Compile

HPC and Data for Lattice QCD

Compile

apeNEXT compile chain HOWTO, October 2005 (author: Nils Christian)

To access the tools for compiling C or TAO code for apeNEXT, one first has to setup the apeNEXT environment. This is done by the following commands (here for [t]csh):

    setenv NROOT /afs/ifh.de/group/ape/nroot
    source $NROOT/nlogin.csh

1) Compiling C code

To compile C code the nlcc compiler is used:


    nlcc -S sourcefile.c

This produces the high-level assembly (SASM) code stored in 'sourcefile.sasm'. Continue at 3). (Recommended) options:

	-S	Instruct compiler to only generate high-level assembly
	-gp	Inline source code into assembler as comment

Remarks:
At the moment there does not exist a linker, which means that you have to combine your sources. Hint: Use cpp include statements (e.g. '#include "afile.c"') to combine code from different files.

2) Compiling TAO code

To compile TAO code, the rtc compiler is used:

    rtc sourcefile.zzt

Remarks:
Since there is no linker available yet one has to include combine all sources. Hint: Use include statements (e.g. '/include "afile.hzt"') for this purpose.

3) Compiling high-level assembly

The next step is to produce the low level-assembly (masm). In this step the operating system that shall be used has to be chosen:

    mpp -os7 sourcefile.sasm

Operating system selector:

  -os1  slow I/O via serial I2C link, stable
  -os3  fast I/O velocity via 7th link initiated via I2C (-> large overhead),
        stable
  -os7  fast I/O via 7th link, still being tested

Other recommended options:

  -v    preserve comments from sasm code

4) Assembler-level optimisation

Now the optional (but recommended) optimization is done by:

    sofan sourcefile.masm sourcefile-sofan.masm

Warning: depending on the code size sofan might require O(1) hours to complete and a lot of memory.

Remarks:
If you don't provide the outputfile 'sourcefile-sofan.masm', the original file will be renamed to sourcefile-nosofan.masm, and the optimized code will be stored in 'sourcefile.masm'. The different optimizations can be turned an/off via command line options. See 'sofan -h' for details.

5) Microcode generation

The last step to be done is to produce the final microcode:

    shaker +a -z sourcefile-sofan.masm

Also this step may require some time. Required/recommended options:


	+a	Enable register allocation (mandatory for assembler generated
		by rtc or nlcc)
	-z	Enable microcode compression (recommended to safe memory
		bandwidth when loading instructions into the processor)