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/*
* 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 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
.ident "@(#)exp10l.s 1.3 06/01/23 SMI"
.file "exp10l.s"
#include "libm.h"
LIBM_ANSI_PRAGMA_WEAK(exp10l,function)
#include "libm_synonyms.h"
.data
.align 16
lt2_hi: .4byte 0xfbd00000, 0x9a209a84, 0x3ffd, 0x0
lt2_lo: .4byte 0x653f4837, 0x8677076a, 0xbfc9, 0x0
ENTRY(exp10l)
movl 16(%rsp),%ecx / cx <--sign&bexp(x)
andl $0x7fff,%ecx / ecx <-- zero_xtnd(bexp(x))
cmpl $0x3ffd,%ecx / Is |x| < log10(2)?
jb .shortcut / If so, take a shortcut.
je .check_tail / maybe |x| only slightly < log10(2)
.general_case: / Here, |x| > log10(2) or x is NaN
cmpl $0x7fff,%ecx / bexp(|x|) = bexp(INF)?
je .not_finite / if so, x is not finite
cmpl $0x400e,%ecx / |x| < 32768 = 2^15?
jb .finite_non_special / if so, proceed with argument reduction
fldt 8(%rsp) / x
fld1 / 1, x
jmp 1f
.finite_non_special: / Here, log10(2) < |x| < 2^15
fldt 8(%rsp) / x
fld %st(0) / x, x
fldl2t / log2(10), x, x
fmul / z := x*log2(10), x
frndint / [z], x
fst %st(2) / [z], x, [z]
PIC_SETUP(1)
fldt PIC_L(lt2_hi) / lt2_hi, [z], x, [z]
fmul / [z]*lt2_hi, x, [z]
fsubrp %st,%st(1) / x-[z]*lt2_hi, [z]
fldt PIC_L(lt2_lo) / lt2_lo, x-[z]*lt2_hi, [z]
PIC_WRAPUP
fmul %st(2),%st / [z]*lt2_lo, x-[z]*lt2_hi, [z]
fsubrp %st,%st(1) / r := x-[z]*log10(2), [z]
fldl2t / log2(10), r, [z]
fmul / f := r*log2(10), [z]
f2xm1 / 2^f-1,[z]
fld1 / 1, 2^f-1, [z]
faddp %st,%st(1) / 2^f, [z]
1:
fscale / 10^x, [z]
fstp %st(1)
ret
.check_tail:
movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x))
cmpl $0x9a209a84,%ecx / Is |x| < log10(2)?
ja .finite_non_special
jb .shortcut
movl 8(%rsp),%edx / edx <-- lo_32(sgnfcnd(x))
cmpl $0xfbcff798,%edx / Is |x| slightly > log10(2)?
ja .finite_non_special / branch if |x| slightly > log10(2)
.shortcut:
/ Here, |x| < log10(2), so |z| = |x/log10(2)| < 1
/ whence z is in f2xm1's domain.
fldt 8(%rsp) / x
fldl2t / log2(10), x
fmul / z := x*log2(10)
f2xm1 / 2^z-1
fld1 / 1, 2^z-1
faddp %st,%st(1) / 10^x
ret
.not_finite:
movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x))
cmpl $0x80000000,%ecx / hi_32(sgnfcnd(x)) = hi_32(sgnfcnd(INF))?
jne .NaN_or_pinf / if not, x is NaN or unsupp.
movl 8(%rsp),%edx / edx <-- lo_32(sgnfcnd(x))
cmpl $0,%edx / lo_32(sgnfcnd(x)) = 0?
jne .NaN_or_pinf / if not, x is NaN
movl 16(%rsp),%eax / ax <-- sign&bexp((x))
andl $0x8000,%eax / here, x is infinite, but +/-?
jz .NaN_or_pinf / branch if x = +INF
fldz / Here, x = -inf, so return 0
ret
.NaN_or_pinf:
/ Here, x = NaN or +inf, so load x and return immediately.
fldt 8(%rsp)
ret
.align 16
SET_SIZE(exp10l)
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