[COMMITTED] process transitive inferred ranges in pre_fold_stmt.

[Andrew MacLeod <amacleod@redhat.com>]

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I was processing the transitive inferred ranges in fold_stmt when it was 
the final statement in the block.  the substitute_and_fold engine 
actually does a bit of work before calling fold_stmt.  this patch moves 
the check to pre_fold_stmt instead so it gets done before the final 
statement in the block is processed... as was the original intention.

I also changed it so we always do this just before the last statement in 
any block.  This allows us to get transitive inferred ranges registered 
for returns, as well as just normal blocks which can feed other blocks. 
   Performance impact is minimal.

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

Andrei


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From dab5d73959cfc8f03cba548777adda9a798e1f0e Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacleod@redhat.com>
Date: Wed, 9 Nov 2022 10:58:15 -0500
Subject: [PATCH] process transitive inferred ranges in pre_fold_stmt.

The subst_and_fold engine can perform some folding activity before
calling fold_stmt, so do this work in pre_fold_stmt instead.

	* tree-vrp.cc (rvrp_folder::rvrp_folder): Init m_last_bb_stmt.
	(rvrp_folder::pre_fold_bb): Set m_last_bb_stmt.
	(rvrp_folder::pre_fold_stmt): Check for transitive inferred ranges.
	(rvrp_folder::fold_stmt): Check in pre_fold_stmt instead.
---
 gcc/tree-vrp.cc | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
index 3393c73a7db..a474d9d11e5 100644
--- a/gcc/tree-vrp.cc
+++ b/gcc/tree-vrp.cc
@@ -4442,6 +4442,7 @@ public:
   {
     m_ranger = r;
     m_pta = new pointer_equiv_analyzer (m_ranger);
+    m_last_bb_stmt = NULL;
   }
 
   ~rvrp_folder ()
@@ -4485,6 +4486,7 @@ public:
     for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
 	 gsi_next (&gsi))
       m_ranger->register_inferred_ranges (gsi.phi ());
+    m_last_bb_stmt = last_stmt (bb);
   }
 
   void post_fold_bb (basic_block bb) override
@@ -4497,19 +4499,14 @@ public:
   void pre_fold_stmt (gimple *stmt) override
   {
     m_pta->visit_stmt (stmt);
+    // If this is the last stmt and there are inferred ranges, reparse the
+    // block for transitive inferred ranges that occur earlier in the block.
+    if (stmt == m_last_bb_stmt)
+      m_ranger->register_transitive_inferred_ranges (gimple_bb (stmt));
   }
 
   bool fold_stmt (gimple_stmt_iterator *gsi) override
   {
-    gimple *s = gsi_stmt (*gsi);
-    // If this is a block ending condition, and there are inferred ranges,
-    // reparse the block to see if there are any transitive inferred ranges.
-    if (is_a<gcond *> (s))
-      {
-	basic_block bb = gimple_bb (s);
-	if (bb && s == gimple_outgoing_range_stmt_p (bb))
-	  m_ranger->register_transitive_inferred_ranges (bb);
-      }
     bool ret = m_simplifier.simplify (gsi);
     if (!ret)
       ret = m_ranger->fold_stmt (gsi, follow_single_use_edges);
@@ -4523,6 +4520,7 @@ private:
   gimple_ranger *m_ranger;
   simplify_using_ranges m_simplifier;
   pointer_equiv_analyzer *m_pta;
+  gimple *m_last_bb_stmt;
 };
 
 /* Main entry point for a VRP pass using just ranger. This can be called
-- 
2.37.3