hypot.s revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
.file "hypot.s"
#include "libm.h"
LIBM_ANSI_PRAGMA_WEAK(hypot,function)
#include "libm_synonyms.h"
#include "libm_protos.h"
#undef fabs
.data
.align 4
inf:
.long 0x7f800000
ENTRY(hypot)
movl 8(%esp),%eax / eax <-- hi_32(x)
andl $0x7fffffff,%eax / eax <-- hi_32(|x|)
jz .x_maybe_0 / if x = +/-0, return |y|
subl $0x7ff00000,%eax / eax <-- hi_32(|x|) - hi_32(INF)
jz .x_maybe_inf
.check_y:
movl 16(%esp),%eax / eax <-- hi_32(y)
andl $0x7fffffff,%eax / eax <-- hi_32(|y|)
jz .y_maybe_0 / if y = +/-0, return |x|
subl $0x7ff00000,%eax / eax <-- hi_32(|y|) - hi_32(INF)
jz .y_maybe_inf
.do_hypot:
fldl 12(%esp) / ,y
fmul %st(0),%st / ,y*y
fldl 4(%esp) / x,y*y
fmul %st(0),%st / x*x,y*y
faddp %st,%st(1) / x*x+y*y
fsqrt / sqrt(x*x+y*y)
subl $8,%esp
fstpl (%esp) / round to double
fldl (%esp) / sqrt(x*x+y*y) rounded to double
PIC_SETUP(1)
flds PIC_L(inf) / inf , sqrt(x*x+y*y)
PIC_WRAPUP
addl $8,%esp
fucomp
fstsw %ax / store status in %ax
sahf / 80387 flags in %ah to 80386 flags
jz .maybe_ovflw
ret
.maybe_ovflw:
jnp .ovflw
ret
.ovflw:
/ overflow occurred
fstp %st(0) / stack empty
pushl %ebp
movl %esp,%ebp
PIC_SETUP(2)
pushl $4
pushl 20(%ebp) / high y
pushl 16(%ebp) / low y
pushl 12(%ebp) / high x
pushl 8(%ebp) / low x
call PIC_F(_SVID_libm_err)
addl $20,%esp
PIC_WRAPUP
leave
ret
.x_maybe_0:
movl 4(%esp),%ecx / ecx <-- lo_32(x)
orl %ecx,%eax / is x = +/-0?
jnz .check_y / branch if x is denormal
/ x = +/-0, so return |y|
fldl 12(%esp)
fabs
ret
.x_maybe_inf:
movl 4(%esp),%ecx / ecx <-- lo_32(x)
orl %ecx,%eax / is x = +/-INF?
jnz .check_y / branch if x is NaN
/ push&pop y in case y is a SNaN
fldl 12(%esp)
fstp %st(0)
/ x = +/-INF, so return |x|
fldl 4(%esp)
fabs
ret
.y_maybe_0:
movl 12(%esp),%ecx / ecx <-- lo_32(y)
orl %ecx,%eax / is y = +/-0?
jnz .do_hypot / branch if y is denormal
/ y = +/-0, so return |x|
fldl 4(%esp)
fabs
ret
.y_maybe_inf:
movl 12(%esp),%ecx / ecx <-- lo_32(y)
orl %ecx,%eax / is y = +/-INF?
jnz .do_hypot / branch if y is NaN
/ push&pop x in case x is a SNaN
fldl 4(%esp)
fstp %st(0)
/ y = +/-INF, so return |y|
fldl 12(%esp)
fabs
ret
.align 4
SET_SIZE(hypot)