http://sourceware.org/ml/gdb-patches/2012-11/msg00312.html

gdb/ChangeLog
        * valarith.c (value_vector_widen): New function for replicating a
        scalar into a vector.
        (value_binop): Use value_vector_widen to widen scalar to vector
        rather than casting, this better matches gcc C behaviour.
        * valops.c (value_casst): Update logic for casting between vector
        types, and for casting from scalar to vector, try to match gcc C
        behaviour.
        * value.h (value_vector_widen): Declare.
        * opencl-lang.c (opencl_value_cast): New opencl specific casting
        function, handle special case for casting scalar to vector.
        (opencl_relop): Use opencl_value_cast.
        (evaluate_subexp_opencl): Use opencl_value_cast instead of
        value_cast, and handle BINOP_ASSIGN, UNOP_CAST, and UNOP_CAST_TYPE
        in order to use opencl_value_cast.

gdb/testsuite/ChangeLog
        * gdb.base/gnu_vector.c: New variable for use in tests.
        * gdb.base/gnu_vector.exp: Update and extend tests to reflect
        changes in scalar to vector casting and widening.
        * gdb.python/py-type.c: New variables for use in tests.
        * gdb.python/py-type.exp: Update vector related tests to reflect
        changes in scalar to vector casting and widening.

1 files changed, 6 insertions, 0 deletions

diff --git a/gdb/value.h b/gdb/value.h
index 67f1d04..5825f6e 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -482,6 +482,12 @@ extern void read_value_memory (struct value *val, int embedded_offset,
 			       int stack, CORE_ADDR memaddr,
 			       gdb_byte *buffer, size_t length);
 
+/* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
+   into each element of a new vector value with VECTOR_TYPE.  */
+
+struct value *value_vector_widen (struct value *scalar_value,
+				  struct type *vector_type);
+
 
 
 #include "symtab.h"