[gcc r12-5409] Limit depth for all GORI expressions.

[gcc r12-5409] Limit depth for all GORI expressions.

[Andrew Macleod]

https://gcc.gnu.org/g:ee448a523d377f9ed882dac806d2f5001bfa2432

commit r12-5409-gee448a523d377f9ed882dac806d2f5001bfa2432
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Wed Nov 17 14:14:06 2021 -0500

    Limit depth for all GORI expressions.
    
    Apply the logical_depth limit ranger uses to all stmts with multiple ssa-names
    to avoid excessive outgoing calculations.
    
            gcc/
            PR tree-optimization/103254
            * gimple-range-gori.cc (range_def_chain::get_def_chain): Limit the
            depth for all statements with multple ssa names.
    
            gcc/testsuite/
            * gcc.dg/pr103254.c: New.

Diff:
---
 gcc/gimple-range-gori.cc        | 20 +++++++++-----------
 gcc/testsuite/gcc.dg/pr103254.c | 25 +++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/gcc/gimple-range-gori.cc b/gcc/gimple-range-gori.cc
index fb2d571ef44..911d7ac4ec8 100644
--- a/gcc/gimple-range-gori.cc
+++ b/gcc/gimple-range-gori.cc
@@ -331,7 +331,6 @@ range_def_chain::get_def_chain (tree name)
 {
   tree ssa1, ssa2, ssa3;
   unsigned v = SSA_NAME_VERSION (name);
-  bool is_logical = false;
 
   // If it has already been processed, just return the cached value.
   if (has_def_chain (name))
@@ -348,15 +347,6 @@ range_def_chain::get_def_chain (tree name)
   gimple *stmt = SSA_NAME_DEF_STMT (name);
   if (gimple_range_handler (stmt))
     {
-      is_logical = is_gimple_logical_p (stmt);
-      // Terminate the def chains if we see too many cascading logical stmts.
-      if (is_logical)
-	{
-	  if (m_logical_depth == param_ranger_logical_depth)
-	    return NULL;
-	  m_logical_depth++;
-	}
-
       ssa1 = gimple_range_ssa_p (gimple_range_operand1 (stmt));
       ssa2 = gimple_range_ssa_p (gimple_range_operand2 (stmt));
       ssa3 = NULL_TREE;
@@ -376,6 +366,14 @@ range_def_chain::get_def_chain (tree name)
       return NULL;
     }
 
+  // Terminate the def chains if we see too many cascading stmts.
+  if (m_logical_depth == param_ranger_logical_depth)
+    return NULL;
+
+  // Increase the depth if we have a pair of ssa-names.
+  if (ssa1 && ssa2)
+    m_logical_depth++;
+
   register_dependency (name, ssa1, gimple_bb (stmt));
   register_dependency (name, ssa2, gimple_bb (stmt));
   register_dependency (name, ssa3, gimple_bb (stmt));
@@ -383,7 +381,7 @@ range_def_chain::get_def_chain (tree name)
   if (!ssa1 && !ssa2 & !ssa3)
     set_import (m_def_chain[v], name, NULL);
 
-  if (is_logical)
+  if (ssa1 && ssa2)
     m_logical_depth--;
 
   return m_def_chain[v].bm;
diff --git a/gcc/testsuite/gcc.dg/pr103254.c b/gcc/testsuite/gcc.dg/pr103254.c
new file mode 100644
index 00000000000..62d2415f216
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103254.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+/* { dg-timeout 10 } */
+
+short int i;
+
+void
+foo (void)
+{
+  for (i = 1; i < 2; i += 4)
+    {
+      int j;
+
+      for (j = 0; j < 5; j += 4)
+        {
+          int k;
+
+          for (k = 0; k < 68; k += 4)
+            {
+              i &= j;
+              j &= i;
+            }
+        }
+    }
+}