From: Richard Biener <rguenther@suse.de>
Date: Mon, 4 Dec 2023 14:46:38 +0000 (+0100)
Subject: tree-optimization/112827 - more SCEV cprop fixes
X-Git-Tag: basepoints/gcc-15~4007
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=50f2a3370d177f8fe9bea0461feb710523e048a2;p=thirdparty%2Fgcc.git

tree-optimization/112827 - more SCEV cprop fixes

The insert iteration can be corrupted by foldings of replace_uses_by,
within this particular PHI replacement but also with subsequent ones.
Recompute the insert location before insertion instead.

This fixes an obvserved ICE of gcc.dg/tree-ssa/ssa-sink-16.c.

	PR tree-optimization/112827
	PR tree-optimization/112848
	* tree-scalar-evolution.cc (final_value_replacement_loop):
	Compute the insert location for each insert.
---

diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
index 7556d89e9f88..385fc64ab8ca 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -3739,7 +3739,6 @@ final_value_replacement_loop (class loop *loop)
     split_loop_exit_edge (exit);
 
   /* Set stmt insertion pointer.  All stmts are inserted before this point.  */
-  gimple_stmt_iterator gsi = gsi_after_labels (exit->dest);
 
   class loop *ex_loop
     = superloop_at_depth (loop,
@@ -3880,6 +3879,7 @@ final_value_replacement_loop (class loop *loop)
 	      gsi_next (&gsi2);
 	    }
 	}
+      gimple_stmt_iterator gsi = gsi_after_labels (exit->dest);
       gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
       if (dump_file)
 	{