Fixes are available
XL C/C++ for Linux Fix Pack 9 (August 2013 Update) for 11.1
July 2011 Update for XL C/C++ for Linux, V11.1
October 2011 Update for XL C/C++ for Linux, V11.1
June 2012 Update for XL C/C++ for Linux, V11.1
October 2012 Update for XL C/C++ for Linux, V11.1
XL C/C++ for Linux Fix Pack 8 (June 2013 Update) for 11.1
APAR status
Closed as program error.
Error description
The following test case gives out incorrect runtime results if compile with -qsmp=omp option. $cat simple_omp_bug.cpp #include <complex> #include <iostream> #include <vector> #ifdef _OPENMP # include "omp.h" #endif void Aggrevate ( std::complex<double> alpha, int height, int width, std::complex<double>* ABuf, const std::complex<double>* BBuf ) { #ifdef _OPENMP #pragma omp parallel for #endif for( int j=0; j<width; ++j ) { const std::complex<double>* BCol = &BBuf[j*height]; std::complex<double>* ACol = &ABuf[j*height]; for( int i=0; i<height; ++i ) ACol[i] += alpha*BCol[i]; } } int main( int argc, char* argv[] ) { const int height = 100; const int width = 100; std::vector< std::complex<double> > C(height*width,1.0); std::vector< std::complex<double> > D(height*width,0.7); std::complex<double> beta(0.3,0.); std::cout << "C[0] before: " << C[0] << "\n" << "D[0] before: " << D[0] << "\n" << "beta before: " << beta << "\n" << "height: " << height << "\n" << "width: " << width << "\n" << "C.size(): " << C.size() << "\n" << "D.size(): " << D.size() << std::endl; std::cout << "Started complex OpenMP section." << std::endl; Aggrevate( beta, height, width, &C[0], &D[0] ); std::cout << "C[0] := C[0] + beta D[0] = " << C[0] << std::endl; return 0; } ${bgxlC} -g -O0 simple_omp_bug.cpp -o simple_omp_bug_O0.x ${bgxlC_r} -qsmp=omp:noauto -g -O0 simple_omp_bug.cpp -o simple_omp_bug_omp_O0.x ${bgxlC} -g -O3 simple_omp_bug.cpp -o simple_omp_bug_O3.x ${bgxlC_r} -qsmp=omp:noauto -g -O3 simple_omp_bug.cpp -o simple_omp_bug_omp_O3.x ${bgxlC} -g -O4 simple_omp_bug.cpp -o simple_omp_bug_O4.x ${bgxlC_r} -qsmp=omp:noauto -g -O4 simple_omp_bug.cpp -o simple_omp_bug_omp_O4.x diff O0_omp.output O0.output 9c9 < C[0] := C[0] + beta D[0] = (1,4.10606e-313) --- > C[0] := C[0] + beta D[0] = (1.21,0) diff O3_omp.output O3.output 9c9 < C[0] := C[0] + beta D[0] = (1,4.10606e-313) --- > C[0] := C[0] + beta D[0] = (1.21,0) diff O4_omp.output O4.output 9c9 < C[0] := C[0] + beta D[0] = (1,0) --- > C[0] := C[0] + beta D[0] = (1.21,0)
Local fix
N/A
Problem summary
PROBLEM DESCRIPTION: Incorrect calculation of complex number with -qsmp=omp USERS AFFECTED: Complex numbers using -qsmp=omp to compile.
Problem conclusion
In an outlined procedure the real and complex members of a complex number were not privatized into that procedure but the owner was. So the stores into them did not go into the location of the owner causing runtime failures when the owner was referenced. The problem is fixed. Apply recommended service.
Temporary fix
Comments
APAR Information
APAR number
LI76276
Reported component name
XL C/C++ FOR LI
Reported component ID
5724X1400
Reported release
B10
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2011-07-12
Closed date
2011-07-12
Last modified date
2011-07-12
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
XL C/C++ FOR LI
Fixed component ID
5724X1400
Applicable component levels
RB10 PSY
UP
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSXVZZ","label":"XL C\/C++ for Linux"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"B10","Line of Business":{"code":"LOB57","label":"Power"}}]
Document Information
Modified date:
16 October 2021