c-common.c (noplt): New attribute.

c-common.c (noplt): New attribute.

2015-06-04  Sriraman Tallam  <tmsriram@google.com>

	* c-family/c-common.c (noplt): New attribute.
	(handle_noplt_attribute): New handler.
	* calls.c (prepare_call_address): Check for noplt
	attribute.
	* config/i386/i386.c (ix86_expand_call): Check
	for noplt attribute.
	(ix86_nopic_noplt_attribute_p): New function.
	(ix86_output_call_insn): Output indirect call for non-pic
	no plt calls.
	* doc/extend.texi (noplt): Document new attribute.
	* doc/invoke.texi: Document new attribute.
	* testsuite/gcc.target/i386/noplt-1.c: New test.
	* testsuite/gcc.target/i386/noplt-2.c: New test.
	* testsuite/gcc.target/i386/noplt-3.c: New test.
	* testsuite/gcc.target/i386/noplt-4.c: New test.

This patch does two things:

* Adds new generic function attribute "noplt" that is similar in functionality
  to -fno-plt except that it applies only to calls to functions that are marked
  with this attribute.
* For x86_64, it makes -fno-plt(and the attribute) also work for non-PIC code by
  directly generating an indirect call via a GOT entry.

From-SVN: r224138