Pass counting in VRP is used to decide when to call early VRP, pass the flag to enable warnings, and when the final pass is.

If you try to add additional passes, this becomes quite fragile. This patch simply chooses the pass based on the data pointer passed in, and remove the pass counter.   The first FULL VRP pass invokes the warning code, and the flag passed in now represents the FINAL pass of VRP.  There is no longer a global flag which, as it turns out, wasn't working well with the JIT compiler, but when undetected.  (Thanks to dmalcolm for helping me sort out what was going on there)


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

Andrew
From 29abc475a360ad14d5f692945f2805fba1fdc679 Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacl...@redhat.com>
Date: Thu, 28 Sep 2023 09:19:32 -0400
Subject: [PATCH 2/5] Remove pass counting in VRP.

Rather than using a pass count to decide which parameters are passed to
VRP, makemit explicit.

	* passes.def (pass_vrp): Use parameter for final pass flag..
	* tree-vrp.cc (vrp_pass_num): Remove.
	(run_warning_pass): New.
	(pass_vrp::my_pass): Remove.
	(pass_vrp::final_p): New.
	(pass_vrp::set_pass_param): Set final_p param.
	(pass_vrp::execute): Choose specific pass based on data pointer.
---
 gcc/passes.def  |  4 ++--
 gcc/tree-vrp.cc | 26 +++++++++++++++++---------
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/gcc/passes.def b/gcc/passes.def
index 4110a472914..2bafd60bbfb 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -221,7 +221,7 @@ along with GCC; see the file COPYING3.  If not see
       NEXT_PASS (pass_fre, true /* may_iterate */);
       NEXT_PASS (pass_merge_phi);
       NEXT_PASS (pass_thread_jumps_full, /*first=*/true);
-      NEXT_PASS (pass_vrp, true /* warn_array_bounds_p */);
+      NEXT_PASS (pass_vrp, false /* final_p*/);
       NEXT_PASS (pass_dse);
       NEXT_PASS (pass_dce);
       /* pass_stdarg is always run and at this point we execute
@@ -348,7 +348,7 @@ along with GCC; see the file COPYING3.  If not see
       NEXT_PASS (pass_dominator, false /* may_peel_loop_headers_p */);
       NEXT_PASS (pass_strlen);
       NEXT_PASS (pass_thread_jumps_full, /*first=*/false);
-      NEXT_PASS (pass_vrp, false /* warn_array_bounds_p */);
+      NEXT_PASS (pass_vrp, true /* final_p */);
       /* Run CCP to compute alignment and nonzero bits.  */
       NEXT_PASS (pass_ccp, true /* nonzero_p */);
       NEXT_PASS (pass_warn_restrict);
diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
index d7b194f5904..05266dfe34a 100644
--- a/gcc/tree-vrp.cc
+++ b/gcc/tree-vrp.cc
@@ -1120,36 +1120,44 @@ const pass_data pass_data_early_vrp =
   ( TODO_cleanup_cfg | TODO_update_ssa | TODO_verify_all ),
 };
 
-static int vrp_pass_num = 0;
+static bool run_warning_pass = true;
 class pass_vrp : public gimple_opt_pass
 {
 public:
   pass_vrp (gcc::context *ctxt, const pass_data &data_)
-    : gimple_opt_pass (data_, ctxt), data (data_), warn_array_bounds_p (false),
-      my_pass (vrp_pass_num++)
-  {}
+    : gimple_opt_pass (data_, ctxt), data (data_),
+      warn_array_bounds_p (false), final_p (false)
+  {
+    // Only the frst VRP pass should run warnings.
+    if (&data == &pass_data_vrp)
+      {
+	warn_array_bounds_p = run_warning_pass;
+	run_warning_pass = false;
+      }
+  }
 
   /* opt_pass methods: */
   opt_pass * clone () final override { return new pass_vrp (m_ctxt, data); }
   void set_pass_param (unsigned int n, bool param) final override
     {
       gcc_assert (n == 0);
-      warn_array_bounds_p = param;
+      final_p = param;
     }
   bool gate (function *) final override { return flag_tree_vrp != 0; }
   unsigned int execute (function *fun) final override
     {
       // Early VRP pass.
-      if (my_pass == 0)
-	return execute_ranger_vrp (fun, /*warn_array_bounds_p=*/false, false);
+      if (&data == &pass_data_early_vrp)
+	return execute_ranger_vrp (fun, /*warn_array_bounds_p=*/false,
+				   /*final_p=*/false);
 
-      return execute_ranger_vrp (fun, warn_array_bounds_p, my_pass == 2);
+      return execute_ranger_vrp (fun, warn_array_bounds_p, final_p);
     }
 
  private:
   const pass_data &data;
   bool warn_array_bounds_p;
-  int my_pass;
+  bool final_p;
 }; // class pass_vrp
 
 const pass_data pass_data_assumptions =
-- 
2.41.0

Reply via email to