[PATCH] tree-optimization/112320 - bougs debug IL after SCCP

[PATCH] tree-optimization/112320 - bougs debug IL after SCCP

[Richard Biener]

The following addresses wrong debug IL created by SCCP rewriting stmts
to defined overflow.  I addressed another inefficiency there but
needed to adjust the API of rewrite_to_defined_overflow for this
which is now taking a stmt iterator for in-place operation and a
stmt for sequence producing because gsi_for_stmt doesn't work for
stmts not in the IL.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	PR tree-optimization/112320
	* gimple-fold.h (rewrite_to_defined_overflow): New overload
	for in-place operation.
	* gimple-fold.cc (rewrite_to_defined_overflow): Add stmt
	iterator argument to worker, define separate API for
	in-place and not in-place operation.
	* tree-if-conv.cc (predicate_statements): Simplify.
	* tree-scalar-evolution.cc (final_value_replacement_loop):
	Likewise.
	* tree-ssa-ifcombine.cc (pass_tree_ifcombine::execute): Adjust.
	* tree-ssa-reassoc.cc (update_range_test): Likewise.

	* gcc.dg/pr112320.c: New testcase.
---
 gcc/gimple-fold.cc              | 25 ++++++++++++++++++-------
 gcc/gimple-fold.h               |  3 ++-
 gcc/testsuite/gcc.dg/pr112320.c | 14 ++++++++++++++
 gcc/tree-if-conv.cc             | 19 +------------------
 gcc/tree-scalar-evolution.cc    | 15 ++++-----------
 gcc/tree-ssa-ifcombine.cc       |  2 +-
 gcc/tree-ssa-reassoc.cc         |  2 +-
 7 files changed, 41 insertions(+), 39 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr112320.c

diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index 853edd9e5d4..a5be2ee048b 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -8769,12 +8769,14 @@ arith_code_with_undefined_signed_overflow (tree_code code)
    its operand, carrying out the operation in the corresponding unsigned
    type and converting the result back to the original type.
 
-   If IN_PLACE is true, adjust the stmt in place and return NULL.
+   If IN_PLACE is true, *GSI points to STMT, adjust the stmt in place and
+   return NULL.
    Otherwise returns a sequence of statements that replace STMT and also
    contain a modified form of STMT itself.  */
 
-gimple_seq
-rewrite_to_defined_overflow (gimple *stmt, bool in_place /* = false */)
+static gimple_seq
+rewrite_to_defined_overflow (gimple_stmt_iterator *gsi, gimple *stmt,
+			     bool in_place)
 {
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
@@ -8801,9 +8803,8 @@ rewrite_to_defined_overflow (gimple *stmt, bool in_place /* = false */)
   gimple_set_modified (stmt, true);
   if (in_place)
     {
-      gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
       if (stmts)
-	gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
+	gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
       stmts = NULL;
     }
   else
@@ -8811,8 +8812,7 @@ rewrite_to_defined_overflow (gimple *stmt, bool in_place /* = false */)
   gimple *cvt = gimple_build_assign (lhs, NOP_EXPR, gimple_assign_lhs (stmt));
   if (in_place)
     {
-      gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
-      gsi_insert_after (&gsi, cvt, GSI_SAME_STMT);
+      gsi_insert_after (gsi, cvt, GSI_SAME_STMT);
       update_stmt (stmt);
     }
   else
@@ -8821,6 +8821,17 @@ rewrite_to_defined_overflow (gimple *stmt, bool in_place /* = false */)
   return stmts;
 }
 
+void
+rewrite_to_defined_overflow (gimple_stmt_iterator *gsi)
+{
+  rewrite_to_defined_overflow (gsi, gsi_stmt (*gsi), true);
+}
+
+gimple_seq
+rewrite_to_defined_overflow (gimple *stmt)
+{
+  return rewrite_to_defined_overflow (nullptr, stmt, false);
+}
 
