diff options
Diffstat (limited to 'usr/src/libm/src/i386/common/exp10f.s')
| -rw-r--r-- | usr/src/libm/src/i386/common/exp10f.s | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/usr/src/libm/src/i386/common/exp10f.s b/usr/src/libm/src/i386/common/exp10f.s new file mode 100644 index 0000000..b949f89 --- /dev/null +++ b/usr/src/libm/src/i386/common/exp10f.s @@ -0,0 +1,122 @@ +/* + * 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 "@(#)exp10f.s 1.7 06/01/23 SMI" + + .file "exp10f.s" + +#include "libm.h" +LIBM_ANSI_PRAGMA_WEAK(exp10f,function) +#include "libm_synonyms.h" + + ENTRY(exp10f) + movl 4(%esp),%ecx / ecx <-- x + andl $0x7fffffff,%ecx / ecx <-- |x| + cmpl $0x3e9a209a,%ecx / Is |x| < log10(2)? + jbe .shortcut / If so, take a shortcut. + cmpl $0x7f800000,%ecx / |x| >= INF? + jae .not_finite / if so, x is not finite + flds 4(%esp) / push x (=arg) + + subl $8,%esp / save RP and set round-to-64-bits + fstcw (%esp) + movw (%esp),%ax + movw %ax,4(%esp) + orw $0x0300,%ax + movw %ax,(%esp) + fldcw (%esp) + + fldl2t / push log2(10) }NOT for xtndd_dbl + fmulp %st,%st(1) / z = x*log2(10) }NOT for xtndd_dbl + fld %st(0) / duplicate stack top + frndint / [z],z + fucom / z integral? + fstsw %ax + sahf + je .z_integral / branch if z integral + fxch / z, [z] + fsub %st(1),%st / z-[z], [z] + f2xm1 / 2**(z-[z])-1, [z] + fld1 / 1,2**(z-[z])-1, [z] + faddp %st,%st(1) / 2**(z-[z]), [z] + fscale / 2**z = 10**(arg), [z] + fstp %st(1) + + fstcw (%esp) / restore old RP + movw (%esp),%dx + andw $0xfcff,%dx + movw 4(%esp),%cx + andw $0x0300,%cx + orw %dx,%cx + movw %cx,(%esp) + fldcw (%esp) + add $8,%esp + + ret + +.z_integral: / here, z is integral + fstp %st(0) / ,z + fld1 / 1 = 2**0, z + fscale / 2**(0 + z) = 2**z = 10**(arg), z + fstp %st(1) / 10**(arg) + + fstcw (%esp) / restore old RP + movw (%esp),%dx + andw $0xfcff,%dx + movw 4(%esp),%cx + andw $0x0300,%cx + orw %dx,%cx + movw %cx,(%esp) + fldcw (%esp) + add $8,%esp + + ret + +.shortcut: + / Here, |x| < log10(2), so |z| = |x*log2(10)| < 1 + / whence z is in f2xm1's domain. + flds 4(%esp) / push x (=arg) + fldl2t / push log2(10) }NOT for xtndd_dbl + fmulp %st,%st(1) / z = x*log2(10) }NOT for xtndd_dbl + f2xm1 / 2**z - 1 + fld1 / 1,2**z - 1 + faddp %st,%st(1) / 2**z = 10**x + ret + +.not_finite: + ja .NaN_or_pinf / branch if x is NaN + movl 4(%esp),%eax / eax <-- x + andl $0x80000000,%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. + flds 4(%esp) + fwait + ret + .align 4 + SET_SIZE(exp10f) |