diff options
Diffstat (limited to 'arch/mips/math-emu/dp_tint.c')
-rw-r--r-- | arch/mips/math-emu/dp_tint.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_tint.c b/arch/mips/math-emu/dp_tint.c new file mode 100644 index 000000000..0e6ad35e7 --- /dev/null +++ b/arch/mips/math-emu/dp_tint.c | |||
@@ -0,0 +1,96 @@ | |||
1 | // SPDX-License-Identifier: GPL-2.0-only | ||
2 | /* IEEE754 floating point arithmetic | ||
3 | * double precision: common utilities | ||
4 | */ | ||
5 | /* | ||
6 | * MIPS floating point support | ||
7 | * Copyright (C) 1994-2000 Algorithmics Ltd. | ||
8 | */ | ||
9 | |||
10 | #include "ieee754dp.h" | ||
11 | |||
12 | int ieee754dp_tint(union ieee754dp x) | ||
13 | { | ||
14 | u64 residue; | ||
15 | int round; | ||
16 | int sticky; | ||
17 | int odd; | ||
18 | |||
19 | COMPXDP; | ||
20 | |||
21 | ieee754_clearcx(); | ||
22 | |||
23 | EXPLODEXDP; | ||
24 | FLUSHXDP; | ||
25 | |||
26 | switch (xc) { | ||
27 | case IEEE754_CLASS_SNAN: | ||
28 | case IEEE754_CLASS_QNAN: | ||
29 | ieee754_setcx(IEEE754_INVALID_OPERATION); | ||
30 | return ieee754si_indef(); | ||
31 | |||
32 | case IEEE754_CLASS_INF: | ||
33 | ieee754_setcx(IEEE754_INVALID_OPERATION); | ||
34 | return ieee754si_overflow(xs); | ||
35 | |||
36 | case IEEE754_CLASS_ZERO: | ||
37 | return 0; | ||
38 | |||
39 | case IEEE754_CLASS_DNORM: | ||
40 | case IEEE754_CLASS_NORM: | ||
41 | break; | ||
42 | } | ||
43 | if (xe > 31) { | ||
44 | /* Set invalid. We will only use overflow for floating | ||
45 | point overflow */ | ||
46 | ieee754_setcx(IEEE754_INVALID_OPERATION); | ||
47 | return ieee754si_overflow(xs); | ||
48 | } | ||
49 | /* oh gawd */ | ||
50 | if (xe > DP_FBITS) { | ||
51 | xm <<= xe - DP_FBITS; | ||
52 | } else if (xe < DP_FBITS) { | ||
53 | if (xe < -1) { | ||
54 | residue = xm; | ||
55 | round = 0; | ||
56 | sticky = residue != 0; | ||
57 | xm = 0; | ||
58 | } else { | ||
59 | residue = xm << (64 - DP_FBITS + xe); | ||
60 | round = (residue >> 63) != 0; | ||
61 | sticky = (residue << 1) != 0; | ||
62 | xm >>= DP_FBITS - xe; | ||
63 | } | ||
64 | /* Note: At this point upper 32 bits of xm are guaranteed | ||
65 | to be zero */ | ||
66 | odd = (xm & 0x1) != 0x0; | ||
67 | switch (ieee754_csr.rm) { | ||
68 | case FPU_CSR_RN: | ||
69 | if (round && (sticky || odd)) | ||
70 | xm++; | ||
71 | break; | ||
72 | case FPU_CSR_RZ: | ||
73 | break; | ||
74 | case FPU_CSR_RU: /* toward +Infinity */ | ||
75 | if ((round || sticky) && !xs) | ||
76 | xm++; | ||
77 | break; | ||
78 | case FPU_CSR_RD: /* toward -Infinity */ | ||
79 | if ((round || sticky) && xs) | ||
80 | xm++; | ||
81 | break; | ||
82 | } | ||
83 | /* look for valid corner case 0x80000000 */ | ||
84 | if ((xm >> 31) != 0 && (xs == 0 || xm != 0x80000000)) { | ||
85 | /* This can happen after rounding */ | ||
86 | ieee754_setcx(IEEE754_INVALID_OPERATION); | ||
87 | return ieee754si_overflow(xs); | ||
88 | } | ||
89 | if (round || sticky) | ||
90 | ieee754_setcx(IEEE754_INEXACT); | ||
91 | } | ||
92 | if (xs) | ||
93 | return -xm; | ||
94 | else | ||
95 | return xm; | ||
96 | } | ||