更新:在我的內核int4
是錯誤的。與PyOpenCL結構對齊
我正在使用pyopencl,但無法使結構對齊正常工作。在下面調用內核兩次的代碼中,b
值正確返回(如1),但c
值有一些「隨機」值。
換句話說:我想讀一個結構的兩個成員。我可以閱讀第一個,但不是第二個。爲什麼?
無論我使用numpy結構化數組還是使用struct打包,都會發生同樣的問題。並且評論中的_-attribute__
設置也沒有幫助。
我懷疑我在代碼的其他地方做了些愚蠢的事,但看不到它。任何幫助讚賞。
import struct as s
import pyopencl as cl
import numpy as n
ctx = cl.create_some_context()
queue = cl.CommandQueue(ctx)
for use_struct in (True, False):
if use_struct:
a = s.pack('=ii',1,2)
print(a, len(a))
a_dev = cl.Buffer(ctx, cl.mem_flags.WRITE_ONLY, len(a))
else:
# a = n.array([(1,2)], dtype=n.dtype('2i4', align=True))
a = n.array([(1,2)], dtype=n.dtype('2i4'))
print(a, a.itemsize, a.nbytes)
a_dev = cl.Buffer(ctx, cl.mem_flags.WRITE_ONLY, a.nbytes)
b = n.array([0], dtype='i4')
print(b, b.itemsize, b.nbytes)
b_dev = cl.Buffer(ctx, cl.mem_flags.READ_ONLY, b.nbytes)
c = n.array([0], dtype='i4')
print(c, c.itemsize, c.nbytes)
c_dev = cl.Buffer(ctx, cl.mem_flags.READ_ONLY, c.nbytes)
prg = cl.Program(ctx, """
typedef struct s {
int4 f0;
int4 f1 __attribute__ ((packed));
// int4 f1 __attribute__ ((aligned (4)));
// int4 f1;
} s;
__kernel void test(__global const s *a, __global int4 *b, __global int4 *c) {
*b = a->f0;
*c = a->f1;
}
""").build()
cl.enqueue_copy(queue, a_dev, a)
event = prg.test(queue, (1,), None, a_dev, b_dev, c_dev)
event.wait()
cl.enqueue_copy(queue, b, b_dev)
print(b)
cl.enqueue_copy(queue, c, c_dev)
print(c)
輸出(我不得不重新格式化,同時切+粘貼,所以可能會搞砸線略微突破;我還添加了評論,指出各種打印值):
# first using struct
/home/andrew/projects/personal/kultrung/env/bin/python3.2 /home/andrew/projects/personal/kultrung/src/kultrung/test6.py
b'\x01\x00\x00\x00\x02\x00\x00\x00' 8 # the struct packed values
[0] 4 4 # output buffer 1
[0] 4 4 # output buffer 2
/home/andrew/projects/personal/kultrung/env/lib/python3.2/site-packages/pyopencl/cache.py:343: UserWarning: Build succeeded, but resulted in non-empty logs: Build on <pyopencl.Device 'Intel(R) Core(TM)2 CPU T5600 @ 1.83GHz' at 0x1385a20> succeeded, but said:
Build started Kernel <test> was successfully vectorized Done. warn("Build succeeded, but resulted in non-empty logs:\n"+message)
[1] # the first value (correct)
[240] # the second value (wrong)
# next using numpy
[[1 2]] 4 8 # the numpy struct
[0] 4 4 # output buffer
[0] 4 4 # output buffer
/home/andrew/projects/personal/kultrung/env/lib/python3.2/site-packages/pyopencl/__init__.py:174: UserWarning: Build succeeded, but resulted in non-empty logs: Build on <pyopencl.Device 'Intel(R) Core(TM)2 CPU T5600 @ 1.83GHz' at 0x1385a20> succeeded, but said:
Build started Kernel <test> was successfully vectorized Done. warn("Build succeeded, but resulted in non-empty logs:\n"+message)
[1] # first value (ok)
[67447488] # second value (wrong)
Process finished with exit code 0
謝謝,我只是試了一下,但它沒有解決問題(也是在這裏「包裝」下的第一個例子http://www.khronos.org/registry/cl/sdk/1.0/docs/man/ xhtml/attributes-variables.html表明它應該是我擁有它的地方,我認爲) –