IV52638: INTERNAL COMPILER ERROR WITH -Q32 -O2

XL C for AIX Fix Pack 8 (March 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 8 (March 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 11 (February 2015 PTF) for 12.1
XL C for AIX Fix Pack 12 (May 2015 PTF) for 12.1
XL C/C++ for AIX Fix Pack 12 (May 2015 PTF) for 12.1
XL C/C++ for AIX Fix Pack 13 (August 2015 Update) for 12.1
XL C/C++ for AIX Fix Pack 14 (December 2015 Update) for 12.1
XL C for AIX Fix Pack 15 (April 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 15 (April 2016 Update) for 12.1
XL C for AIX Fix Pack 16 (July 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 16 (July 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C/C++ for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C for AIX Fix Pack 9 (July 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 9 (July 2014 PTF) for 12.1
XL C for AIX Fix Pack 10 (October 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 10 (October 2014 PTF) for 12.1
XL C for AIX Fix Pack 11 (February 2015 PTF) for 12.1
XL C for AIX Fix Pack 13 (August 2015 Update) for 12.1
XL C for AIX Fix Pack 14 (December 2015 Update) for 12.1
XL C/C++ for AIX Fix Pack 21 (January 2019 Update) for 12.1
XL C for AIX Fix Pack 21 (January 2019 Update) for 12.1

APAR status

• Closed as program error.

Error description

• The following test case shows the internal compiler when
  compiled with xlC_r -q32 -O2
  
  #ifdef __cplusplus
  #include <builtins.h>
  #endif
  
  #include <stdint.h>
  
  #define plasma_endian_swap64_const(x)          \
          ( (((x)>>56))                          \
          | (((x)<<40) & 0x00FF000000000000LL)   \
          | (((x)<<24) & 0x0000FF0000000000LL)   \
          | (((x)<<8)  & 0x000000FF00000000LL)   \
          | (((x)>>8)  & 0x00000000FF000000LL)   \
          | (((x)>>24) & 0x0000000000FF0000LL)   \
          | (((x)>>40) & 0x000000000000FF00LL)   \
          | (((x)<<56)) )
  
  static uint64_t
  plasma_endian_swap64_func (const uint64_t x)
  {
      return __rldimi((uint64_t)__load4r(((uint32_t *)(&x))+1),
                      (uint64_t)__load4r(((uint32_t *)(&x))),
                      32u, 0xFFFFFFFF00000000uLL);
  }
  
  #define plasma_endian_swap64(x)     \
    (__builtin_constant_p(x)          \
      ? plasma_endian_swap64_const(x) \
      : plasma_endian_swap64_func(x))
  
  int main (void)
  {
      const struct {
          uint64_t d_input;
      } DATA = { 0xFFFFFFFFFFFFFFFFuLL };
  
  #ifndef _GOOD_ONE /* compiler failure */
      const uint64_t INPUT = DATA.d_input;
      uint64_t hostToLE = plasma_endian_swap64(INPUT);
  #else /* compiles successfully */
      uint64_t hostToLE = plasma_endian_swap64(DATA.d_input);
  #endif
  
  #if 0
  /* (not needed to reproduce compile failure) */
      const uint64_t EXPECTED = 0xFFFFFFFFFFFFFFFFuLL;
      return (EXPECTED != hostToLE);  /* 0 == success; 1 ==
  failure */
  #endif
  
      return 0;
  }
  

Local fix

• Use -q64
  

Problem summary

• PROBLEM DESCRIPTION: Internal Compiler Error with
  __builtin_constant_p with -q32 -O2
  
  USERS AFFECTED: who use __builtin_constant_p and the expression
  is complex enough
  

Problem conclusion

• Problem  is fixed.
  

Temporary fix

Comments

APAR Information

• 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 FOR AIX

• Fixed component ID

  5725C7100

Applicable component levels

• RC10 PSY UP

     C