1/* SPDX-License-Identifier: GPL-2.0 */ 2/*---------------------------------------------------------------------------+ 3 | round_Xsig.S | 4 | | 5 | Copyright (C) 1992,1993,1994,1995 | 6 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | 7 | Australia. E-mail billm@jacobi.maths.monash.edu.au | 8 | | 9 | Normalize and round a 12 byte quantity. | 10 | Call from C as: | 11 | int round_Xsig(Xsig *n) | 12 | | 13 | Normalize a 12 byte quantity. | 14 | Call from C as: | 15 | int norm_Xsig(Xsig *n) | 16 | | 17 | Each function returns the size of the shift (nr of bits). | 18 | | 19 +---------------------------------------------------------------------------*/ 20 .file "round_Xsig.S" 21 22#include "fpu_emu.h" 23 24 25.text 26SYM_FUNC_START(round_Xsig) 27 pushl %ebp 28 movl %esp,%ebp 29 pushl %ebx /* Reserve some space */ 30 pushl %ebx 31 pushl %esi 32 33 movl PARAM1,%esi 34 35 movl 8(%esi),%edx 36 movl 4(%esi),%ebx 37 movl (%esi),%eax 38 39 movl $0,-4(%ebp) 40 41 orl %edx,%edx /* ms bits */ 42 js L_round /* Already normalized */ 43 jnz L_shift_1 /* Shift left 1 - 31 bits */ 44 45 movl %ebx,%edx 46 movl %eax,%ebx 47 xorl %eax,%eax 48 movl $-32,-4(%ebp) 49 50/* We need to shift left by 1 - 31 bits */ 51L_shift_1: 52 bsrl %edx,%ecx /* get the required shift in %ecx */ 53 subl $31,%ecx 54 negl %ecx 55 subl %ecx,-4(%ebp) 56 shld %cl,%ebx,%edx 57 shld %cl,%eax,%ebx 58 shl %cl,%eax 59 60L_round: 61 testl $0x80000000,%eax 62 jz L_exit 63 64 addl $1,%ebx 65 adcl $0,%edx 66 jnz L_exit 67 68 movl $0x80000000,%edx 69 incl -4(%ebp) 70 71L_exit: 72 movl %edx,8(%esi) 73 movl %ebx,4(%esi) 74 movl %eax,(%esi) 75 76 movl -4(%ebp),%eax 77 78 popl %esi 79 popl %ebx 80 leave 81 RET 82SYM_FUNC_END(round_Xsig) 83 84 85 86SYM_FUNC_START(norm_Xsig) 87 pushl %ebp 88 movl %esp,%ebp 89 pushl %ebx /* Reserve some space */ 90 pushl %ebx 91 pushl %esi 92 93 movl PARAM1,%esi 94 95 movl 8(%esi),%edx 96 movl 4(%esi),%ebx 97 movl (%esi),%eax 98 99 movl $0,-4(%ebp) 100 101 orl %edx,%edx /* ms bits */ 102 js L_n_exit /* Already normalized */ 103 jnz L_n_shift_1 /* Shift left 1 - 31 bits */ 104 105 movl %ebx,%edx 106 movl %eax,%ebx 107 xorl %eax,%eax 108 movl $-32,-4(%ebp) 109 110 orl %edx,%edx /* ms bits */ 111 js L_n_exit /* Normalized now */ 112 jnz L_n_shift_1 /* Shift left 1 - 31 bits */ 113 114 movl %ebx,%edx 115 movl %eax,%ebx 116 xorl %eax,%eax 117 addl $-32,-4(%ebp) 118 jmp L_n_exit /* Might not be normalized, 119 but shift no more. */ 120 121/* We need to shift left by 1 - 31 bits */ 122L_n_shift_1: 123 bsrl %edx,%ecx /* get the required shift in %ecx */ 124 subl $31,%ecx 125 negl %ecx 126 subl %ecx,-4(%ebp) 127 shld %cl,%ebx,%edx 128 shld %cl,%eax,%ebx 129 shl %cl,%eax 130 131L_n_exit: 132 movl %edx,8(%esi) 133 movl %ebx,4(%esi) 134 movl %eax,(%esi) 135 136 movl -4(%ebp),%eax 137 138 popl %esi 139 popl %ebx 140 leave 141 RET 142SYM_FUNC_END(norm_Xsig) 143