Fixes are available
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 º Ü 017 þ à Ý ð \r º Ü 017 þ à Ý ð \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
LI77450
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
2013-06-11
Closed date
2013-06-11
Last modified date
2013-06-11
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 PSN IV31404
UP06/09/13
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Document Information
Modified date:
14 October 2021