Fix segfault with -O2 -fnon-call-exceptions -ftracer

The GIMPLE SSA store merging pass blows up when it is rewriting the
stores because it didn't realize that they don't belong to the same
EH region.  Fixed by refusing to merge them.

	PR tree-optimization/94717
	* gimple-ssa-store-merging.c (try_coalesce_bswap): Return false if
	one of the stores doesn't have the same landing pad number as the
	first.
	(coalesce_immediate_stores): Do not try to coalesce the store using
	bswap if it doesn't have the same landing pad number as the first.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e58d040..e8d397a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2019-04-23  Eric Botcazou  <ebotcazou@adacore.com>
+
+       PR tree-optimization/94717
+       * gimple-ssa-store-merging.c (try_coalesce_bswap): Return false if one
+       of the stores doesn't have the same landing pad number as the first.
+       (coalesce_immediate_stores): Do not try to coalesce the store using
+       bswap if it doesn't have the same landing pad number as the first.
+
 2020-04-23  Bill Schmidt  <wschmidt@linux.ibm.com>
 
        * gcc/doc/extend.texi (PowerPC AltiVec/VSX Built-in Functions):

diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c
index a6687cd..2575351 100644 (file)
--- a/gcc/gimple-ssa-store-merging.c
+++ b/gcc/gimple-ssa-store-merging.c
@@ -2435,6 +2435,7 @@ imm_store_chain_info::try_coalesce_bswap (merged_store_group *merged_store,
   for (unsigned int i = first + 1; i < len; ++i)
     {
       if (m_store_info[i]->bitpos != m_store_info[first]->bitpos + width
+         || m_store_info[i]->lp_nr != merged_store->lp_nr
          || m_store_info[i]->ins_stmt == NULL)
        return false;
       width += m_store_info[i]->bitsize;
@@ -2682,6 +2683,7 @@ imm_store_chain_info::coalesce_immediate_stores ()
       if (info->bitpos == merged_store->start + merged_store->width
          && merged_store->stores.length () == 1
          && merged_store->stores[0]->ins_stmt != NULL
+         && info->lp_nr == merged_store->lp_nr
          && info->ins_stmt != NULL)
        {
          unsigned int try_size;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 249a152..f9ab061 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2019-04-23  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * g++.dg/opt/store-merging-4.C: New test.
+
 2020-04-23 Iain Sandoe <iain@sandoe.co.uk>
 
        PR c++/94288

diff --git a/gcc/testsuite/g++.dg/opt/store-merging-4.C b/gcc/testsuite/g++.dg/opt/store-merging-4.C
new file mode 100644 (file)
index 0000000..8a51dcd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/store-merging-4.C
@@ -0,0 +1,29 @@
+// PR tree-optimization/94717
+// Reported by Zdenek Sojka <zsojka@seznam.cz>
+
+// { dg-do compile }
+// { dg-options "-O2 -fnon-call-exceptions -ftracer" }
+
+int abs (int);
+
+static inline void
+bar (int d)
+{
+  d && abs (d);
+}
+
+struct S
+{
+  int a;
+  int b;
+  int c;
+  S (unsigned a, unsigned b) : a (a), b (b) { }
+};
+
+void
+foo (S *x)
+{
+  bar (x->c);
+  new S (x->a, x->b);
+  bar (0);
+}