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