Fixes are available
APAR status
Closed as program error.
Error description
The following demonstrates how the compiler fails to produce a store for the __d128_to_signed_BCD() function when using the -qdfp option. ===== COMPILE COMMAND: xlC -q64 -O -qarch=pwr7 -qdfp -c load_store_bcd31.C ======= Test case: $cat load_store_bcd31.C #include <builtins.h> extern "C" void storeBCD(_Decimal128 dfp, unsigned char *cp, unsigned long long* op) { __d128_to_signed_BCD (dfp, 1, (unsigned long long *)cp, (unsigned long long *)(cp+8)); } extern "C" void storeBCD_urg(_Decimal128 dfp, unsigned char *cp, unsigned long long* op) { unsigned long long upper; unsigned long long lower; __d128_to_signed_BCD (dfp, 1, &upper, &lower); *((unsigned long long *)cp) = upper; *((unsigned long long *)(cp+8)) = lower; } extern "C" _Decimal128 loadBCD(unsigned char *cp) { return __signed_BCD_to_d128(*(unsigned long long *)cp, *(unsigned long long *)(cp+8)); } $ ===== ACTUAL LISTING: >>>>> OBJECT SECTION, OPTIMIZATION <<<<< GPR's set/used: ---- ---- ---- ---- ---- ---- ---- ---- FPR's set/used: ---- ---- ---- ---- ---- ---- ---- ---- CCR's set/used: ---- ---- VR's set/used: ---- ---- ---- ---- ---- ---- ---- ---- | 000000 PDEF storeBCD 0| PROC dfp,cp,op,vs2,vs3,gr5,gr6 9| 000000 bclr 4E800020 1 BA lr | Tag Table ======= EXPECTED LISTING: >>>>> OBJECT SECTION, OPTIMIZATION <<<<< GPR's set/used: ---- -u-- ---- ---- ---- ---- ---- ---- FPR's set/used: ssuu ---- ---- ---- ---- ---- ---- ---- CCR's set/used: ---- ---- VR's set/used: ---- ---- ---- ---- ---- ---- ---- ---- | 000000 PDEF storeBCD 0| PROC dfp,cp,op,vs2,vs3,gr5,gr6 7| 000000 ddedpdq FC181284 1 CVDFESB vs0,vs1=vs2,vs3,1 7| 000004 stfd D8250008 1 STFL (unsigned long long;unsigned char)(gr5,8)=vs1 7| 000008 stfd D8050000 1 STFL (unsigned long long;unsigned char)(gr5,0)=vs0 9| 00000C bclr 4E800020 1 BA lr | Tag Table
Local fix
n/a
Problem summary
USERS AFFECTED: Users using -qdfp with the __d128_to_signed_BCD function and optimization maybe affected by this issue. PROBLEM DESCRIPTION: The compiler is optimizing out a store that is should not be removing due to incorrect symbols for the store.
Problem conclusion
The compiler has now been fixed to avoid removing the stores that are needed.
Temporary fix
Comments
APAR Information
APAR number
LI76662
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
2012-02-06
Closed date
2012-02-06
Last modified date
2012-02-06
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 IV10079
UP06/09/13
[{"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:
17 October 2021