| /* |
| * Written by J.T. Conklin <jtc@netbsd.org>. |
| * Public domain. |
| * |
| * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>. |
| * Changed to use fyl2xp1 for values near 1, <drepper@cygnus.com>. |
| * Adapted for i686 instructions. |
| */ |
| |
| #include <machine/asm.h> |
| |
| .section .rodata.cst8,"aM",@progbits,8 |
| |
| .p2align 3 |
| .type one,@object |
| one: .double 1.0 |
| ASM_SIZE_DIRECTIVE(one) |
| /* It is not important that this constant is precise. It is only |
| a value which is known to be on the safe side for using the |
| fyl2xp1 instruction. */ |
| .type limit,@object |
| limit: .double 0.29 |
| ASM_SIZE_DIRECTIVE(limit) |
| |
| |
| #ifdef PIC |
| # define MO(op) op##@GOTOFF(%edx) |
| #else |
| # define MO(op) op |
| #endif |
| |
| .text |
| ENTRY(__ieee754_logl) |
| fldln2 // log(2) |
| fldt 4(%esp) // x : log(2) |
| fucomi %st |
| jp 3f |
| #ifdef PIC |
| LOAD_PIC_REG (dx) |
| #endif |
| fld %st // x : x : log(2) |
| movzwl 4+8(%esp), %eax |
| cmpl $0xc000, %eax |
| jae 5f // x <= -2, avoid overflow from -LDBL_MAX - 1. |
| fsubl MO(one) // x-1 : x : log(2) |
| 5: fld %st // x-1 : x-1 : x : log(2) |
| fabs // |x-1| : x-1 : x : log(2) |
| fld MO(limit) // 0.29 : |x-1| : x-1 : x : log(2) |
| fcomip %st(1) // |x-1| : x-1 : x : log(2) |
| fstp %st(0) // x-1 : x : log(2) |
| jc 2f |
| fxam |
| fnstsw |
| andb $0x45, %ah |
| cmpb $0x40, %ah |
| jne 4f |
| fabs // log(1) is +0 in all rounding modes. |
| 4: fstp %st(1) // x-1 : log(2) |
| fyl2xp1 // log(x) |
| ret |
| |
| 2: fstp %st(0) // x : log(2) |
| fyl2x // log(x) |
| ret |
| |
| 3: fstp %st(1) |
| fadd %st(0) |
| ret |
| END (__ieee754_logl) |
| |
| ENTRY(__logl_finite) |
| fldln2 // log(2) |
| fldt 4(%esp) // x : log(2) |
| #ifdef PIC |
| LOAD_PIC_REG (dx) |
| #endif |
| fld %st // x : x : log(2) |
| fsubl MO(one) // x-1 : x : log(2) |
| fld %st // x-1 : x-1 : x : log(2) |
| fabs // |x-1| : x-1 : x : log(2) |
| fld MO(limit) // 0.29 : |x-1| : x-1 : x : log(2) |
| fcomip %st(1) // |x-1| : x-1 : x : log(2) |
| fstp %st(0) // x-1 : x : log(2) |
| jc 2b |
| fxam |
| fnstsw |
| andb $0x45, %ah |
| cmpb $0x40, %ah |
| jne 6f |
| fabs // log(1) is +0 in all rounding modes. |
| 6: fstp %st(1) // x-1 : log(2) |
| fyl2xp1 // log(x) |
| ret |
| END(__logl_finite) |
