glibc/sysdeps/sparc/sparc64/fpu/s_nearbyintf.S
Aurelien Jarno 2cbec36566 SPARC: fix nearbyint on sNaN input
nearbyint and nearbyintf should not trigger inexact exceptions, but
should still trigger an invalid exception for a sNaN input.

The SPARC specific implementations of these functions save the FSR at
the beginning of the function and restore it at the end to not trigger
an inexact exception. This however doesn't work for an sNaN input which
need to trigger an invalid exception. Fix that by adding a fcmp
instruction using the input value before saving FSR, so that an invalid
exception is triggered for a sNaN input.

This fixes the math/test-nearbyint-except test on SPARC.

Changelog:
	* sparc/sparc32/sparcv9/fpu/s_nearbyint.S (__nearbyint): Trigger an
	invalid exception for a sNaN input.
	* sparc/sparc32/sparcv9/fpu/s_nearbyintf.S (__nearbyintf): Likewise.
	* sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S
	(__nearbyint_vis3): Likewise
	* sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S
	(__nearbyintf_vis3): Likewise
	* sparc/sparc64/fpu/s_nearbyint.S (__nearbyint): Likewise.
	* sparc/sparc64/fpu/s_nearbyintf.S (__nearbyintf): Likewise.
	* sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S (__nearbyint_vis3):
	Likewise.
	* sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S (__nearbyintf_vis3):
	Likewise.
2016-07-01 16:36:41 +02:00

64 lines
2.1 KiB
ArmAsm

/* Round float to int floating-point values without generating
an inexact exception, sparc64 version.
Copyright (C) 2013-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by David S. Miller <davem@davemloft.net>, 2013.
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
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
/* We pop constants into the FPU registers using the incoming
argument stack slots, since this avoid having to use any PIC
references. We also thus avoid having to allocate a register
window.
VIS instructions are used to facilitate the formation of
easier constants, and the propagation of the sign bit. */
#define TWO_TWENTYTHREE 0x4b000000 /* 2**23 */
#define ZERO %f10 /* 0.0 */
#define SIGN_BIT %f12 /* -0.0 */
ENTRY (__nearbyintf)
fcmps %fcc3, %f1, %f1 /* Check for sNaN */
stx %fsr, [%sp + STACK_BIAS + 144]
sethi %hi(0xf8003e0), %o5
sethi %hi(TWO_TWENTYTHREE), %o2
ldx [%sp + STACK_BIAS + 144], %o4
or %o5, %lo(0xf8003e0), %o5
fzeros ZERO
andn %o4, %o5, %o4
fnegs ZERO, SIGN_BIT
st %o2, [%sp + STACK_BIAS + 128]
stx %o4, [%sp + STACK_BIAS + 136]
ldx [%sp + STACK_BIAS + 136], %fsr
fabss %f1, %f14
ld [%sp + STACK_BIAS + 128], %f16
fcmps %fcc3, %f14, %f16
fmovsuge %fcc3, ZERO, %f16
fands %f1, SIGN_BIT, SIGN_BIT
fors %f16, SIGN_BIT, %f16
fadds %f1, %f16, %f5
fsubs %f5, %f16, %f0
fabss %f0, %f0
fors %f0, SIGN_BIT, %f0
retl
ldx [%sp + STACK_BIAS + 144], %fsr
END (__nearbyintf)
weak_alias (__nearbyintf, nearbyintf)