blob: cf039bfc21e2d40429383c97a02d5fcfa0476761 [file] [log] [blame]
 # 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; } } """