gfx/angle/src/libGLESv2/Float16ToFloat32.py@6474c204b198
gfx/angle/src/libGLESv2/Float16ToFloat32.py
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
1 # Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
2 # Use of this source code is governed by a BSD-style license that can be
3 # found in the LICENSE file.
4 #
6 # This script generates a function that converts 16-bit precision floating
7 # point numbers to 32-bit.
8 # It is based on ftp://ftp.fox-toolkit.org/pub/fasthalffloatconversion.pdf.
10 def convertMantissa(i):
11 if i == 0:
12 return 0
13 elif i < 1024:
14 m = i << 13
15 e = 0
16 while not (m & 0x00800000):
17 e -= 0x00800000
18 m = m << 1
19 m &= ~0x00800000
20 e += 0x38800000
21 return m | e
22 else:
23 return 0x38000000 + ((i - 1024) << 13)
25 def convertExponent(i):
26 if i == 0:
27 return 0
28 elif i in range(1, 31):
29 return i << 23
30 elif i == 31:
31 return 0x47800000
32 elif i == 32:
33 return 0x80000000
34 elif i in range(33, 63):
35 return 0x80000000 + ((i - 32) << 23)
36 else:
37 return 0xC7800000
39 def convertOffset(i):
40 if i == 0 or i == 32:
41 return 0
42 else:
43 return 1024
45 print """//
46 // Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
47 // Use of this source code is governed by a BSD-style license that can be
48 // found in the LICENSE file.
49 //
51 // This file is automatically generated.
53 namespace gl
54 {
55 """
57 print "const static unsigned g_mantissa[2048] = {"
58 for i in range(0, 2048):
59 print " %#010x," % convertMantissa(i)
60 print "};\n"
62 print "const static unsigned g_exponent[64] = {"
63 for i in range(0, 64):
64 print " %#010x," % convertExponent(i)
65 print "};\n"
67 print "const static unsigned g_offset[64] = {"
68 for i in range(0, 64):
69 print " %#010x," % convertOffset(i)
70 print "};\n"
72 print """float float16ToFloat32(unsigned short h)
73 {
74 unsigned i32 = g_mantissa[g_offset[h >> 10] + (h & 0x3ff)] + g_exponent[h >> 10];
75 return *(float*) &i32;
76 }
77 }
78 """
