blob: cf039bfc21e2d40429383c97a02d5fcfa0476761 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
# Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# This script generates a function that converts 16-bit precision floating
# point numbers to 32-bit.
# It is based on ftp://ftp.fox-toolkit.org/pub/fasthalffloatconversion.pdf.
def convertMantissa(i):
if i == 0:
return 0
elif i < 1024:
m = i << 13
e = 0
while not (m & 0x00800000):
e -= 0x00800000
m = m << 1
m &= ~0x00800000
e += 0x38800000
return m | e
else:
return 0x38000000 + ((i - 1024) << 13)
def convertExponent(i):
if i == 0:
return 0
elif i in range(1, 31):
return i << 23
elif i == 31:
return 0x47800000
elif i == 32:
return 0x80000000
elif i in range(33, 63):
return 0x80000000 + ((i - 32) << 23)
else:
return 0xC7800000
def convertOffset(i):
if i == 0 or i == 32:
return 0
else:
return 1024
print """//
// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// This file is automatically generated.
namespace gl
{
"""
print "const static unsigned g_mantissa[2048] = {"
for i in range(0, 2048):
print " %#010x," % convertMantissa(i)
print "};\n"
print "const static unsigned g_exponent[64] = {"
for i in range(0, 64):
print " %#010x," % convertExponent(i)
print "};\n"
print "const static unsigned g_offset[64] = {"
for i in range(0, 64):
print " %#010x," % convertOffset(i)
print "};\n"
print """float float16ToFloat32(unsigned short h)
{
unsigned i32 = g_mantissa[g_offset[h >> 10] + (h & 0x3ff)] + g_exponent[h >> 10];
return *(float*) &i32;
}
}
"""
|
