1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/angle/src/libGLESv2/Float16ToFloat32.py Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,78 @@
1.4 +# Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
1.5 +# Use of this source code is governed by a BSD-style license that can be
1.6 +# found in the LICENSE file.
1.7 +#
1.8 +
1.9 +# This script generates a function that converts 16-bit precision floating
1.10 +# point numbers to 32-bit.
1.11 +# It is based on ftp://ftp.fox-toolkit.org/pub/fasthalffloatconversion.pdf.
1.12 +
1.13 +def convertMantissa(i):
1.14 + if i == 0:
1.15 + return 0
1.16 + elif i < 1024:
1.17 + m = i << 13
1.18 + e = 0
1.19 + while not (m & 0x00800000):
1.20 + e -= 0x00800000
1.21 + m = m << 1
1.22 + m &= ~0x00800000
1.23 + e += 0x38800000
1.24 + return m | e
1.25 + else:
1.26 + return 0x38000000 + ((i - 1024) << 13)
1.27 +
1.28 +def convertExponent(i):
1.29 + if i == 0:
1.30 + return 0
1.31 + elif i in range(1, 31):
1.32 + return i << 23
1.33 + elif i == 31:
1.34 + return 0x47800000
1.35 + elif i == 32:
1.36 + return 0x80000000
1.37 + elif i in range(33, 63):
1.38 + return 0x80000000 + ((i - 32) << 23)
1.39 + else:
1.40 + return 0xC7800000
1.41 +
1.42 +def convertOffset(i):
1.43 + if i == 0 or i == 32:
1.44 + return 0
1.45 + else:
1.46 + return 1024
1.47 +
1.48 +print """//
1.49 +// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
1.50 +// Use of this source code is governed by a BSD-style license that can be
1.51 +// found in the LICENSE file.
1.52 +//
1.53 +
1.54 +// This file is automatically generated.
1.55 +
1.56 +namespace gl
1.57 +{
1.58 +"""
1.59 +
1.60 +print "const static unsigned g_mantissa[2048] = {"
1.61 +for i in range(0, 2048):
1.62 + print " %#010x," % convertMantissa(i)
1.63 +print "};\n"
1.64 +
1.65 +print "const static unsigned g_exponent[64] = {"
1.66 +for i in range(0, 64):
1.67 + print " %#010x," % convertExponent(i)
1.68 +print "};\n"
1.69 +
1.70 +print "const static unsigned g_offset[64] = {"
1.71 +for i in range(0, 64):
1.72 + print " %#010x," % convertOffset(i)
1.73 +print "};\n"
1.74 +
1.75 +print """float float16ToFloat32(unsigned short h)
1.76 +{
1.77 + unsigned i32 = g_mantissa[g_offset[h >> 10] + (h & 0x3ff)] + g_exponent[h >> 10];
1.78 + return *(float*) &i32;
1.79 +}
1.80 +}
1.81 +"""
