about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc32/fpu/s_lround.S
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/powerpc32/fpu/s_lround.S')
-rw-r--r--sysdeps/powerpc/powerpc32/fpu/s_lround.S100
1 files changed, 100 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/fpu/s_lround.S b/sysdeps/powerpc/powerpc32/fpu/s_lround.S
new file mode 100644
index 0000000000..dcb97e373b
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/fpu/s_lround.S
@@ -0,0 +1,100 @@
+/* lround function.  PowerPC32 version.
+   Copyright (C) 2004 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+	.section	.rodata
+	.align 3
+	.type	NEGZERO.0,@object
+	.size	NEGZERO.0,8
+NEGZERO.0:
+	.long 0x00000000
+	.long 0
+	.type	POINTFIVE.0,@object
+	.size	POINTFIVE.0,8
+POINTFIVE.0:
+	.long 0x3fe00000
+	.long 0
+
+	.section	.rodata.cst8,"aM",@progbits,8
+	.align 3
+.LC0:	/* 0.0 */
+	.long 0x00000000
+	.long 0
+.LC1:	/* 0.5 */
+	.long 0x3fe00000
+	.long 0
+
+	.section	".text"
+	
+/* long [r3] lround (float x [fp1])
+   IEEE 1003.1 lround function.  IEEE specifies "round to the nearest 
+   integer value, rounding halfway cases away from zero, regardless of
+   the current rounding mode."  However PowerPC Architecture defines
+   "round to Nearest" as "Choose the best approximation. In case of a 
+   tie, choose the one that is even (least significant bit o).". 
+   So we can't use the PowerPC "round to Nearest" mode. Instead we set
+   "round toward Zero" mode and round by adding +-0.5 before rounding
+   to the integer value.  */
+
+ENTRY (__lround)
+#ifdef SHARED
+	mflr	r11
+	bl	_GLOBAL_OFFSET_TABLE_@local-4
+	mflr	r10
+	lwz	r9,.LC0@got(10)
+	mtlr	r11
+	lfd	fp12,0(r9)
+#else
+	lis	r9,.LC0@ha
+	lfd	fp12,.LC0@l(r9)
+#endif
+#ifdef SHARED
+	lwz	r9,.LC1@got(10)
+	lfd	fp10,0(r9)
+#else
+	lis	r9,.LC1@ha
+	lfd	fp10,.LC1@l(r9)
+#endif
+	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
+	ble-	cr6,.L4
+	fadd	fp1,fp1,fp10	/* x+= 0.5;  */
+.L9:
+	fctiwz	fp2,fp1		/* Convert To Integer DW lround toward 0.  */
+	stfd	fp2,-8(r1)
+	nop	/* Insure the following load is in a different dispatch group */
+	nop	/* to avoid pipe stall on POWER4&5.  */
+	nop
+	lwz	r3,-4(r1)
+	blr
+.L4:
+	fsub	fp1,fp1,fp10	/* x-= 0.5;  */
+	b	.L9
+	END (__lround)
+
+strong_alias (__lround, __lround)
+weak_alias (__lround, lround)
+
+strong_alias (__lround, __lroundf)
+weak_alias (__lround, lroundf)
+
+#ifdef NO_LONG_DOUBLE
+weak_alias (__lround, lroundl)
+strong_alias (__lround, __lroundl)
+#endif