README.s390 - platform/external/valgrind - Gitiles


 Requirements
 ------------
 - You need GCC 3.4 or later to compile the s390 port.
 - A working combination of autotools is required.
 - To run valgrind a z900 machine or any later model is needed.


 Limitations
 -----------
 - 31-bit client programs are not supported.
 - Hexadecimal floating point is not supported.
 - Decimal floating point is not supported yet.
 - Currently, only memcheck, massif, lackey, and none are supported
 - helgrind and drd seem to work on SLES10,11 and RHEL5,6 on z9,z10 and z196
   but might fail on other hardware/software combinations.
 - exp-sgcheck, cachegrind, and callgrind are currently not supported.
 - Some gcc versions use mvc to copy 4/8 byte values. This will affect some
   debug messages. Valgrind will complain about 4 or 8 one-byte reads/writes
   instead of just 1 read/write.


 Hardware facilities
 -------------------
 Valgrind does not require that the host machine has the same hardware
 facilities as the machine for which the client program was compiled.
 This is convenient. The JIT compiler will translate the client instructions
 according to the facilities available on the host.
 This means, though, that probing for hardware facilities by issuing
 instructions from that facility and observing whether SIGILL is thrown
 may not work. As a consequence, programs that attempt to do so may
 behave differently. It is believed that this is a rare use case.


 Recommendations
 ---------------
 Applications should be compiled with -fno-builtin to avoid
 false positives due to builtin string operations when running memcheck.


 Reading Material
 ----------------
 (1) Linux for zSeries ELF ABI Supplement
     http://refspecs.linuxfoundation.org/ELF/zSeries/index.html
 (2) z/Architecture Principles of Operation
     http://publibfi.boulder.ibm.com/epubs/pdf/dz9zr009.pdf
 (3) z/Architecture Reference Summary
     http://publibfi.boulder.ibm.com/epubs/pdf/dz9zs007.pdf

	Requirements
	------------
	- You need GCC 3.4 or later to compile the s390 port.
	- A working combination of autotools is required.
	- To run valgrind a z900 machine or any later model is needed.


	Limitations
	-----------
	- 31-bit client programs are not supported.
	- Hexadecimal floating point is not supported.
	- Decimal floating point is not supported yet.
	- Currently, only memcheck, massif, lackey, and none are supported
	- helgrind and drd seem to work on SLES10,11 and RHEL5,6 on z9,z10 and z196
	but might fail on other hardware/software combinations.
	- exp-sgcheck, cachegrind, and callgrind are currently not supported.
	- Some gcc versions use mvc to copy 4/8 byte values. This will affect some
	debug messages. Valgrind will complain about 4 or 8 one-byte reads/writes
	instead of just 1 read/write.


	Hardware facilities
	-------------------
	Valgrind does not require that the host machine has the same hardware
	facilities as the machine for which the client program was compiled.
	This is convenient. The JIT compiler will translate the client instructions
	according to the facilities available on the host.
	This means, though, that probing for hardware facilities by issuing
	instructions from that facility and observing whether SIGILL is thrown
	may not work. As a consequence, programs that attempt to do so may
	behave differently. It is believed that this is a rare use case.


	Recommendations
	---------------
	Applications should be compiled with -fno-builtin to avoid
	false positives due to builtin string operations when running memcheck.


	Reading Material
	----------------
	(1) Linux for zSeries ELF ABI Supplement
	http://refspecs.linuxfoundation.org/ELF/zSeries/index.html
	(2) z/Architecture Principles of Operation
	http://publibfi.boulder.ibm.com/epubs/pdf/dz9zr009.pdf
	(3) z/Architecture Reference Summary
	http://publibfi.boulder.ibm.com/epubs/pdf/dz9zs007.pdf