Optimized nearbyint for PPC

1 files changed, 80 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc32/fpu/s_nearbyint.S b/sysdeps/powerpc/powerpc32/fpu/s_nearbyint.S
new file mode 100644
index 0000000000..0102aa3318
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/fpu/s_nearbyint.S
@@ -0,0 +1,80 @@
+/* Round to int floating-point values.  PowerPC32 version.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011
+
+   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, write to the Free
+   Software Foundation, Inc., 1 Franklin Street, Fifth Floor, Boston MA
+   02110-1301 USA.  */
+
+/* This has been coded in assembler because GCC makes such a mess of it
+   when it's coded in C.  */
+
+#include <sysdep.h>
+#include <math_ldbl_opt.h>
+
+
+/* double [fp1] nearbyint(double [fp1] x) */
+
+	.section	.rodata.cst4,"aM",@progbits,4
+	.align	2
+.LC0:	/* 2**52 */
+	.long 0x59800000	/* TWO52: 2**52 */
+
+	.section	".text"
+ENTRY (__nearbyint)
+#ifdef SHARED
+	mflr	r11
+	cfi_register(lr,r11)
+	bcl	20,31,1f
+1:	mflr	r9
+	addis	r9,r9,.LC0-1b@ha
+	lfs	fp13,.LC0-1b@l(r9)
+	mtlr	r11
+	cfi_same_value (lr)
+#else
+	lis	r9,.LC0@ha
+	lfs	fp13,.LC0@l(r9)
+#endif
+	fabs	fp0,fp1
+	fsub    fp12,fp13,fp13	/* generate 0.0  */
+	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO52 */
+	bgelr	cr7
+	fcmpu	cr7,fp1,fp12	/* if (x > 0.0 */
+	ble	cr7,L(lessthanzero)
+	mtfsb0	4*cr7+lt	/* Disable FE_INEXACT exception */
+	fadd	fp0,fp1,fp13	/* x += TWO52 */
+	fsub	fp1,fp0,fp13	/* x -= TWO52 */
+	fabs	fp1,fp1		/* if (x == 0.0 */
+	mtfsb0	4*cr1+eq	/* Clear any FE_INEXACT exception */
+	blr
+L(lessthanzero):
+	bgelr	cr7
+	mtfsb0	4*cr7+lt	/* Disable FE_INEXACT exception */
+	fsub	fp0,fp13,fp1	/* x -= TWO52 */
+	fsub	fp0,fp0,fp13	/* x += TWO52 */
+	fneg	fp1,fp0		/* if (x == 0.0) */
+	mtfsb0	4*cr1+eq	/* Clear any FE_INEXACT exception */
+	blr
+END (__nearbyint)
+
+weak_alias (__nearbyint, nearbyint)
+
+#ifdef NO_LONG_DOUBLE
+weak_alias (__nearbyint, nearbyintl)
+strong_alias (__nearbyint, __nearbyintl)
+#endif
+#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)
+compat_symbol (libm, __nearbyint, nearbyintl, GLIBC_2_0)
+#endif