I was wandering through the DSE BZs. pr86061 is something I just
recently fixed. I've added markers to the relevant ChangeLog entries
and added the test from the BZ to the testsuite as well.
jeff
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d405921425f..c6c0f4a70af 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -400,6 +400,7 @@
2019-07-19 Jeff Law <l...@redhat.com>
+ PR tree-optimization/86061
* tree-ssa-dse.c (initialize_ao_ref_for_dse): Handle
strncpy. Drop some trivial dead code.
(maybe_trim_memstar_call): Handle strncpy.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8e6b02668fb..14fe6b9cb27 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-07-23 Jeff Law <l...@redhat.com>
+
+ PR tree-optimization/86061
+ * gcc.dg/tree-ssa/pr86061.c: New test.
+
2019-07-23 Richard Biener <rguent...@suse.de>
PR tree-optimization/83518
@@ -176,6 +181,7 @@
2019-07-19 Jeff Law <l...@redhat.com>
+ PR tree-optimization/86061
* gcc.dg/tree-ssa/ssa-dse-37.c: New test.
* gcc.dg/tree-ssa/ssa-dse-38.c: New test.
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr86061.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr86061.c
new file mode 100644
index 00000000000..f2b079298c4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr86061.c
@@ -0,0 +1,20 @@
+/* { dg-options "-O2 -fdump-tree-dse-details -fno-tree-fre" } */
+
+
+struct S { int i; char n[128]; int j; };
+
+void f (char*);
+
+void g (struct S *p)
+{
+ char a[sizeof p->n + 1];
+
+ __builtin_memset (a, 0, sizeof a); // dead store, can be eliminated
+
+ __builtin_strncpy (a, p->n, sizeof a - 1);
+ a[sizeof a - 1] = '\0';
+
+ f (a);
+}
+
+/* { dg-final { scan-tree-dump-times "Deleted dead call" 1 "dse1" } } */