 /* The valueization hook we use for the gimple_build API simplification.
    This makes us match fold_buildN behavior by only combining with
diff --git a/gcc/gimple-fold.h b/gcc/gimple-fold.h
index 2fd58db9a2e..f69bcc7d3e4 100644
--- a/gcc/gimple-fold.h
+++ b/gcc/gimple-fold.h
@@ -60,7 +60,8 @@ extern tree gimple_fold_indirect_ref (tree);
 extern bool gimple_fold_builtin_sprintf (gimple_stmt_iterator *);
 extern bool gimple_fold_builtin_snprintf (gimple_stmt_iterator *);
 extern bool arith_code_with_undefined_signed_overflow (tree_code);
-extern gimple_seq rewrite_to_defined_overflow (gimple *, bool = false);
+extern void rewrite_to_defined_overflow (gimple_stmt_iterator *);
+extern gimple_seq rewrite_to_defined_overflow (gimple *);
 extern void replace_call_with_value (gimple_stmt_iterator *, tree);
 extern tree tree_vec_extract (gimple_stmt_iterator *, tree, tree, tree, tree);
 extern void gsi_replace_with_seq_vops (gimple_stmt_iterator *, gimple_seq);
diff --git a/gcc/testsuite/gcc.dg/pr112320.c b/gcc/testsuite/gcc.dg/pr112320.c
new file mode 100644
index 00000000000..15cf39f898c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112320.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O -g" } */
+
+unsigned void0_effective_addr2;
+int void0_i, void0_m, void0_p2;
+void void0()
+{
+  void0_m = 800 - (void0_effective_addr2 & 5);
+  int b1;
+  void0_i = 0;
+  for (; void0_i < void0_m; void0_i++)
+    b1++;
+  void0_p2 = b1++;
+}
diff --git a/gcc/tree-if-conv.cc b/gcc/tree-if-conv.cc
index 262765139ff..16e06d82f59 100644
--- a/gcc/tree-if-conv.cc
+++ b/gcc/tree-if-conv.cc
@@ -2774,24 +2774,7 @@ predicate_statements (loop_p loop)
 		   && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (lhs))
 		   && arith_code_with_undefined_signed_overflow
 						(gimple_assign_rhs_code (stmt)))
-	    {
-	      gsi_remove (&gsi, true);
-	      gimple_seq stmts = rewrite_to_defined_overflow (stmt);
-	      bool first = true;
-	      for (gimple_stmt_iterator gsi2 = gsi_start (stmts);
-		   !gsi_end_p (gsi2);)
-		{
-		  gassign *stmt2 = as_a <gassign *> (gsi_stmt (gsi2));
-		  gsi_remove (&gsi2, false);
-		  if (first)
-		    {
-		      gsi_insert_before (&gsi, stmt2, GSI_NEW_STMT);
-		      first = false;
-		    }
-		  else
-		    gsi_insert_after (&gsi, stmt2, GSI_NEW_STMT);
-		}
-	    }
+	    rewrite_to_defined_overflow (&gsi);
 	  else if (gimple_vdef (stmt))
 	    {
 	      tree lhs = gimple_assign_lhs (stmt);
diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
index a6524de7b92..70b17c5bca1 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -3864,21 +3864,14 @@ final_value_replacement_loop (class loop *loop)
 	  while (!gsi_end_p (gsi2))
 	    {
 	      gimple *stmt = gsi_stmt (gsi2);
-	      gimple_stmt_iterator gsi3 = gsi2;
-	      gsi_next (&gsi2);
-	      gsi_remove (&gsi3, false);
 	      if (is_gimple_assign (stmt)
 		  && arith_code_with_undefined_signed_overflow
-		  (gimple_assign_rhs_code (stmt)))
-		gsi_insert_seq_before (&gsi,
-				       rewrite_to_defined_overflow (stmt),
-				       GSI_SAME_STMT);
-	      else
-		gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
+		       (gimple_assign_rhs_code (stmt)))
+		rewrite_to_defined_overflow (&gsi2);
+	      gsi_next (&gsi2);
 	    }
 	}
-      else
-	gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
+      gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
       if (dump_file)
 	{
 	  fprintf (dump_file, "\n final stmt:\n  ");
diff --git a/gcc/tree-ssa-ifcombine.cc b/gcc/tree-ssa-ifcombine.cc
index 46b076804f4..1906a7e14c6 100644
--- a/gcc/tree-ssa-ifcombine.cc
+++ b/gcc/tree-ssa-ifcombine.cc
@@ -882,7 +882,7 @@ pass_tree_ifcombine::execute (function *fun)
 		     || POINTER_TYPE_P (TREE_TYPE (lhs)))
 		    && arith_code_with_undefined_signed_overflow
 			 (gimple_assign_rhs_code (ass)))
-		  rewrite_to_defined_overflow (ass, true);
+		  rewrite_to_defined_overflow (&gsi);
 	      }
 	    cfg_changed |= true;
 	  }
diff --git a/gcc/tree-ssa-reassoc.cc b/gcc/tree-ssa-reassoc.cc
index 41ee36413b5..26321aa4fc5 100644
--- a/gcc/tree-ssa-reassoc.cc
+++ b/gcc/tree-ssa-reassoc.cc
@@ -2933,7 +2933,7 @@ update_range_test (struct range_entry *range, struct range_entry *otherrange,
 		    gimple_stmt_iterator gsin = gsi;
 		    gsi_prev (&gsip);
 		    gsi_next (&gsin);
-		    rewrite_to_defined_overflow (stmt, true);
+		    rewrite_to_defined_overflow (&gsi);
 		    unsigned uid = gimple_uid (stmt);
 		    if (gsi_end_p (gsip))
 		      gsip = gsi_after_labels (bb);
-- 
2.35.3