Allow SLP store of mixed external and constant

vect_build_slp_tree_1 rejected this during SLP discovery because it
ran into the rhs code comparison code for stores.  The following
skips that completely for loads and stores as those are handled
later anyway.

This needs a heuristic adjustment in vect_get_and_check_slp_defs
to avoid fallout with regard to BB vectorization and splitting
of a store group vs. demoting one operand to external.

gcc.dg/Wstringop-overflow-47.c needs adjustment given we now have
vast improvements for code generation.  gcc.dg/strlenopt-32.c
needs adjustment because the strlen pass doesn't handle

  _11 = {0, b_6(D)};
  __builtin_memcpy (&a, "foo.bar", 8);
  MEM <vector(2) char> [(char *)&a + 3B] = _11;
  _9 = strlen (&a);

I have opened PR117057 for this.

	* tree-vect-slp.cc (vect_build_slp_tree_1): Do not compare
	RHS codes for loads or stores.
	(vect_get_and_check_slp_defs): Only demote operand to external
	in case there is more than one operand.

	* gcc.dg/vect/slp-57.c: New testcase.
	* gcc.dg/Wstringop-overflow-47.c: Adjust.
	* gcc.dg/strlenopt-32.c: XFAIL parts.

4 files changed, 26 insertions, 21 deletions

diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-47.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-47.c
index 9fb78e5..aa5402a 100644
--- a/gcc/testsuite/gcc.dg/Wstringop-overflow-47.c
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-47.c
@@ -31,15 +31,15 @@ void nowarn_c32 (char c)
 
 void warn_c32 (char c)
 {
-  extern char warn_a32[32];   // { dg-message "at offset (32|1) into destination object 'warn_a32' of size 32" "pr97027" }
+  extern char warn_a32[32];   // { dg-message "at offset (32|1|17) into destination object 'warn_a32' of size 32" "pr97027" }
 
   void *p = warn_a32 + 1;
-  *(C32*)p = (C32){ c };      // { dg-warning "writing (1 byte|32 bytes) into a region of size (0|31)" "pr97027" }
+  *(C32*)p = (C32){ c };      // { dg-warning "writing (1 byte|16 bytes|32 bytes) into a region of size (0|15|31)" "pr97027" }
 
   /* Verify a local variable too. */
   char a32[32];
   p = a32 + 1;
-  *(C32*)p = (C32){ c };      // { dg-warning "writing (1 byte|32 bytes) into a region of size (0|31)" "pr97027" }
+  *(C32*)p = (C32){ c };      // { dg-warning "writing (1 byte|16 bytes|32 bytes) into a region of size (0|15|31)" "pr97027" }
   sink (p);
 }
 
diff --git a/gcc/testsuite/gcc.dg/strlenopt-32.c b/gcc/testsuite/gcc.dg/strlenopt-32.c
index 4220314..c531685 100644
--- a/gcc/testsuite/gcc.dg/strlenopt-32.c
+++ b/gcc/testsuite/gcc.dg/strlenopt-32.c
@@ -190,4 +190,5 @@ main ()
   return 0;
 }
 
-/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen1" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen1" { xfail vect_slp_v2qi_store_unalign } } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen1" { target vect_slp_v2qi_store_unalign } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/slp-57.c b/gcc/testsuite/gcc.dg/vect/slp-57.c
new file mode 100644
index 0000000..a35c4ef
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/slp-57.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target vect_int } */
+
+int a[1024];
+void foo (int x)
+{
+  for (int i = 0; i < 1024; i += 2)
+    {
+      a[i] = x;
+      a[i+1] = 1;
+    }
+}
+
+/* { dg-final { scan-tree-dump "vectorizing stmts using SLP" "vect" } } */
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 9bb765e..8b53b0f 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -905,7 +905,8 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned char swap,
 	    }
 
 	  if (is_a <bb_vec_info> (vinfo)
-	      && !oprnd_info->any_pattern)
+	      && !oprnd_info->any_pattern
+	      && number_of_oprnds > 1)
 	    {
 	      /* Now for commutative ops we should see whether we can
 		 make the other operand matching.  */
@@ -1305,10 +1306,12 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
 	      /* Mismatch.  */
 	      continue;
 	    }
-	  if (first_stmt_code != rhs_code
+	  if (!ldst_p
+	      && first_stmt_code != rhs_code
 	      && alt_stmt_code == ERROR_MARK)
 	    alt_stmt_code = rhs_code;
-	  if ((first_stmt_code != rhs_code
+	  if ((!ldst_p
+	       && first_stmt_code != rhs_code
 	       && (first_stmt_code != IMAGPART_EXPR
 		   || rhs_code != REALPART_EXPR)
 	       && (first_stmt_code != REALPART_EXPR
@@ -1325,20 +1328,7 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
 		    && (TREE_CODE_CLASS (tree_code (first_stmt_code))
 			== tcc_comparison)
 		    && (swap_tree_comparison (tree_code (first_stmt_code))
-			== tree_code (rhs_code)))
-	       && !(STMT_VINFO_GROUPED_ACCESS (stmt_info)
-		    && (first_stmt_code == ARRAY_REF
-			|| first_stmt_code == BIT_FIELD_REF
-			|| first_stmt_code == COMPONENT_REF
-			|| first_stmt_code == REALPART_EXPR
-			|| first_stmt_code == IMAGPART_EXPR
-			|| first_stmt_code == MEM_REF)
-		    && (rhs_code == ARRAY_REF
-			|| rhs_code == BIT_FIELD_REF
-			|| rhs_code == COMPONENT_REF
-			|| rhs_code == REALPART_EXPR
-			|| rhs_code == IMAGPART_EXPR
-			|| rhs_code == MEM_REF)))
+			== tree_code (rhs_code))))
 	      || (ldst_p
 		  && (STMT_VINFO_GROUPED_ACCESS (stmt_info)
 		      != STMT_VINFO_GROUPED_ACCESS (first_stmt_info)))