projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* IEEE754 floating point arithmetic |
| 2 | * single precision | |
| 3 | */ | |
| 4 | /* | |
| 5 | * MIPS floating point support | |
| 6 | * Copyright (C) 1994-2000 Algorithmics Ltd. | |
| 1da177e4 | 7 | * |
| 1da177e4 LT |
8 | * This program is free software; you can distribute it and/or modify it |
| 9 | * under the terms of the GNU General Public License (Version 2) as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | * | |
| 12 | * This program is distributed in the hope it will be useful, but WITHOUT | |
| 13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 | * for more details. | |
| 16 | * | |
| 17 | * You should have received a copy of the GNU General Public License along | |
| 18 | * with this program; if not, write to the Free Software Foundation, Inc., | |
| 3f7cac41 | 19 | * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 1da177e4 LT |
20 | */ |
| 21 | ||
| 1da177e4 | 22 | #include "ieee754sp.h" |
| b3a7ad2b | 23 | #include "ieee754dp.h" |
| 1da177e4 | 24 | |
| d19cf86e MR |
25 | static inline union ieee754sp ieee754sp_nan_fdp(int xs, u64 xm) |
| 26 | { | |
| 27 | return buildsp(xs, SP_EMAX + 1 + SP_EBIAS, | |
| 28 | xm >> (DP_FBITS - SP_FBITS)); | |
| 29 | } | |
| 30 | ||
| 2209bcb1 | 31 | union ieee754sp ieee754sp_fdp(union ieee754dp x) |
| 1da177e4 | 32 | { |
| b0c2f8fb | 33 | union ieee754sp y; |
| 3f7cac41 RB |
34 | u32 rm; |
| 35 | ||
| 1da177e4 | 36 | COMPXDP; |
| b0c2f8fb | 37 | COMPYSP; |
| 1da177e4 LT |
38 | |
| 39 | EXPLODEXDP; | |
| 40 | ||
| 9e8bad1f | 41 | ieee754_clearcx(); |
| 1da177e4 LT |
42 | |
| 43 | FLUSHXDP; | |
| 44 | ||
| 45 | switch (xc) { | |
| 46 | case IEEE754_CLASS_SNAN: | |
| 90d53a91 MR |
47 | x = ieee754dp_nanxcpt(x); |
| 48 | EXPLODEXDP; | |
| 49 | /* Fall through. */ | |
| 1da177e4 | 50 | case IEEE754_CLASS_QNAN: |
| b0c2f8fb | 51 | y = ieee754sp_nan_fdp(xs, xm); |
| 90d53a91 MR |
52 | if (!ieee754_csr.nan2008) { |
| 53 | EXPLODEYSP; | |
| 54 | if (!ieee754_class_nan(yc)) | |
| 55 | y = ieee754sp_indef(); | |
| 56 | } | |
| b0c2f8fb | 57 | return y; |
| 3f7cac41 | 58 | |
| 1da177e4 LT |
59 | case IEEE754_CLASS_INF: |
| 60 | return ieee754sp_inf(xs); | |
| 3f7cac41 | 61 | |
| 1da177e4 LT |
62 | case IEEE754_CLASS_ZERO: |
| 63 | return ieee754sp_zero(xs); | |
| 3f7cac41 | 64 | |
| 1da177e4 LT |
65 | case IEEE754_CLASS_DNORM: |
| 66 | /* can't possibly be sp representable */ | |
| 9e8bad1f RB |
67 | ieee754_setcx(IEEE754_UNDERFLOW); |
| 68 | ieee754_setcx(IEEE754_INEXACT); | |
| 56a64733 RB |
69 | if ((ieee754_csr.rm == FPU_CSR_RU && !xs) || |
| 70 | (ieee754_csr.rm == FPU_CSR_RD && xs)) | |
| 90efba36 RB |
71 | return ieee754sp_mind(xs); |
| 72 | return ieee754sp_zero(xs); | |
| 3f7cac41 | 73 | |
| 1da177e4 LT |
74 | case IEEE754_CLASS_NORM: |
| 75 | break; | |
| 76 | } | |
| 77 | ||
| 3f7cac41 RB |
78 | /* |
| 79 | * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift. | |
| 80 | */ | |
| 81 | rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) | | |
| 82 | ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0); | |
| 1da177e4 | 83 | |
| 3f7cac41 | 84 | return ieee754sp_format(xs, xe, rm); |
| 1da177e4 | 85 | } |