diff mbox series

tree-optimization/113018 - ICE with BB reduction vectorization

Message ID 20231214155543.0B013138F2@imap2.dmz-prg2.suse.org
State New
Headers show
Series tree-optimization/113018 - ICE with BB reduction vectorization | expand

Commit Message

Richard Biener Dec. 14, 2023, 3:55 p.m. UTC 
When BB reduction vectorization picks up a chain with an ASM def
in it and that's inside the vectorized region we fail to get its
LHS.  Instead of trying to get the correct def the following
avoids vectorizing such def and instead keeps it as def to add
in the epilog.

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

	PR tree-optimization/113018
	* tree-vect-slp.cc (vect_slp_check_for_roots): Only start
	SLP discovery from stmts with a LHS.
---
 gcc/tree-vect-slp.cc | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index f8a168caa60..a82fca45161 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -7419,7 +7419,12 @@  vect_slp_check_for_roots (bb_vec_info bb_vinfo)
 		      invalid = true;
 		      break;
 		    }
-		  if (chain[i].dt != vect_internal_def)
+		  if (chain[i].dt != vect_internal_def
+		      /* Avoid stmts where the def is not the LHS, like
+			 ASMs.  */
+		      || (gimple_get_lhs (bb_vinfo->lookup_def
+						      (chain[i].op)->stmt)
+			  != chain[i].op))
 		    remain_cnt++;
 		}
 	      if (!invalid && chain.length () - remain_cnt > 1)
@@ -7431,8 +7436,11 @@  vect_slp_check_for_roots (bb_vec_info bb_vinfo)
 		    remain.create (remain_cnt);
 		  for (unsigned i = 0; i < chain.length (); ++i)
 		    {
-		      if (chain[i].dt == vect_internal_def)
-			stmts.quick_push (bb_vinfo->lookup_def (chain[i].op));
+		      stmt_vec_info stmt_info;
+		      if (chain[i].dt == vect_internal_def
+			  && ((stmt_info = bb_vinfo->lookup_def (chain[i].op)),
+			      gimple_get_lhs (stmt_info->stmt) == chain[i].op))
+			stmts.quick_push (stmt_info);
 		      else
 			remain.quick_push (chain[i].op);
 		    }