backport: re PR c++/33819 (Miscompiled shift of C++ bitfield)

2008-02-05  Richard Guenther  <rguenther@suse.de>

        Backport from mainline:
        2008-01-16  Richard Guenther  <rguenther@suse.de>

        PR c++/33819
        * typeck.c (is_bitfield_expr_with_lowered_type): Recurse
        for conversions to type variants.

        * g++.dg/torture/pr33819.C: New testcase.

From-SVN: r132118

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 37c7a2f8693a714abda2880e1393033a7f8fbbd8..408126bea3786f15070cfbb19ad583dc543f8743 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,12 @@
+2008-02-05  Richard Guenther  <rguenther@suse.de>
+
+       Backport from mainline:
+       2008-01-16  Richard Guenther  <rguenther@suse.de>
+
+       PR c++/33819
+       * typeck.c (is_bitfield_expr_with_lowered_type): Recurse
+       for conversions to type variants.
+
 2008-02-01  Release Manager
 
        * GCC 4.2.3 released.

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 9e8ca6eabe14125c53699c876f64e61e06dc5ffd..76ac3f03ee6e596e78ad0cec342c39aaac8b0627 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1443,6 +1443,13 @@ is_bitfield_expr_with_lowered_type (tree exp)
        return DECL_BIT_FIELD_TYPE (field);
       }
 
+    case NOP_EXPR:
+    case CONVERT_EXPR:
+      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
+         == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
+       return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
+      /* Fallthrough.  */
+
     default:
       return NULL_TREE;
     }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e3c1670106c72b3a2c755886983cc0e4b932f270..feda984adaf998288ef3ad9b84bc6d5a1fa080eb 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2008-02-05  Richard Guenther  <rguenther@suse.de>
+
+       Backport from mainline:
+       2008-01-16  Richard Guenther  <rguenther@suse.de>
+
+       PR c/34768
+       * gcc.c-torture/execute/pr34768-1.c: New testcase.
+       * gcc.c-torture/execute/pr34768-2.c: Likewise.
+
 2008-02-04  Daniel Franke  <franke.daniel@gmail.com>
 
        * gfortran.dg/where_operator_assign_4.f90: Fix typo in error message

diff --git a/gcc/testsuite/g++.dg/torture/pr33819.C b/gcc/testsuite/g++.dg/torture/pr33819.C
new file mode 100644 (file)
index 0000000..a2f868d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr33819.C
@@ -0,0 +1,22 @@
+/* { dg-do run } */
+
+class s
+{
+public:
+  s(long long aa) : a(aa), i1(0) { }
+  long long id() const { return (this->a << 16) >> 16; }
+  bool operator< (s sv) { return this->a < sv.id(); }
+private:
+  long long a : 48;
+  int i1 : 16;
+};
+s g(1);
+extern "C" void abort (void);
+int
+main(int, char**)
+{
+  if (g < (1LL << 38) - 1)
+    return 0;
+  abort ();
+}
+