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-rwxr-xr-xgfx/angle/src/common/Float16ToFloat32.py80
1 files changed, 80 insertions, 0 deletions
diff --git a/gfx/angle/src/common/Float16ToFloat32.py b/gfx/angle/src/common/Float16ToFloat32.py
new file mode 100755
index 000000000..7705f7b61
--- /dev/null
+++ b/gfx/angle/src/common/Float16ToFloat32.py
@@ -0,0 +1,80 @@
+# 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.
+
+#include "common/mathutil.h"
+
+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 bitCast<float>(i32);
+}
+}
+"""