2016-01-08 Thomas Preud'homme <thomas.preudhomme@arm.com>

    gcc/
    PR tree-optimization/67781
    * tree-ssa-math-opts.c (find_bswap_or_nop): Zero out bytes in cmpxchg
    and cmpnop in two steps: first the ones not accessed in original
    gimple expression in a endian independent way and then the ones not
    accessed in the final result in an endian-specific way.

    gcc/testsuite/
    PR tree-optimization/67781
    * gcc.c-torture/execute/pr67781.c: New file.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@232154 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 34 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr67781.c b/gcc/testsuite/gcc.c-torture/execute/pr67781.c
new file mode 100644
index 00000000000..bf50aa2f6c3
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr67781.c
@@ -0,0 +1,34 @@
+#ifdef __UINT32_TYPE__
+typedef __UINT32_TYPE__ uint32_t;
+#else
+typedef unsigned uint32_t;
+#endif
+
+#ifdef __UINT8_TYPE__
+typedef __UINT8_TYPE__ uint8_t;
+#else
+typedef unsigned char uint8_t;
+#endif
+
+struct
+{
+  uint32_t a;
+  uint8_t b;
+} s = { 0x123456, 0x78 };
+
+int pr67781()
+{
+  uint32_t c = (s.a << 8) | s.b;
+  return c;
+}
+
+int
+main ()
+{
+  if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
+    return 0;
+
+  if (pr67781 () != 0x12345678)
+    __builtin_abort ();
+  return 0;
+}