From e0abd7b05709e41b2e2fda5bde7f5802c6d953ef Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Mon, 29 Nov 2021 12:52:45 +0100
Subject: [PATCH] Remove can_throw_non_call_exceptions special case from
 operator_div::wi_fold.

	PR 103451

gcc/ChangeLog:

	* range-op.cc (operator_div::wi_fold): Remove
	can_throw_non_call_exceptions special case.
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Check for
	can_throw_non_call_exceptions.
	* tree-ssa-dse.c (pass_dse::execute): Same.
	* tree-ssa-sink.c (sink_code_in_bb): Same.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr103451.c: New test.
---
 gcc/range-op.cc                 |  7 -------
 gcc/testsuite/gcc.dg/pr103451.c | 19 +++++++++++++++++++
 gcc/tree-ssa-dce.c              |  3 ++-
 gcc/tree-ssa-dse.c              |  3 ++-
 gcc/tree-ssa-sink.c             |  4 +++-
 5 files changed, 26 insertions(+), 10 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr103451.c

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index bbf2924f815..6fe5f1cb4e0 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -1832,13 +1832,6 @@ operator_div::wi_fold (irange &r, tree type,
       return;
     }
 
-  // If flag_non_call_exceptions, we must not eliminate a division by zero.
-  if (cfun->can_throw_non_call_exceptions)
-    {
-      r.set_varying (type);
-      return;
-    }
-
   // If we're definitely dividing by zero, there's nothing to do.
   if (wi_zero_p (type, divisor_min, divisor_max))
     {
diff --git a/gcc/testsuite/gcc.dg/pr103451.c b/gcc/testsuite/gcc.dg/pr103451.c
new file mode 100644
index 00000000000..c701934603e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103451.c
@@ -0,0 +1,19 @@
+// { dg-do compile }
+// { dg-options "-O2 -w -fnon-call-exceptions -fno-delete-dead-exceptions -fdump-tree-optimized" }
+
+int func_10_ptr_12;
+
+void func_10(long li_8) 
+{
+  long *ptr_9 = &li_8;
+  li_8 &= *ptr_9 / 0 ?: li_8;
+  for (;;)
+    func_10_ptr_12 &= 4 ? *ptr_9 : 4;
+}
+
+void func_9_s_8() 
+{ 
+  func_10(func_9_s_8); 
+}
+
+// { dg-final { scan-tree-dump " / 0" "optimized" } }
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index 1f817b95fab..1c1a5cc0811 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -304,7 +304,8 @@ mark_stmt_if_obviously_necessary (gimple *stmt, bool aggressive)
   /* If a statement could throw, it can be deemed necessary unless we
      are allowed to remove dead EH.  Test this after checking for
      new/delete operators since we always elide their EH.  */
-  if (!cfun->can_delete_dead_exceptions
+  if ((!cfun->can_delete_dead_exceptions
+       || cfun->can_throw_non_call_exceptions)
       && stmt_could_throw_p (cfun, stmt))
     {
       mark_stmt_necessary (stmt, true);
diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c
index 8717d654e5a..aa16565b429 100644
--- a/gcc/tree-ssa-dse.c
+++ b/gcc/tree-ssa-dse.c
@@ -1446,7 +1446,8 @@ pass_dse::execute (function *fun)
 		  && !gimple_has_side_effects (stmt)
 		  && !is_ctrl_altering_stmt (stmt)
 		  && (!stmt_could_throw_p (fun, stmt)
-		      || fun->can_delete_dead_exceptions))
+		      || (fun->can_delete_dead_exceptions
+			  && !cfun->can_throw_non_call_exceptions)))
 		{
 		  if (dump_file && (dump_flags & TDF_DETAILS))
 		    {
diff --git a/gcc/tree-ssa-sink.c b/gcc/tree-ssa-sink.c
index 92f444ec1c8..c5d67840be3 100644
--- a/gcc/tree-ssa-sink.c
+++ b/gcc/tree-ssa-sink.c
@@ -696,7 +696,9 @@ sink_code_in_bb (basic_block bb)
 	  /* If we face a dead stmt remove it as it possibly blocks
 	     sinking of uses.  */
 	  if (zero_uses_p
-	      && ! gimple_vdef (stmt))
+	      && !gimple_vdef (stmt)
+	      && (cfun->can_delete_dead_exceptions
+		  || !stmt_could_throw_p (cfun, stmt)))
 	    {
 	      gsi_remove (&saved, true);
 	      release_defs (stmt);
-- 
2.31.1