diff options
Diffstat (limited to 'arch/mips/math-emu/sp_tint.c')
-rw-r--r-- | arch/mips/math-emu/sp_tint.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_tint.c b/arch/mips/math-emu/sp_tint.c new file mode 100644 index 000000000..f7a5cf5e1 --- /dev/null +++ b/arch/mips/math-emu/sp_tint.c | |||
@@ -0,0 +1,100 @@ | |||
1 | // SPDX-License-Identifier: GPL-2.0-only | ||
2 | /* IEEE754 floating point arithmetic | ||
3 | * single precision | ||
4 | */ | ||
5 | /* | ||
6 | * MIPS floating point support | ||
7 | * Copyright (C) 1994-2000 Algorithmics Ltd. | ||
8 | */ | ||
9 | |||
10 | #include "ieee754sp.h" | ||
11 | |||
12 | int ieee754sp_tint(union ieee754sp x) | ||
13 | { | ||
14 | u32 residue; | ||
15 | int round; | ||
16 | int sticky; | ||
17 | int odd; | ||
18 | |||
19 | COMPXSP; | ||
20 | |||
21 | ieee754_clearcx(); | ||
22 | |||
23 | EXPLODEXSP; | ||
24 | FLUSHXSP; | ||
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 | /* look for valid corner case */ | ||
45 | if (xe == 31 && xs && xm == SP_HIDDEN_BIT) | ||
46 | return -0x80000000; | ||
47 | /* Set invalid. We will only use overflow for floating | ||
48 | point overflow */ | ||
49 | ieee754_setcx(IEEE754_INVALID_OPERATION); | ||
50 | return ieee754si_overflow(xs); | ||
51 | } | ||
52 | /* oh gawd */ | ||
53 | if (xe > SP_FBITS) { | ||
54 | xm <<= xe - SP_FBITS; | ||
55 | } else { | ||
56 | if (xe < -1) { | ||
57 | residue = xm; | ||
58 | round = 0; | ||
59 | sticky = residue != 0; | ||
60 | xm = 0; | ||
61 | } else { | ||
62 | /* Shifting a u32 32 times does not work, | ||
63 | * so we do it in two steps. Be aware that xe | ||
64 | * may be -1 */ | ||
65 | residue = xm << (xe + 1); | ||
66 | residue <<= 31 - SP_FBITS; | ||
67 | round = (residue >> 31) != 0; | ||
68 | sticky = (residue << 1) != 0; | ||
69 | xm >>= SP_FBITS - xe; | ||
70 | } | ||
71 | odd = (xm & 0x1) != 0x0; | ||
72 | switch (ieee754_csr.rm) { | ||
73 | case FPU_CSR_RN: | ||
74 | if (round && (sticky || odd)) | ||
75 | xm++; | ||
76 | break; | ||
77 | case FPU_CSR_RZ: | ||
78 | break; | ||
79 | case FPU_CSR_RU: /* toward +Infinity */ | ||
80 | if ((round || sticky) && !xs) | ||
81 | xm++; | ||
82 | break; | ||
83 | case FPU_CSR_RD: /* toward -Infinity */ | ||
84 | if ((round || sticky) && xs) | ||
85 | xm++; | ||
86 | break; | ||
87 | } | ||
88 | if ((xm >> 31) != 0) { | ||
89 | /* This can happen after rounding */ | ||
90 | ieee754_setcx(IEEE754_INVALID_OPERATION); | ||
91 | return ieee754si_overflow(xs); | ||
92 | } | ||
93 | if (round || sticky) | ||
94 | ieee754_setcx(IEEE754_INEXACT); | ||
95 | } | ||
96 | if (xs) | ||
97 | return -xm; | ||
98 | else | ||
99 | return xm; | ||
100 | } | ||