[PATCH] tree-optimization/103551 - Always set EDGE_EXECUTABLE in ranger vrp.

[Andrew MacLeod via Gcc-patches]

The simplify_and_fold engine uses the EDGE_EXECUTABLE flag to eliminate 
branches:

substitute_and_fold_dom_walker::before_dom_children:
     if (gimple_code (stmt) == GIMPLE_COND)
        {
          if ((EDGE_SUCC (bb, 0)->flags & EDGE_EXECUTABLE)
              ^ (EDGE_SUCC (bb, 1)->flags & EDGE_EXECUTABLE))

... but if certain passes before VRP2 are turned off, the flag can be in 
an uninitialized state upon entry to VRP2.  This patch simply always 
sets EDGE_EXECUTABLE on all edges before invoking ranger and the S&F engine.

Bootstraps on  x86_64-pc-linux-gnu with no regressions.

OK for trunk?

Andrew





commit 09934a28871701f3cef5175c2a510cd09ec13836
Author: Andrew MacLeod <amacl...@redhat.com>
Date:   Tue Jan 11 09:59:21 2022 -0500

    Always set EDGE_EXECUTABLE in VRP2.
    
            PR tree-optimization/103551
            * tree-vrp.c (execute_ranger_vrp): Always set EDGE_EXECUTABLE.

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 804f3171ccc..62946450b13 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -4332,6 +4332,7 @@ execute_ranger_vrp (struct function *fun, bool warn_array_bounds_p)
   scev_initialize ();
   calculate_dominance_info (CDI_DOMINATORS);
 
+  set_all_edges_as_executable (fun);
   gimple_ranger *ranger = enable_ranger (fun);
   rvrp_folder folder (ranger);
   folder.substitute_and_fold ();