re PR c++/85052 (Implement support for clang's __builtin_convertvector)

	PR c++/85052
	* tree-vect-generic.c: Include insn-config.h and recog.h.
	(expand_vector_piecewise): Add defaulted ret_type argument,
	if non-NULL, use that in preference to type for the result type.
	(expand_vector_parallel): Formatting fix.
	(do_vec_conversion, do_vec_narrowing_conversion,
	expand_vector_conversion): New functions.
	(expand_vector_operations_1): Call expand_vector_conversion
	for VEC_CONVERT ifn calls.
	* internal-fn.def (VEC_CONVERT): New internal function.
	* internal-fn.c (expand_VEC_CONVERT): New function.
	* fold-const-call.c (fold_const_vec_convert): New function.
	(fold_const_call): Use it for CFN_VEC_CONVERT.
	* doc/extend.texi (__builtin_convertvector): Document.
c-family/
	* c-common.h (enum rid): Add RID_BUILTIN_CONVERTVECTOR.
	(c_build_vec_convert): Declare.
	* c-common.c (c_build_vec_convert): New function.
c/
	* c-parser.c (c_parser_postfix_expression): Parse
	__builtin_convertvector.
cp/
	* cp-tree.h (cp_build_vec_convert): Declare.
	* parser.c (cp_parser_postfix_expression): Parse
	__builtin_convertvector.
	* constexpr.c: Include fold-const-call.h.
	(cxx_eval_internal_function): Handle IFN_VEC_CONVERT.
	(potential_constant_expression_1): Likewise.
	* semantics.c (cp_build_vec_convert): New function.
	* pt.c (tsubst_copy_and_build): Handle CALL_EXPR to
	IFN_VEC_CONVERT.
testsuite/
	* c-c++-common/builtin-convertvector-1.c: New test.
	* c-c++-common/torture/builtin-convertvector-1.c: New test.
	* g++.dg/ext/builtin-convertvector-1.C: New test.
	* g++.dg/cpp0x/constexpr-builtin4.C: New test.

From-SVN: r267632

1 files changed, 38 insertions, 0 deletions

diff --git a/gcc/fold-const-call.c b/gcc/fold-const-call.c
index 004f94e..439043a 100644
--- a/gcc/fold-const-call.c
+++ b/gcc/fold-const-call.c
@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tm.h" /* For C[LT]Z_DEFINED_AT_ZERO.  */
 #include "builtins.h"
 #include "gimple-expr.h"
+#include "tree-vector-builder.h"
 
 /* Functions that test for certain constant types, abstracting away the
    decision about whether to check for overflow.  */
@@ -645,6 +646,40 @@ fold_const_reduction (tree type, tree arg, tree_code code)
   return res;
 }
 
+/* Fold a call to IFN_VEC_CONVERT (ARG) returning TYPE.  */
+
+static tree
+fold_const_vec_convert (tree ret_type, tree arg)
+{
+  enum tree_code code = NOP_EXPR;
+  tree arg_type = TREE_TYPE (arg);
+  if (TREE_CODE (arg) != VECTOR_CST)
+    return NULL_TREE;
+
+  gcc_checking_assert (VECTOR_TYPE_P (ret_type) && VECTOR_TYPE_P (arg_type));
+
+  if (INTEGRAL_TYPE_P (TREE_TYPE (ret_type))
+      && SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg_type)))
+    code = FIX_TRUNC_EXPR;
+  else if (INTEGRAL_TYPE_P (TREE_TYPE (arg_type))
+	   && SCALAR_FLOAT_TYPE_P (TREE_TYPE (ret_type)))
+    code = FLOAT_EXPR;
+
+  tree_vector_builder elts;
+  elts.new_unary_operation (ret_type, arg, true);
+  unsigned int count = elts.encoded_nelts ();
+  for (unsigned int i = 0; i < count; ++i)
+    {
+      tree elt = fold_unary (code, TREE_TYPE (ret_type),
+			     VECTOR_CST_ELT (arg, i));
+      if (elt == NULL_TREE || !CONSTANT_CLASS_P (elt))
+	return NULL_TREE;
+      elts.quick_push (elt);
+    }
+
+  return elts.build ();
+}
+
 /* Try to evaluate:
 
       *RESULT = FN (*ARG)
@@ -1232,6 +1267,9 @@ fold_const_call (combined_fn fn, tree type, tree arg)
     case CFN_REDUC_XOR:
       return fold_const_reduction (type, arg, BIT_XOR_EXPR);
 
+    case CFN_VEC_CONVERT:
+      return fold_const_vec_convert (type, arg);
+
     default:
       return fold_const_call_1 (fn, type, arg);
     }