[LLVMdev] FileCheck for instructions of indeterminate order?

William J. Schmidt wschmidt at linux.vnet.ibm.com
Wed Sep 19 10:06:13 PDT 2012

To test some recent changes, I need to verify that seven instructions
are generated.  However, the order of those instructions doesn't matter
(they are all independent loads from memory).  Is there a way to tell
FileCheck to reset its scan position rather than assuming all CHECK:
instructions must be in the given order?

My initial version of the test was to use -O0, attempting to ensure that
the instructions weren't rescheduled.  Although this gave a reproducible
order on my PowerPC machine, various buildbots of other architectures
produced codegen in a different order when cross-compiling to PowerPC.
Needless to say, the test is XFAILed until I can figure a way to test
this more safely.

All help appreciated!


N.B. I found the nondeterminacy at -O0 to be somewhat surprising...is
there some other option I need to avoid instruction reordering?

Bill Schmidt, Ph.D.
IBM Advance Toolchain for PowerLinux
IBM Linux Technology Center
wschmidt at us.ibm.com
wschmidt at linux.vnet.ibm.com

More information about the llvm-dev mailing list