New submission from Xiongzhi Gao:
The version of windows is Windows 7 Service Pack 1.
The version of Python is 2.7.11 (v2.7.11:6d1b6a68f775, Dec 5 2015, 20:32:19)
[MSC v.1500 32 bit (Intel)] on win32.
The version of compiler in visual studio 10 is 16.00.40219.01 for 80x86.
I try to use SWIG to port a function that use _mm_xor_si64 like this:
packed_sse.i
> %module packed_sse
> %{
> extern long long _packed_mm_xor_si64(long long m1, long long m2);
> %}
> extern long long _packed_mm_xor_si64(long long m1, long long m2);
packed_sse.c
> #include <mmintrin.h>
>
> __inline __m64 int64_to_m64 (const long long i) {
> union {
> long long i;
> __m64 v;
> } u;
> u.i = i;
> return u.v;
> }
>
> __inline long long m64_to_int64 (const __m64 v) {
> union {
> long long i;
> __m64 v;
> } u;
> u.v = v;
> return u.i;
> }
>
> long long _packed_mm_xor_si64(long long m1, long long m2) {
> __m64 m64_m1 = int64_to_m64(m1), m64_m2 = int64_to_m64(m2);
> __m64 m64_result = _mm_xor_si64(m64_m1, m64_m2);
> return m64_to_int64(m64_result);
I use swig and compiler to port C to Python.
I try to test like this, it works:
test_swig.py
> # -*- coding: utf-8 -*-
> # !/bin/env python2
>
> import random
>
> import packed_sse
>
>
> if __name__ == "__main__":
> for i in range(100000):
> a, b = random.getrandbits(20), random.getrandbits(20)
> _ = packed_sse._packed_mm_xor_si64(
> a, b
> )
> assert a ^ b == _
But when I try to profile the function like this, the output of first `print
time.time() - _beg` is `nan` and Python crashed when run into second `print
time.time() - _beg`:
profile_swig.py
> # -*- coding: utf-8 -*-
> # !/bin/env python2
>
> import random
> import time
>
> import packed_sse
>
>
> if __name__ == "__main__":
> _beg = time.time()
> for i in range(100000):
> _ = packed_sse._packed_mm_xor_si64(
> random.getrandbits(20), random.getrandbits(20)
> )
> print time.time() - _beg # First
> _beg = time.time()
> for i in range(100000):
> _ = random.getrandbits(20) ^ random.getrandbits(20)
> print time.time() - _beg # Second
I try to use `gdb` on MingGW to debug it, it said:
> (gdb) stop
> (gdb) c
> Continuing.
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 7172.0xadc]
> 0x534fbe6c in python27!_Py_dg_dtoa () from C:\Windows\system32\python27.dll
----------
components: Windows
messages: 257337
nosy: Xiongzhi Gao, paul.moore, steve.dower, tim.golden, zach.ware
priority: normal
severity: normal
status: open
title: Crashed when call time.time() after using _mm_xor_si64
type: crash
versions: Python 2.7
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue25993>
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