From: Richard Biener <rguenther@suse.de>
Date: Tue, 2 May 2023 08:34:48 +0000 (+0200)
Subject: tree-optimization/109672 - properly check emulated plus during vect
X-Git-Tag: basepoints/gcc-15~9748
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f385252b2336a4a57a30fddf82e558c73bcc85cc;p=thirdparty%2Fgcc.git

tree-optimization/109672 - properly check emulated plus during vect

The following refactors the check for emulated vector support for
the cases of plus, minus and negate.  In the PR we end up with
a SImode plus, supported by the target but emulated and in this
context fail to verify we are dealing with exactly word_mode.

	PR tree-optimization/109672
	* tree-vect-stmts.cc (vectorizable_operation): For plus,
	minus and negate always check the vector mode is word mode.
---

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index c71e28737ee3..3ad6a7d28d77 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -6384,29 +6384,26 @@ vectorizable_operation (vec_info *vinfo,
     }
 
   bool using_emulated_vectors_p = vect_emulated_vector_p (vectype);
-  if (!target_support_p)
+  if (!target_support_p || using_emulated_vectors_p)
     {
       if (dump_enabled_p ())
 	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-                         "op not supported by target.\n");
+			 "op not supported by target.\n");
       /* Check only during analysis.  */
-      if (maybe_ne (GET_MODE_SIZE (vec_mode), UNITS_PER_WORD)
+      if (((code == PLUS_EXPR || code == MINUS_EXPR || code == NEGATE_EXPR)
+	   && maybe_ne (GET_MODE_SIZE (vec_mode), UNITS_PER_WORD))
 	  || (!vec_stmt && !vect_can_vectorize_without_simd_p (code)))
-        return false;
+	{
+	  if (dump_enabled_p ())
+	    dump_printf (MSG_NOTE, "using word mode not possible.\n");
+	  return false;
+	}
       if (dump_enabled_p ())
 	dump_printf_loc (MSG_NOTE, vect_location,
                          "proceeding using word mode.\n");
       using_emulated_vectors_p = true;
     }
 
-  if (using_emulated_vectors_p
-      && !vect_can_vectorize_without_simd_p (code))
-    {
-      if (dump_enabled_p ())
-	dump_printf (MSG_NOTE, "using word mode not possible.\n");
-      return false;
-    }
-
   int reduc_idx = STMT_VINFO_REDUC_IDX (stmt_info);
   vec_loop_masks *masks = (loop_vinfo ? &LOOP_VINFO_MASKS (loop_vinfo) : NULL);
   internal_fn cond_fn = get_conditional_internal_fn (code);