From 550f589116003fa7748c676136a99827de801143 Mon Sep 17 00:00:00 2001
From: Yichao Yu <yyc1992@gmail.com>
Date: Mon, 12 May 2014 19:31:51 -0400
Subject: [PATCH] add bitlog
---
pyopencl/c_wrapper/wrap_cl_core.h | 2 ++
pyopencl/tools.py | 2 ++
setup.py | 1 +
src/c_wrapper/bitlog.cpp | 28 ++++++++++++++++++++++
src/c_wrapper/bitlog.h | 40 +++++++++++++++++++++++++++++++
src/c_wrapper/wrap_cl.h | 2 --
6 files changed, 73 insertions(+), 2 deletions(-)
create mode 100644 src/c_wrapper/bitlog.cpp
create mode 100644 src/c_wrapper/bitlog.h
diff --git a/pyopencl/c_wrapper/wrap_cl_core.h b/pyopencl/c_wrapper/wrap_cl_core.h
index a3b6f54e..2e3132b9 100644
--- a/pyopencl/c_wrapper/wrap_cl_core.h
+++ b/pyopencl/c_wrapper/wrap_cl_core.h
@@ -85,3 +85,5 @@ void pyopencl_free_pointer(void*);
void pyopencl_free_pointer_array(void**, uint32_t size);
int pyopencl_have_gl();
+
+unsigned pyopencl_bitlog2(unsigned long v);
diff --git a/pyopencl/tools.py b/pyopencl/tools.py
index 635dfb63..b335dee3 100644
--- a/pyopencl/tools.py
+++ b/pyopencl/tools.py
@@ -32,6 +32,7 @@ import pyopencl.np as np
from decorator import decorator
import pyopencl as cl
from pytools import memoize, memoize_method
+from pyopencl._cffi import _lib
import re
@@ -61,6 +62,7 @@ _register_types()
# {{{ imported names
+bitlog2 = _lib.pyopencl_bitlog2
from pyopencl.mempool import ( # noqa
PooledBuffer, DeferredAllocator, ImmediateAllocator, MemoryPool)
diff --git a/setup.py b/setup.py
index 23f14b1f..a6a220a6 100644
--- a/setup.py
+++ b/setup.py
@@ -231,6 +231,7 @@ def main():
Extension("_wrapcl",
["src/c_wrapper/wrap_cl.cpp",
"src/c_wrapper/wrap_constants.cpp",
+ "src/c_wrapper/bitlog.cpp",
#"src/c_wrapper/wrap_mempool.cpp",
],
include_dirs=(
diff --git a/src/c_wrapper/bitlog.cpp b/src/c_wrapper/bitlog.cpp
new file mode 100644
index 00000000..f7951729
--- /dev/null
+++ b/src/c_wrapper/bitlog.cpp
@@ -0,0 +1,28 @@
+#include "bitlog.h"
+#include "wrap_cl.h"
+
+/* from http://graphics.stanford.edu/~seander/bithacks.html */
+const char pyopencl::log_table_8[] =
+{
+ 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
+};
+
+unsigned pyopencl_bitlog2(unsigned long v)
+{
+ return pyopencl::bitlog2(v);
+}
diff --git a/src/c_wrapper/bitlog.h b/src/c_wrapper/bitlog.h
new file mode 100644
index 00000000..fde67e8d
--- /dev/null
+++ b/src/c_wrapper/bitlog.h
@@ -0,0 +1,40 @@
+// Base-2 logarithm bithack.
+
+#ifndef _AFJDFJSDFSD_PYOPENCL_HEADER_SEEN_BITLOG_HPP
+#define _AFJDFJSDFSD_PYOPENCL_HEADER_SEEN_BITLOG_HPP
+
+#include <climits>
+#include <stdint.h>
+
+namespace pyopencl
+{
+ extern const char log_table_8[];
+
+ static inline unsigned bitlog2_16(uint16_t v)
+ {
+ if (unsigned long t = v >> 8)
+ return 8 + log_table_8[t];
+ else
+ return log_table_8[v];
+ }
+
+ static inline unsigned bitlog2_32(uint32_t v)
+ {
+ if (uint16_t t = v >> 16)
+ return 16 + bitlog2_16(t);
+ else
+ return bitlog2_16(v);
+ }
+
+ static inline unsigned bitlog2(unsigned long v)
+ {
+#if (ULONG_MAX != 4294967295)
+ if (uint32_t t = v >> 32)
+ return 32 + bitlog2_32(t);
+ else
+#endif
+ return bitlog2_32(v);
+ }
+}
+
+#endif
diff --git a/src/c_wrapper/wrap_cl.h b/src/c_wrapper/wrap_cl.h
index f15e3deb..ee029fbf 100644
--- a/src/c_wrapper/wrap_cl.h
+++ b/src/c_wrapper/wrap_cl.h
@@ -74,5 +74,3 @@ extern "C" {
#endif
#endif
-
-
--
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