree_to_uhwi (bitsize);
+	  tree compute_type = TREE_TYPE (vectype);
+	  gimple_seq stmts = NULL;
           FOR_EACH_VEC_ELT (new_phis, i, new_phi)
             {
               int bit_offset;
@@ -5120,12 +5138,8 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
                 vec_temp = PHI_RESULT (new_phi);
               else
                 vec_temp = gimple_assign_lhs (new_phi);
-              tree rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize,
-				 bitsize_zero_node);
-              epilog_stmt = gimple_build_assign (new_scalar_dest, rhs);
-              new_temp = make_ssa_name (new_scalar_dest, epilog_stmt);
-              gimple_assign_set_lhs (epilog_stmt, new_temp);
-              gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT);
+	      new_temp = gimple_build (&stmts, BIT_FIELD_REF, compute_type,
+				       vec_temp, bitsize, bitsize_zero_node);
 
               /* In SLP we don't need to apply reduction operation, so we just
                  collect s' values in SCALAR_RESULTS.  */
@@ -5137,14 +5151,9 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
                    bit_offset += element_bitsize)
                 {
                   tree bitpos = bitsize_int (bit_offset);
-                  tree rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp,
-                                     bitsize, bitpos);
-
-                  epilog_stmt = gimple_build_assign (new_scalar_dest, rhs);
-                  new_name = make_ssa_name (new_scalar_dest, epilog_stmt);
-                  gimple_assign_set_lhs (epilog_stmt, new_name);
-                  gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT);
-
+		  new_name = gimple_build (&stmts, BIT_FIELD_REF,
+					   compute_type, vec_temp,
+					   bitsize, bitpos);
                   if (slp_reduc)
                     {
                       /* In SLP we don't need to apply reduction operation, so 
@@ -5153,13 +5162,8 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
                       scalar_results.safe_push (new_name);
                     }
                   else
-                    {
-		      epilog_stmt = gimple_build_assign (new_scalar_dest, code,
-							 new_name, new_temp);
-                      new_temp = make_ssa_name (new_scalar_dest, epilog_stmt);
-                      gimple_assign_set_lhs (epilog_stmt, new_temp);
-                      gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT);
-                    }
+		    new_temp = gimple_build (&stmts, code, compute_type,
+					     new_name, new_temp);
                 }
             }
 
@@ -5170,24 +5174,28 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
           if (slp_reduc)
             {
               tree res, first_res, new_res;
-	      gimple *new_stmt;
             
               /* Reduce multiple scalar results in case of SLP unrolling.  */
               for (j = group_size; scalar_results.iterate (j, &res);
                    j++)
                 {
                   first_res = scalar_results[j % group_size];
-		  new_stmt = gimple_build_assign (new_scalar_dest, code,
-						  first_res, res);
-                  new_res = make_ssa_name (new_scalar_dest, new_stmt);
-                  gimple_assign_set_lhs (new_stmt, new_res);
-                  gsi_insert_before (&exit_gsi, new_stmt, GSI_SAME_STMT);
+		  new_res = gimple_build (&stmts, code, compute_type,
+					  first_res, res);
                   scalar_results[j % group_size] = new_res;
                 }
+	      for (k = 0; k < group_size; k++)
+		scalar_results[k] = gimple_convert (&stmts, scalar_type,
+						    scalar_results[k]);
             }
           else
-            /* Not SLP - we have one scalar to keep in SCALAR_RESULTS.  */
-            scalar_results.safe_push (new_temp);
+	    {
+	      /* Not SLP - we have one scalar to keep in SCALAR_RESULTS.  */
+	      new_temp = gimple_convert (&stmts, scalar_type, new_temp);
+	      scalar_results.safe_push (new_temp);
+	    }
+
+	  gsi_insert_seq_before (&exit_gsi, stmts, GSI_SAME_STMT);
         }
 
       if ((STMT_VINFO_REDUC_TYPE (reduc_info) == INTEGER_INDUC_COND_REDUCTION)