math: Add math-use-builtins-fabs (BZ#29027)

Both float, double, and _Float128 are assumed to be supported
(float and double already only uses builtins).  Only long double
is parametrized due GCC bug 29253 which prevents its usage on
powerpc.

It allows to remove i686, ia64, x86_64, powerpc, and sparc arch
specific implementation.

On ia64 it also fixes the sNAN handling:

  math/test-float64x-fabs
  math/test-ldouble-fabs

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc-linux-gnu,
powerpc64-linux-gnu, sparc64-linux-gnu, and ia64-linux-gnu.

3 files changed, 8 insertions, 86 deletions

diff --git a/sysdeps/powerpc/fpu/math-use-builtins-fabs.h b/sysdeps/powerpc/fpu/math-use-builtins-fabs.h
new file mode 100644
index 0000000000..8976d0b956
--- /dev/null
+++ b/sysdeps/powerpc/fpu/math-use-builtins-fabs.h
@@ -0,0 +1,8 @@
+/* Generic implementations already assume builtin support for
+   float, double, and _Float128 .  */
+
+/* We can't enable it for long double due GCC Bugzilla Bug 29253
+   "expand_abs wrong default code for floating point" where it can
+   cause spurious "invalid" exceptions from comparisons with NaN in
+   the code sequence generated.  */
+#define USE_FABSL_BUILTIN 0
diff --git a/sysdeps/powerpc/powerpc32/fpu/s_fabsl.S b/sysdeps/powerpc/powerpc32/fpu/s_fabsl.S
deleted file mode 100644
index 8bdcdc8cfb..0000000000
--- a/sysdeps/powerpc/powerpc32/fpu/s_fabsl.S
+++ /dev/null
@@ -1,52 +0,0 @@
-/* Copy a sign bit between floating-point values.
-   IBM extended format long double version.
-   Copyright (C) 2004-2022 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
-ENTRY(__fabsl)
-/* long double [f1,f2] fabs (long double [f1,f2] x);
-   fabs(x,y) returns a value with the magnitude of x and
-   with the sign bit of y.  */
-#ifdef _ARCH_PPCGR
-	/* fsel available.  */
-	fmr	fp0,fp1
-#else
-	/* Use integer operations to test sign of high part to avoid
-	   exceptions on sNaNs.  */
-	stwu	r1,-16(r1)
-	cfi_adjust_cfa_offset (16)
-	stfd	fp1,8(r1)
-#endif
-	fabs	fp1,fp1
-#ifdef _ARCH_PPCGR
-	fneg	fp3,fp2
-	fsel	fp2,fp0,fp2,fp3
-#else
-	lwz	r3,8+HIWORD(r1)
-	cmpwi	cr6,r3,0
-	addi	r1,r1,16
-	cfi_adjust_cfa_offset (-16)
-	bgelr	cr6
-	fneg	fp2,fp2
-#endif
-	blr
-END (__fabsl)
-
-long_double_symbol (libm, __fabsl, fabsl)
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_fabsl.S b/sysdeps/powerpc/powerpc64/fpu/s_fabsl.S
deleted file mode 100644
index ec796a1cd3..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/s_fabsl.S
+++ /dev/null
@@ -1,34 +0,0 @@
-/* Copy a sign bit between floating-point values.
-   IBM extended format long double version.
-   Copyright (C) 2004-2022 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
-ENTRY_TOCLESS (__fabsl)
-/* long double [f1,f2] fabs (long double [f1,f2] x);
-   fabs(x,y) returns a value with the magnitude of x and
-   with the sign bit of y.  */
-	fmr	fp0,fp1
-	fabs	fp1,fp1
-	fneg	fp3,fp2
-	fsel	fp2,fp0,fp2,fp3
-	blr
-END (__fabsl)
-
-long_double_symbol (libm, __fabsl, fabsl)