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Diffstat (limited to 'REORG.TODO/sysdeps/i386/fpu/s_expm1.S')
| -rw-r--r-- | REORG.TODO/sysdeps/i386/fpu/s_expm1.S | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/i386/fpu/s_expm1.S b/REORG.TODO/sysdeps/i386/fpu/s_expm1.S new file mode 100644 index 0000000000..59fded2d5a --- /dev/null +++ b/REORG.TODO/sysdeps/i386/fpu/s_expm1.S @@ -0,0 +1,113 @@ +/* ix87 specific implementation of exp(x)-1. + Copyright (C) 1996-2017 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, see + <http://www.gnu.org/licenses/>. */ + + /* Using: e^x - 1 = 2^(x * log2(e)) - 1 */ + +#include <sysdep.h> +#include <machine/asm.h> +#include <i386-math-asm.h> + + .section .rodata + + .align ALIGNARG(4) + .type minus1,@object +minus1: .double -1.0 + ASM_SIZE_DIRECTIVE(minus1) + .type one,@object +one: .double 1.0 + ASM_SIZE_DIRECTIVE(one) + .type l2e,@object +l2e: .tfloat 1.442695040888963407359924681002 + ASM_SIZE_DIRECTIVE(l2e) + +DEFINE_DBL_MIN + +#ifdef PIC +#define MO(op) op##@GOTOFF(%edx) +#else +#define MO(op) op +#endif + + .text +ENTRY(__expm1) + movzwl 4+6(%esp), %eax + xorb $0x80, %ah // invert sign bit (now 1 is "positive") + cmpl $0xc086, %eax // is num >= 704? + jae HIDDEN_JUMPTARGET (__exp) + + fldl 4(%esp) // x + fxam // Is NaN, +-Inf or +-0? + xorb $0x80, %ah + cmpl $0xc043, %eax // is num <= -38.0? + fstsw %ax + movb $0x45, %ch + jb 4f + + // Below -38.0 (may be -NaN or -Inf). + andb %ah, %ch +#ifdef PIC + LOAD_PIC_REG (dx) +#endif + cmpb $0x01, %ch + je 5f // If -NaN, jump. + jmp 2f // -large, possibly -Inf. + +4: // In range -38.0 to 704.0 (may be +-0 but not NaN or +-Inf). + andb %ah, %ch + cmpb $0x40, %ch + je 3f // If +-0, jump. +#ifdef PIC + LOAD_PIC_REG (dx) +#endif + +5: fldt MO(l2e) // log2(e) : x + fmulp // log2(e)*x + fld %st // log2(e)*x : log2(e)*x + // Set round-to-nearest temporarily. + subl $8, %esp + cfi_adjust_cfa_offset (8) + fstcw 4(%esp) + movl $0xf3ff, %ecx + andl 4(%esp), %ecx + movl %ecx, (%esp) + fldcw (%esp) + frndint // int(log2(e)*x) : log2(e)*x + fldcw 4(%esp) + addl $8, %esp + cfi_adjust_cfa_offset (-8) + 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) + DBL_CHECK_FORCE_UFLOW + ret + +2: fstp %st + fldl MO(minus1) // Set result to -1.0. +3: ret +END(__expm1) +weak_alias (__expm1, expm1) |