re PR tree-optimization/91180 (wrong code at -O and above with __builtin_memset())

2019-07-17  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91180
	* tree-ssa-sccvn.c (vn_reference_lookup_3): Fix offset
	computation for memset partial defs.

	* gcc.dg/torture/pr91180.c: New testcase.

From-SVN: r273548

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0c1c133..877de19 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-07-17  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/91180
+       * tree-ssa-sccvn.c (vn_reference_lookup_3): Fix offset
+       computation for memset partial defs.
+
 2019-07-17  Jakub Jelinek  <jakub@redhat.com>
 
        * gimple.h (enum gf_mask): Remove GF_OMP_FOR_SIMD, change

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5c156c7..f9ee482 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-07-17  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/91180
+       * gcc.dg/torture/pr91180.c: New testcase.
+
 2019-07-17  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/91157

diff --git a/gcc/testsuite/gcc.dg/torture/pr91180.c b/gcc/testsuite/gcc.dg/torture/pr91180.c
new file mode 100644 (file)
index 0000000..02b2425
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr91180.c
@@ -0,0 +1,13 @@
+/* { dg-do run } */
+
+int
+main ()
+{
+#if __SIZEOF_INT__ == 4
+  unsigned x = 0xffffffff;
+  __builtin_memset (1 + (char *) &x, 0, 2);
+  if (x != 0xff0000ff)
+    __builtin_abort ();
+#endif
+  return 0;
+}

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 73c77d1..830d37b 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -2486,7 +2486,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
        {
          pd_data pd;
          pd.rhs = build_constructor (NULL_TREE, NULL);
-         pd.offset = offset2i - offseti;
+         pd.offset = (offset2i - offseti) / BITS_PER_UNIT;
          pd.size = leni;
          return data->push_partial_def (pd, vuse, maxsizei);
        }