automatic import of gccopeneuler22.03_LTS_SP2

1 files changed, 98 insertions, 0 deletions

diff --git a/0010-Backport-tree-optimization-94963-avoid-bogus-uninit-.patch b/0010-Backport-tree-optimization-94963-avoid-bogus-uninit-.patch
new file mode 100644
index 0000000..e5dbbf2
--- /dev/null
+++ b/0010-Backport-tree-optimization-94963-avoid-bogus-uninit-.patch
@@ -0,0 +1,98 @@
+From b8b3e29e4cceae2bab6e0774b1af994dbe713d97 Mon Sep 17 00:00:00 2001
+From: zhanghaijian <z.zhanghaijian@huawei.com>
+Date: Thu, 15 Jul 2021 09:13:11 +0800
+Subject: [PATCH 10/13] [Backport]tree-optimization/94963 - avoid bogus uninit
+ warning with store-motion
+
+Reference: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=371905d12259c180efb9b1f1b5716e969feb60f9
+
+Eliding the load for store-motion causes an uninitialized variable
+flowing into the loop, conditionally initialized and used.  The
+uninit warning cannot relate the flag used to guard the initialization
+and use with the actual initialization so the following robustifies
+the previous approach of marking the conditional store as not to
+be warned on by instead initializing the variable on loop entry
+from an uninitialized variable we mark as not to be warned for.
+
+diff --git a/gcc/testsuite/gcc.dg/pr94963.c b/gcc/testsuite/gcc.dg/pr94963.c
+new file mode 100644
+index 00000000000..09c0524fb3a
+--- /dev/null
++++ b/gcc/testsuite/gcc.dg/pr94963.c
+@@ -0,0 +1,35 @@
++/* { dg-do compile } */
++/* { dg-options "-O2 -Wall" } */
++
++typedef struct
++{
++  int p1;
++  int p2;
++  int p3;
++} P;
++struct S
++{
++  int field;
++};
++extern int v2;
++extern void foo (struct S *map);
++static struct S var;
++const P *pv;
++int ps;
++void
++f (void)
++{
++  if (pv != 0)
++    for (const P *ph = pv; ph < &pv[ps]; ++ph)
++      switch (ph->p1)
++       {
++       case 1:
++       v2 = ph->p2;
++       break;
++       case 2:
++       var.field = ph->p3;
++       break;
++       }
++  if (var.field != 0) /* { dg-bogus "uninitialized" } */
++    foo (&var);
++}
+diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c
+index 8c33735b1fa..d74a46ef352 100644
+--- a/gcc/tree-ssa-loop-im.c
++++ b/gcc/tree-ssa-loop-im.c
+@@ -1994,8 +1994,6 @@ execute_sm_if_changed (edge ex, tree mem, tree tmp_var, tree flag,
+   gsi = gsi_start_bb (then_bb);
+   /* Insert actual store.  */
+   stmt = gimple_build_assign (unshare_expr (mem), tmp_var);
+-  /* Make sure to not warn about maybe-uninit uses of tmp_var here.  */
+-  gimple_set_no_warning (stmt, true);
+   gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
+ 
+   edge e1 = single_succ_edge (new_bb);
+@@ -2149,13 +2147,19 @@ execute_sm (class loop *loop, vec<edge> exits, im_mem_ref *ref)
+      store then.  */
+   if ((!always_stored && !multi_threaded_model_p)
+       || (ref->loaded && bitmap_bit_p (ref->loaded, loop->num)))
++    load = gimple_build_assign (tmp_var, unshare_expr (ref->mem.ref));
++  else
+     {
+-      load = gimple_build_assign (tmp_var, unshare_expr (ref->mem.ref));
+-      lim_data = init_lim_data (load);
+-      lim_data->max_loop = loop;
+-      lim_data->tgt_loop = loop;
+-      gsi_insert_before (&gsi, load, GSI_SAME_STMT);
++      /* If not emitting a load mark the uninitialized state on the
++        loop entry as not to be warned for.  */
++      tree uninit = create_tmp_reg (TREE_TYPE (tmp_var));
++      TREE_NO_WARNING (uninit) = 1;
++      load = gimple_build_assign (tmp_var, uninit);
+     }
++  lim_data = init_lim_data (load);
++  lim_data->max_loop = loop;
++  lim_data->tgt_loop = loop;
++  gsi_insert_before (&gsi, load, GSI_SAME_STMT);
+ 
+   if (multi_threaded_model_p)
+     {
+-- 
+2.21.0.windows.1
+