| 1 | /* ix87 specific frexp implementation for long double. |
|---|
| 2 | Copyright (C) 1997-2022 Free Software Foundation, Inc. |
|---|
| 3 | This file is part of the GNU C Library. |
|---|
| 4 | |
|---|
| 5 | The GNU C Library is free software; you can redistribute it and/or |
|---|
| 6 | modify it under the terms of the GNU Lesser General Public |
|---|
| 7 | License as published by the Free Software Foundation; either |
|---|
| 8 | version 2.1 of the License, or (at your option) any later version. |
|---|
| 9 | |
|---|
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
|---|
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
|---|
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|---|
| 13 | Lesser General Public License for more details. |
|---|
| 14 | |
|---|
| 15 | You should have received a copy of the GNU Lesser General Public |
|---|
| 16 | License along with the GNU C Library; if not, see |
|---|
| 17 | <https://www.gnu.org/licenses/>. */ |
|---|
| 18 | |
|---|
| 19 | #include <libm-alias-ldouble.h> |
|---|
| 20 | #include <machine/asm.h> |
|---|
| 21 | |
|---|
| 22 | .section .rodata |
|---|
| 23 | |
|---|
| 24 | .align ALIGNARG(4) |
|---|
| 25 | .type two64,@object |
|---|
| 26 | two64: .byte 0, 0, 0, 0, 0, 0, 0xf0, 0x43 |
|---|
| 27 | ASM_SIZE_DIRECTIVE(two64) |
|---|
| 28 | |
|---|
| 29 | #ifdef PIC |
|---|
| 30 | #define MO(op) op##@GOTOFF(%edx) |
|---|
| 31 | #else |
|---|
| 32 | #define MO(op) op |
|---|
| 33 | #endif |
|---|
| 34 | |
|---|
| 35 | #define PARMS 4 /* no space for saved regs */ |
|---|
| 36 | #define VAL0 PARMS |
|---|
| 37 | #define VAL1 VAL0+4 |
|---|
| 38 | #define VAL2 VAL1+4 |
|---|
| 39 | #define EXPP VAL2+4 |
|---|
| 40 | |
|---|
| 41 | .text |
|---|
| 42 | ENTRY (__frexpl) |
|---|
| 43 | |
|---|
| 44 | movl VAL0(%esp), %ecx |
|---|
| 45 | movl VAL2(%esp), %eax |
|---|
| 46 | orl VAL1(%esp), %ecx |
|---|
| 47 | movl %eax, %edx |
|---|
| 48 | andl $0x7fff, %eax |
|---|
| 49 | orl %eax, %ecx |
|---|
| 50 | jz 1f |
|---|
| 51 | xorl %ecx, %ecx |
|---|
| 52 | cmpl $0x7fff, %eax |
|---|
| 53 | je 3f |
|---|
| 54 | |
|---|
| 55 | cmpl $0, %eax |
|---|
| 56 | jne 2f |
|---|
| 57 | |
|---|
| 58 | fldt VAL0(%esp) |
|---|
| 59 | #ifdef PIC |
|---|
| 60 | LOAD_PIC_REG (dx) |
|---|
| 61 | #endif |
|---|
| 62 | |
|---|
| 63 | fmull MO(two64) /* It's not necessary to use a 80bit factor */ |
|---|
| 64 | movl $-64, %ecx |
|---|
| 65 | fstpt VAL0(%esp) |
|---|
| 66 | fwait |
|---|
| 67 | movl VAL2(%esp), %eax |
|---|
| 68 | movl %eax, %edx |
|---|
| 69 | andl $0x7fff, %eax |
|---|
| 70 | |
|---|
| 71 | 2: andl $0x8000, %edx |
|---|
| 72 | subl $16382, %eax |
|---|
| 73 | orl $0x3ffe, %edx |
|---|
| 74 | addl %eax, %ecx |
|---|
| 75 | movl %edx, VAL2(%esp) |
|---|
| 76 | |
|---|
| 77 | /* Store %ecx in the variable pointed to by the second argument, |
|---|
| 78 | get the factor from the stack and return. */ |
|---|
| 79 | 1: movl EXPP(%esp), %eax |
|---|
| 80 | fldt VAL0(%esp) |
|---|
| 81 | movl %ecx, (%eax) |
|---|
| 82 | |
|---|
| 83 | ret |
|---|
| 84 | |
|---|
| 85 | /* Infinity or NaN; ensure signaling NaNs are quieted. */ |
|---|
| 86 | 3: movl EXPP(%esp), %eax |
|---|
| 87 | fldt VAL0(%esp) |
|---|
| 88 | fadd %st |
|---|
| 89 | movl %ecx, (%eax) |
|---|
| 90 | ret |
|---|
| 91 | END (__frexpl) |
|---|
| 92 | libm_alias_ldouble (__frexp, frexp) |
|---|
| 93 | |
|---|
