2 from soc
.decoder
.selectable_int
import SelectableInt
, onebit
3 from nmutil
.divmod import trunc_divs
, trunc_rems
4 from operator
import floordiv
, mod
5 from soc
.decoder
.selectable_int
import selectltu
as ltu
6 from soc
.decoder
.selectable_int
import selectgtu
as gtu
15 * https://bugs.libre-soc.org/show_bug.cgi?id=324 - add trunc_div and trunc_rem
18 def exts(value
, bits
):
19 sign
= 1 << (bits
- 1)
20 return (value
& (sign
- 1)) - (value
& sign
)
24 """ extends sign bit out from current MSB to all 256 bits
26 assert isinstance(value
, SelectableInt
)
27 return SelectableInt(exts(value
.value
, value
.bits
) & ((1 << 256)-1), 256)
30 """ extends sign bit out from current MSB to 64 bits
32 assert isinstance(value
, SelectableInt
)
33 return SelectableInt(exts(value
.value
, value
.bits
) & ((1 << 64)-1), 64)
36 # signed version of MUL
38 a_s
= a
.value
& (1<<(a
.bits
-1)) != 0
39 b_s
= b
.value
& (1<<(b
.bits
-1)) != 0
40 result
= abs(a
) * abs(b
)
41 print ("MULS", result
, a_s
, b_s
)
47 # XXX should this explicitly extend from 32 to 64?
49 if isinstance(value
, SelectableInt
):
51 return SelectableInt(value
& ((1<<32)-1), 64)
54 def rotl(value
, bits
, wordlen
):
55 if isinstance(bits
, SelectableInt
):
57 mask
= (1 << wordlen
) - 1
58 bits
= bits
& (wordlen
- 1)
59 return ((value
<< bits
) |
(value
>> (wordlen
-bits
))) & mask
62 def ROTL64(value
, bits
):
63 return rotl(value
, bits
, 64)
66 def ROTL32(value
, bits
):
67 if isinstance(value
, SelectableInt
):
68 value
= SelectableInt(value
.value
, 64)
69 return rotl(value |
(value
<< 32), bits
, 64)
73 if isinstance(x
, SelectableInt
):
75 if isinstance(y
, SelectableInt
):
80 mask_a
= ((1 << x
) - 1) & ((1 << 64) - 1)
81 mask_b
= ((1 << y
) - 1) & ((1 << 64) - 1)
87 mask_a
= ((1 << x
) - 1) & ((1 << 64) - 1)
88 mask_b
= (~
((1 << y
) - 1)) & ((1 << 64) - 1)
89 return mask_a ^ mask_b
101 return onebit(a
>= b
)
107 return onebit(a
<= b
)
112 # For these tests I tried to find power instructions that would let me
113 # isolate each of these helper operations. So for instance, when I was
114 # testing the MASK() function, I chose rlwinm and rldicl because if I
115 # set the shift equal to 0 and passed in a value of all ones, the
116 # result I got would be exactly the same as the output of MASK()
118 class HelperTests(unittest
.TestCase
):
120 # Verified using rlwinm, rldicl, rldicr in qemu
122 # rlwinm reg, 1, 0, 5, 15
123 self
.assertHex(MASK(5+32, 15+32), 0x7ff0000)
124 # rlwinm reg, 1, 0, 15, 5
125 self
.assertHex(MASK(15+32, 5+32), 0xfffffffffc01ffff)
126 self
.assertHex(MASK(30+32, 2+32), 0xffffffffe0000003)
127 # rldicl reg, 1, 0, 37
128 self
.assertHex(MASK(37, 63), 0x7ffffff)
129 self
.assertHex(MASK(10, 63), 0x3fffffffffffff)
130 self
.assertHex(MASK(58, 63), 0x3f)
131 # rldicr reg, 1, 0, 37
132 self
.assertHex(MASK(0, 37), 0xfffffffffc000000)
133 self
.assertHex(MASK(0, 10), 0xffe0000000000000)
134 self
.assertHex(MASK(0, 58), 0xffffffffffffffe0)
138 self
.assertHex(MASK(32, 63-5), 0xffffffe0)
140 self
.assertHex(MASK(32, 33), 0xc0000000)
141 self
.assertHex(MASK(32, 32), 0x80000000)
142 self
.assertHex(MASK(33, 33), 0x40000000)
144 def test_ROTL64(self
):
145 # r1 = 0xdeadbeef12345678
146 value
= 0xdeadbeef12345678
148 # rldicl reg, 1, 10, 0
149 self
.assertHex(ROTL64(value
, 10), 0xb6fbbc48d159e37a)
150 # rldicl reg, 1, 35, 0
151 self
.assertHex(ROTL64(value
, 35), 0x91a2b3c6f56df778)
152 self
.assertHex(ROTL64(value
, 58), 0xe37ab6fbbc48d159)
153 self
.assertHex(ROTL64(value
, 22), 0xbbc48d159e37ab6f)
155 def test_ROTL32(self
):
159 # rlwinm reg, 1, 10, 0, 31
160 self
.assertHex(ROTL32(value
, 10), 0xb6fbbf7a)
161 # rlwinm reg, 1, 17, 0, 31
162 self
.assertHex(ROTL32(value
, 17), 0x7ddfbd5b)
163 self
.assertHex(ROTL32(value
, 25), 0xdfbd5b7d)
164 self
.assertHex(ROTL32(value
, 30), 0xf7ab6fbb)
166 def test_EXTS64(self
):
167 value_a
= SelectableInt(0xdeadbeef, 32) # r1
168 value_b
= SelectableInt(0x73123456, 32) # r2
169 value_c
= SelectableInt(0x80000000, 32) # r3
172 self
.assertHex(EXTS64(value_a
), 0xffffffffdeadbeef)
174 self
.assertHex(EXTS64(value_b
), SelectableInt(value_b
.value
, 64))
176 self
.assertHex(EXTS64(value_c
), 0xffffffff80000000)
178 def assertHex(self
, a
, b
):
180 if isinstance(a
, SelectableInt
):
183 if isinstance(b
, SelectableInt
):
185 msg
= "{:x} != {:x}".format(a_val
, b_val
)
186 return self
.assertEqual(a
, b
, msg
)
189 if __name__
== '__main__':
190 print (SelectableInt
.__bases
__)