Hmdes2 is read by the Hmdes2 preprocessor and translator to create a new Lmdes2 machine description.

• Hmdes2( High-level machine description language & is a schema expressed in "DBL" ) : An human writable and readable file for specifying machine features precisely.
• Lmdes2 : An optimized lowlevel machine representation.

[ Translator ]

1. hc : The main script to convert *.hmdes2 to *.lmdes2, and not IMPACT-specific customization.
2. hmdesc : This script does the same job as hc, however, the generated *.lmdes2 file is customized for the IMPACT front-end’s interface to the MDES module.
3. md_processor, md_compiler, lmdes2_customizer : These are the main binaries which actually do the pre-processing and compilation of MDES files are called by the hc, hmdesc scripts.

DBL : An incremental relational database description language.

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How to modify target machine?

• Via the GUI : Most common features :
  • # & types of functional units.
  • # of types of register files.
  • ??instruction set??,instruction latencies.
• Hmdes2 description : Extensive modifications.

How to apply a Hmdes2 to "codegen" & "simulation"?

• ??Hmdes2

How to apply a ?Hmdes2? to "user created compile module"?

• The mdes Query System, mQS.

There is a limit, however, to the extent that a machine
can be modified and still be the target for the Trimaran
compiler, and be simulated using the Trimaran
simulator.
    – The machine must remain in the HPL-PD architecture space.
    – The instruction set cannot be significantly changed.

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mdes Query system ( mQS ) : configure the compiler & simulator based on the specified machine features.

• The interface between the compiler and the machine

description is the mQS.