Predefine __NO_MATH_ERRNO__ for -fno-math-errno.

This patch adds a predefined macro __NO_MATH_ERRNO__ for when
-fno-math-errno is passed or implied.  This allows math.h to provide a
more accurate definition of the C99 math_errhandling macro that takes
this option into account, and allows for choice of libm functions to
be optimized at compile time based on this option.

(There may be a case for such interfaces for -fno-rounding-math
(default) and -fno-trapping-math as well, but as C99 standard pragmas
would allow those to vary on a per-block basis, predefined macros
would be problematic as the interface; you can't select a
-fno-trapping-math or -fno-rounding-math version of a function in a
standard header if a conforming program could then use "#pragma STDC
FENV_ACCESS ON" to require a -ftrapping-math -frounding-math version
in a particular block.  So built-in functions might be a better way of
providing access to information about those options.)

Bootstrapped with no regressions on x86_64-unknown-linux-gnu.  OK to
commit?

	* cppbuiltin.c (define_builtin_macros_for_compilation_flags):
	Define __NO_MATH_ERRNO__ if -fno-math-errno.
	* doc/cpp.texi (__NO_MATH_ERRNO__): Document predefined macro.

c-family:
	* c-cppbuiltin.c (c_cpp_builtins_optimize_pragma): Define and
	undefine __NO_MATH_ERRNO__ based on changes to -fmath-errno state.

testsuite:
	* gcc.dg/no-math-errno-1.c, gcc.dg/no-math-errno-2.c,
	gcc.dg/no-math-errno-3.c, gcc.dg/no-math-errno-4.c: New tests.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217420 138bc75d-0d04-0410-961f-82ee72b054a4
2014-11-12  Richard Biener  <rguenther@suse.de>

	* match.pd: Implement simple complex operations cancelling.
	* fold-const.c (fold_unary_loc): Remove them here.

	* gcc.dg/tree-ssa/ssa-fre-32.c: Disable forwprop.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217421 138bc75d-0d04-0410-961f-82ee72b054a4
2014-11-12  Richard Biener  <rguenther@suse.de>

	Merge from match-and-simplify branch
	2014-11-04  Prathamesh Kulkarni  <bilbotheelffriend@gmail.com>

	* genmatch.c (user_id): Add new member is_oper_list.
	(user_id::user_id): Add new default argument.
	(parser::parse_operator_list): New function.
	(parser::parse_for): Allow operator-list.
	(parser::parse_pattern): Call parser::parse_operator_list.
	(parser::parse_operation): Reject operator-list.
	* match-builtin.pd: Define operator lists POWs, CBRTs and SQRTs.

	2014-10-31  Prathamesh Kulkarni  <bilbotheelffriend@gmail.com>

	* genmatch.c (parser::parse_c_expr): Mark user-defined ops as used.

	2014-10-30  Prathamesh Kulkarni  <bilbotheelffriend@gmail.com>

	* genmatch.c (parser::parse_op): Check if predicate is used in
	result operand.

	2014-10-29  Prathamesh Kulkarni  <bilbotheelffriend@gmail.com>

	* genmatch.c (parser::parse_for): Make sure to have a valid
	token to report errors at.

	2014-10-28  Prathamesh Kulkarni  <bilbotheelffriend@gmail.com>

	* genmatch.c (parser): Add new member parsing_match_operand.
	(parser::parse_operation): Check for conditional convert in result
	operand.
	(parser::parse_expr): Check for commutative operator in result operand.
	Check for :type in match operand.
	(parser::parse_simplify): Set/unset parsing_match_operand.
	(parser::parser): Initialize parsing_match_operand.

	2014-10-28  Richard Biener  <rguenther@suse.de>

	* genmatch.c (parser::parse_for): Properly check for already
	defined operators.

	2014-10-28  Prathamesh Kulkarni  <bilbotheelffriend@gmail.com>

	* genmatch.c (error_cb): Adjust for printing warnings.
	(warning_at): New function.
	(user_id): Add new member used.
	(get_operator): Mark user_id as used.
	(parse_for): Warn for unused operators.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217422 138bc75d-0d04-0410-961f-82ee72b054a4
gcc/testsuite

	* gcc.target/i386/pr52252-atom-1.c: Extend assembler scan on AVX2 case.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217423 138bc75d-0d04-0410-961f-82ee72b054a4
	* fold-const.c (fold_binary_loc): Don't fold if the result
	is undefined.
	* match.pd (A + (-B) -> A - B, A - (-B) -> A + B,
	-(-A) -> A): Likewise.

	* c-c++-common/ubsan/overflow-sub-4.c: New test.
	* c-c++-common/ubsan/overflow-sub-2.c: Adjust dg-output.
	* c-c++-common/ubsan/overflow-int128.c: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217427 138bc75d-0d04-0410-961f-82ee72b054a4