gfx/angle/src/libGLESv2/Float16ToFloat32.py@6474c204b198 (annotated)
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.
| michael@0 | 1 | # Copyright (c) 2012 The ANGLE Project Authors. All rights reserved. |
| michael@0 | 2 | # Use of this source code is governed by a BSD-style license that can be |
| michael@0 | 3 | # found in the LICENSE file. |
| michael@0 | 4 | # |
| michael@0 | 5 | |
| michael@0 | 6 | # This script generates a function that converts 16-bit precision floating |
| michael@0 | 7 | # point numbers to 32-bit. |
| michael@0 | 8 | # It is based on ftp://ftp.fox-toolkit.org/pub/fasthalffloatconversion.pdf. |
| michael@0 | 9 | |
| michael@0 | 10 | def convertMantissa(i): |
| michael@0 | 11 | if i == 0: |
| michael@0 | 12 | return 0 |
| michael@0 | 13 | elif i < 1024: |
| michael@0 | 14 | m = i << 13 |
| michael@0 | 15 | e = 0 |
| michael@0 | 16 | while not (m & 0x00800000): |
| michael@0 | 17 | e -= 0x00800000 |
| michael@0 | 18 | m = m << 1 |
| michael@0 | 19 | m &= ~0x00800000 |
| michael@0 | 20 | e += 0x38800000 |
| michael@0 | 21 | return m | e |
| michael@0 | 22 | else: |
| michael@0 | 23 | return 0x38000000 + ((i - 1024) << 13) |
| michael@0 | 24 | |
| michael@0 | 25 | def convertExponent(i): |
| michael@0 | 26 | if i == 0: |
| michael@0 | 27 | return 0 |
| michael@0 | 28 | elif i in range(1, 31): |
| michael@0 | 29 | return i << 23 |
| michael@0 | 30 | elif i == 31: |
| michael@0 | 31 | return 0x47800000 |
| michael@0 | 32 | elif i == 32: |
| michael@0 | 33 | return 0x80000000 |
| michael@0 | 34 | elif i in range(33, 63): |
| michael@0 | 35 | return 0x80000000 + ((i - 32) << 23) |
| michael@0 | 36 | else: |
| michael@0 | 37 | return 0xC7800000 |
| michael@0 | 38 | |
| michael@0 | 39 | def convertOffset(i): |
| michael@0 | 40 | if i == 0 or i == 32: |
| michael@0 | 41 | return 0 |
| michael@0 | 42 | else: |
| michael@0 | 43 | return 1024 |
| michael@0 | 44 | |
| michael@0 | 45 | print """// |
| michael@0 | 46 | // Copyright (c) 2012 The ANGLE Project Authors. All rights reserved. |
| michael@0 | 47 | // Use of this source code is governed by a BSD-style license that can be |
| michael@0 | 48 | // found in the LICENSE file. |
| michael@0 | 49 | // |
| michael@0 | 50 | |
| michael@0 | 51 | // This file is automatically generated. |
| michael@0 | 52 | |
| michael@0 | 53 | namespace gl |
| michael@0 | 54 | { |
| michael@0 | 55 | """ |
| michael@0 | 56 | |
| michael@0 | 57 | print "const static unsigned g_mantissa[2048] = {" |
| michael@0 | 58 | for i in range(0, 2048): |
| michael@0 | 59 | print " %#010x," % convertMantissa(i) |
| michael@0 | 60 | print "};\n" |
| michael@0 | 61 | |
| michael@0 | 62 | print "const static unsigned g_exponent[64] = {" |
| michael@0 | 63 | for i in range(0, 64): |
| michael@0 | 64 | print " %#010x," % convertExponent(i) |
| michael@0 | 65 | print "};\n" |
| michael@0 | 66 | |
| michael@0 | 67 | print "const static unsigned g_offset[64] = {" |
| michael@0 | 68 | for i in range(0, 64): |
| michael@0 | 69 | print " %#010x," % convertOffset(i) |
| michael@0 | 70 | print "};\n" |
| michael@0 | 71 | |
| michael@0 | 72 | print """float float16ToFloat32(unsigned short h) |
| michael@0 | 73 | { |
| michael@0 | 74 | unsigned i32 = g_mantissa[g_offset[h >> 10] + (h & 0x3ff)] + g_exponent[h >> 10]; |
| michael@0 | 75 | return *(float*) &i32; |
| michael@0 | 76 | } |
| michael@0 | 77 | } |
| michael@0 | 78 | """ |
