我正在使用 ATLAS 进行 LAPACK 和多线程 BLAS 例程，并且注意到当我的矩阵变得足够大以便 ATLAS 使用 BLAS 的多线程版本时，我从 Valgrind 收到初始化错误。这是我代码中的一个最小示例：
#include <stdio.h>
#include <stdlib.h>
extern void dgetrf_(int *, int *, double *, int *, int *, int *);
extern void dgetri_(int *, double *, int *, int *, double *, int *, int *);
extern void dgemm_(char *, char *, int *, int *, int *, double *, double *, int *, double *, int *, double *, double *, int *);
int main(void)
{
double *m1,*m2,*work,*temp;
int dim = 576;
int i,j,info;
int lwork = dim * dim;
int *ipiv;
char transA = 'N';
char transB = 'N';
double alpha = 1.0;
double beta = 0.0;
m1 = malloc(dim*dim*sizeof(double));
m2 = malloc(dim*dim*sizeof(double));
temp = malloc(dim*dim*sizeof(double));
ipiv = malloc(dim*sizeof(int));
work = malloc(lwork*sizeof(double));
for(i=0; i<dim; i++)
{
for(j=0; j<dim; j++)
{
if(i==j)
{
m1[i+dim*j] = .25;
m2[i+dim*j] = .5;
}
else
{
m1[i+dim*j] = 0.0;
m2[i+dim*j] = 0.0;
}
}
}
dgetrf_(&dim, &dim, m1, &dim, ipiv, &info);
dgetri_(&dim, m1, &dim, ipiv, work, &lwork, &info);
dgemm_(&transA, &transB, &dim, &dim, &dim, &alpha, m1, &dim, m2, &dim, &beta, temp, &dim);
for(i=0; i<dim*dim; i++)
m1[i] = temp[i];
dgetrf_(&dim, &dim, m1, &dim, ipiv, &info);
dgetri_(&dim, m1, &dim, ipiv, work, &lwork, &info);
free(m1);
free(m2);
free(ipiv);
free(work);
free(temp);
return 0;
}
(注意：我已经检查以确保矩阵不是单数的，也不是。
我编译程序：
gcc -Wall -DATLAS -m64 -g -c fermi.c
gcc -o fermi fermi.o -L/usr/lib64/atlas/ -lm -ltatlas
并运行瓦尔格林德：
valgrind --leak-check=yes ./fermi
当我这样做时，当遇到 dgetrf_ 和dgetri_的第二个实例时，我从 11 个上下文中收到 193 个错误"条件跳转或移动取决于未初始化的值"。
==24999== Memcheck, a memory error detector
==24999== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==24999== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==24999== Command: ./fermi
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x524C62B: ??? (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C29E3: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x524C66A: ??? (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C29E3: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x524C6BE: ??? (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C29E3: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x51C2A0B: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x51C2A0D: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x51C2A4E: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x51C2A61: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x524C2D7: ATL_daxpy (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x53426BB: ATL_dgerk_axpy (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C2AC7: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x524C751: ??? (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C29E3: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51CD2BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x5210416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400A97: main (fermi.c:52)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x51CD8E5: ATL_dtrtri (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C2EC3: ATL_dgetriC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520EFA5: atl_f77wrap_dgetri_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F684: dgetri_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400AC0: main (fermi.c:53)
==24999==
==24999== Conditional jump or move depends on uninitialised value(s)
==24999== at 0x51CD8E7: ATL_dtrtri (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x51C2EC3: ATL_dgetriC (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520EFA5: atl_f77wrap_dgetri_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x520F684: dgetri_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==24999== by 0x400AC0: main (fermi.c:53)
==24999==
==24999==
==24999== HEAP SUMMARY:
==24999== in use at exit: 0 bytes in 0 blocks
==24999== total heap usage: 2,024 allocs, 2,024 frees, 54,831,424 bytes allocated
==24999==
==24999== All heap blocks were freed -- no leaks are possible
==24999==
==24999== For counts of detected and suppressed errors, rerun with: -v
==24999== Use --track-origins=yes to see where uninitialised values come from
==24999== ERROR SUMMARY: 193 errors from 11 contexts (suppressed: 0 from 0)
我发现一些链接表明这可能是来自图书馆做事方式的误报，尽管它们与我的上下文没有太大关系。
dgemm_内存泄漏
https://www.open-mpi.org/community/lists/users/2007/05/3192.php
所以我的问题：瓦尔格林德给了我误报错误吗？
瓦尔格林德给了我误报错误吗？
看起来没有。
与其用--leak-check=yes运行 valgrind，不如用--track-origins=yes运行它，以查看未初始化的值来自哪里，正如 valgrind 在输出末尾所建议的那样。这是我对--track-origins=yes所拥有的：
[ ~]$ valgrind --track-origins=yes ./a.out
==17533== Memcheck, a memory error detector
==17533== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==17533== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==17533== Command: ./a.out
==17533==
==17533== Conditional jump or move depends on uninitialised value(s)
==17533== at 0x4F4362B: ??? (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4EB99E3: ATL_dgetf2 (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4EC42BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4EC42BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4EC42BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4EC42BF: ATL_dtgetrfC (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4F06538: atl_f77wrap_dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x4F07416: dgetrf_ (in /usr/lib64/atlas/libtatlas.so.3.10)
==17533== by 0x400A29: main (fermi.c:50)
==17533== Uninitialised value was created by a heap allocation
==17533== at 0x4C2DB9D: malloc (vg_replace_malloc.c:299)
==17533== by 0x40080B: main (fermi.c:22)
因此，未初始化值的来源是以下代码行：
temp = malloc(dim*dim*sizeof(double));
然后，它用于初始化传递给第 50 行dgetrf_()的m1。
我不熟悉 ATLAS 库，但我想你应该以某种方式初始化temp变量。例如，使用calloc初始化temp零可以解决所有这些 valgrind 错误：
temp = calloc(dim*dim,sizeof(double));