Add float128 support for x86_64, x86.

This patch enables float128 support for x86_64 and x86.  All GCC
versions that can build glibc provide the required support, but since
GCC 6 and before don't provide __builtin_nanq / __builtin_nansq, sNaN
tests and some tests of NaN payloads need to be disabled with such
compilers (this does not affect the generated glibc binaries at all,
just the tests).  bits/floatn.h declares float128 support to be
available for GCC versions that provide the required libgcc support
(4.3 for x86_64, 4.4 for i386 GNU/Linux, 4.5 for i386 GNU/Hurd);
compilation-only support was present some time before then, but not
really useful without the libgcc functions.

fenv_private.h needed updating to avoid trying to put _Float128 values
in registers.  I make no assertion of optimality of the
math_opt_barrier / math_force_eval definitions for this case; they are
simply intended to be sufficient to work correctly.

Tested for x86_64 and x86, with GCC 7 and GCC 6.  (Testing for x32 was
compilation tests only with build-many-glibcs.py to verify the ABI
baseline updates.  I have not done any testing for Hurd, although the
float128 support is enabled there as for GNU/Linux.)

	* sysdeps/i386/Implies: Add ieee754/float128.
	* sysdeps/x86_64/Implies: Likewise.
	* sysdeps/x86/bits/floatn.h: New file.
	* sysdeps/x86/float128-abi.h: Likewise.
	* manual/math.texi (Mathematics): Document support for _Float128
	on x86_64 and x86.
	* sysdeps/i386/fpu/fenv_private.h: Include <bits/floatn.h>.
	(math_opt_barrier): Do not put _Float128 values in floating-point
	registers.
	(math_force_eval): Likewise.
	[__x86_64__] (SET_RESTORE_ROUNDF128): New macro.
	* sysdeps/x86/fpu/Makefile [$(subdir) = math] (CPPFLAGS): Append
	to Makefile variable.
	* sysdeps/x86/fpu/e_sqrtf128.c: New file.
	* sysdeps/x86/fpu/sfp-machine.h: Likewise.  Based on libgcc.
	* sysdeps/x86/math-tests.h: New file.
	* math/libm-test-support.h (XFAIL_FLOAT128_PAYLOAD): New macro.
	* math/libm-test-getpayload.inc (getpayload_test_data): Use
	XFAIL_FLOAT128_PAYLOAD.
	* math/libm-test-setpayload.inc (setpayload_test_data): Likewise.
	* math/libm-test-totalorder.inc (totalorder_test_data): Likewise.
	* math/libm-test-totalordermag.inc (totalordermag_test_data):
	Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist: Update.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
	* sysdeps/i386/fpu/libm-test-ulps: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.

1 files changed, 16 insertions, 16 deletions

diff --git a/math/libm-test-totalorder.inc b/math/libm-test-totalorder.inc
index d92e2aa..9941aab 100644
--- a/math/libm-test-totalorder.inc
+++ b/math/libm-test-totalorder.inc
@@ -212,22 +212,22 @@ static const struct test_ff_i_data totalorder_test_data[] =
     TEST_ff_b (totalorder, -snan_value_pl ("0x200000000"), -snan_value_pl ("0x100000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
 #endif
 #if PAYLOAD_DIG >= 66
-    TEST_ff_b (totalorder, qnan_value_pl ("0xffffffffffffffff"), qnan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -qnan_value_pl ("0xffffffffffffffff"), -qnan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, qnan_value_pl ("0x10000000000000000"), qnan_value_pl ("0xffffffffffffffff"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -qnan_value_pl ("0x10000000000000000"), -qnan_value_pl ("0xffffffffffffffff"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, snan_value_pl ("0xffffffffffffffff"), snan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -snan_value_pl ("0xffffffffffffffff"), -snan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, snan_value_pl ("0x10000000000000000"), snan_value_pl ("0xffffffffffffffff"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -snan_value_pl ("0x10000000000000000"), -snan_value_pl ("0xffffffffffffffff"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, qnan_value_pl ("0x10000000000000000"), qnan_value_pl ("0x20000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -qnan_value_pl ("0x10000000000000000"), -qnan_value_pl ("0x20000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, qnan_value_pl ("0x20000000000000000"), qnan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -qnan_value_pl ("0x20000000000000000"), -qnan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, snan_value_pl ("0x10000000000000000"), snan_value_pl ("0x20000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -snan_value_pl ("0x10000000000000000"), -snan_value_pl ("0x20000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, snan_value_pl ("0x20000000000000000"), snan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
-    TEST_ff_b (totalorder, -snan_value_pl ("0x20000000000000000"), -snan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_b (totalorder, qnan_value_pl ("0xffffffffffffffff"), qnan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -qnan_value_pl ("0xffffffffffffffff"), -qnan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, qnan_value_pl ("0x10000000000000000"), qnan_value_pl ("0xffffffffffffffff"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -qnan_value_pl ("0x10000000000000000"), -qnan_value_pl ("0xffffffffffffffff"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, snan_value_pl ("0xffffffffffffffff"), snan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -snan_value_pl ("0xffffffffffffffff"), -snan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, snan_value_pl ("0x10000000000000000"), snan_value_pl ("0xffffffffffffffff"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -snan_value_pl ("0x10000000000000000"), -snan_value_pl ("0xffffffffffffffff"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, qnan_value_pl ("0x10000000000000000"), qnan_value_pl ("0x20000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -qnan_value_pl ("0x10000000000000000"), -qnan_value_pl ("0x20000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, qnan_value_pl ("0x20000000000000000"), qnan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -qnan_value_pl ("0x20000000000000000"), -qnan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, snan_value_pl ("0x10000000000000000"), snan_value_pl ("0x20000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -snan_value_pl ("0x10000000000000000"), -snan_value_pl ("0x20000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, snan_value_pl ("0x20000000000000000"), snan_value_pl ("0x10000000000000000"), 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
+    TEST_ff_b (totalorder, -snan_value_pl ("0x20000000000000000"), -snan_value_pl ("0x10000000000000000"), 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED|XFAIL_FLOAT128_PAYLOAD),
 #endif
     TEST_ff_b (totalorder, 1, 0x1.000002p0, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_b (totalorder, 0x1.000002p0, 1, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),