1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun NetWinder Floating Point Emulator
4*4882a593Smuzhiyun (c) Rebel.COM, 1998,1999
5*4882a593Smuzhiyun (c) Philip Blundell, 2001
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include "fpa11.h"
12*4882a593Smuzhiyun #include "fpopcode.h"
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun unsigned int SingleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
15*4882a593Smuzhiyun unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
16*4882a593Smuzhiyun unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
17*4882a593Smuzhiyun
EmulateCPDO(const unsigned int opcode)18*4882a593Smuzhiyun unsigned int EmulateCPDO(const unsigned int opcode)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun FPA11 *fpa11 = GET_FPA11();
21*4882a593Smuzhiyun FPREG *rFd;
22*4882a593Smuzhiyun unsigned int nType, nDest, nRc;
23*4882a593Smuzhiyun struct roundingData roundData;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun /* Get the destination size. If not valid let Linux perform
26*4882a593Smuzhiyun an invalid instruction trap. */
27*4882a593Smuzhiyun nDest = getDestinationSize(opcode);
28*4882a593Smuzhiyun if (typeNone == nDest)
29*4882a593Smuzhiyun return 0;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun roundData.mode = SetRoundingMode(opcode);
32*4882a593Smuzhiyun roundData.precision = SetRoundingPrecision(opcode);
33*4882a593Smuzhiyun roundData.exception = 0;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun /* Compare the size of the operands in Fn and Fm.
36*4882a593Smuzhiyun Choose the largest size and perform operations in that size,
37*4882a593Smuzhiyun in order to make use of all the precision of the operands.
38*4882a593Smuzhiyun If Fm is a constant, we just grab a constant of a size
39*4882a593Smuzhiyun matching the size of the operand in Fn. */
40*4882a593Smuzhiyun if (MONADIC_INSTRUCTION(opcode))
41*4882a593Smuzhiyun nType = nDest;
42*4882a593Smuzhiyun else
43*4882a593Smuzhiyun nType = fpa11->fType[getFn(opcode)];
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun if (!CONSTANT_FM(opcode)) {
46*4882a593Smuzhiyun register unsigned int Fm = getFm(opcode);
47*4882a593Smuzhiyun if (nType < fpa11->fType[Fm]) {
48*4882a593Smuzhiyun nType = fpa11->fType[Fm];
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun rFd = &fpa11->fpreg[getFd(opcode)];
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun switch (nType) {
55*4882a593Smuzhiyun case typeSingle:
56*4882a593Smuzhiyun nRc = SingleCPDO(&roundData, opcode, rFd);
57*4882a593Smuzhiyun break;
58*4882a593Smuzhiyun case typeDouble:
59*4882a593Smuzhiyun nRc = DoubleCPDO(&roundData, opcode, rFd);
60*4882a593Smuzhiyun break;
61*4882a593Smuzhiyun #ifdef CONFIG_FPE_NWFPE_XP
62*4882a593Smuzhiyun case typeExtended:
63*4882a593Smuzhiyun nRc = ExtendedCPDO(&roundData, opcode, rFd);
64*4882a593Smuzhiyun break;
65*4882a593Smuzhiyun #endif
66*4882a593Smuzhiyun default:
67*4882a593Smuzhiyun nRc = 0;
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun /* The CPDO functions used to always set the destination type
71*4882a593Smuzhiyun to be the same as their working size. */
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun if (nRc != 0) {
74*4882a593Smuzhiyun /* If the operation succeeded, check to see if the result in the
75*4882a593Smuzhiyun destination register is the correct size. If not force it
76*4882a593Smuzhiyun to be. */
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun fpa11->fType[getFd(opcode)] = nDest;
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun #ifdef CONFIG_FPE_NWFPE_XP
81*4882a593Smuzhiyun if (nDest != nType) {
82*4882a593Smuzhiyun switch (nDest) {
83*4882a593Smuzhiyun case typeSingle:
84*4882a593Smuzhiyun {
85*4882a593Smuzhiyun if (typeDouble == nType)
86*4882a593Smuzhiyun rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
87*4882a593Smuzhiyun else
88*4882a593Smuzhiyun rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended);
89*4882a593Smuzhiyun }
90*4882a593Smuzhiyun break;
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun case typeDouble:
93*4882a593Smuzhiyun {
94*4882a593Smuzhiyun if (typeSingle == nType)
95*4882a593Smuzhiyun rFd->fDouble = float32_to_float64(rFd->fSingle);
96*4882a593Smuzhiyun else
97*4882a593Smuzhiyun rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended);
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun break;
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun case typeExtended:
102*4882a593Smuzhiyun {
103*4882a593Smuzhiyun if (typeSingle == nType)
104*4882a593Smuzhiyun rFd->fExtended = float32_to_floatx80(rFd->fSingle);
105*4882a593Smuzhiyun else
106*4882a593Smuzhiyun rFd->fExtended = float64_to_floatx80(rFd->fDouble);
107*4882a593Smuzhiyun }
108*4882a593Smuzhiyun break;
109*4882a593Smuzhiyun }
110*4882a593Smuzhiyun }
111*4882a593Smuzhiyun #else
112*4882a593Smuzhiyun if (nDest != nType) {
113*4882a593Smuzhiyun if (nDest == typeSingle)
114*4882a593Smuzhiyun rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
115*4882a593Smuzhiyun else
116*4882a593Smuzhiyun rFd->fDouble = float32_to_float64(rFd->fSingle);
117*4882a593Smuzhiyun }
118*4882a593Smuzhiyun #endif
119*4882a593Smuzhiyun }
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun if (roundData.exception)
122*4882a593Smuzhiyun float_raise(roundData.exception);
123*4882a593Smuzhiyun
124*4882a593Smuzhiyun return nRc;
125*4882a593Smuzhiyun }
126