Fixes are available
April 2013 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 8 (October 2015 Update) for 12.1
XL C/C++ for Linux Fix Pack 4 (October 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 5 (December 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 6 (February 2014 Update) for 12.1
XL C/C++ for Linux Fix Pack 7 (May 2014 Update) for 12.1
APAR status
Closed as program error.
Error description
Compiling with -O2 and inlining enabled, with a ?: conditional as a template function parameter, is causing valid code to be optimized away, resulting in invalid code behaviour. In the example below, invalid stack data is accessed, and output is incorrect: ==== TEST CASE ==== #include <iostream> struct MyStruct { template <typename T> static void print( T const & x ) { std::cout << x; } }; int main(int argc, char *argv[]) { MyStruct::print(argc == 1?"test1":"test2"); } $ xlC -q64 -O2 apar.cpp $ ./a.out | od -c 0000000 ᄃ レ 017 ナ ■ ￐ \r ᄃ レ 017 ナ ■ ￐ \r 0000020 $ $ ./a.out | od -x 0000000 badc 0ffe e0dd f00d badc 0ffe e0dd f00d 0000020 $
Local fix
- Disable inlining - Convert ?: conditional into an IF statement
Problem summary
PROBLEM DESCRIPTION: Processing of the ?: ternary operator is ignoring the memory location of the result, leading to incorrect code and behaviour. USERS AFFECTED: Users of the ?: ternary operator, the << operator, and optimization.
Problem conclusion
The issue has been corrected.
Temporary fix
Comments
APAR Information
APAR number
LI77335
Reported component name
XL C/C++ FOR LI
Reported component ID
5725C7300
Reported release
C10
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2013-04-27
Closed date
2013-04-27
Last modified date
2013-04-27
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
5725C7300
Applicable component levels
RC10 PSN IV31404
UP06/09/13
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Document Information
Modified date:
14 October 2021