Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /*---------------------------------------------------------------------------+ |
| 2 | | fpu_tags.c | |
| 3 | | | |
| 4 | | Set FPU register tags. | |
| 5 | | | |
| 6 | | Copyright (C) 1997 | |
| 7 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | |
| 8 | | E-mail billm@jacobi.maths.monash.edu.au | |
| 9 | | | |
| 10 | | | |
| 11 | +---------------------------------------------------------------------------*/ |
| 12 | |
| 13 | #include "fpu_emu.h" |
| 14 | #include "fpu_system.h" |
| 15 | #include "exception.h" |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | void FPU_pop(void) |
| 18 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 19 | fpu_tag_word |= 3 << ((top & 7) * 2); |
| 20 | top++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | } |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | int FPU_gettag0(void) |
| 24 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 25 | return (fpu_tag_word >> ((top & 7) * 2)) & 3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | } |
| 27 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | int FPU_gettagi(int stnr) |
| 29 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 30 | return (fpu_tag_word >> (((top + stnr) & 7) * 2)) & 3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | } |
| 32 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | int FPU_gettag(int regnr) |
| 34 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 35 | return (fpu_tag_word >> ((regnr & 7) * 2)) & 3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | } |
| 37 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | void FPU_settag0(int tag) |
| 39 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 40 | int regnr = top; |
| 41 | regnr &= 7; |
| 42 | fpu_tag_word &= ~(3 << (regnr * 2)); |
| 43 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | } |
| 45 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | void FPU_settagi(int stnr, int tag) |
| 47 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 48 | int regnr = stnr + top; |
| 49 | regnr &= 7; |
| 50 | fpu_tag_word &= ~(3 << (regnr * 2)); |
| 51 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | } |
| 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | void FPU_settag(int regnr, int tag) |
| 55 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 56 | regnr &= 7; |
| 57 | fpu_tag_word &= ~(3 << (regnr * 2)); |
| 58 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | } |
| 60 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | int FPU_Special(FPU_REG const *ptr) |
| 62 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 63 | int exp = exponent(ptr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 65 | if (exp == EXP_BIAS + EXP_UNDER) |
| 66 | return TW_Denormal; |
| 67 | else if (exp != EXP_BIAS + EXP_OVER) |
| 68 | return TW_NaN; |
| 69 | else if ((ptr->sigh == 0x80000000) && (ptr->sigl == 0)) |
| 70 | return TW_Infinity; |
| 71 | return TW_NaN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | } |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | int isNaN(FPU_REG const *ptr) |
| 75 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 76 | return ((exponent(ptr) == EXP_BIAS + EXP_OVER) |
| 77 | && !((ptr->sigh == 0x80000000) && (ptr->sigl == 0))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | } |
| 79 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | int FPU_empty_i(int stnr) |
| 81 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 82 | int regnr = (top + stnr) & 7; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 84 | return ((fpu_tag_word >> (regnr * 2)) & 3) == TAG_Empty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | } |
| 86 | |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 87 | int FPU_stackoverflow(FPU_REG ** st_new_ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 89 | *st_new_ptr = &st(-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 91 | return ((fpu_tag_word >> (((top - 1) & 7) * 2)) & 3) != TAG_Empty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | } |
| 93 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr) |
| 95 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 96 | reg_copy(r, &st(stnr)); |
| 97 | FPU_settagi(stnr, tag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | void FPU_copy_to_reg1(FPU_REG const *r, u_char tag) |
| 101 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 102 | reg_copy(r, &st(1)); |
| 103 | FPU_settagi(1, tag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | } |
| 105 | |
| 106 | void FPU_copy_to_reg0(FPU_REG const *r, u_char tag) |
| 107 | { |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 108 | int regnr = top; |
| 109 | regnr &= 7; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 111 | reg_copy(r, &st(0)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | |
Ingo Molnar | 3d0d14f | 2008-01-30 13:30:11 +0100 | [diff] [blame] | 113 | fpu_tag_word &= ~(3 << (regnr * 2)); |
| 114 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | } |