diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/s_expm1l.S')
| -rw-r--r-- | sysdeps/x86_64/fpu/s_expm1l.S | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/sysdeps/x86_64/fpu/s_expm1l.S b/sysdeps/x86_64/fpu/s_expm1l.S new file mode 100644 index 0000000000..fa40e05572 --- /dev/null +++ b/sysdeps/x86_64/fpu/s_expm1l.S @@ -0,0 +1,83 @@ +/* ix87 specific implementation of exp(x)-1. + Copyright (C) 1996, 1997, 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. + Based on code by John C. Bowman <bowman@ipp-garching.mpg.de>. + Corrections by H.J. Lu (hjl@gnu.ai.mit.edu), 1997. + + 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. */ + + /* Using: e^x - 1 = 2^(x * log2(e)) - 1 */ + +#include <machine/asm.h> + +#ifdef __ELF__ + .section .rodata +#else + .text +#endif + .align ALIGNARG(4) + ASM_TYPE_DIRECTIVE(minus1,@object) +minus1: .double -1.0 + ASM_SIZE_DIRECTIVE(minus1) + ASM_TYPE_DIRECTIVE(one,@object) +one: .double 1.0 + ASM_SIZE_DIRECTIVE(one) + ASM_TYPE_DIRECTIVE(l2e,@object) +l2e: .tfloat 1.442695040888963407359924681002 + ASM_SIZE_DIRECTIVE(l2e) + +#ifdef PIC +#define MO(op) op##(%rip) +#else +#define MO(op) op +#endif + + .text +ENTRY(__expm1l) + fldt 8(%rsp) // x + fxam // Is NaN or +-Inf? + fstsw %ax + movb $0x45, %ch + andb %ah, %ch + cmpb $0x40, %ch + je 3f // If +-0, jump. + cmpb $0x05, %ch + je 2f // If +-Inf, jump. + + fldt MO(l2e) // log2(e) : x + fmulp // log2(e)*x + fld %st // log2(e)*x : log2(e)*x + frndint // int(log2(e)*x) : log2(e)*x + fsubr %st, %st(1) // int(log2(e)*x) : fract(log2(e)*x) + fxch // fract(log2(e)*x) : int(log2(e)*x) + f2xm1 // 2^fract(log2(e)*x)-1 : int(log2(e)*x) + fscale // 2^(log2(e)*x)-2^int(log2(e)*x) : int(log2(e)*x) + fxch // int(log2(e)*x) : 2^(log2(e)*x)-2^int(log2(e)*x) + fldl MO(one) // 1 : int(log2(e)*x) : 2^(log2(e)*x)-2^int(log2(e)*x) + fscale // 2^int(log2(e)*x) : int(log2(e)*x) : 2^(log2(e)*x)-2^int(log2(e)*x) + fsubrl MO(one) // 1-2^int(log2(e)*x) : int(log2(e)*x) : 2^(log2(e)*x)-2^int(log2(e)*x) + fstp %st(1) // 1-2^int(log2(e)*x) : 2^(log2(e)*x)-2^int(log2(e)*x) + fsubrp %st, %st(1) // 2^(log2(e)*x) + ret + +2: testl $0x200, %eax // Test sign. + jz 3f // If positive, jump. + fstp %st + fldl MO(minus1) // Set result to -1.0. +3: ret +END(__expm1l) +weak_alias (__expm1l, expm1l) |