[gcc r13-2031] tree-optimization/106593 - fix ICE with backward threading

[Richard Biener <rguenth@gcc.gnu.org>]

https://gcc.gnu.org/g:4cc0d3ebaee4b54280ff0466d8e5b351a3b5bacc

commit r13-2031-g4cc0d3ebaee4b54280ff0466d8e5b351a3b5bacc
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Aug 12 12:20:13 2022 +0200

    tree-optimization/106593 - fix ICE with backward threading
    
    With the last re-org I failed to make sure to not add SSA names
    nor supported by ranger into m_imports which then triggers an
    ICE in range_on_path_entry because range_of_expr returns false.
    
            PR tree-optimization/106593
            * tree-ssa-threadbackward.cc (back_threader::find_paths):
            If the imports from the conditional do not satisfy
            gimple_range_ssa_p don't try to thread anything.

Diff:
---
 gcc/tree-ssa-threadbackward.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/tree-ssa-threadbackward.cc b/gcc/tree-ssa-threadbackward.cc
index 546a776bd91..b886027fccf 100644
--- a/gcc/tree-ssa-threadbackward.cc
+++ b/gcc/tree-ssa-threadbackward.cc
@@ -518,7 +518,11 @@ back_threader::find_paths (basic_block bb, tree name)
       bitmap_clear (m_imports);
       ssa_op_iter iter;
       FOR_EACH_SSA_TREE_OPERAND (name, stmt, iter, SSA_OP_USE)
-	bitmap_set_bit (m_imports, SSA_NAME_VERSION (name));
+	{
+	  if (!gimple_range_ssa_p (name))
+	    return;
+	  bitmap_set_bit (m_imports, SSA_NAME_VERSION (name));
+	}
 
       // Interesting is the set of imports we still not have see
       // the definition of.  So while imports only grow, the